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Disposable protective face masks, the most used personal protective tools during the Covid-19 pandemic, have become a serious environmental concern that needs urgent attention. In this study, disposable protective face masks were disassembled into their components and mechanically recycled through extrusion. Fourier transform infrared spectroscopy and scanning electron microscopy were employed to investigate the effect of recycling on the structure and morphology of the mask material. Microscopy revealed morphological differences among the layers of the mask. Differential scanning calorimetry and thermogravimetric analysis were used to characterise the thermal properties of the samples before and after recycling. Although the mechanical recycling process had minor effect on the thermal properties and stability of the mask material, thermal methods verified differences between the layers of the mask. [ABSTRACT FROM AUTHOR]

In this work, post-consumer poly(ethylene terephthalate) (PET) bottles were gathered, separated from other materials, and re-extruded. In order to evaluate the effect of re-extrusion on the structure of PET, Fourier transform infrared spectroscopy was utilised. No significant effect of the re-extrusion process on the structure of the PET sample was noticed. Obtained samples were also characterised by differential scanning calorimetry (DSC) in order to determine characteristic thermal transitions of PET. DSC results indicated the influence of re-extrusion; extruded PET started to melt at lower temperatures, and the crystallisation of re-extruded PET took place at significantly higher temperatures in comparison to PET. Likewise, thermogravimetric analysis (TG) was used to evaluate the effect of re-extrusion process on the thermal stability of samples. TG analysis revealed that the re-extrusion process had no effect on the thermal stability of the investigated PET samples. Finally, the activation energy of thermal degradation of the investigated samples was calculated using iso-conversional Flynn-Wall-Ozawa and Friedman method. Consequently, higher activation energies were noticed for the re-extruded PET sample in comparison to the PET bottle sample, which is a good argument in support of PET bottle recycling. [ABSTRACT FROM AUTHOR]

In this paper, the influence of researchers on the results of kinetic analysis of non-isothermal thermal decomposition of four polymers was investigated. Four polymers having different degrees of complexity of the degradation process were analysed. The kinetic analysis was performed by three researchers: one scientific advisor with tenure, one research associate and one doctoral student, all of whom used the same experimental thermogravimetric data. Kinetic analysis was performed using the Netzsch Thermokinetics Professional program. The results unequivocally showed that the researchers have a significant influence on the results of kinetic analysis, since they described the processes of the non-isothermal thermal decomposition of all samples by different kinetic schemes, and thus by different kinetic parameters. [ABSTRACT FROM AUTHOR]

The aim of our study was to evaluate cardiovascular function at rest and during exercise in dialysis patients before and after treatment with Epo and to examine the changes in left ventricular mass as the consequence of treatment for anaemia. We applied echocardiography and radionuclide ventriculography at rest and after exercise in our research. Following treatment with Epo there was a decrease in the initially high cardiac output (CO) and cardiac index (CI) from 7.5 to 6.3 1/min and from 4.3 to 3.6 1/min/m respectively. No changes were noted in mean diastolic (DPB) and mean blood pressure (MBP), as well as the initially increased peripheral resistance index (TPRi) of 2582.3 ± 2097.3 dyn-s-cm m. Nevertheless, end-diastolic (EDV) and endsystolic (ESV) volume were significantly decreased ( < 0.05), but the ejection fraction (EF) remained unchanged (73.9%). The decrease in the mean values for left ventricular mass (LVM) was significant only within the subgroup of dialysed patients who initially had larger left ventricular mass ( < 0.01). The functional capacity of the CV system measured during exercise increased from four metabolic equivalents (METs) to 6 METs ( < 0.01). A significant increase in blood volume was also observed following treatment of anaemia. The haemodynamic consequences of Epo therapy for the treatment of anaemia were quite positive. However, we would like to point out certain concerns regarding the dialysed patients with initially lower values for left ventricular mass and cardiac output, since the patients within this group developed left ventricular hypertrophy and an increase in cardiac output. [ABSTRACT FROM PUBLISHER]

Ultra-wideband (UWB) sensors are a radio frequency technology that use wireless communication between devices to precisely determine the position. The most recent applications focus on locating and sensor data collecting on mobile phones, car keys and other similar devices. However, this technology is still not being utilized in the mining sector. To overcome this gap, this perspective offers implementation options and solutions. Additionally, it evaluated the benefits and drawbacks of using ultra-wideband for mining. The measurements provided were made using QORVO two-way ranging sensors, and these were compared to theoretical and existing technological solutions. To ensure the optimal use of UWB sensors, a special emphasis was placed on certain influencing factors, such as ways of locating via UWB and factors affecting measurement accuracies, such as the line of sight, multipath propagation, the effect of shielding and the ideal measurement setup. A conducted experiment showed that the most accurate results are obtained when there is no multipath propagation and the arriving signal travels directly from the transmitter to the receiver.

Roof falls are currently one of the most dangerous threats associated with underground mining at great depth. Every occurrence of such an event poses a significant risk to the mining crew and disturbs the continuity of the mining process, which clearly affects the economy of the exploitation process. The development of a reliable monitoring system may significantly reduce the impact of eventual roof failure and will have a positive effect on the sustainability of the extraction process. Within this research study, a prototype of an instrumented rock bolt developed for continuous stress measurement is presented. The procedure of a 4-groove multilevel instrumented rock bolt is described and the calibration process is shown. Then, preliminary results of long-term in situ monitoring are presented. Based on the continuous monitoring of stress distribution within immediate roof strata, it was concluded that the developed instrumented rock bolt provides reliable results and is a very useful device, ensuring the possibility of early warning for miners about increasing roof fall risk.

A novel ion-selective electrode with membranes based on iron(III) phosphate and silver sulfide integrated into a completely new electrode body design has been developed for the determination of iron(III) cations. The best response characteristics with linear potential change were found in the iron(III) concentration range from 3.97 × 10 -5 to 10 -2 mol L -1 . The detection limit was found to be 2.41 × 10 -5 mol L -1 with a slope of -20.53 ± 0.63 and regression coefficient of 0.9925, while the quantification limit was 3.97 × 10 -5 M. The potential change per concentration decade ranged from -13.59 ± 0.54 to -20.53 ± 1.56 for Electrode Body 1 (EB1) and from -17.28 ± 1.04 to -24 ± 1.87 for Electrode Body 2 (EB2), which is presented for the first time in this work. The prepared electrode has a long lifetime and the ability to detect changes in the concentration of iron cations within 20 s. Membrane M1 showed high recoveries in the determination of iron cations in iron(III) standard solutions (98.2-101.2%) as well as in two different pharmaceuticals (98.6-106.5%). This proves that this type of sensor is applicable in the determination of ferric cations in unknown samples, and the fact that all sensor parts are completely manufactured in our laboratory proves the simplicity of the method.

Non-isothermal thermogravimetry in an inert atmosphere was used to investigate the thermal stability of poly(e-caprolactone) (PCL), polylactide (PLA), thermoplastic starch (TPS) and their binary (PCL/PLA,PCL/TPS andPLA/TPS) and ternary (PCL/PLA/TPS) blends. All investigated blends were prepared by Brabender kneading chamber. A two-stage degradation pattern is seen in the case ofPCL, whilePLAexhibits only single stage degradation. On the other hand, the degradation of neat TPS proceeds through three degradation stages. It was found that addition ofPLAaffects the degradation ofPCL/PLAblends indicatingPLA's destabilising effect onPCL. TPS addition thermally destabilizes both,PCLandPLA, but notably thePCLsample. Likewise, that addition of TPS thermally destabilized all investigated ternary blends. The obtained data were used for the kinetic analysis of the degradation process. By using the isoconversional Friedman method and the multivariate nonlinear regression method kinetic analysis was performed. Kinetic analysis revealed the complexity of the thermal degradation process for neat samples and all investigated blends. Kinetic parameters (activation energy, pre-exponential factor and kinetic model) for each degradation stage of neat samples and all investigated blends were calculated.

Malnutrition, inflammation, and anemia are common in peritoneal dialysis (PD) patients. In this study, correlations between Malnutrition Inflammation Score (MIS), laboratory and anthropometric parameters, and anemia indices in Croatian PD patients were analyzed. One hundred and one PD patients (males/females 54/47, age 58.71 ± 14.68 years, mean PD duration 21.82 ± 21.71 months) were included. Clinical, laboratory, and anthropometric parameters were measured. Statistically significant correlations between MIS and erythropoietin weekly dose per kg of body weight (ESA weekly dose), hemoglobin (Hb), and erythrocytes were found ( r = 0.439, p < 0.001; r = -0.032, p < 0.001; r = -0.435, p < 0.001), respectively. Also, statistically significant correlations were found between MIS and mean corpuscular volume ( r = 0.344, p < 0.001), iron ( r = -0.229, p = 0.021), and total iron binding capacity (TIBC) ( r = -0.362, p < 0.001), respectively. Furthermore, statistically significant correlations between ESA weekly dose and serum albumin level and body mass index (BMI) were found ( r = -0.272, p = 0.006; r = -0.269, p = 0.006), respectively. When we divided PD patients into 2 groups according Hb level (Hb ≥ 110 [ N = 60, 59.41 %]) and Hb < 110 [ N = 41, 40.59%]), statistically significant differences were found in MIS score (3.02 ± 2.54 vs 4.54 ± 3.54, p = 0.014), C-reactive protein (CRP) (3.52 ± 6.36 vs 7.85 ± 7.96, p = 0.005), and serum albumin level (44.22 ± 8.54 vs 39.94 ± 8.56, p = 0.003), respectively. Our findings suggest that anemia is correlated with malnutrition and inflammation in Croatian PD patients. Further studies are needed to assess whether modulating inflammatory or nutritional processes can improve anemia management in PD patients., (Copyright © 2017 International Society for Peritoneal Dialysis.)

Disturbances of bone mineral metabolism are common complications of chronic kidney disease with bone fractures as one of the most important consequences. The aim of this study was to estimate prevalence of bone fractures among Croatian hemodialysis patients and to determine the possible fracture risk. The study was carried out in 767 hemodialysis patients from nine Croatian hemodialysis centers. Demographic, laboratory and bone fracture data were collected from medical records as well as therapy with vitamin D analogs. Fragility fractures were defined according to the World Health Organization definition. In 31 patient a total of 36 fractures were recorded. The prevalence of patients with bone fractures was 4.0%. The mean age of patients with fractures was 68.6 years. There were 9 male and 22 female patients with frac- tures. The mean hemodialysis duration was 63.3 months. Among all fractures the most common were hip fractures (39%) followed by forearm fractures (22%). This is the first study regarding epidemiology of bone fractures in Croatian hemodialysis patients. The prevalence of patients with bone fractures in our group of hemodialysis patients is high. Fractures were more frequent among women and older patients, patients who have been longer on dialysis and in patients with higher concentration of PTH.

There is a high incidence of cardiovascular morbidity and mortality among patients with chronic kidney disease (CKD) and malnutrition is a powerful predictor of cardiovascular morbidity and mortality in this population of patients. A multitude of factors related to CKD and renal replacement therapy can affect the nutritional status of CKD patients and lead to the development of malnutrition. In patients with CKD, protein energy wasting (PEW) is a condition that is distinct from undernutrition and is associated with inflammation, increased resting energy expenditure, low serum levels of albumin and prealbumin, sarcopenia, weight loss and poor clinical outcomes. Nutritional and metabolic derangements are implicated for the development of PEW in CKD and leading to the development of chronic catabolic state with muscle and fat loss. Prevention is the best way in treating PEW. Appropriate management of CKD patients at risk for PEW requires a comprehensive combination of strategies to diminish protein and energy depletion, and to institute therapies that will avoid further losses. The mainstay of nutritional treatment in MHD patients is nutritional counselling and provision of an adequate amount of protein and energy, using oral supplementation as needed. Intradialytic parenteral nutrition and total enteral nutrition should be attempted in CKD patients who cannot use the gastrointestinal tract efficiently. Other strategies such as anemia correction, treatment of secondary hyperparathyroidism and acidosis, delivering adequate dialysis dose can be considered as complementary therapies in CKD patients. Multidisciplinary work of nephrologists, gastroenterologist and dietician is needed to achieve best therapeutic goals in treating CKD patients with PEW.

Fabry disease (Anderson-Fabry disease) is one of the most common lysosomal storage diseases (after Gaucher disease) caused by deficient activity of the α-galactosidase A (α-Gal A) enzyme, which leads to progressive accumulation of globotriaosylceramide in various cells, predominantly in endothelium and vascular smooth muscles, with multisystem clinical manifestations. Estimates of the incidence range from one per 40,000 to 60,000 in males, and 1:117,000 in the general population. Pain is usually the first symptom and is present in 60%-80% of affected children, as well as gastrointestinal disturbances, ophthalmologic abnormalities and hearing loss. Renal failure, hypertrophic cardiomyopathy, or stroke as the presenting symptom may also be found even as isolated symptoms of the disease. Life expectancy is reduced by approximately 20 years in males and 10-15 years in females, therefore enzyme replacement therapy should be introduced in patients of any age and either sex, who meet treatment criteria for Anderson-Fabry disease.

Renal anemia is the result of chronic kidney disease (CKD) and deteriorates with disease progression. Anemia may be the first sign of kidney disease. In all patients with anemia and CKD, diagnostic evaluation is required. Prior to diagnosing renal anemia, it is necessary to eliminate the other possible causes. Direct correlation between the concentration of hemoglobin and the stage of renal failure is well known. Early development of anemia is common in diabetic patients. Correction of anemia may slow the progression of CKD. Anemia is an independent risk factor for developing cardiovascular disease in patients with CKD. Treatment of anemia in patients with CKD is based on current guidelines. Recently, the Kidney Disease: Improving Global Outcomes (KDIGO) group has produced comprehensive clinical practice guidelines for the management of anemia in CKD patients and ERBP (European Renal Best Practice) group its position statement and comments on the KDIGO guidelines. The Croatian Society of Nephrology, Dialysis and Transplantation (HDNDT) has already published its own guidelines based on the recommendations and positive experience of European and international professional societies, as well as on own experience. The latest version of Croatian guidelines was published in 2008. Since then, on the basis of research and clinical practice, there have been numerous changes in the modern understanding of the treatment of anemia in CKD. Consequently, HDNDT hereby publishes a review of the recent recommendations of international professional societies, expressing the attitude about treating anemia in CKD as a basis for new guidelines tailored to the present time.

Protein-energy wasting (PEW) is a frequent problem in patients with end-stage renal disease, which is associated with adverse outcome. Risk factors for development of PEW in dialysis patients include anorexia, limitations in food intake due to problems with mineral metabolism (hyperphosphatemia, hyperkalemia). Prevention of PEW in dialysis population demands different therapeutic measures to correct abnormalities and to prevent loss of energy and proteins. Therapeutic approach should be individualized based on the specific problems of each patient in order to correct metabolic problems and to optimize food intake. In patients with inability to maintain nutritional status with standard oral feeding, other measures which include oral nutrition supplements and intradialytic parenteral feeding should be applied. Anabolic steroids, growth hormone and adequate oral nutritional supplements, together with physical activity may prevent further catabolism and correct abnormalities. Appetite stimulators, antiinflammatory interventions and anabolic drugs seem promising; however, their efficacy should be investigated in future clinical trials.

Fabry disease (Anderson-Fabry disease) is one of the most common lysosomal storage diseases (after Gaucher disease) caused by deficient activity of the alpha-galactosidase A (alpha-Gal A) enzyme, which leads to progressive accumulation of globotriaosylceramide in various cells, predominantly in endothelium and vascular smooth muscles, with multisystem clinical manifestations. Estimates of the incidence range from one per 40,000 to 60,000 in males, and 1:117,000 in the general population. Pain is usually the first symptom and is present in 60%-80% of affected children, as well as gastrointestinal disturbances, ophthalmologic abnormalities and hearing loss. Renal failure, hypertrophic cardiomyopathy, or stroke as the presenting symptom may also be found even as isolated symptoms of the disease. Life expectancy is reduced by approximately 20 years in males and 10-15 years in females, therefore enzyme replacement therapy should be introduced in patients of any age and either sex, who meet treatment criteria for Anderson-Fabry disease.

Our aim was to assess the clinical course and outcome of ANCA-positive, pauci-immune renal limited vasculitis, their correlation with laboratory and histopathologic parameters recorded at initial and follow up testing, and to identify the possible outcome predictors. The study included 17 patients with renal biopsy, clinical, serologic and histopathologic parameters meeting the criteria for pauci-immune ANCA-positive glomerulonephritis without extrarenal manifestations of the disease. Creatinine clearance, 24-hour proteinuria and ANCA titer by ELISA method were determined at disease onset, during treatment and at the end of follow up. In 15 patients, the diagnosis was verified by kidney biopsy. Data were processed by Spearman correlation coefficient and Mann-Whitney test, and survival by Kaplan-Meier test. Lower percentage of glomeruli affected with vasculitis, better initial renal function as measured by serum creatinine or creatinine clearance, and lower chronicity on biopsy were identified as favorable indicators of kidney function outcome. Therapy responders had highest initial and lowest final 24-h proteinuria. The highest level of final 24-h proteinuria was recorded in dialysis dependent patients. The cumulative one-year and two-year patient and kidney survival rate was 64% and 50%, and 64% and 38%, respectively.

Aim: Despite of routinely practised living kidney transplantation, data on consequences and impact of unilateral nephrectomy on the quality of life and health of donors are scarce. The aim of the present study was to examine long-term changes and function of the remnant kidney after unilateral nephrectomy in an animal model., Methods: Thirty six female Sprague - Dawley rats at 4 months of age were randomized into the three groups: unilaterally nephrectomized, sham operated and naïve rats. The nephrectomy was done at inclusion in the experiment and their blood was taken at inclusion and six months thereafter., Results: There was a significant increase in serum creatinine concentrations six months after unilateral nephrectomy (39.7 ± 0.8 μmol/l) in comparison with the sham operated (30.1 ± 1.1 μmol/l) and the naïve rats (26.3 ± 3 μmol/l) (p ≤ 0.001). Serum sodium levels remained unchanged (p=0.116). Blood haemoglobin concentration did not differ between the three groups (p=0.115)., Conclusions: Although it has been very well established that kidney possesses huge capacity to compensate severe loss of renal mass, our results implicate that renal function undergoes significant deterioration with time after unilateral nephrectomy. Fortunately, in everyday clinical practice we do not see severe renal dysfunction in patients with a single kidney. However, prolongation of the human life span in the future could face us with renal impairment in living kidney donors. Future examination of specific biomarkers in our rat model (e.g. growth factors) could support our findings.

Renal transplantation is the treatment of choice for many patients with end-stage renal disease. There are a few generally accepted contraindications to transplantation: active infection, malignancy, substance abuse or non-adherence to therapy, chronic illness with life expectancy of less than one year, and poorly controlled psychosis. Potential renal transplant candidates must undergo thorough screening for exclusion of malignant diseases, with an individual approach to each patient. Patients with a history of malignancy might be placed on the waiting list for renal transplantation after a waiting period, which depends on the type of tumor and individual patient characteristics, and there are no signs of tumor. This group of patients require careful surveillance during the waiting time, as well as after transplantation.

Chronic renal failure affects all organ systems. Senses are not exception and hearing impairment is common, particularly sensorineural hearing loss (SNHL). The term SNOS of unknown origin or uremic deafness is related to only a smaller part of the cases with unclear etiology of the impairment. The study searched for SNOS in 66 chronic hemodialysis (HD) patients, mean age 51.50 +/- 12.70 years. They were treated by HD for 69.70 +/- 53.80 months. The relation between the severity of the impairment and the patients' age, duration of HD treatment (months) and a set of laboratory parameters typical for chronic HD patients was examined. The aim of the study was to detect potential causes of the impairment. The increased hearing threshold (HT) of above 20 dB for all frequencies was found in 42 patients (mean HT 26 +/- 10.50 dB), for speaking area frequencies in 22 patients (mean HT 19.70 +/- 8.80 dB), and in 56 patients for high frequencies (mean HT 41.70 +/- 19.70 dB). The significant positive correlation of HT was found only with the patients' age (r = 0.49, p < 0.01). The patients older than 45 years had higher mean HT than those younger, and those older than 65 also had higher HT than the younger ones. Patients with pathological value of HT were significantly more common among the older subgroup of patients, when divided according to the age at both cutoff values of 45 and of 60 years. Mean HT did not differ significantly according to the duration of HD treatment (subgroups A- no longer than 60 months, B- from 61 to 120 months, and C- longer than 120 months). The patients with pathological HT did not differ significantly in frequency among those subgroups, and the subgroups were not different according to the mean age (A--50.30 +/- 13.20 years; B--51.40 +/- 12.75 years; C--55.80 +/- 10.55 years). In conclusion, our results along with other authors'published data report on SNHL as very frequent finding among chronic HD patients and suggest multifactorial etiology. Accurate proportion of those with SNHL of unknown origin is not possible to determine. Those cases are probably not caused by uremic polyneuropathy and/or preterm vascular aging only, although those factors are likely to play crucial roles.

Chronically hemodialyzed (HD) patients frequently suffer from quantitative and even more often qualitative serum lipids disorders. Mostly they have increased triglycerides and VLDL-cholesterol, slightly increased or normal total and LDL-cholesterol and decreased HDL-cholesterol concentrations. The study compared lipid profile between two groups of chronic HD patients coming from regionally distinct areas, the continental and the maritime one. The aim was to examine the hypothetic influence of their different dietary habits on lipid profile. The study included 72 patients from continental region (39 men) and 50 from maritime part of the country (30 men). Patients suffering from diabetes mellitus, hypothyroidism, liver disease, alcoholics as well as sevelamer treated patients were not included. Prior to a HD session the patients were determined fasting total cholesterol, triglycerides, HDL- and LDL-cholesterol, total proteins, albumins and C-reactive protein serum concentrations. All patients were undergoing bicarbonate hemodialysis with polysulphone dialysers of low permeability. The continental group of patients were somewhat older, undergoing HD for longer period of time, of lower height, greater weight, greater body mass index, higher total (4.70 +/- 0.91:4.42 +/- 1.02 mmol/L), and LDL-cholesterol (2.78 +/- 0.74:2.66 +/- 0.75 mmol/L) concentrations, while lower triglycerides (1.72 +/- 0.84:1.81 +/- 0.83 mmol/L) and HDL-cholesterol (1.13 +/- 0.42:1.16 +/- 0.54 mmol/L). However all the differences were without statistical significance. Chi-square test showed that the continental group of patients consumed more often pork, bacon, smoked and cured meats, margarine, butter, walnuts, almonds, garlic, cream and full-fat cheese than fish. They prepare food more often with lard and sunflower oil. Almost every fourth continental patient received statins, while only every 25th in the maritime group of patients. There were not any statistically significant Chi-square values for differences in frequencies of patients with total cholesterol greater than 5.2 mmol/L, triglycerides above 1.6 mmol/L, HDL-cholesterol less than 1.1 mmol/L, LDL-cholesterol greater than 2.6 mmol/L, obesity and malnutrition between the two groups. Based on the results of this study we have concluded that diet has significant influence on lipid profile of HD patients. Even though the continental and the maritime groups of patients differed significantly in diet, they were similar in plasmatic lipoprotein concentrations. However, this similarity was ascribed only to statin treatment, which was more frequent in the continental group of patients. The influence of ESRD and HD as a method of renal replacement therapy on lipid profile was not more dominant than diet.

Cardiorenal syndrome (CRS) presents concomitant heart and kidney failure. Chronic heart failure (CHF) and chronic kidney failure (CKF) prevail in the majority of the cases, although by definition both the acute and the chronic dysfunction of either organ can be the cause. Anemia is thus the consequence of the both organ systems' failures. At the same time, anemia tends to worsen the failures of the both organ systems themselves. Each decrement of the hemoglobin blood concentration for 10 g/L increase overall mortality rate in this population for 20%. CRS with anemia forms a spellbound triangle called cardiorenal-anemia syndrome (CRAS). Mutual associations between the three compounds of the syndrome are subjects of numerous studies. The question arises weather anemia the point of convergence or divergence for CHF and CKD. Actually, anemia correction by erythropoietin does not achieve same effect in patients with CHF as in those with CKD. It becomes clearer that erythropoietin does not have only hematopoetic effects and that erythropoietin treatment does not mean only anemia correction. Erythropoietin plays the major role in treating anemia, but it is not a solo play. The leading feature by that treatment is the renal compound of the syndrome. Target hemoglobin values have then adjusted according to the renal compound of the syndrome, although it is not sureif those values are still convenient for a patient having concomitant CHF. Patients with CHF and anemia without apparent CKF do not even need erythropoietin. Although CKF often follows CHF and vice versa, and despite the fact that the failure of the both organ systems is frequently accompanied by anemia, there is an important proportion of CHF patients with normal kidney function and also not small number of CKF patients with normal cardiac function. Nevertheles, there is a significant percentage of patients with CHF and/or CKF without anemia. The paper presents a review of the published data related to the CRAS with a special attention devoted to anemia, usually a successfully treatable component of the syndrome.

Body water volume (BWV) equals urea distribution volume (UDV), crucial for accurate calculation of dialysis dosage from urea clearance in patients treated with peritoneal dialysis. BWV is precisely determined only by monitoring tritium--or deuterium--labeled water concentration in patient plasma. These are not routine methods, thus a number of alternative methods and anthropometric formulas have been used instead trying to determine BWV from patient body weight and body height, age and sex. These methods are relatively simple but not fully reliable. In the present study, BWV being mostly determined by use of Watson formula at the time of peritoneal dialysis and upon switching to hemodialysis or undergoing kidney transplantation, was monitored in peritoneal dialysis patients to demonstrate that it significantly exceeded the value obtained by the formula. Immediately before switching to hemodialysis or undergoing kidney transplantation, 39 patients (14 female, 25 male) without dialysate in the abdomen had a mean body weight of 74.60 +/- 12 kg and mean BWV of 37.90 +/- 5.80 L according to Watson formula. In the first month of switching to another dialysis method, all patients reduced their body weight by a mean of 3.35 +/- 2.55 kg. Now, their mean body weight was 71.25 +/- 11.45 kg and mean BWV 36.80 +/- 5.50 L. However, differences in the mean body weight and BWV did not reach statistical significance (t body weight = 1.25; t body water = 0.84; p>0.05). The body weight reduction during the period of observation could have almost certainly been ascribed to the accumulated fluid elimination. This in turn implies that immediately before switching to hemodialysis or undergoing kidney transplantation, peritoneal dialysis patients had a total body water greater by a mean of 3.35 +/- 2.55 L than the figure obtained by Watson formula. Thus, their BWV was not 37.90 +/- 5.80 L (50.80 +/- 7.75% of body weight) but 41.25 +/- 6.85 L (55.16 +/- 9.15% of body weight). According to t-test, then their true BWV statistically significantly (by 8.83%) exceeded the figure yielded by the formula (t=2.39; p<0.05), the Kt/V was falsely higher by approximately the same percentage, and the BWV reduction upon switching from peritoneal dialysis to another dialysis method or undergoing kidney transplantation was statistically significant (41.25 +/- 6.85 vs. 36.80 +/- 5.50 L; t=3.20; p<0.01). In conclusion, retrograde assessment of BWV in patients treated by peritoneal dialysis showed the BWV calculated by the most widely used anthropometric formula to be considerably underestimated and urea clearance overestimated for the same reason.

There is an ongoing trend of a rapid increment in the frequency of diabetes mellitus, expecially the non-insulin dependent form. By the end of the 2nd millenium 150 million cases were recorded worldwide, while the estimations predicted doubling the number by the year 2030. Numerous chronic complications accompany the disease, among them micro-, as well as macrovascular prevail, affecting small and large blood vessels. This paper provides a literature review on the topic of diabetic nephropathy, the main microvascular complication of diabetic disease. Microalbuminuria is the earliest sign of the diabetic renal involvement, with more than 30 mg and less than 300 mg of albumins in 24 h urine sample. The reduction of renal function begins with albuminuria leaving microalbuminuria level and entering the pathologic proteinuria range. Renal failure advances through the 5 stages, the final fifth occurring fortunately only in a minor proportion of the patients. The final stage ensues in 232 of 100 000 diabetic patients, according to the US data. However, in many developed countries there are 30-40% of new patients entering chronic dialysis treatment for diabetic nephropathy. Pathogenesis of diabetic nephropathy is based on hyperglycemia and distinct hemodynamic changes, glomerular hyperfiltration and high intraglomerular pressure. The important role have oxidative stress, advanced glycation end products, some cytokines, growth factors and sorbitol pathway. Nevertheless, genetic influence is considered by far the most important risk factor for diabetic nephropathy. Heritage determines the susceptibility in one and the protection in another diabetic patient. At the moment of pathologic proteinuria occurrence, glomerular filtration rate begins to decline for 1.2 ml/min/monthly in some patients, making the annual reduction of 7-14 ml/min/1.73 m2 of body surface area. Improving glycemia, blood pressure control, renal anemia correction with rHu-Epo, dyslipidemia control, reduction in protein intake, i.e. management of the nongenetic factors, could slower the renal function loss in some of the patients. Hence, these measures could reduce the proportion of the patients reaching end-stage renal disease, having in mind that morphological and functional changes are reversible only within certain limits. Therefore, the success of kidney protection is better if commenced earlier.

Duplex sonography was used to assess functional features of arteriovenous fistula (AVF) for hemodialysis (HD). Internal diameter (ID), resistance index (RI) and blood flow (BF) velocity in feeding artery and in vein ofAVF, and venous BF volume were analyzed with purpose to determine the normal values. Presumed normal BF velocities are those of clinically well functioning shunts, allowing BF through HD lines of minimally 250 ml/min. Study included 66 nondiabetic HDpatients (30 women, 36 men), mean age 52-13 years, treated by HD for median 61 (4-252) months. Measurements in 47patients with clinically well functioning AVF were as followed: mean arterial ID 5.2 +/- 1.4 mm, median arterial RI 0.3 (0.3-0.9), median arterial BF velocity 1.5 (0.6-3.6) m/s, mean venous ID 7.6 +/- 2.2 mm, median venous RI 0.3 (0.3-0.9), mean venous BF velocity 1.6 +/- 0.7 m/s, and median venous BF volume 530 (120-1890) ml/min. Patients with poor functioning AVF had significantly less arterial ID, higher arterial RI, less venous ID, less venous BF velocity and volume. Duplex sonography findings obtained for clinically estimated well functioning shunt should be considered as normal Doppler values. Blood vessels' morphologic features depend upon age, and older patients have more pronounced changes.

Unlabelled: During the last century children of the same age experienced a progressive rise in the mean body height and weight. The phenomenon is termed secular trend or acceleration of growth. It is ascribed to the improvement of environmental factors, which, together with genetic legacy, determine both height velocity and final height. Genetic and environmental factors have distinct impact on the two indices of growth. Therefore, one could expect that once reached optimal environmental conditions would lead to the achievement of a peak in height value, and a further rise in weight., Aim: The aim of the study was to determine body height and weight differences between two groups of urban children entering primary school, recorded by school entry medical examination., Subjects and Results: One group consisted of 200 children (98 girls, 102 boys) enrolling primary school in 1991, in the war time, and the other included 397 children (195 girls, 202 boys) enrolling primary school in 2003. The groups were matched by age (6.67 +/- 0.33 and 6.70 +/- 0.30 years). The mean body height increased by only 0.20 cm and weight by 0.08 kg, i. e. increments per decade were 0.17 cm for body height and 0.067 kg for weight. The rise in the mean body height and weight was not significant (theight =0.44, p>0.05, tweight=0.21, p>0.05). The mean rise in body height was about 3.5 times lower than the lowest mean rise in the height of 6-year-old children in the rest of the world., Discussion and Conclusion: Although the study did not analyze particular environmental factors affecting body growth (socioeconomic, dietary, hygienic, family size), it was clear that the acceleration in body growth, slower than expected, was not due to the achievement of optimal environmental conditions and growth plateau. The recorded values probably resulted from the war induced degradation in economic conditions and augmentation of psychological tensions.

Physical growth is usually estimated by body weight and height measurements. Both parameters are strongly influenced by genetic and environmental factors. The study investigated the effect of war related psychological stress and socioeconomic deterioration on growth of children who were born and grew during the war-years. We compared body weight and height in 2 groups of preschool children at time of admission to the first grade of elementary school. In the first group of children, school entry medical examination was performed in spring 1990 and 1991 (pre-war group), while the second group of children had school entry medical examination in spring 1998, 1999 and 2000 (war group). The mean body weight of children in pre-war group (n = 200; 98 girls) was M = 24.52, SD = 4.16 kg, height M = 122.50, SD = 4.71 cm, and the average age was M = 6.67, SD = 0.33 years. The war-group (n = 214; 100 girls) were of the same mean age (M = 6.67, SD = 0.34 years), but they were 500 g lighter and 5 mm lower in average. However, the differences in body weight and height were not statistically significant (t(weight) = 1.21, p > 0.05; t(height) = 1.13, p > 0.05). The two groups matched in gender (chi2-test = 0.13, p > 0.05). More educated parent of every child in pre-war group was employed, while 4 more educated parents (1.87%) in war-group were unemployed, but the difference was not statistically significant (chi2-test = 2.07, p > 0.05). We conclude that growth of preschool children in our region was not statistically significantly affected by stressful war events and war related socioeconomic situation. One could expect that these influences might be significant if we could examine the secular growth trend if there had been no war.

A proportion of peritoneal dialysis (PD) patients experience substantial body weight (BW) gain with time. It is caused by fat tissue accumulation or fluid retention. It is believed that fat tissue accumulates due to caloric contribution of glucose absorbed from dialysis solution or to the mitochondrial fat regulatory uncoupling protein (UCP) gene polymorphism. This study examined BW fluctuations in 40 patients (24 females, 16 males), treated by PD at least 36 months (initial mean age 54.50+/-9.00 years, mean BW 68.00+/-8.50 kg and mean height 164.00+/-8.50 cm), relation of the BW fluctuation and caloric contribution of glucose absorbed from dialysis solution and characteristics of the patients with BW gain. Initial BW increased after 6, 12, 24 and 36 months by 5.90+/-3.50 kg, 7.90+/-4.90 kg, 9.50+/-5.00 and 11.00+/-5.00 kg, or for 8.68, 11.62, 13.97 and 16.18% of the initial value, respectively. After the first 6 and 12 months 38 patients gained weight, 39 after 24 and all 40 patients after 36 months. There was not significant correlation between BW gain and caloric contribution of glucose absorbed from dialysis solution. Female patients had initially lower BW, but for the first 12 months period significantly increased BW more than males, and not for the other observed periods. High transporters (patients with higher transport, higher transmission of glucose from peritoneal solution into the blood, and urea and creatinine in the opposite direction, with rapid decrement of osmolality gradient between dialysate and blood that is necessary for excessive fluid elimination), had lower initial BW and, although without statistical significance, only within the first period increased BW more than low transporters. In conclusion, with time BW gain was found in all the PD dialysis patients, it was not related to caloric contribution of glucose absorbed from dialysis solution, and women and high transporters increased BW weight more than men and low transporters in the first year of treatment. The BW gain is at least in part caused by fluid retention.

Red blood cell osmotic resistance (RBCOR) is defined as resistance to osmotic changes in cell integrity after their exposure to hypotonic saline solution. The investigation examined the effect of rHuEPO on RBCOR in hemodialysed patients. The study included 58 patients aged 49 +/- 14 years, treated by hemodialysis for 59 +/- 43 months on average. Half of the patients received rHuEPO for anemia correction. RBCOR was determined in all patients as 3 values: hemolysis start point (HSP), hemolysis end point (HEP) and middle osmotic resistance (MOR). The patients underwent laboratory checkup for parameters characteristically changed in the uremic syndrome. In the control group of healthy subjects (n = 16) RBCOR was only determined. No differences were found in the average values of HSP, HEP and MOR between the rHuEPO treated group of patinets and the untreated group. Compared to healthy individuals, the hemodialysed patients displayed significantly higher values of HSP, HEP and MOR. The only one significant correlation of RBCOR and routine laboratory features was found between MOR and predialytic serum concentrations of calcium (r = 0.28, p < 0.05) and hydrogen ions (r = 0.37, p < 0.05). Our results suggest that the administration of rHuEPO does not affect RBCOR in hemodialysed patients, that RBCOR is not always reduced in this population and that it correlates with a small number of laboratory parameters characteristic for the uremic syndrome.

Health-risk behaviour in children, its kind and frequency, result from genetic and environmental factors. This survey examined health-risk behaviours (smoking, alcohol drinking and drug abuse, sexual experience) in high school students, the relation of their health-risk behaviours with certain health-risk behaviours in their parents (smoking, alcohol abuse), and interrelations among the examined types of risky behaviours. The study included 1009 of 1144 inquired students (426 girls, 583 boys) of high school (of 5 grammar schools and 4 trade schools) aged 15-19 years (17.50+/-0.70 years). In the period of time preceding the inquiry (3 months) 55.80% of the students smoked, 74.13% of them drank alcohol, 18.43% took drugs, whereas 45.09% of them previously had sexual intercourse. Children of smokers (n=563) smoke more often (chi-square=17.06, p<0.01), drink alcohol more often (chi-square=16.58, p<0.01), and have sexual experience more often (chi-square=9.84, p<0.01) in comparison with children of non-smokers (n=446). Children of parents who drink alcohol (n=240) drink it themselves more often (chi-square=20.14, p<0.01), take drugs more often (chi-square=27.02, p<0.01), smoke more often (chi-square=5.99, p<0.01), and have sexual experience more often (chi-square=8.33, p<0.01) in comparison with children of non-drinking parents (n=769). Certain kinds of health-risk behaviours show a tendency to form clusters, i. e. among the examinees, there are 287 students (28.44%) smoking, drinking alcohol and with sex experience at the same time. Almost every tenth examinee has all four health-risk behaviours (100 students, 9.91%). Only every seventh student has none of the health-risk behaviours (136 students, 13.48%), making 6 of 7 examinees positive in at least one of the risky behavioural types (873 students, 86.52%). In conclusion, the paper confirms a strong influence of parental health-risk behaviours on their children's health-risk behaviours. Therefore, preventive measures should be at least bidirectional, addressed not only to students, but to their parents as well.

Aim of the Study: Peritoneal dialysis adequacy is usually estimated using the ratio of total weekly urea clearance (Kt) and urea distribution volume (V), the later being identical to total body water volume. It is observed that even patients with acceptable Kt/V values sometimes show signs and symptoms of dialysis inadequacy. A question arose whether the discrepancy came from a falsely assessed urea distribution volume, because the less the urea distribution volume measured the higher the Kt/V gained., Patients: The survey included 32 patients (15 women, 17 men) in whom 62 total weekly urea clearances were calculated during a 2-year period. Each Kt was used in 4 different equations (A-Watson's method, B-Hume's method, C-58% of body mass for urea distribution volume, D-for urea distribution volume: 58% of body mass reduced by 2 kg, and then augmented by 2 kg added for dialysate volume assumed). It resulted in 4 different Kt/V for each Kt, i.e. a total of 248 Kt/V values., Results and Discussion: At the moment of the examination the patients were aged 57.66 +/- 8.66 years, weighted 75.54 +/- 11.04 kg (with dialysate intraperitoneally), and were treated with peritoneal dialysis for a mean of 23.28 +/- 27.55 months. Their mean total weekly urea clearance was 79.94 +/- 12.53 L. Depending on the method used, the mean urea distribution volumes were as follows: A = 37.24 +/- 5.27 L, B = 37.89 +/- 5.22 L, C = 43.81 +/- 6.40 L and D = 44.65 +/- 6.47 L, and mean Kt/V 2.15 +/- 0.32 (A), 2.11 +/- 0.32 (B), 1.82 +/- 0.33 (C) and 1.79 +/- 0.34 (D). The highest mean urea distribution volume (D) was higher than the lowest value (A) by 19.90%, and the difference between those values was statistically significant (tV D: A = 6.99, p < 0.01). The highest mean total weekly Kt/V (A) was higher than the lowest value (D) by 20.11%, and the difference was also significant ((tKt/V A: D = 6.08, p < 0.01)., Conclusion: The estimation of urea distribution volume has a direct impact on calculation results of total weekly Kt/V in peritoneal dialysis patients. Urea distribution volumes as assessed by the anthropometrical methods or by a certain percentage of body mass were approximate values. We suggest replacing "nondeuterial methods" by deuterial, in order to get more comparable results.

Risky behaviour of young people is related to their individual features as well as to the influence of parents, dominant friends and social circumstances. This paper presents results of a survey on highschool students risky behaviours (smoking, alcohol and drug abuse, sexual activity) in respect with war events (loss of one or both parents, or of another close relative, moving) and post-war events (loss of job of one or both parents). Five years after the war had ended, 1009 students of the last class of 5 gymnasiums and 4 trade schools (girls 42.22%, boys 57.78%) aged from 15 to 19 years (17.50 +/- 0.70 years) were examined. The students who had moved because of war events consumed alcohol more frequently than those who had not changed the place of living (chi 2-test = 5.34; p < 0.01). Those students who experienced a loss of a parent, or of both parents, or of another close relative for the war reasons, were not found to behave more riskily in respect with smoking (chi 2-test = 0.004; p > 0.05), alcohol (chi 2-test = 0.04; p > 0.05) and drug abuse (chi 2-test = 0.03; p > 0.05), nor sexual activity (chi 2-test = 0.09; p > 0.05). Neither the loss of job of one or both parents had an influence on the risky behaviours (chi 2-test(smoking) = 1.26, p > 0.05; chi 2-test(alchol abuse) = 0.01, p > 0.05; chi 2-test(drug abuse) = 1.26, p > 0.05; chi 2-test(sexual activity) = 2.97, p > 0.05). The results obtained indicate only a partial influence of the war and the post-war events on the risky behaviours in highschool students. The reason for such low influence could be found perhaps in a relatively short duration of those events, or on the special motivations provoked by them.

End-stage renal disease affects all organ systems. Nevertheless, frequency of some pathologic conditions does not differ in end-stage renal disease patients in comparison with their age- and sex-matched controls recruited from general population. The paper presents the results of the survey on the prevalence of gallstones in a relatively big group of hemodialysis patients (n = 114; 49 females, 65 males). The goal of the study was to examine whether the genesis of gallstones could be explained by renal failure itself. Gallstones have been found in 24 of 114 hemodialysis patients (21.05%), predominantly females (n = 14). Gallstones have been found in 28.75% of female patients, and in only 15.38% of male patients. The frequency of gallstones correlated significantly with age of the patients (r = 0.26, p < 0.05), number of pregnancies (r = 0.20, p < 0.005) and deliveries (r = 0.22, p < 0.05). Patients suffering from gallstones were significantly older (60.58 +/- 11.99:51.72 +/- 14.01 years, t = 3.10, p < 0.01), with every third older than 54 affected. The results observed do not differ from the results of other authors that report the morbidity in general population. In conclusion, gallstones in hemodialysis patients show same frequency as in general population and probably result from the same pathophysiologic mechanisms.