Improving electrotactile communication with a multi-pad electrode under cognitive load

BACKGROUND

Electrotactile systems are compact interfaces that can be used to convey information through the skin by producing a range of haptic sensations. In many applications, however, the user needs to perceive and interpret haptic stimulation while being engaged in parallel activities. Developing methods that ensure reliable recognition of electrotactile messages despite additional cognitive load is, therefore, an important step for the practical application of electrotactile displays.

METHODS

This study investigated if a simple strategy of repeating electrotactile messages can improve message identification during multitasking. Ten participants identified 36 spatiotemporal electrotactile messages delivered through a 3 × 2 pad-matrix electrode placed on the torso while performing a concomitant cognitive task in three conditions: the messages were presented once (No-REP), and each message was repeated three (REP3) and five (REP5) times. The main outcome measure was the success rate (SR) of message identification.

RESULTS

During multitasking, in the No-REP condition, the SR (median (IQR)) dropped to 56.25% (22.62%), demonstrating that the cognitive task decreased performance. However, the SR significantly improved with message repetitions, reaching 72.92% (21.87%) and 81.25% (18.66%) in REP3 and REP5 conditions respectively, without a statistically significant difference between REP3 and REP5.

CONCLUSIONS

Multitasking affected the efficacy of haptic communication, but message repetition was shown to be an effective strategy for improving performance. Additionally, only three repetitions were enough, as an additional increase in the duration of message transmission (5 repetitions) did not lead to further improvement. This study is an important step toward delivering electrotactile communication that can cope with the demands of real-world applications.

How do different bile acid derivatives affect rat macrophage function - Friends or foes?

Due to an increased need for new immunomodulatory agents, many previously known molecules have been structurally modified in order to obtain new drugs, preserving at the same time some of the benevolent characteristics of the parent molecule. This study aimed to evaluate the immunomodulatory potential of a selected library of bile acid derivatives (BAD) using a broad spectrum of assays, evaluating rat peritoneal macrophages viability, cell membrane damage, lysosomal and adhesion function, and nitric oxide and cytokine production as a response to lipopolysaccharide stimulation. Also, in silico studies on two bile acid-activated receptors were conducted and the results were related to the observed in vitro effects. All tested BAD exerted significant toxicity in concentrations higher than 10 μM, which was determined based on mitochondria and cell membrane damage in a panel of assays. On the other hand, at lower concentrations, the tested BAD proved to be immunomodulatory since they affected lysosomal function, cell adhesion capacities and the ability to produce inflammatory cytokines in response to a stimulus. One of the compounds proved to exhibit significant toxicity toward macrophages, but also caused a concentration-dependent decrease in nitric oxide levels and was identified as a potential farnesoid X receptor agonist.

The influence of the tooth preparation finish line position on the expression of matrix metalloproteinase-9 and the presence of periodontopathogens in the gingival crevicular fluid

OBJECTIVE

The objective of the study was to determine the concentration of matrix metalloproteinase 9 (MMP-9) and changes in the presence of periodontopathogens in the gingival crevicular fluid before and after tooth preparation with the subgingival and equigingival finish line position.

PATIENTS AND METHODS

The clinical prospective study included 20 subjects with an indication for upper canine preparation, with the subgingival (group 1) and equigingival finish line (group 2). Samples were taken in four observation intervals: 5 minutes before (control samples), as well as 15 minutes, 24 and 72 hours after tooth preparation (experimental samples). Measurement of MMP-9 was done using Enzyme-linked Immunosorbent Assay (ELISA). The presence of bacteria in the gingival fluid was proven by the Polymerase chain reaction (PCR) analysis.

RESULTS

The MMP-9 values did not differ statistically significantly between the groups (p=0.524). The MMP-9 values showed a statistically significant difference in the given observation period (p<0.001) with a significant linear increase in values (p<0.001). A significant quadratic trend recorded a decrease in the MMP-9 values 15 minutes after preparation, and an increase 24 hours after preparation, without a significant difference in the interaction between groups (p=0.392). After preparation, a significant difference in the presence of periodontopathogens was confirmed, i.e., a decrease in the presence of Prevotella intermedia (p=0.025) and Tannerella forsythia (p=0.016) in group 1, and an increase in the presence of Aggregatibacter actinomycetemcomitans in both groups (p=0.029, p=0.026).

CONCLUSIONS

The study is a good basis for determining the influence of tooth preparation on gingival inflammation, with therapeutic (choice of preparation technique) and preventive significance regarding the protection of the periodontal tissue from possible iatrogenic damage.

Electrotactile Communication via Matrix Electrode Placed on the Torso Using Fast Calibration, and Static vs. Dynamic Encoding

Electrotactile stimulation is a technology that reproducibly elicits tactile sensations and can be used as an alternative channel to communicate information to the user. The presented work is a part of an effort to develop this technology into an unobtrusive communication tool for first responders. In this study, the aim was to compare the success rate (SR) between discriminating stimulation at six spatial locations (static encoding) and recognizing six spatio-temporal patterns where pads are activated sequentially in a predetermined order (dynamic encoding). Additionally, a procedure for a fast amplitude calibration, that includes a semi-automated initialization and an optional manual adjustment, was employed and evaluated. Twenty subjects, including twelve first responders, participated in the study. The electrode comprising the 3 × 2 matrix of pads was placed on the lateral torso. The results showed that high SRs could be achieved for both types of message encoding after a short learning phase; however, the dynamic approach led to a statistically significant improvement in messages recognition (SR of 93.3%), compared to static stimulation (SR of 83.3%). The proposed calibration procedure was also effective since in 83.8% of the cases the subjects did not need to adjust the stimulation amplitude manually.

Encoding of spatial patterns using electrotactile stimulation via a multi-pad electrode placed on the torso

BACKGROUND

Tactile stimulation can be used to convey information to a user in different scenarios while avoiding overloading other senses. Tactile messages can be transmitted as spatial patterns, potentially allowing for a high information throughput. The aim of the present study was to design and test different encoding schemes to determine the best approach for conveying spatial patterns.

METHODS

Encoding schemes with simultaneous (SIM) and sequential pad activation (SEQ) were evaluated, including four SEQ variants designed to potentially facilitate the recognition. In SEQ-col and SEQ-row, the column and row of the activated pad were signified using different frequencies, while SEQ-all and SEQ-all-fast included the activation of all pads where those belonging to the pattern were indicated by changes in frequency (ON pads). The success rate (SR) of the pattern identification and the response time were quantified in 15 participants who recognized 20 patterns delivered through a 3 × 2 pad matrix placed on the lateral torso.

RESULTS

SIM was not a feasible method to present the patterns (median, 15%; IQR, 5%). The SR improved with SEQ (median, 60%; IQR, 20%) and further increased with additional cues, particularly with SEQ-row (median, 78.3%; IQR, 23.3%) and SEQ-all (median, 96.7%; IQR, 5%). Importantly, the stimulation time of SEQ-all could be decreased without a substantial drop in accuracy (SEQ-all-fast: median, 89.2%; IQR, 19.2%).

CONCLUSIONS

The spatiotemporal stimulation with sequential activation of all pads (SEQ-all) seems to be the method of choice when conveying tactile messages as spatial patterns. This is an important outcome for increasing the information bandwidth of communication through the tactile channel.

Effects of galectin-1 on immunomodulatory properties of human monocyte-derived dendritic cells

Our study aimed to evaluate the effects of Gal-1 in dose depending manner on maturation and immunomodulatory properties of monocyte-derived (Mo) DCs in-vitro. The effects were analyzed by monitoring their phenotypic characteristics, cytokine profile, and the ability to direct the immune response in the co-culture with allogeneic CD4⁺T cells. Gal-1 reduced the expression of CD80 and CD86 molecules on MoDCs compared to untreated MoDCs. Gal-1 at concentrations of 1 and 6 μg/mL significantly reduced IL-12 production, while the concentration of 3 μg/mL led to its significant increase. Gal-1 in all concentrations induced a significant increase in the production of IL-10. Treatment of MoDCs with 3 and 6 μg/mL of Gal-1 stimulated the production of IL-2 and IFN-γ in the co-culture with CD4⁺T lymphocytes. This study demonstrated a dual immunomodulatory effect of Gal-1 on MoDCs in terms of immune stimulation and immune suppression, depending on the applied concentration.

Can Salivary Biomarkers Be Used as Predictors of Dental Caries in Young Adolescents?

Background

Identifying caries predictors in the subpopulation at risk is one of the preconditions for developing effective caries prevention measures. The present exploratory study aimed to examine the significance of socio-demographic characteristics, dietary-hygiene habits, salivary pH, and salivary antimicrobial HNP-1, hBD-2, and LL-37 peptides as potential caries risk predictors in children ages 11–13 years.

Material/Methods

This prospective 1-year study enrolled 213 children ages 11–13 years. The subjects underwent a dental examination and their mothers were interviewed. Unstimulated saliva was collected from the subjects to determine its pH value, as well as the salivary levels of HNP-1, hBD-2, and LL-37 peptides in 85 of the subjects. After 12 months, the 1-year caries incidence rate was recorded. Logistic regression analysis was used to estimate the ability of selected variables to predict caries risk.

Results

The univariable logistic regression analysis determined that the most significant independent caries risk predictors were: sex (female) (OR=2.132, p=0.007), mothers’ education (OR=1.986, p=0.020), salivary pH (OR=0.270, p=0.043), oral hygiene index (OR=1.886, p=0.015), and daily tooth brushing frequency (OR=0.565, p=0.042). The multivariable model showed that sex and oral hygiene-related variables were the most important caries predictors.

Conclusions

Salivary HNP-1, hBD-2, and LL-37 peptides were not found to have a significant predictive value. Therefore, socio-demographic and oral hygiene variables remain important caries predictors in early adolescents, suggesting the importance of the mechanical control of biofilm as the key measure for preventing caries. However, there is still a need for effective caries risk biomarkers, and additional research is needed in this area of caries risk prediction.

Hypertrophic recurring lichen planus of the external auditory canal

INTRODUCTION

We report a case of unilateral progressive primary hypertrophic lichen planus of the external auditory canal requiring several surgical interventions to deal with constant pruritus, otorrhoea, stenosis and conductive hearing loss.

CASE SUMMARY

A 58-year-old woman was initially treated with meatoplasty for suspected chronic obliterating otitis externa. She remained symptom-free for 5 years, before the disease recurred, affecting other body surfaces as well. Otorrhoea, conductive hearing loss and pruritus worsened, and a canal wall down tympanomastoidectomy was performed, removing the skin of the external auditory canal and the tympanic membrane completely. Lichen planus was confirmed histopathologically.

DISCUSSION

Very few surgical results have been published on stenosis of the external auditory canal caused by lichen planus. Complete medial external auditory canal skin elevation and removal with postoperative split-skin grafting is advised for initial treatment. We discuss treatment options and surgical outcome after initial surgical failure.

Synthesis of mesoporous triple-metal nanosorbent from layered double hydroxide as an efficient new sorbent for removal of dye from water and wastewater

In this study, co-precipitation synthesis of the mesoporous triple-metal nanosorbent from Fe, Cu, Ni layered double hydroxide (FeCuNi-LDH), on the basis of the data obtained from the TG analysis was carried out. The FTIR spectroscopy and XRD results confirm the formation of CuO, NiO and Fe₂O₃ nanoparticles, while the EDX analysis does not show significant variations on the surface in elemental composition. BET analysis shows that FeCuNi-280 (FeCuNi-LDH calcinated at 280 °C) with mesoporous structure, has larger surface area compared to FeCuNi-LDH and FeCuNi-550 (FeCuNi-LDH calcinated at 550 °C). The value of pH_PZC of FeCuNi-280 is found to be 8.66. Obtained FeCuNi-280 material showed the ability for efficient removal of dye Reactive Blue 19 (RB19) from water, with a very high sorption capacity of 480.79 mg/g at optimal conditions: the sorbent dose of 0.6 g/dm³, stirring speed of 280 rpm and pH 2. The kinetics results of the sorption process were well fitted by pseudo-second order and Chrastil model, and the sorption isotherm was well described by Sips, Langmuir and Brouers-Sotolongo model. FeCuNi-280 was easily regenerated with aqueous solution of NaOH, and reutilization was successfully done in five sorption cycles. The present study show that easy-to-prepare, relatively inexpensive nanosorbent FeCuNi-280 is among the best sorbents for the removal of RB19 dye from water solution and wastewater from textile industry in wide range of pH.

Removal of cationic pollutants from water by xanthated corn cob: optimization, kinetics, thermodynamics, and prediction of purification process

The removal of Cr(III) ions and methylene blue (MB) from aqueous solutions by xanthated corn cob (xCC) in batch conditions was investigated. The sorption capacity of xCC strongly depended of the pH, and increase when the pH rises. The kinetics was well fitted by pseudo-second-order and Chrastil's model. Sorption of Cr(III) ions and MB on xCC was rapid during the first 20 min of contact time and, thereafter, the biosorption rate decrease gradually until reaching equilibrium. The maximum sorption capacity of 17.13 and 83.89 mg g^-1 for Cr(III) ions and MB, respectively, was obtained at 40 °C, pH 5, and sorbent dose 4 g dm^-3 for removal of Cr(III) ions and 1 g dm^-3 for removal of MB. The prediction of purification process was successfully carried out, and the verification of theoretically calculated amounts of sorbent was confirmed by using packed-bed column laboratory system with recirculation of the aqueous phase. The wastewater from chrome plating industry was successfully purified, i.e., after 40 min concentration of Cr(III) ions was decreased lower than 0.1 mg dm^-3. Also, removal of MB from the river water was successfully carried out and after 40 min, removal efficiency was about 94%.

Tumor-Infiltrating Lymphocytes and Breast Cancer: Are Immune Checkpoint Inhibitors Ready for Prime Time in Breast Cancer?

In recent years, results obtained from different studies with large cohorts have revealed a bond between the presence of extensive lymphocytic infiltration and favourable prognostic associations in the early-stage of breast cancer (BC) and high response rates to neoadjuvant chemotherapy. Examiners used tumors from large cohorts of patients who took part in randomized neoadjuvant and adjuvant clinical trials. The importance of tumor infiltrating lymphocytes (TILs) appears to be subtype-specific and varies depending on the histological characteristics of the tumor. TILs have proven to be a good prognostic marker, but only in highly proliferative breast tumors such as triple negative breast tumors (TNBC) or HER 2 positive BC.

In the era when standard, well-known, prognostic and predictive biomarkers are ever changing and the use of molecular profiling analyses are increasing, we are looking for techniques to improve our understanding of tumor biology and improve patient outcome. The relevance of TILs cannot be ignored but needs to be properly evaluated in larger prospective studies which must encompass the parameters set out in previous studies. The use of TILs as prognostic biomarkers in early breast cancer may represent a new dawn, and use of immunotherapy, especially immune checkpoint inhibitors, probably is the future for the breast cancer but it is not yet ready for prime time.

Evolution of Surface Motor Activation Zones in Hemiplegic Patients During 20 Sessions of FES Therapy with Multi-pad Electrodes

The purpose of this study was to examine surface motor activation zones for wrist, fingers and thumb extension movements and their temporal change during 20 therapy sessions using advanced multi-pad functional electrical stimulation system. Results from four hemiplegic patients indicate that certain zones have higher probability of eliciting each of the target movements. However, mutual overlap and variations of the zones are present not just between the subjects, but also on the intrasubject level, reflected through these session to session transformations of the selected virtual electrodes. The obtained results could be used as a priori knowledge for semi-automated optimization algorithm and could shorten the time required for calibration of the multi-pad electrode.

[Prosthetic rehabilitation in patient with forced class III malocclusion]

The paper presents clinical case of 63 years old edentulous patient with slight class III malocclusion. For 15 years he was using inadequately fabricated dentures causing forced severe class III malocclusion. Forced progeny was corrected by newly fabricated dentures which restored normal orofacial function and facial harmony.

[The Lesch-Nyhan syndrome]

Deficiency of hypoxanthine phosphoribosyltransferase (HPRT) has a broad spectrum of clinical manifestations, from the complete enzyme defect, the Lesch-Nyhan syndrome with severe neurological deficiency to the partial defect associated only with uric acid overproduction and its consequences. We present a 5-year old boy with Lesch-Nyhan syndrome. He came to our hospital because of abdominal pain, vomiting and gross haematuria. At the age of 8 months he was categorized as a "cerebral palsy" patient due to involuntary movements and high degree of spastically and tonic spasms. He remained incapable of sitting or standing alone. The patient's brother and two uncles were also categorized as "cerebral palsy" cases and died at the age of 8-14 years. Clinical examination revealed hyperuricaemia and hyperuricosuria, radiolucent renal and urinary bladder stones. HPRT enzyme activity was totally absent, while adenine phosphoribosyl transferase activity was increased compared to control. The patient was treated with allopurinol, urinary alkalization, low-purine diet and adequate hydration while he was in hospital. However, his parents refused further treatment and follow-up. The most important issue is whether the healthy sisters of the patients are heterozygotes for HPRT deficiency. This DNA analysis is now in progress.

Hyponatremic hypertensive syndrome

We report on a 4-year-old girl with hyponatremic-hypertensive syndrome (HHS), a rare entity in childhood. The girl was referred to us from a local hospital with a history of recurrent fever, vomiting, and seizures. On admission she was markedly dehydrated. Initial investigations revealed severe hyponatremia (serum Na 120 mmol/l), hypochloremia (serum Cl 68 mmol/l), and mild hypokalemia (serum K 3.3 mmol/l), while serum calcium and magnesium were normal. Serum urea was 5 mmol/l and serum creatinine was 62 mumol/l. Despite hyponatremic dehydration, her urine output was high (2050 ml/24 h), as was her urinary sodium (168 mmol/24 h). She had massive transient proteinuria (maximal 1642 mg/24 h) while being severely hypertensive (blood pressure 210/160 mmHg). Further investigations revealed right kidney scarring, hyper-reflexive bladder dysfunction, massive brain infarcts, and myocardial left ventricular hypertrophy. Renal arteries were normal on arteriography. Blood pressure control resulted in normalization of serum and urinary electrolytes and decrease of proteinuria. Hyponatremia and transient massive proteinuria in this patient seem to be caused by high-pressure-forced diuresis due to malignant renoparenchymal hypertension.

[20 years' experience in the treatment of children with terminal renal insufficiency in Yugoslavia]

The first specialized haemodialysis (HD) paediatric centre in former Yugoslavia was established at the University Children's Hospital in Belgrade in January 1980. A total of 194 children (F: 98, M: 96), aged less than 19 years (10.12 +/- 4.23), were treated for renal replacement therapy (RRT) over 20 years. Average annual incidence rate was 1.59 per million of child population (pmcp) aged less than 19 years for the period 1980-1990 (former Yugoslavia) and 2.85 pmcp aged less than 19 years for the period 1990-2000 (present Yugoslavia). Reflux nephropathy was the most frequent underlying disease and accounted for 37.06% of total cases, while other primary renal diseases were: glomerulonephritis (GN) 17.26%, cystic/hereditary familial nephropathy 12.69%, congenital disease 11.68%, interstitial nephritis 5.58%, non-recovered tubular necrosis 3.55%, secondary GN 1.52% and 10.66% remained with doubtful diagnosis. HD was the first RRT in 84.02%, peritoneal dialysis (PD) in 14.43% and pre-emptive transplantation in 1.55% of all patients. A total of 53 patients (27.3% of total terminal renal failure (TRF) patients) received 56 kidney transplants (58.93% live related, 37.50% cadaveric, 3.57% live-non related). Actual survival in RRT was 64.53% 5 in years; 51.68% in 10 and 48.23% in 15 years. Patient survival in HD was significantly better over the last ten-year period than in the first ten-year period (35.88% vs. 75.75%; p < 0.005) as well as the survival of transplanted patients in the same two periods (67.62% vs. 95.45%). Graft survival was 79.85% in 5 and 70.50% in 10 years. Cardiovascular complications were the most common cause of death of patients on RRT (56.10 posto) followed by infection (24.39). On December 31, 1999, 54 patients on RRT were alive less than 19 years: 75.92% in HD; 22.22% with functioning graft and 1.85% on automatic PD. This is the first national-wide long-term study of incidence and aetiology of paediatric TRF and outcome of paediatric RRT in Yugoslavia.

[The captopril test--an aid in the detection of scarring nephropathy as a cause of arterial hypertension in children]

Renal scarring with and without vesicoureteral reflux (VUR) has been now recognized as an important cause of paediatric hypertension for many years [1-5]. However, its pathogenesis has still remained uncleared. The widespread concept implicated the activation of renin-angiotensin system finding a powerfull support in higher peripheral plasma renin activity (PRA) in children with reflux nephropathy than in controls [6, 7] and in beneficial antihypertensive effects of ACE inhibitors. The latter, in form of captopril, has also been used in captopril test and in renal scintigraphy and isotope renography following the administration of captopril to provide evidence for renin dependent hypertension [8, 9]. Published studies of captopril test have centred on the identification of renovascular as opposed to essential hypertension [10-18, 20-22]. The aim of our study was to assess the usefulness of captopril test in differentiation between hypertensive children with renal scarring from those with essential hypertension. We studied blood pressure (BP) and PRA responses to a single dose of captopril in two groups of hypertensive children. Group A consisted of 29 patients, 14 boys and 15 girls, who had renal scaring as demonstrated by renal 99mTc dimercaptosuccinid acid scan (99m Tc DMSA) and/or intravenous pyelography. Group B included 19 patients, 19 boys and 10 girls who had arterial hypertension, while clinical examination excluded renal and other definable causes of BP elevation, and they were therefore considered to have essential hypertension. At the time of the study all patients had normal glomerular filtration rate and were not salt depleted. They did not receive any antihypertensive medication for at least two weeks. The test was performed in the morning in fasting sitting patients. At the start of the test a small vein in the hand or forearm was cannulated to permit blood sampling. BP was measured 10, 20, and 30 minutes before captopril administration to get baseline BP (mean of these three measurements) and to allow the children to become accustomed to the test procedure. A single oral dose of captopril 0.64 +/- 0.04 mg/kg body weight was given to patients from group A and almost the same dose of captopril, 0.63 +/- 0.05 mg/kg body weight, to patients from group B. The patients remained sitting and BP was measured every 15 minutes during an hour. Blood for PRA was drown in the sitting position (17 patients from group A and 16 patients from group B) before and one hour after the dose of captopril. Samples of blood for basal PRA were collected from 16 patients from group A and in 14 patients from in B in lying position after waking up in the morning. PRA was measured by radioimmunoassay using a commercially available kit, SB-REN 2, from CIS Bio International. According to the criteria of Muller et al. [10] the captopril test was positive if the post-captopril PRA (ng/ml/h) was greater than or equal to 12 with an increase of greater than or equal to 10 and relative increase of greater than or equal to 15% (400% if initial PRA was < 3). The results of our study are presented in Tables 1 and 2 and in Graphs 1 and 2. The age of patients, doses of captopril, initial BP and PRA before the use of captopril did not much differ between studied groups. Fall of BP and PRA increase were highly significant (p < 0.001) both in group A and group B. However, the hypotensive reaction of diastolic BP and MAP were more pronounced in group A (14.45 +/- 1.67% and 15.81 +/- 1.62%) than in group B (6.95 +/- 2.21% and 8.96 +/- 1.75%; p < 0.01), but there were no significant differences in PRA and systolic BP changes and positive results of captopril test between the studied groups. Hypotensive responses of diastolic BP and MAP greater than 10% of initial values were found to be more frequent in group A (79.32% and 79.31%) than in group B (26.61% and 31.57 degrees %; p < 0.001 and p < 0.01). Diastolic BP and MAP were directly related to the dose of cap

[Renal tubular function in children with hypercalciuria]

INTRODUCTION

Renal stone disease is commonly due to hypercalciuria [1, 2], which may be assessed either from a 24-hour urinary collection or from the fasting first morning urine. Hypercalciuria during childhood has been defined by a 24-hour calcium excretion greater than 3.5 mg/kg per day and/or calcium to creatinine ratio greater than 0.20 [3]. The alteration in the calcium transporting systems plays a pathogenetic role in promoting hypercalciuria [4, 5]. Since calcium reabsorption along the nephron is intimately related to that of other electrolytes and substances, it can be hypothesized that patients with hypercalciuria may have other renal tubular defects. The aim of the study was to investigate proximal tubular function (tubular reabsorption of sodium, potassium, phosphate and glucose) and distal tubular function (urinary concentrating capacity and acidifying capacity) in children with hypercalciuria.

PATIENTS AND METHODS

Two groups of children were studied: hypercalciuric group included 23 children with hypercalciuria (10 males, aged 11.9 +/- 4.1 years), of whom 6 with nephrolithiasis, and control group included 42 healthy children (20 males, aged 11.2 +/- 3.8 years). All subjects had normal serum values for calcium, sodium, potassium, phosphate and glucose, as well as normal renal function. The urinary excretion of calcium, sodium, potassium, phosphate, glucose and creatinine was measured in a 24-hour urine specimen by standard laboratory methods. Urine osmolality and urinary specific gravity were measured following 12-hour water-deprivation test. A short ammonium chloride loading test was performed in 3 patients with urinary pH above 5.5. The fractional excretion of sodium, tubular phosphate reabsorption and renal threshold phosphate concentration were calculated according to standard formula. Statistical analysis was performed using the t-test and analysis of variance (ANOVA). Kruskal-Wallis method was used to compare urinary phosphate excretion between two groups.

RESULTS

Table 1 summarizes urinary excretion of electrolytes in children with hypercalciuria compared with healthy controls. We found that urinary sodium excretion was significantly increased in patients with hypercalciuria when compared with controls (p < 0.05). Urinary phosphate excretion was significantly higher in patients with hypercalciuria in comparison to controls, and this was accompanied by a significant lowering of the tubular phosphate reabsorptive threshold (p < 0.05). Urinary potassium excretion tended to be lower, although not significantly, in the hypercalciuric children than in normal subjects. Table 2 shows the mean values +/- standard deviation of urinary specific gravity, urinary osmolality and urinary pH. Urinary specific gravity mean value was significantly lower in patients with hypercalciuria in comparison to controls (p < 0.05). Urinary pH was found below 5.5 in all patients. Glycosuria was detected in 3 patients (13.3%). As shown in Graph. 1, a significant correlation between the urinary excretion of calcium and sodium was demonstrated in both groups of children (r = 0.29; p < 0.01).

DISCUSSION

The present study shows that children with hypercalciuria have significantly higher urinary sodium and urinary phosphate excretion in comparison to controls, while urinary potassium excretion is normal in both groups of children. According to some recent reports [6-9], these findings may indicated defects of the renal tubular transport of sodium and phosphate which may be interpreted as a cause or a consequence of the alteration of the calcium transporting system. Defects in both proximal and distal renal tubular functions have been demonstrated in patients with nephrolithiasis, particularly those with hypercalciuria. Proximal renal tubular defects include defects in sodium, fluid, phosphate and glucose reabsorption, which were evident also in our patients. (ABSTRACT TRUNCATED)

[Continuous ambulatory measurement of blood pressure in children--personal experience]

Ambulatory blood pressure monitoring (ABPM) during normal daily activities and during night, when the patient is asleep, is a new method of measuring blood pressure (BP) in children, used for better diagnosis and treatment of hypertension. Compared to casual BP measurements, it documents normal daily BP variations, BP during sleep, the influence of emotional and physical stress on BP and is a better predictor of hypertension associated with end-organ damage. However, the experience in ABPM in children is still limited. In our country ABPM has been used since recently, and first results are referred to children with end-stage renal failure.

SUBJECTS AND METHODS

ABPM was performed in two groups of children: group A consisted of 61 children, aged 14.3 +/- 2.9 (mean +/- SD) yrs in whom intermittent outpatient BP measurements (for at least 3 months) suggested the diagnosis of hypertension (according to the data of Second Task Force); group B consisted of 52 patients (pts), aged 12.8 +/- 4.6 yr with renal disease. Four pts from group A (6.6%) and 20 pts from group B (38.5%) received antihypertensive therapy (captopril, nifedipine, furosemide and propranolol ). All children from group A and half of the children from group B had normal renal function. Eighteen pts from group B were on chronic haemodialysis (34.6%). Blood pressure was recorded during a 24-hour period except in haemodialyzed pts (48 h) (Table 1). Results of BP measurements are presented as the mean values of BP during a 24-hour period, during normal daily activities and during sleep. We used the age- and gender-appropriate 95th percentile from the Task Force Study as the daytime upper-limit of normal and 10% lower for the upper-limit at night. According to BP load (the percentage of BPs exceeding the upper limits of normal for age), children were assumed to have mild-to-moderate hypertension (BP load between 20% and 40%) or severe hypertension (BP load more than 40%). The success of antihypertensive therapy was evaluated after 1-3 months in 11 pts (twice in 10 pts and three times in one pt).

RESULTS

In group A 39.4% of pts were normotensive and 36.1% were without antihypertensive therapy, 58.4% of normotensive and 40.5% of hypertensive pts had blunted circadian BP rhythm (nocturnal BP reduction of less than 10% of diurnal values) (Graph. 1). In group B 38.5% of pts were normotensive and 27% were without antihypertensive therapy. In the group of normotensive pts alteration of circadian BP rhythm was found in 40% of pts with normal renal function, 80% of pts with chronic renal failure and in 100% of pts with terminal renal failure, while in the hypertensive group, altered circadian BP rhythm had 68%, 100% and 92% of pts, respectively (Graph 2). Mild-to-moderate hypertension had 54% of hypertensive pts from group A and 37.5% of hypertensive pts from group B. Severe hypertension was more frequent in group B (62.5%) comparing to group A (46%). The effectiveness of antihypertensive therapy was assessed in 11 pts. In 69.2% of pts BP became normal or was significantly decreased, in 23.1% of pts BP was not changed and 7.7% of pts had higher values of BP.

DISCUSSION

ABPM is very useful for diagnosing white coat hypertension. Like other authors, we have pointed out that more than one third of pts who were hypertensive according to usual BP measurements had normal 24-hour BP and we classified them as white coat hypertensives. More than a half of the pts had blunted circadian BP rhythm, and as it is not certain whether they will become hypertensive in adulthood they should be periodically controlled. There are several proofs that results of ABPM have a better correlation with hypertensive end-organ damage; therefore ABPM is used for assessing the severity of hypertension. In our former work, we showed excellent correlation of BP with left ventricular mass index in children with end-stage renal failure. (ABSTRACT TRUNCATED)

[Serum osteocalcin in children with chronic renal insufficiency]

The research of the bone metabolism has undergone a long evolution which began with the use of radioisotopes in calcium kinetic studies and went through the determination of several humoral parameters like alkaline phosphatase (ALP), hydroxyproline and intact immunoreactive parathyroid hormone (iPTH) and finally to the assay of a new serum and urinary parameters of bone metabolism, like osteocalcine (OC) and procollagen and collagen metabolites. The X-ray study of the skeleton, densitometric techniques, computerized tomography, scintigraphy and NMR are used for visualization of bone changes, but bone biopsy and histomorphometry provide the most precise evaluation [1]. Disorders of bone and mineral metabolism in children with chronic renal failure (CRF) are an almost regular occurrence; so early discovery and treatment of these changes are very important [2]. The aim of this study was to measure the serum OC level in children with CRF and terminal renal failure (TRF), treated with chronic haemodialysis, and to evaluate the significance of OC compared to other humoral parameters of renal osteodistrophy, such as ALP and iPTH.

MATERIALS AND METHODS

We studied the fasting levels of OC in three different groups of children: group A consisted of 18 patients with TRF; group B consisted of 12 patients at different stages of CRF, and group C consisted of 32 healthy children, all of the approximately same age. Clinical characteristics of the examinded children are presented in Table 1. Of 30 patients, 26 were treated with calcium carbonate and 21 with vitamin D analogues. None were treated with aluminium hydroxide. Additional parameters included serum calcium, phosphate, ALP and body height, while serum concentrations of iPTH and ionized serum calcium were measured only in group A. Serum OC was measured by radioimmunoassay using OSTK PR RIA (CIS), while ELISA-PTH (CIS) radioimmunoassay was used to determine iPTH plasma levels. Statistical analyses were performed using Kolmogorov-Smirnov test to confirm normal distribution, the Pearson and Spearman rank sum test for correlation between variables of interest, while analysis of variance was used to compare the findings.

RESULTS

Serum OC levels were significantly different in all groups (p < 0.01); they were three times higher in group A than in group C. Similar increase was noticed in plasma iPTH, assuming that "normal" uremic iPTH was raised up to threefold above normal range (between 10 and 60 pg/ml) [2]. However, the total serum ALP activity was not sensitive as OC and iPTH, since ALP increases were less as compared to them. OC was age related only in group A (p < 0.01), with a positive correlation between OC and duration of haemodialysis (p < 0.05), as well as between OC and serum phosphate (p < 0.05), but there was no correlation between OC and growth retardation (expressed by SDS), bone age and current therapy for renal osteodistrophy. A direct correlation between OC and ALP was found only in healthy children (p < 0.01), while in groups A and B it was remarkable, although not statistically significant (p = 0.08) (Graphs 1, 2, 3). In group A, ALP and iPTH were directly correlated (p < 0.001), but the correlation of OC with iPTH was less significant (p = 0.06). In patients with CRF no correlation was found between glomerular filtration rate and OC.

DISCUSSION

OC is a bone-derived noncollagenous protein of low molecular weight (about 5800 D), containing residues of the vitamin K dependent amino acid gamma-carboxyglutamic acid and is synthesized by osteoblasts and odontoblasts. Calcitriol is a potent stimulator of OC synthesis, acting at the transcriptional level and increasing mRNA severalfold. OC is found mainly in bone, but nanomolar concentrations circulate in the blood. Its serum levels are an expression of the bone formation process and are age related (higher in the neonatal and adolescent period). ABSTRACT TRUNCATED.

Endothelin-1 in acute renal failure

To study the pathological significance of circulating endothelin (ET) in ARF, we measured plasma ET in seven children (mean age 8.8 +/- 4.4 years) with ARF in the most severe phase and 3.7 +/- 3.5 months later in the recovery period. Twenty-seven healthy children were included in the study as controls. Plasma ET level was measured by highly sensitive and specific radioimmunoassay for ET-1 and ET-2 (ET-1/2, Biomedica, Vienna). Plasma ET was significantly higher in the most severe phase of ARF (4.75 +/- 4.08 fM/ml) than in the recovery period (0.78 +/- 0.24 fM/ml; p < 0.01), but comparing to plasma ET in the healthy children, the difference was only of borderline statistical significance (Pf, 0.0573). Since plasma concentrations of creatinine did not correlate with plasma ET in patients, either in acute or in the recovery phase of disease, we concluded that decreased GFR is not the main factor determining an increased ET in ARF. We suggest that elevated plasma ET in ARF may be secondary to vascular endothelial dysfunction and speculate that enhancement synthesis of endothelial relaxing factor (EDRF) inhibits ET synthesis during the recovery period. We did not find any relationship between plasma ET and blood pressure (BP) in patients with ARF, so we conclude that circulating ET is not the main factor determining BP in ARF.

[Kidney transplantation in children]

During the last 14 years, since the opening of the Center for Childrens' Hemodialysis the University Children's Hospital of Belgrade, 174 children with terminal renal failure were treated by chronic hemodialysis. Of these, only 35 patients (20.1%), 14 girls and 21 boys, mean age 12.6 +/- 4.9 years, were transplanted. The average waiting time for transplantation was 24.6 months (range 0-120 months). Twenty-five patients were transplanted with paternal kidney, the others were cadaveric transplantations. More than half of transplantations were done abroad. Of 35 patients, 20 were under follow-up for over 6 months (45.7 +/- 7.2 range 6 to 102 months). Five year patient survival was 94.1% and the graft survival over the same period was 76.4%. 45.7 +/- 7.2 months after transplantation the outcome was the following: 11 patients (55%) had GFR over 60 ml/min/1.73 m2, 5 patients (25%) had GFR from 25 to 60 ml/min/1.73 m2, 2 patients (10%) returned to chronic hemodialysis, 1 patient was retransplanted and 1 patient died. All patients with GFR of over 60 ml/min/1.73 m2 are well psychosocially rehabilitated, 62.4% are normotensive without antihypertensive therapy, and only 9.9% are growth retarded.

[Cystic tumefaction in the minor pelvis--the agenesis-dysplasia syndrome (case report)]

Ectopic kidney often shows signs of parenchyma maldifferentiation. Multicystic or dysplastic kidney is usually associated with congenital urogenital and skeletal system anomalies. In the Unilateral form of the agenesia-dysplasis syndrome, the kidney, if it is present, is small dysplastic and usually cystically changed. Ipsilateral uterus horn or vaginal agenesia are the most frequently associated anomalies. Case report. A six years old girl was clinically examined due to recurrent urinary tract infections. On ultrasound, the left kidney was enlarged, while the right kidney was absent in normal position. Cystic mass 4x5 cm was seen in the pelvis. The right kidney was not seen on IVP. CT scan showed a cystic formation in the pelvis, described as cystically changed dysplastic kidney. Pelviceal mass was extirpated. Exploration of the genital system revealed vaginal arch blinded in the hypoplastic right uterus horn. On pathohystology tumefaction corresponded to the dysplastic kidney.

IN CONCLUSION

unilateral renal aplasia or dysplasia may indicate genital anomalies having in mind the hereditary character of unilateral form of the agenesia-dysplasia syndrome therefore, it could be helpful in prenatal diagnosis of cystic pelvic mass of fetus in families with this syndrome.

[Jeune's syndrome (3 case reports)]

Jeune's syndrome or asphyxiating thoracic dystrophy is an autosomal recessive osteochondrodysplasia with multisystem involvement. In patients who survive neonatal period in the main clinical feature progressive renal failure is. Renal lesions are variable but is familial juvenile nephronophtisis the most frequent one. We present three patients with Jeune's syndrome phenotype and chronic tubulointerstitial disease. All patients developed terminal renal failure in the eyrly childhood. Renal histology, examined in two cases, was consistent with juvenile nephronophtisis in one case and with renal dysplasia in other case. All our patients had hepatic fibrosis and two of them had pigmentary retinophaty. We want to underline the importance of regular check-up of children with typical phenotype by pediatrician-nephrologist as wel as possibility of prenatal diagnosis of Jeune's syndrome.

[Vesicoureteral reflux as a familial disease]

Vesicoureteral reflux and reflux nephropathy are causes of end-stage renal failure in 43 percent of our patients on haemodialysis. Aiming at early discovering of vesicoureteral reflux and preventing reflux nephropathy, we started an investigation of the familial character or the primary vesicoureteral reflux in the families of 44 our patients with the diagnosed anomaly. Investigations which consist of urinalysis, urine culture and ultrasound of kidneys have so far been carried out for siblings of our patients in ten families. Complete investigations, including voiding cystourethrogram where indicated, have been carried out in five families. Familial vesicoureteral reflux ascertained in three families.

[Cystic kidney disease--genetics, pathogenesis and clinical aspects in children]

This paper reviews recent studies producing insight into genetics and cellular abnormalities causing kidney cysts, their growth and development. Clinical features of various cystic kidney diseases in our patients are described. Special attention has been paid to those rarely reported in our literature. Important discovery concerns location of the gene for autosomal dominant polycystic kidney disease (ADPKD) 1 and 2 on the short arms of chromosome 16 and 4 respectively, as well as for autosomal recessive polycystic kidney disease (ARPKD) on chromosome 6 and for juvenile nephronophtisis on the short arm of chromosome 2. Two basic abnormalities necessary for cyst formation are increased: epithelial cell proliferation and altered fluid transport. Mitogenic action of epidermal growth factor (EGF) is significantly increased and EGF receptors have been demonstrated on apical as well as on basal surface of cyst lining epithelium. TGF-beta shows marked loos of inhibitory activity with regard to EGF. Cystic epithelium has altered polarity; Na-K-ATP-ase is located exclusively on the apical cell membrane. Tubular basement membrane shows alteration in structural components. Complex medullar cystic disease--nephronophtisis, complex as well as the hepatorenal complex of nephoronophtisis--congenital hepatic fibrosis are emphasized in this paper. The later has proved to be rather frequent in our population. We described a distinctive variant of hepato-renal disorder in 4 patients and reviewed 5 similar patients in the literature. The main characteristics are progressive tubulointerstitial nephritis and cholestatic liver disease. We strongly suggest that this variant represents a new syndrome (Popović-Rolović M, Kostić M, Sindić M. et al Progressive tubulointerstitialnephritis and chronic cholestatic liver disease.

[Urinary bladder dysfunction and vesicoureteral reflux in patients with enuresis]

We present preliminary results of prospective study on 38 children (aged 4-15 y.) with enuresis. The aim of the study was to document the association between bladder disfunction and urinary tract abnormalities. Enuresis was more common in girls (71%). Twenty one children (44.7%) suffered from secondary, and 17 (55.3%) from primary enuresis. High incidence of enuresis (31.6%) or voiding dysfunction, renal lithiasis, constipation of other kidney disease (42%) were disclosed among family members of children with enuresis. Urodynamic studies revealed bladder dysfunction in 84.0% of children with enuresis mostly in the form of dyssingeric (45.5%) or unstable/hyperactive bladder (45.5%). In 9% of patients bladder dysfunction as in the form of inadequate bladder with small and poor detrusor contractions often associated with large residue. Ultrasonography revealed dilatation of pyelocaliceal system in 13.2%, and vesicoureteral reflux was confirmed in 10.5% of patients. We stress out high incidence of bladder dysfunction among children with enuresis as well as among their family members.

[The effect of hemodialysis on endothelin-1 plasma levels in children with terminal renal insufficiency]

We analysed the effect of hemodialysis (HD) on endothelin (ET) plasma level in children with terminal renal failure. Twenty-five patients (pts) and 27 healthy children as controls were included in the study. There was no difference in ET plasma levels in pts before HD (1.97 +/- 1.45) and controls (2.08 +/- 1.47), but ET increased in plasma of pts after HD (4.10 +/- 3.66). To estimate the relationship of volume depletion or depuration on ET plasma level changes in pts during HD, ET was measured at three time points of HD (before ultrafiltration-UF, after UF, and after HD without fluid removal) in 10 pts. ET level was not significantly changed after UF (1.93 +/- 2.25 vs 1.71 +/- 1.50; ns), but was significantly increased after depuration (4.46 +/- 3.56; p < 0.05). There was no correlation between ET and blood pressure in controls and pts in either period of testing, neither with plasma renin activity, left ventricular mass index, and body weight changes during HD.

[Continuous blood pressure monitoring over a 24-hour period in children with terminal renal failure treated with hemodialysis]

Recent evidence suggests that circadian blood pressure changes are common in patients with impaired renal function and has excellent correlation with end-organ damage. The aim of this paper was to: 1) evaluate if children with end-stage renal failure have altered circadian blood pressure rhythm; 2) assess whether pre- or postdialytic blood pressure is representative for the average interdialytic blood pressure; 3) assess whether pre- or postdialytic blood pressure is representative for the average interdialytic blood pressure; 3) determine influence of pre-, post and interdialytic blood pressure. Ambulatory blood pressure monitoring was performed in two groups of patients: group A-13 children with end-stage renal failure, aged 15.15 +/- 5.58 years, on chronic haemodialysis from 2 to 156 (mean 45.3) months, 4 of whom were hypertensive and 9 normotensive; group B-19 children with chronic hypertension (essential or renal hypertension) aged 15.28 +/- 2.27 years. 84.62% of children from group A and 31.58% from group B (p = 0.0037) had blunted circadian blood pressure rhythm (a nocturnal reduction of blood pressure is less than 10% of daytime values). Pre- and postdialytic systolic, diastolic and mean arterial blood pressure did not differ significantly and were in correlation with interdialytic blood pressure (r = 0.9; p < 0.01). Pre-, post- and interdialytic blood pressures correlated well with left ventricular mass index (r = 0.6; p < 0.05), but were not in correlation with the degree of hypervolemia (p < 0.05).

[Treatment of duodenal ulcer with famotidine and proglumide]

In an open study the clinical efficacy of famotidine 40 mg on a duodenal ulcer was compared to that of proglumide 1600 mg. The study included 106 patients with acute duodenal ulcer, divided into two groups: A-famotidine and B-proglumide. There were no significant differences between the groups in baseline characteristics. Due to different reasons nine patients were excluded from analysis. Duodenal ulcer diagnosis and healing were determined exclusively by endoscopy. Ulcer healing was observed after four weeks in 40/49 (81.6%) patients in group A and 35/48 (72.9%) patients in group B and in 46/49 (94%) and 40/48 (83.3) after eight weeks, respectively. There were no statistically significant differences between the healing rates for both groups (p > 0.05). The reduction of ulcer related symptoms and antacid consumption was equal in both groups. No adverse effects were reported in the group A, but there were three patients with transient skin rush in the group B. Reported adverse effects were minor and did not merit exclusion from the study. It was concluded that the efficacy of famotidine 40 mg vs. proglumide 1600 mg was similar, although famotidine had proportionally better effect than proglumide. These findings supported the hypothesis that famotidine suppressed acid secretion stronger than proglumide.

[Significance of endothelin in arterial hypertension in children]

Concentration of plasma endothelin and the activity of Na(+)-K(+)-ATP-ase were determined in 3 different groups of children: the 1st group comprised 13 children with essential hypertension, aged 12.9+/-4.8; the 2nd group concerned 16 children with renal hypertension, but with preserved global renal function, aged 13.7+/-2.8, and the 3rd group consisted of 27 healthy children, aged 11.6+/-6.3 years. Plasma endothelin concentrations were measured by radioimmunological method, using a set manufactured by "Biomedica". The activity of Na(+)-K(+)-ATPase was determined in erythrocyte haemolysate by measuring the quantity of released inorganic phosphate in samples with and without ouabaine. Concentration of plasma endothelin was not significantly different between the children with arterial hypertension and healthy children, and there was no significant correlation between endothelin concentration and blood pressure in either of the 3 groups of children. The activity of Na(+)-K(+)-ATP-ase was significantly decreased only in the 1st group of children. There was no evidence of correlation between the Na(+)-K(+)-ATPase activity and blood pressure or plasma endothelin either in healthy, or in hypertensive children.

CONCLUSION

Endothelin in blood circulation has no significance in regulating blood pressure in healthy children. It also has no direct role on the development of essential and renal hypertension in children. The activity of Na(+)-K(+)-ATP-ase is decreased in children with essential hypertension, but it seems that it has no direct impact on hypertension. Endothelin in circulation and Na(+)-K(+)-ATP-ase activity are not interdependant.

[Determination of the level of urinary tract infection in children by antibodies coating bacteria from urinary sediment]

The article deals with the evaluation of the significance of surface antibodies in urinary sediment bacteria by direct immunofluorescence in children with urinary tract infection caused by Escherichia coli (E. coli), so as of determination of location of the infection. Sixty five children were studied, aged from 1 to 16.5 years. Based on the recognized criteria in literature, all patients were classified into three groups: chronic pyelonephritis (CP)--10 patients, acute pyelonephritis (AP)--34 patients, and lower urinary tract infections (LUTI)--21 patients. On the basis of the analysis of the relationship among the three groups of patients in relation to the absence or various presence rates (up to 5%, 6-10% and 11-15% respectively) of fluorescent antibodies in urine sediment, and using the Fischer's test of absolute probability, we obtained a highly significant difference (p = 0.00006) only between the groups AP and LUTI. This difference caused the presence of fluorescence in the AP group and its absence in the LUTI group. By adding the positive fluorescence findings we found that it was present in 80% of CP patients, in 91.17% of AP patients, and in 14.28% of LUTI patients. chi2 test showed a highly significant difference (chi2 = 34.79; p < 0.01), which confirmed that bacterial fluorescence was most often present in the urine of AP patients and absent in LUTI patients. Bacterial fluorescence was significantly more frequent in CP patients in relation to LUTI patients. These results indicate that the method for detecting surface antibodies in urine bacteria, aimed at determinig the location of infection, is more reliable and noninvasive as compared to other methods.

[The influence of protein and phosphorous restricted diet supplemented with essential aminoacids (EAA) and their alpha-keto-analogues (KAA) on nutritional status of children with chronic renal failure (CRF)]

The purpose of the study was to establish the influence of protein restricted diet supplemented with EAA/KAA on nutritional status of children with CRF. Seven childredn (four girls and three boys), aged from 7 years and eight months to 14 years and two months, with glomerular filtration rate of 42.6-9.2 ml/min/1.73 m2 and proteinuria of 0.025-1.125 g/24 h, who were on conservative treatment and who lived at home, were observed for six months. In prescribing energy value and protein intake WHO recommendations were used for healthly children (age for height). Through food 80-90% of energy and 80-85% of protein needs were provided. The remaining energy and proteins were provided by glucodextrin and EAA/KAA supplements respectevely. Average daily phosphorous intake amounted to about 550-800 mg. The obtained results showed that stunting and kwashiorkor like aminoacid disbalance were the prominent nutritional problems. This dietary regimen had a beneficial effect on all studied parameters. especially on height standard deviation score which increased from 1.71 +/- 2.6 to 1.5 +/- 4.3 (t = 2.809, p < 0.05); total essential/nonessential aminoacid score increased from 0.38 +/- 0.2 to 0.56 +/- 0.2 (t = 2.763, p < 0.05). The ratio between plasma concentration of four nonessential (glycine+serinet glutamine+taurine) to four essential (leucine+isoleucine+valine+methionine) amino acids decreased from 3.82 +/- 1.2 to 2.7 +/- 0.4 (t = 2.528, p < 0.05). Lymphocyte count increased from 1.809 x 10(9) +/- 0.268 x 10(9)/l to 2.314 x 10(9) +/- 0.922 x 10(9)/l (t = 2.431, p < 0.05). No significant changes were found in the values of relative body weight, arm circumpherence, triceps skinfold thickness, total plasma protein, albumin, transferine, complement C3 and plasma valin/glycin and phenylalanine/thyrosine ratio. It should be noted that the significant changes were not found in the results of these latter anthropometric biochemical parameters in relation to their primary almost insignificant values.

[Clinical significance of serotypization of Escherichia coli isolated in children urinary tract]

The paper deals with the study of 65 children, aged from 1 to 16,5 years (7 years and 5 months +/- 2 years and 7 months), with urinary tract infection caused by Escherichia coli (E. coli). All patients were classified into three groups according to accepted criteria from literature (clinical features, urographic characteristics, immunological analyses and laboratory signs of inflammatory reaction: (1) 10 patients with chronic pyelonephritis (CP); (2) 34 patients with acute pyelonephritis (AP), and (3) 21 patients with lower urinary tract infection (LUTI). Using 7 antisera antigen preparations O1, O2, 04, O7, O11, O15 and O18, 46 (70.8%) isolated strains were serotyped, while 19 (29.2%) isolated strains of E. coli remained unserotyped. None of the patients showed the presence of more than one serotype in urine. Due to the small number of cases in some groups and low number of serotype strains within the groups, break-down of serotype by patient groups was not done. The prevalent serogroup was O7 found in 22 (47.8%) patients, then O11 in 9 (19.6%), O1 in 4 (8.7%), O15 in 4 (8.7%), O4 in 3 (6.5%), O2 in 2 (4.3%) and O18 in 2 (4.3%) patients. Serogroup O7 was present in all three groups of patients. Statistical analysis showed that the incidence of serogroup O7 was not significantly different (p > 0.05); this suggests that a specific serogroup does not cause only one type of infection. Having in mind that all existing antisera were not used, the possibility of intra-hospital infection provoked by O7 serogroup should be taken into consideration.