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V Senft

Publications and source records attributed to V Senft.

At least 19 recordsLinked to original sources

[Effect of a dialysis solution with icodextrin on ultrafiltration and selected metabolic parameters in patients treated with peritoneal dialysis].

BACKGROUND: To date, peritoneal dialysis has been performed almost exclusively using dialysis solutions containing glucose as the osmotic agent. Use of these solutions is fraught with problems regarding adequate fluid removal from the body and is also associated with undesirable metabolic effects; hence the search for alternative osmotic agents. A dialysis solution with the glucose polymer icodextrin generates ultrafiltration on the principle of colloidal osmosis. The aim of the study was to establish the effect of icodextrin-base dialysis solution on the magnitude of ultrafiltration and evaluate selected metabolic parameters of patients treated by ambulatory peritoneal dialysis. METHODS AND RESULTS: A total of 9 patients whose glucose-based solution was replaced by an icodextrin-based solution during the night-time exchange were evaluated. A control group of 9 patients used glucose-solution during all exchanges. Night-time bag ultrafiltration, blood pressure, and the serum levels of lipids, insulin, leptin, maltose, and amylase were determined before icodextrin administration (time 0), at one-month intervals (time 1, 2, 3), and one month after study completion (time 4). In icodextrin-treated patients, ultrafiltration rose from 246.5 +/- 60.5 ml (mean +/- SEM) at time 0 to 593.1 +/- 87.4 ml; p < 0.01, at time 1, to 547 +/- 67 ml; p < 0.05, at time 2, and to 586.7 +/- 58.8 ml; p < 0.01, at time 3, the icodextrin administration led to a rise in maltose from 0.02 +/- 0.01 g/l at time 0 to 0.1 +/- 0.1 g/l; p < 0.01, at time 1, to 1.0 +/- 0.09 g/l; p < 0.01, at time 2, and to 1.1 +/- 0.09 g/l; p < 0.01, at time 3, with a fall to zero values at time 4 (NS). Icodextrin administration was followed by a decrease in leptinemia from 34.6 +/- 17.2 ng/ml at time 0 to 21.7 +/- 8.9 ng/ml; p < 0.05, at time 1, to 21.4 +/- 9.5 ng/ml; p < 0.05, at time 2, and to 15.9 +/- 24.1 ng/ml; p < 0.05 at time 4. Insulin and lipid levels were not affected. There was no change in the above parameters in the control group. Icodextrin-treated patients reduced their antihypertensive medication, but not statistically significantly. CONCLUSION: Icodextrin administration significantly increase ultrafiltration thus providing for effective control of hydration status without the need for high-level glucose-based dialysis solutions. The use of a glucose polymer-based dialysis solution is associated with a significant yet reversible rise in serum maltose. The decrease in leptin may signal a reduction in body weight after replacing glucose in dialysis solutions with icodextrin, or enhanced rates of leptin elimination as a result of ultrafiltration-induced convective transport.

Adult↗

[Effect of antioxidant therapy on indicators of free radical activity in workers at risk of lead exposure].

The authors administered to 36 workers exposed to lead, for four weeks the preparation Prolong which contains vitamin C, vitamin E, beta-carotene, selenium, zinc and chromium and investigated the effect on indicators of free radicals. A statistically significant increase of the following occurred: superoxide dismutase (p < 0.001), glutathione peroxidase (p < 0.01), an increase of the total antioxidant capacity (p < 0.01) and an increase of uricaemia (p < 0.05). Based on these results the authors consider supplementation with antioxidants indicated in workers exposed to lead.

Adult↗

Influence of hemodialysis on selenium blood levels.

Selenium (Se) is considered an essential and very important trace element for humans. Blood Se levels in chronic hemodialysis (HD) patients are frequently reported to be lower than in controls. The aim of this study was to evaluate these lower Se blood levels with respect to the basic renal disease, duration of dialysis treatment, type of the membrane and dialysis solution used. We tried also to use the polynomial curve as a graphical method for rapid evaluation of a large number of Se blood levels. Se blood levels were measured before and after HD in 95 patients on chronic hemodialysis and in a control group of 20 healthy volunteers. Se blood levels were measured by atomic absorption spectrophotometry. Statistically significant increases of Se blood levels were found after HD (p < 0.001). During HD, the relatively high Se blood levels decreased and low levels increased but remained below the range of physiological values. These levels were lower than those of the control group (p < 0.001). Of the different dialysis membranes used, the greatest changes in Se blood levels were measured after HD with cuprophan membranes (p < 0.001). No significant difference in Se blood level in respect to the underlying kidney disease (chronic glomerulonephritis, tubulointerstitial nephritis, polycystic kidney disease, diabetic nephropathy) was revealed. No association of predialytic Se blood levels and the length of dialysis treatment was found. Concluding our results suggests low selenium content in dialysis solution and show that, in respect to the importance of Se for humans, its substitution is desirable.

Adult↗

[Problems with trace elements in hemodialysis. Evaluation of serum levels].

BACKGROUND: During dialysis substances are eliminate in particular according to the concentration gradient between plasma and the dialysation solution. Evaluation of a suitable setting of the basic concentration of a substance in the dialysation solution from results of different patients is problematic because of possible individual distortion. The objective of the present work was to suggest and test a practical way of evaluation of group data. METHODS AND RESULTS: The authors examined a group of 87 dialyzed patients. Using the AAS method they assessed the serum concentrations of Mg, Zn and Cu always before and after dialysis. During dialysis of significant decline of serum Mg occurred (below 0.8 mmol/l). This drop would signalize the need to reduce the concentration gradient, i.e. increase the Mg concentration in the dialysation solution above the current 0.5 mmol/l. However assessment of Mg in red blood cells revealed that dialyzed patients have a significantly increased depot of Mg in the organism (2.67 mmol/l ery as compared with normal 2 mmol/l ery) and thus reduction of Mg in serum during dialysis is desirable. CONCLUSIONS: The authors suggested and on the basis of Mg tested a graphical way making rapid screening of extensive group data possible when evaluating the adequacy of the composition of the dialysation solution with regard to the concentration gradient of eliminated and retained substances resp. Evaluation of the concentration gradient from group data may be the baseline for optimalization of further individually set parameters of dialysis in individual patients.

Adult↗

[Trace elements in biological materials. Preanalysis safeguards].

In order to obtain objective information from estimations of trace elements (Al, As, Cd, Cr, Co, Cu, Pb, Li, Mn, Hg, Ni, Se, Zn) on deficiency or intake beyond the toxic limit it is necessary to pay attention among others also to preanalytical safeguarding, i.e. obtain all relevant information on the patient, ensure proper selection of material and sampling time, proper sampling and safeguarding the sample before the estimation proper. If the above rules and principles are respected, possible significant distortion on the results, which can be caused e.g. by contamination of the sample, can be prevented.

Humans↗

[Indicators of effects of free radicals in workers at risk of lead exposure].

The authors examined indicators of the action of free radicals in 40 workers exposed to the risk of lead (work with lead containing glazing and prints). The lead concentration in the atmosphere did not exceed the highest permissible concentrations and the biological exposure tests as regards lead exposure did not exceed the highest permissible limits. In the examined subjects the authors found a significantly elevated level of superoxide dismutase activity (p < 0.05) which suggests long-term increased peroxide formation. The correlation of the selenium concentration in blood and the period of lead exposure was at the borderline of statistical significance (p = 0.1159). Further investigations will be focused on subjects with symptoms of increased exposure to lead and lead intoxication where the probability of pathological findings is greater.

Adult↗

[Copper and the human body].

Copper is one of the essential trace elements. It is part of a number of enzymes. Deficiency of the element is manifested by impaired haematopoesis, bone metabolism, disorders of the digestive, cardiovascular and nervous system. Deficiency occurs in particular in patients suffering from malnutrition, malabsorption, great copper losses during administration of penicillamine. Sporadically copper intoxications are described (suicidal intentions or accidental ingestion of beverages with a high copper content). Acute exposure to copper containing dust is manifested by metal fume fever. Copper salts can produce local inflammations. Wilson's disease is associated with inborn impaired copper metabolism. In dialyzed patients possible contaminations of the dialyzate with copper must be foreseen as well as the possible release of copper from some dialyzation membranes. With the increasing amount of copper in the environment it is essential to monitor the contamination of the environment.

Copper↗

[Zinc--physiology and pathophysiology].

The authors discuss the physiology and pathophysiology of zinc. They mention the main sources of exposure to zinc and its components. Zinc absorption in the digestive tract is regulated by cells of the intestinal mucosa, the main route of excretion is via faeces. Zinc is essential for the function of several enzymes, there are ample data on its participation in immune processes. The authors analyse the most commonly quoted causes of zinc deficiency and pathological conditions caused by acute exposure to zinc and its compounds. Chronic zinc intoxication was not described in human so far.

Humans↗

[Mercury in dental amalgams--a stress on the body or poisoning?].

The human organism is exposed to mercury from the environment and working environment. In the diet the main source of mercury are marine fish. Amalgam fillings participate in the mercury load of the organism as was proved by investigations of the mercury content of the brain, kidneys and lenses. However, it was not confirmed that the mercury load from amalgam fillings caused intoxication.

Dental Amalgam↗

[Aluminum and the human body].

Aluminium is one of the trace elements in the human organism the presence of which is described as contamination. The authors describe the toxic action in subjects working in an environment contaminated with powdered aluminium or its compounds. Non-professional exposure is observed in subjects with renal failure as aluminium is retained, in particular in case of concurrent antacid therapy on the basis of aluminium salts. Dialyzation encephalopathy may develop, aluminium osteopathy and microcytic anaemia. The most effective prevention is dialysis using a dialyzation solution with a low aluminium content and elimination of aluminium binding phosphates. The results of hitherto accomplished studies call for further research into the action of this element on the human organism.

Aluminum↗

[The effect of antioxidant therapy on indicators of activity of free radicals in workers exposed to risks of styrene].

To 30 workers exposed to the risk of styrene for a period of 30 days a mixture of antioxidants was administered: vitamin C 200 mg, vitamin E 300 mg, selenium 20 mg, troxerutin 600 mg and beta-carotene 6 mg. Before the onset of supplementation and immediately afterwards laboratory indicators of antioxidant protection and lipid peroxidation were investigated. Before treatment workers exposed to the risk of styrene had a significantly higher malondialdehyde concentration (p < 0.01) and antioxidant capacity (p < 0.01) as compared with the control group. Due to the established positive correlation between these parameters (r = 0.42, p < 0.05) the findings can be evaluated as the result of increased exposure to free radicals. After supplementation a marked decline of the malondialdehyde concentration occurred p < 0.001) and a further rise of the antioxidant capacity (p < 0.001). The selenium concentration increased also markedly, the rise being more marked in subjects who had originally a lower concentration. There was a significant rise of uric acid which has an antioxidant effect (p < 0.01). The antioxidant enzymes superoxide dismutase and gluathione peroxidase did not change significantly. The results indicate the favourable effect of antioxidant treatment in subjects exposed to the risk of styrene.

Adult↗

[Is chromium an essential or a toxic element?].

Chromium holds a frequent and important place in toxicological literature. The large number of more or less important toxicological facts (e.g. allergic dermatoses, ulcer, perforations of the nasal septum, bronchitis, cancerogenity etc.) are the reason why chromium is conceived rather as a toxic element. On the other hand in the non-toxicological literature favourable actions of chromium are described (its relationship to carbohydrate utilization, the glucose tolerance factor, diabetes etc.) which may induce us to consider chromium an essential element. Is chromium toxic or essential? It is both. The concept of essential or toxic cannot be conceived statically, these terms are relative and depend on a number of other facts and data (dose, time, chemical form, individuality of the organism, interaction with other substances in the environment etc). This relative view has a more general validity not only for chromium but for trace elements in general and it is very important in particular with regard to prevention of health damage caused by deficiency or excess of a substance.

Chromium↗

[Free radial activity in patients with pneumoconioses].

The authors examined indicators of the effect of free radicals (MDA, SOD, GSHPx, selenium) in 20 patients with notified simple silicosis or miner's pneumoconiosis, in 11 patients with complicated silicosis or miner's pneumoconiosis and in 10 patients exposed to fibrogenic dust without an X-ray finding of pneumoconiosis. No statistically significant differences between individual groups were found. Subsequent investigations should be focused on subjects with incipient pneumoconiosis who are not yet entitled to damages.

Aged↗

[Determination of free radical activity in workers at risk for styrene exposure].

The authors examined indicators of the effect of free radicals (MDA, SOD, GSHPx, selenium) in 38 workers exposed to styrene. They revealed a statistically significant (p < 0.01) correlation of SOD activity and the period of exposure to styrene and also a statistically significant correlation (p < 0.05) between urinary selenium excretion and the period of exposure to styrene as well as a statistically significant correlation (p < 0.01) between the MDA serum concentration and urinary selenium excretion. There is no statistically significant difference between the MDA plasma concentration among smokers and non-smokers, the SOD activity is significantly higher in non-smokers (p < 0.05). Based on the revealed findings the authors assume that free radicals may also play a part in the action of styrene on the organism.

Adult↗

Biochemical renal changes in workers exposed to soluble nickel compounds.

1. Biochemical markers of kidney damage were examined in 14 male and 12 female workers highly exposed to soluble nickel compounds in a chemical plant. The results were compared to those obtained in 12 male and 12 female matched controls. 2. The concentration of nickel in urine of male and female workers averaged 5.0 and 10.3 micrograms g-1 creatinine, respectively. The mean duration of exposure in male and female workers was 25 and 15 years. 3. No difference was found in the mean urinary excretion of lactate dehydrogenase, albumin and transferrin in both sexes, total proteins, beta 2-microglobulin (beta 2-m) and retinol-binding protein (RBP) in males and lysozyme in females. Lysozyme and N-acetyl-beta-D-glucosaminidase (NAG) were increased in male and total proteins, beta 2-m, NAG and RBP in female exposed workers. Significant correlations between urinary concentrations of nickel on one side and that of beta 2-m in women (r = 0.462, P = 0.022) and men (r = 0.41, P = 0.018) and of NAG in men (r = 0.405, P = 0.019) on the other side were found in exposed subjects. 4. Results indicate adverse effects of soluble nickel compounds on the kidney tubular function. In agreement with literature data it seems that those effects occur only at high exposure levels.

Acetylglucosaminidase↗

Cytogenetic analysis of chromosomal aberrations of peripheral lymphocytes in workers occupationally exposed to nickel.

The authors carried out a cytogenetic examination of chromosomal aberrations of peripheral lymphocytes (100 cells evaluated in each sample) with simultaneous monitoring of the level of exposure by means of determination of nickel in the urine, serum and hair. The series included 21 workers occupationally exposed to nickel at two workshops producing NiO (6 persons) and NiSO4 (15 persons) in a chemical plant. At the same time a comparable control group, i.e., 19 workers of the same chemical plant but without any direct occupational nickel exposure (clerks, service men, etc.), were examined in the same way. In the exposed group chromosomal aberrations of peripheral lymphocytes were detected with an average value of 6.41 +/- 1.9% (range 2-14%); in the group producing NiO it was, on the average, 9.5 +/- 3.2% (range 7-14%) whereas in the NiSO4 production workers it was only 5.2 +/- 1.9% (range 2-10%). There was a dependence of chromosomal aberrations of peripheral lymphocytes on the exposure time and on the nickel content of the biological material. Significantly increased values (in contrast to the normal value of chromosomal aberrations of peripheral lymphocytes, up to 2%) were detected in the control group as well (average value of 4.05 +/- 2.27%, range 1-10%). The authors explain this fact by the nickel-polluted environment of the whole observed chemical plant.

Adult↗

[Evaluation of the effect of cadmium exposure in a worker in Ni-Cd storage battery production by biological tests in vivo and the cadmium content of tissues postmortem].

The paper deals with the case of a 49 years old man having been exposed to cadmium in the production of alkaline Ni-Cd accumulators for a long period. It presents and compares the results of some years lasting biological monitoring of the exposition in vivo (beta 2 microglobulin in urine and serum, Cd in urine, blood, serum and hair, Zn in urine, serum and hair, Ni in urine and hair, alpha 1 antitrypsin in serum, dehydratase activity of delta-aminolevulinic acid in blood, cholinesterase activity in blood, etc., with the Cd concentrations found out in the tissues post mortem (nail 12 micrograms/g, cerebrum 0.4 microgram/g, lungs 19 micrograms/g, liver 165 micrograms/g, kidneys 245 micrograms/g). The Cd contents in the tissue were significantly increased compared with the non-exposed population and in fact, they confirmed the data and conclusions from the biological monitoring in vivo signalling the light tubular renal impairment as the most significant symptom of the exposition.

Cadmium↗