Clinical profile of a Polish cohort of children and young adults with cystinuria.

BACKGROUND: Cystinuria is an inherited disorder that results in increased excretion of cystine in the urine. It accounts for about 1-2% of pediatric kidney stones. In this study, we sought to identify the clinical characteristics of patients with cystinuria in a national cohort. METHODS: This was a retrospective study involving 30 patients from the Polish Registry of Inherited Tubulopathies. Initial data and that from a 6-month follow-up were analyzed. Mutational analysis was performed by targeted Sanger sequencing and, if applicable, MLPA analysis was used to detect large rearrangements. RESULTS: SLC7A9 mutations were detected in 15 children (50%; 10 males, 5 females), SLC3A1 mutations in 14 children (47%; 5 males, 9 females), and bigenic mutations in one male patient. The first clinical symptoms of the disease were detected at a median of 48 months of age (range 3-233 months). When individuals with different mutations were compared, there were no differences identified in gender, age of diagnosis, presence of UTI or urolithiasis, eGFR, calcium, or cystine excretion. The most common initial symptoms were urolithiasis in 26 patients (88%) and urinary tract infections in 4 patients (13%). Urological procedures were performed in 18 out of 30 (60%). CONCLUSIONS: The clinical course of cystinuria is similar among patients, regardless of the type of genetic mutation. Most patients require surgery before diagnosis or soon after it. Patients require combined urological and pharmacological treatment for prevention of stone recurrence and renal function preservation.

Determining normal values of urinary phosphorus excretion in 3913 healthy children aged 2-18 to aid early diagnosis and treatment for urolithiasis.

AIM: This study determined the specific reference values for urinary phosphorus excretion in healthy children and adolescents aged 2-18 years and evaluated whether they changed with age during growth and were gender dependent. METHODS: We enrolled 3913 healthy children and adolescents aged 2-18 years to this study. The study population was divided into age groups, and the analysis was performed in one-year periods, separately for boys and girls. Urinary phosphorus excretion was analysed using four categories: P1 in mmol/24 hour units, P2 in mmol/kg/24 hours, P3 in mmol/1.73 m2 /24 hours and P4 in mmol/mmol creatinine. RESULTS: Clear differences in urinary exertion for girls and boys were observed as well as systematic changes with age. The boys presented with significantly higher daily urinary phosphorus excretion independent of its manner of expression (p < 0.001). The median urinary phosphorus (P1) rose with age (p < 0.001). Percentile tables of phosphorous exertion are presented. CONCLUSION: This was the largest study of urinary phosphate excretion based on a randomly selected sample of girls and boys aged 2-18 years. It highlights the importance of determining phosphorus reference values for children of different ages to provide early diagnosis and treatment for urolithiasis.

Does obesity or hyperuricemia influence lithogenic risk profile in children with urolithiasis?

BACKGROUND: There are indications that obesity and hyperuricemia may influence the formation and composition of urinary stones. The aim of our study was to determine the effect of obesity and hyperuricemia on the urinary lithogenic risk profile in a large cohort of pediatric patients. METHODS: The study population comprised 478 children with urolithiasis and 517 healthy children (reference group). We studied the effects of obesity on the lithogenic profile by dividing the patients with urolithiasis into two groups based on body mass index Z-score (patients who were overweight/obese vs. those with normal weight for age) and comparing the two groups. To study the effect of hyperuricemia on the lithogenic profile, we divided the patients with urolithiasis into two groups based on the presence or not of hyperuricemia (110 patients with urolithiasis accompanied by hyperuricemia vs. 368 patients with urolithiasis and normal serum uric acid levels) and compared the groups. RESULTS: Among the children and adolescents with urolithiasis and hyperuricemia, there was a significantly lower excretion of crystallization inhibitors (citrates, magnesium). We also found significantly negative correlations between serum uric acid levels and the urine citrate/creatinine ratio (citrate/cr.; r = -0.30, p < 0.01), as well as the magnesium/cr. ratio (Mg/cr.; r = -0.33, p < 0.01). There was no statistically significant differences in the urinary excretion of oxalates, citrates, calcium, phosphorus, magnesium and uric acid between children with urolithiasis who were either overweight or obese and children with urolithiasis who had a normal body weight. CONCLUSIONS: In our pediatric patient cohort, hyperuricemia was associated with a decrease in the excretion of crystallization inhibitors in the urine, but the clinical relevance of this observation needs to be confirmed in future studies. Obesity and overweight had no direct influence on the lithogenic risk profile in the urinary stone formers in our study, but there was an indication that higher serum uric acid may be associated with impairment in renal function, which in turn could influence the excretion of lithogenic parameters.

Urodynamic Findings and Renal Function in Children with Neurogenic Bladder after Myelomeningocele.

INTRODUCTION: Myelomeningocele (MMC) is a congenital central nervous system malformation caused by a failure of the neurulation process in early pregnancy. Patients with MMC present many abnormalities and the nervous, skeletal and urinary systems are the most affected. The aim of this study was to clinically evaluate patients with MMC, estimate renal and lower urinary tract (LUT) function and to ascertain whether urodynamic findings can predict the deterioration of urinary tract function. MATERIALS AND METHODS: Medical records of 112 patients were gathered from a database and evaluated retrospectively. The data included age, sex, BMI Z-score WHO, physical activity, urodynamic parameters and diagnosis and renal function. RESULTS: A total of 112 patients with MMC were enrolled in the study. There were no differences in age, sex, BMI Z-score WHO, physical activity, renal function and urodynamic findings (apart from cystometric capacity) between boys and girls. Detrusor overactivity was the most frequent urodynamic diagnosis in all groups of physical activity, level of lesion and in catheterized and non-catheterized children. The correlations between urodynamic findings and renal function tests were found. CONCLUSIONS: Patients with neurogenic bladder after MMC most often present detrusor overactivity. LUT function is disturbed in all MMC patients independent of lesion level and physical activity.

Urinary citrate excretion in healthy children depends on age and gender.

BACKGROUND: Hypocitraturia is considered a major risk factor for calcium stone formation. However, there is no widely accepted reference database of urinary citrate excretion in children. The aim of our study was to determine the amount of citrate eliminated in the urine over a 24-h period in a pediatric cohort and to determine an optimal unit reflecting excretion. METHODS: The study cohort comprised 2,334 healthy boys and girls aged 2-18 years. The levels of urinary citrate were assessed by an enzymatic method in 24-hour urine and expressed in absolute values, as urinary concentration, citrate/creatinine ratio, per kilogram of body weight, in relation to 1.73 m2, and as the calcium/citrate index. RESULTS: Similar incremental age-related citraturia rates were observed in both male and female subjects until puberty during which time citrate excretion became significantly higher in girls. Urinary citrate adjusted for creatinine and for body weight showed a significantly decreasing trend with increasing age in both sexes. Urinary citrate corrected for body surface was weakly correlated with age. Thus, the assumption of 180 mg/1.73 m2/24 h for males and 250 mg/1.73 m2/24 h for females as lower cut-off values appeared to be reliable from a practical perspective. CONCLUSIONS: We found distinct sex-dependent differences in citraturia at the start of puberty, with significantly higher values of urinary citrate in girls than in boys. Further prospective studies are warranted to elucidate whether this difference represents a differentiated risk of urolithiasis.

Correspondence between Ca²âº and calciuria, citrate level and pH of urine in pediatric urolithiasis.

BACKGROUND: Hypercalciuria and hypocitraturia are considered the most important risk factors for urolithiasis. Citrate binds to urinary calcium to form a soluble complex which decreases the availability of ionized calcium (Ca(2+)) necessary for calcium oxalate formation and phosphate crystallization. The aims of this study were to assess the Ca(2+) fraction in relation to total calciuria, citraturia and urinary pH and to determine whether urinary Ca(2+) concentration is a helpful biomarker in metabolic evaluation of children with urolithiasis. METHODS: We collected 24-h urine samples from 123 stone-forming children and adolescents with hypocitraturia and from 424 healthy controls. Total calciuria (total calcium, Catotal), Ca(2+), pH, citrate, oxalate and Bonn Risk Index (BRI) were assessed and compared between the two groups. RESULTS: Total calciuria and Ca(2+) content were higher in stone-formers than in the healthy children. In both stone-formers and controls, Ca(2+) content was inversely related to citraturia and urinary pH, whereas the Ca(2+)/Catotal ratio differed slightly between the groups. A large variability in Ca(2+) level was found across individuals in both groups. The BRI increased with increasing calciuria and urine acidity. CONCLUSIONS: Compared to controls, stone-formers with hypocitraturia demonstrated a higher urinary Ca(2+) concentration, but this was proportional to calciuria. The large individual variability in urinary Ca(2+) content limits its practical use in metabolic evaluation of children with urolithiasis. However, the Ca/Citrate ratio may be a useful clinical tool in evaluating children with urolithiasis.

[Serum and urinary homocysteine in children with steroid-dependent nephrotic syndrome]. / Homocysteina w surowicy i moczu dzieci ze steroidozaleznym zespolem nerczycowym.

UNLABELLED: Hyperhomocysteinemia is independent risk factor of cardiovascular diseases. Similarly to nephrotic syndrome (NS) predisposes to vein thrombosis. THE AIM OF THE STUDY: To evaluate serum and urinary total homocysteine (stHcy and utHcy) levels in children with the symptoms of SN, and to determine a correlation between its concentration and some parameters of hemostasis, as well as doses and the time of prednisone therapy and serum cortisol level. MATERIAL AND METHODS: The examined group consisted of 18 children with NS, aged 7.64 +/- 5.1 years, divided on two groups: A--in time o proteinuria; B--during treatment with prednisone after regression of proteinuria. Control group (C) consisted of 20 children, aged 8.5 +/- 3.6 years. Serum and urinary tHcy levels were assayed by enzyme-linked immunosorbent assay method using the Axis-Shield set. RESULTS: Serum total Hcy concentration in groups A and B did not differ from the control group (p > 0.05). Urinary total Hcy concentration in groups A and B was significantly higher than that of control (p < 0.05). A positive correlation was observed between stHcy and serum albumin as well as cortisol levels, and between utHcy and serum AT III level. CONCLUSIONS: In children with steroid-dependent NS, subclinical disturbances in hemostasis were independent of serum tHcy concentration. There was no correlation between serum tHcy and cumulated doses, as well as time of prednisone treatment, however positive correlation was found with serum cortisone. Urinary excretion of Hcy significantly increases, in comparison to control, and correlates with serum AT III level.

Assessment of lithogenic risk in children based on a morning spot urine sample.

PURPOSE: The Bonn Risk Index has been used to evaluate the risk of urinary calcium oxalate stone formation. According to the original method, risk should be determined based on 24-hour urine collection. We studied whether the Bonn Risk Index could be measured in spot urine samples and which part of the day is most suitable for this purpose. MATERIALS AND METHODS: We collected total and fractionated 24-hour urine (in a 6-hour nocturnal portion and 9 consecutive 2-hour diurnal samples) in 42 children and adolescents with calcium oxalate urolithiasis and 46 controls. Bonn Risk Index values determined from each of the urine fractions were compared to those obtained from related 24-hour urine collections. RESULTS: Both groups exhibited similar circadian patterns of Bonn Risk Index values. Median Bonn Risk Index for the nighttime portion of urine in the stone group was 1.4 times higher than that obtained from the total 24-hour urine. The morning hours between 08:00 and 10:00 showed the peak lithogenic risk, and this fraction had the highest sensitivity and selectivity regarding discrimination between stone formers and healthy subjects. The afternoon hours demonstrated lower and less fluctuating crystallization risk. Despite diurnal fluctuations in Bonn Risk Index, there was still a well-defined cutoff between the groups. CONCLUSIONS: Bonn Risk Index determined from urine samples collected between 08:00 and 10:00 appears optimal in separating stone formers from healthy subjects, and appears as useful as the value determined from 24-hour urine collection. Investigation of this diurnal sample simplifies diagnosis in pediatric stone disease without loss of clinical information.

Spontaneous urinary calcium oxalate crystallization in hypercalciuric children.

Idiopathic hypercalciuria is the most important predisposing risk factor for calcium oxalate (CaOx) renal stone formation. We assessed the associations between spontaneous CaOx crystallization based on the Bonn Risk Index (BRI), urinary pH, calciuria, oxaluria, and citraturia in 140 Caucasian patients with hypercalciuria, aged 4-17 years, and compared the findings with those in 210 normocalciuric controls. Of the 140 hypercalciuric patients, 58 had renal stones, and 82 had recurrent erythrocyturia, renal colic, or urinary obstructive symptoms-but without stones. Urinary ionized calcium ([Ca(2+)]) levels were measured using a selective electrode, while the onset of crystallization was determined using a photometer and titration with 40 mmol/L ammonium oxalate (Ox(2-)). The calculation of the BRI was based on the [Ca(2+)]:Ox(2-) ratio. The BRI values were 12-fold higher in hypercalciuric children than in healthy controls, but no differences were found in the BRI between subjects with urinary stones and those with urolithiasis-like symptoms. An increased BRI suggested an association with hypercalciuria, lower urinary pH, hypocitraturia, and hypooxaluria. These data indicate that hypercalciuria is an important factor associated with increased urinary CaOx crystallization, although the causal pathways need further investigation. Determination of the BRI in children with hypercalciuria may improve the risk assessment of kidney stones.

[Matrix metalloproteinases 2 and 9 and their tissue inhibitors 1 and 2 in the urine of children with pyelonephritis]. / Metaloproteinazy 2 i 9 oraz ich tkankowe inhibitory 1 i 2 w moczu dzieci chorych na odmiedniczkowe zapalenie nerek.

UNLABELLED: In small children, pyelonephritis (PN) is an important cause of scarring in the renal and disturbed in the production and degradation of extracellulare matrix proteins (ECM). Aim of the study was to assess the urinary levels metalloproteinases 2 and 9 (MMP-2 and MMP-9) and their inhibitors 1 and 2 (TIMP-1 and TIMP-2) in children with pyelonephritis (PN). MATERIALS AND METHODS: Study group (I) consisted of 42 children with PN, aged 1-15 years, examined twice: A--prior to treatment (1-3 days of fever), B--after antibacterial treatment (10-14 days). The control group (K) consisted of 30 healthy children. Enzyme-linked immunosorbent assay kits were used for measurements of total human MMP-2, MMP-9, TIMP-1 and TIMP-2 in first morning urine. RESULTS: In children with PN (I) prior to treatment (A), urinary concentration of all parameters were increased as compared to the control (K) (p<0.05). After treatment (B), only the levels of TIMP-1 was still elevated (p = 0.02). In PN before (A) and after (B) treatment MMP-9/TIMP-1 ratio. However MMP-2/TIMP-2 ratio was normal. CONCLUSION: In children with PN the balance MMP-9/TIMP-1 is disturbed, with the predominance of TIMP-1 production over MMP-9. It may lead to renal fibrosis.

Upper metastable limit osmolality of urine as a predictor of kidney stone formation in children.

High fluid intake has been universally recommended for kidney stone prophylaxis. We evaluated 24-h urine osmolality regarded as the best biomarker of optimal hydration and upper metastable limit osmolality after water evaporation from urine sample to the onset of spontaneous crystallization and its usefulness as a new risk index that would describe an individual lithogenic potential. We collected 24-h urine from 257 pediatric patients with kidney stones and 270 controls. After volume and osmolality assessment, the urine samples were subjected to volume reduction in vacuum rotavapor continued to the onset of an induced urinary crystallization. The upper metastable limit osmolality of urine sample was calculated based on its initial osmolality value and the amount of water reduction. Pediatric stone formers presented with higher urine volume and lower urine osmolality than healthy controls. Despite that, their urine samples required much lower volume reduction to induce the spontaneous crystallization than those of controls. The ROC analysis revealed an AUC for the upper metastable limit osmolality of 0.9300 (95% CI 0.9104-0.9496) for distinguishing between stone formers and healthy subjects. At the cutoff of 2696 mOsm/kg, the test provided sensitivity and specificity of 0.8638 and 0.8189, respectively. 24-h urine osmolality provided the information about current hydration status, whereas evaporation test estimated the urinary potential to crystalize dependent on urine composition. Upper metastable limit osmolality may estimate the individual lithogenic capability and identify people at risk to stone formation when exposed to dehydration.

[The evaluation of urinary tract dysfunction in children with monosymptomatic primary nocturnal enuresis]. / Ocena czynnosci dolnych dróg moczowych u dzieci z pierwotnym izolowanym moczeniem nocnym (PIMN).

UNLABELLED: The reason for our search was various investigations about urinary tract dysfunctions in enuretic children. AIM: The aim of our study was estimation of lover urinary tract function in children with monosymptomatic primary nocturnal enuresis without positive reaction for a long non pharmacological therapy. MATERIAL AND METHODS: 54 children after 9-12 months behavioral therapy and short pharmacological treatment (desmopresin) was undergoing urodynamic investigation (uroflowmetry and cystometry). RESULTS: Urodynamic disorders was found in 44/54 of estimated children. In 34 of children it was overactive bladder, in 6 patients we found detrusor-sphincter discoordination. Five children had decreased bladder capacity. Next to non pharmacological treatment we used anticholinergic or Baclofen depending on the results of urodynamic tests. The response to the treatment (non bedwetting at all) we observed in 34 children (in 9 of them after 3 months of therapy, in 16 after 6 months of therapy and in 12 after 12 months of therapy). The rest of children had decreased number of wet night per month. CONCLUSION: The pharmacological treatment of urodynamic disorders helps to children with monosymptomatic primary nocturnal enuresis to lost this symptom.

Citrate usage in the leading causes of blindness: new possibilities for the old metabolite.

INTRODUCTION: Citrate is an old metabolite which is best known for the role in the Krebs cycle. Citrate is widely used in many branches of medicine. In ophthalmology citrate is considered as a therapeutic agent and an useful diagnostic tool-biomarker. OBJECTIVES: To summarize the published literature on citrate usage in the leading causes of blindness and highlight the new possibilities for this old metabolite. METHODS: We conducted a systematic search of the scientific literature about citrate usage in ophthalmology up to January 2018. The reference lists of identified articles were searched for providing in-depth information. RESULTS: This systematic review included 30 articles. The role of citrate in the leading causes of blindness is presented. CONCLUSIONS: Citrate might help inhibit cataract progression, in case of questions confirm glaucoma diagnosis or improve cornea repair treatment as adjuvant agent (therapy of ulcerating cornea after alkali injury, crosslinking procedure). However, the knowledge about possible citrate usage in ophthalmology is not widely known. Promoting recent scientific knowledge about citrate usage in ophthalmology may not only benefit of medical improvement but may also limit economic costs caused by leading causes of blindness. Further studies on citrate usage in ophthalmology should continuously be the field of scientific interest.

[The concentration of plasma anion oxalate in children treatment antibiotics beta lactame]. / Stezenie anionu szczawianowego w osoczu dzieci leczonych antybiotykami beta-laktamowymi.

UNLABELLED: The aim of work was the assessment of plasma anion oxalate (Ox) concentration in children during antibacterial treatment depending on way and time of antibiotic administration. MATERIAL AND METHODS: The examinations were carried out in 80 children, without nephrolithiasis, aged 10.1 +/- 4.3 years with bronchopneumonia, treated with beta-lactame antibiotics. The children were divided in two groups: I--children treated with oral amoxicillin + clavulanic acid or cefuroxime axetil (n=40), II--children treated with the same antibiotics intravenously (n=40). The Ox concentration in plasma and urine was measured using an enzymatic method with oxalate oxidase, four times. (0)--before treatment, (a)--in third day and (b)--in last day of administration (10 to 14 day), (c)--3 weeks after finishing treatment with antibiotics. RESULTS: The result showed that in children before treatment (0) mean plasma Ox concentration was 2.439 +/- 0.645 micromol/l. In 3rd day (a) the Ox concentration increased to 7.848 +/- 0.999 micromol/l (p < 0.01), in last day of treatment (b) decreased to 5.681 +/- 0.871 micromol/l, and after 3 weeks (c) came back to initial values (p > 0.05). Intravenous antibiotics administration did not influence plasma Ox concentration. CONCLUSIONS: Plasma oxalate concentration increases during oral administration of beta-lactame antibiotics caused by increased intestinal absorption, as a result of saprophytic microflora deterioration. However intravewous administration of the same antibiotics does not change the concentration of plasma oxalate.

[Serum cystatin C concentration in children with urinary stones]. / Stezenie cystatyny C w surowicy dzieci z kamica moczowa.

UNLABELLED: Stone formation precedes long period, when the crystals are accumulated in basement membranes of renal tubules and intestinal tissue. Accumulated, inside of renal tubules crystals and stones in urinary tract cause urinary tract obstruction, what may lead to impairment of renal function. The aim of work was the assessment of serum cystatin C (cys C) concentration in children with urolithiasis, confirmed by the presence of renal stones in renal pelvis in comparison to serum creatinine concentration and creatinine clearance (Cr cl). MATERIAL AND METHODS: Examined group (B) consisted of 30 children aged (13.08 +/- 4.14 years) with urolithiasis, which was divided into 3 subgroups (I, II, Ill) in dependence on stones' diameter (0.35-1.6cm). Control group (C) consisted of 26 healthy children at the same age. Nephelometric method was used to determine serum cystatin C level, Jaffe method to assess serum creatinine and the Schwartz formula to estimate glomerular filtration rate. RESULTS: In control group (C) serum cys C did not exceed 0.95 mg/l. In group B serum cystatin C and serum creatinine concentration and Cr cl was similar to the results of control group (p > 0.05). However in 16% of children with urolithiasis, in whom the stones of 0.8-1.6cm diameter were found in both renal pelvis, the concentration of serum cys C exceed 1.2 mg/l, and the value differed significantly from the results of control group (p < 0.05). A weak positive correlation between cys C and creatinine concentration and also between cys C and Cr cl was found. The serum cys C concentration in children with single stones of 0.35-0.8 diameter was normal. CONCLUSION: Serum cystatin C increases with increased degrees of urolithiasis assessed by stone size and their number in kidney.

[Urinary TGF-beta1 excretion in children with renal cysts]. / Wydalanie TGF-beta1 w moczu dzieci z torbielowatoscia nerek.

UNLABELLED: Autosomal dominant polycystic disease is characterised by abnormal polycystin, protein, which is a component of basement membrane and extracellular matrix. Transforming growth factor (TGF-beta1) is a cytokine, which takes part in development of renal tubule epithelium and stimulates the synthesis of extracellular matrix proteins. The aim of work was the assessment of TGF-beta1 concentration in children with renal polycystic disease. MATERIAL AND METHODS: The examined group (I) consisted of 33 children aged (median 14.7 years, range 4.0-17.9): A--11 children with solitary cyst, B--22 with polycystic renal disease. Control group (C) consisted of 20 healthy children at the same age. The concentration of urinary TGF-b1 was measured using immunoenzymatic ELISA method. The results showed that mean concentration of urinary TGF-beta 1 (121.9 +/- 168 pg/mg cr.) was lower than in group B, in which it was 207.2 +/- 361 pg/mg cr. However the difference was not statistically significant (p>0.05). In both subgroups (A and B) urinary excretion of TGF-beta1 was higher than in control group (C) (p<0.05). In 4 (36%) children from group A and 8 (36%) from group B the urinary concentration of TGF-beta 1 was below the sensitivity of the method. No correlation between TGF-beta 1 and children's age, urinary osmolality and GRF according to Schwartz was found. It was a positive correlation between urinary TGF-betal concentration and total diameter of renal cysts. CONCLUSIONS: TGF-betal takes part in renal cyst formation and increased urinary excretion of TGF-b1 in proportion to the dimension of renal cysts may be an evidence of that fact.

[Assessment of oxalate concentration in serum and urine of children with renal stones]. / Ocena stezenia szczawianów w osoczu i moczu dzieci z kamica moczowa.

UNLABELLED: Oxalate crystals are the main component of renal stones and oxalate urolithiasis is the most common type both in adults and children. The aim of the work was the assessment of oxalate concentration in plasma and urine of children with renal stones. MATERIAL: The examined group (I) consisted of 29 children (12.0 +/- 3.87 years) with confirmed stones in caliceal-pelvic system. The control group (C) was composed of 30 healthy children. METHODS: The oxalate concentration in plasma and urine was measured using an enzymatic method after 3-4 days of hypooxalate diet. Children with congenital abnormalities of urinary tract were excluded. We found 1-5 stones, 0.35-1.5 in diameter. RESULTS: In I group mean plasma oxalate concentration (4.89 +/- 1.58 micromol/l) was higher than in control group (p<0,05). However urinary oxalate concentration exceeded 95 percentile of those obtained in healthy group only in 16 (55%) children, mainly with II and III degree of urolithiasis. In children with urolithiasis we also found hypercalciuria with normal serum calcium concentration. No correlation between plasma and urinary oxalate concentration was found. CONCLUSIONS: 1. Plasma oxalate concentration in children with renal stones is higher than in healthy children. 2. Hyperoxaluria was found in 16 (55%) children with first attack of nephrolithiasis.

A semi-micromethod for determination of oxalate in human plasma.

An enzymatic semi-micromethod for oxalate determination in human plasma was elaborated. The principle of the method depends on the oxalate isolation from deproteinized plasma, following determination by the calorimetric oxalate oxidase-peroxidase-indamine system. This method protects against internal oxalate losses and excludes an interference of contaminations. Results, obtained by this method, were reliable and ideally suited for use as real normal values (less than or equal to 6 microM) of oxalate content in the plasma of healthy individuals. The elaborated method, which can assay plasma oxalate accurately in normal individuals as well as in hyperoxalemic conditions is superior to those previously used. The procedure of semi-micromethod does not require expensive equipments and apparatus: it is simple and easy to perform in every laboratory and takes little time.

[Reference values of arterial pressure depending on age, assessed by 24-hour ambulatory monitoring]. / Wartosci referencyjne cisnienia tetniczego w zaleznosci od wieku oceniane metoda calodobowego ambulatoryjnego monitorowania.

UNLABELLED: 24-hour blood pressure monitoring has been ever more widely used in children. However, percentile ranks for healthy children have not been prepared yet. The aim of the study was to define percentile ranks of blood pressure measured by ambulatory blood pressure monitoring in healthy children aged 7-17 years depending on sex in children from the Province of Podlasie. The examinations were carried out in a group of 540 children: group I-girls--265, group II boys--275, who were divided into subgroups according to age. Blood pressure was measured by ambulatory blood pressure monitors: BR-102 f. Schiller, Poland LTD and Quiet Tycos, USA according to the principles in force. The results showed that mean systolic blood pressure (RRs) increased with age from 103.2 to 117.7 mm Hg in girls and from 98.8 to 125.6 mm Hg in boys. The differences were statistically significant (p > 0.05). Diastolic blood pressure (RRr) increased less (p > 0.05). Mean systolic blood pressure at night was 9-10% and diastolic pressure 10-11% lower, irrespective of sex. The range of normal blood pressure values (5-95 centile) was established. In group I in the youngest girls the range of RRs was 89-110 mmHg, that of RRr was from 51 to 75 mm Hg while in group II in the youngest boys RRs range was from 95 to 108 mm Hg and RRr--from 52 to 73 mm Hg. In group I and II in the oldest girls and boys the values were higher. The percentile ranks (5-95) were prepared for systolic and diastolic blood pressure based on blood pressure monitoring during 24-hours and separately during activity (day) and resting time (night). CONCLUSIONS: 1. Systolic blood pressure in children aged 7-17 years increases with age more than diastolic blood pressure. 2. Percentile ranks for healthy children aged 7-17 years depending on age, sex and daily time period were established.

[Assessment of fructose-1,6-biphosphatase in urine of children with acute pyelonephritis]. / Ocena aktywnosci fruktozo-1,6 dwufosfatazy w moczu dzieci chorych na ostre odmiedniczkowe zapalenie nerek.

UNLABELLED: We assessed the excretion of fructose-1,6-bisphosphatase (FBP) and N-acetyl-beta-D-glucosaminidase (NAG) in 52 children (aged 4.1 +/- 2.3): group I--26 children with acute pyelonephritis (APN), in whom the examination were carried out twice: A--before treatment, B--after 14-21 days of antibacterial treatment, group II--21 healthy children. Activity of FBP in urine was found in 80% children from group I and II, and activity of NAG was found in all children from both groups. In examination A mean excretion of FBP and NAG was higher than in healthy children (p < 0.05). After antibacterial treatment excretion of both enzymes decreased to values, which did not differ from control group (p > 0.05). High correlation between FBP and NAG (r = 0.9355; p = 0.00001) was shown only in 14 children, in whom the course of acute pyelonephritis was serious (CRP > 20 mg%, leucocytosis > 10 x 10(9), and renal swelling in ultrasonography). CONCLUSION: Increased excretion of FBP in urine is found mainly in children with severe course of acute pyelonephritis, in whom the correlation between NAG and FBP is observed.