Carvedilol does not modulate moderate exercise-induced hyperkalemia in hemodialysis patients.

BACKGROUND AND AIM: Non-selective beta-adrenergic blockers may cause hyperkalemia in patients with end-stage renal failure. In contrast, alpha-adrenergic blockade has been found to decrease the hyperkalemic effect of physical exercise in healthy subjects, although we were unable to confirm this effect in hemodialysis patients. In a crossover design, we studied the effect of carvedilol, a non-selective beta-adrenergic blocker with an additional alpha1-blocking activity, on exercise-induced hyperkalemia in 17 anuric hemodialysis patients. METHODS: All subjects were given either carvedilol (25 mg/day) or placebo for 2 weeks in a random order with a 2-week wash-out period. At the end of each treatment period they underwent a 30-minute exercise test on a bicycle ergometer with a fixed load of 20 W. RESULTS: The treatment with carvedilol caused a significant decrease in blood pressure. Serum potassium before exercise tests was similar (5.37 +/- 0.2 and 5.24 +/- 0.2 mmol/l on carvedilol and placebo, respectively; mean +/- SE). During the exercise, serum potassium increased significantly (p < 0.001 in both tests) and subsequently decreased during 30 minutes of recovery (p < 0.05). The mean rate of potassium increment during the exercise was similar (23.3 +/- 3.3 micromol/l/min on carvedilol and 20.0 +/- 3.6 micromol/l/min on placebo). During recovery, the mean rate of potassium decrement was 5.0 +/- 3.0 micromol/l/min and 6.7 +/- 2.7 micromol/l/min, respectively. Serum sodium, ionized calcium, insulin and plasma renin activity were similar before the exercise tests and did not change during the exercise. CONCLUSION: Carvedilol does not enhance the hyperkalemic effect of moderate physical exercise in anuric hemodialysis patients.

Relationship between body composition, sex hormones and leptinemia in hemodialyzed patients with chronic renal failure.

BACKGROUND: Females are characterized by significantly higher plasma leptin concentration than males. It seems likely that sex hormones influence leptinemia independently from differences in body composition. The aim of the present study was to analyze the contribution of plasma concentrations of testosterone and estradiol on leptinemia in hemodialyzed patients. METHODS: 110 hemodialyzed patients--HD (60 M, 50 F) and 70 healthy subjects (HS) (30 M, 40 F) were enrolled in this study. Plasma leptin, testosterone or estradiol and CRP concentrations and body composition by dual-energy X-ray absorptiometry (DEXA) were assessed. RESULTS: Total body fat was significantly higher in females than in males (27.5 +/- 1.5% vs. 17.2 +/- 1.0% of body weight in HD and 36.0 +/- 1.0% vs. 18.2 +/- 1.4% in HS, respectively). Plasma leptin concentrations were markedly higher in females than in males both in HD (27.9 +/- 5.4 ng/ml vs. 9.6 +/- 1.9 ng/ml) and HS (16.5 +/- 1.7 ng/ml vs.3.1 +/- 0.4 ng/ml). A highly significant, strong positive correlation was found between total fat mass (TFM) and leptinemia in all studied groups. No significant univaried correlation between plasma leptin and testosterone or estradiol concentrations respectively was found both in HD and HS. Multiple regression analyses showed that the main determinant of leptinemia is TFM (beta = 0.623 and 0.798 in HS females and males respectively, and beta = 1.058 and 0.797 in HD females and males respectively). Plasma concentration of testosterone (beta = -0.139 and beta = -0.075 in male HD and HS respectively) and estradiol (beta = 0.199 and beta = 0.046 in females HD and HS, respectively) contributed to leptinemia only in a minor degree. CONCLUSION: Both testosterone and estradiol are minor contributors to leptinemia both in HS and HD patients. The main determinant of leptinemia in these subjects is total body fat mass.

[Chronic allograft nephropathy]. / Przewlekla nefropatia nerki przeszczepionej.

In spite of improved one year renal allograft survival long-term results of renal transplantation did not change since several years. Progressive decline of graft function developing few years after renal transplantation remains a significant problem in renal replacement therapy. The clinical manifestation of progressive impairment of the kidney transplant is heterogeneous and the differential diagnosis of chronic graft rejection is difficult, even if histopathological examination is performed. Improvement of immunosuppressive therapy and avoidance of nonimmunologic factors which increase the risk of graft failure seem to influence markedly function of kidney grafts.

Change in refractive error after unilateral levator resection for congenital ptosis.

PURPOSE: To analyze refractive change in children with congenital ptosis who have undergone unilateral levator resection. METHODS: All charts of patients with congenital ptosis who underwent one levator resection performed by 2 pediatric ophthalmologists at the University of Minnesota from 1981 through 1995 were reviewed. Postoperative refractive changes were analyzed within the group of eyes that underwent ptosis repair and within the group of fellow eyes that served as age-matched controls. The preoperative and postoperative refractive error of each operated eye was also compared with its paired unoperated eye. RESULTS: Complete preoperative and postoperative refractive data were available for 28 patients with congenital ptosis requiring only one levator resection. The mean age at surgery was 3 years 8 months. The preoperative mean ptosis was 3.5 mm (range, 1.5-6 mm). At the last postoperative visit (mean, 20 months; SD, 11 months), the mean refractive change in the operated eye was 1.23 D sphere (range, 0-3.50 D; P =.061) and 0.83 D cylinder (range, 0-3.00 D; P =.002). Within the group of control eyes, no significant mean spherical or cylindrical changes were found at the last postoperative visit. Fourteen eyes with preoperative ptosis had a cylindrical change of 0.75 D or more, compared with a similar change in 4 control eyes. When refractive errors were compared interocularly, no statistically significant differences were found. CONCLUSIONS: Our results showed significant cylindrical change in eyes that underwent levator resection for unilateral congenital ptosis. Careful refraction is necessary after unilateral levator resection.

Atrial natriuretic peptide and arginine-vasopressin secretion in patients with active renal stone disease.

The pathogenesis of active renal stone disease (ARSD) is still not fully elucidated. In the present study the role of atrial natriuretic peptide (ANP) and arginine-vasopressin (AVP) as potential pathogenetic factors in ARSD were examined. Thirty patients with ARSD and 21 healthy subjects (HS) were examined both under bed rest (BR) and head-out water immersion (WI) conditions. Serum concentrations of electrolytes (Na, Ca, Mg), ANP and AVP were assessed before (0'), and after 60 and 120 minutes of BR or WI, respectively. Urinary excretions of Na, Ca, Mg, and oxalates were also estimated during BR and WI. Patients with ARSD showed higher basal plasma levels of ANP and a greater response of ANP secretion, but a lower suppression of plasma AVP to WI induced hypervolaemia as compared with the controls. In addition, in patients with ARSD the physiological relationship between plasma AVP concentration and urinary excretion of Ca and Mg (positive correlation), between plasma ANP level and urinary excretion of Ca and Mg (negative correlation), and between plasma ANP and AVP concentration (negative correlation), respectively, were absent. In addition, patients with ARSD showed a positive correlation between plasma ANP and urinary oxalate excretion. From the results obtained in this study we conclude that both AVP and ANP may be involved in the pathogenesis of ARSD.

[Secretion of atrial natriuretic peptide in patients with active renal stone disease]. / Wydzielanie przedsionkowego peptydu natriuretycznego u chorych na aktywna kamice nerkowa.

The role of the atrial natriuretic peptide (ANP) in Na and water metabolism is well recognized. Much less known is the physiological importance of ANP in the metabolism of other electrolytes e.g. calcium and magnesium, which are presumably involved in the pathogenesis of active renal stone disease (ARSD). The present study aimed to assess the potential role of ANP in the pathogenesis of ARSD. Two groups of subjects were examined. The first one comprised 30 patients with ARSD (diagnosed according to Smith's criteria) while the second one consisted of 21 healthy subjects. Both groups were studied under bed rest (BR) and water immersion (IW) conditions. The examined groups were not different by age, sex, serum electrolyte profile (Na, Ca, Mg) and urinary excretion of Na, Ca, Mg and oxalic acid. Patients with ARSD showed significantly higher basal level of ANP and a significantly higher response of ANP secretion to IW as normals. In spite of this abnormality, patients with ARSD showed a similar increase in water, Na, Ca, Mg and oxalic acid excretion stimulated by IW as compared with normals. In contrast to healthy subjects, patients with ARSD showed no significant correlation between serum ANP levels and urinary excretion of Na, Ca and Mg. In addition, only patients with ARSD showed a significant positive correlation between serum ANP and urinary excretion of oxalic acid during WI. Results obtained in this study suggest, that ANP may be involved in the pathogenesis of ARSD.

[Relationship between renal biopsy histopathology and profile of changes in serum protein, lipids and proteinuria in patients with nephrotic syndrome due to chronic glomerulonephritis]. / Zaleznosc pomiedzy obrazem histopatologicznym bioptatu nerki, a profilem zmian proteinogramu i lipidogramu surowicy oraz proteinuria u chorych z zespolem nerczycowym spowodowanym przewleklym klebuszkowym zapaleniem nerek.

UNLABELLED: Relationship was assessed between the type of renal pathology and the degree of plasma protein and lipid abnormalities in 59 patients with nephrotic syndrome due to chronic glomerulonephritis (GN). All patients were divided into 5 subgroups according to the type of renal pathology (extracapillary proliferative GN--23, mesangioproliferative GN--18, membranous GN--5, minimal changes--5, other--8 patients) and according to the presence (22 patients) or absence (37 patients) of altered interstitium (inflammation and/or fibrosis). In all patients the following parameters were analyzed: plasma levels of creatinine, total cholesterol and lipids, triglycerides, total protein, electrophoretic fractions of plasma proteins and urinary protein excretion. Type of renal pathology as well as presence of interstitial lesion did not influence the degree of protein and lipid abnormalities in nephrotic patients. Significantly more marked (p < 0.05) abnormalities in the serum and lipid profile were found in patients in whom 76-100% of all glomeruli were abnormal than in patients with a lower percentage of damaged glomeruli. CONCLUSION: Percentage of damaged glomeruli but not the type of renal pathology (glomerular or/and interstitial) are the main factors influencing the magnitude of abnormal serum protein and lipid profiles in nephrotic patients.

[Analysing cause of death in chronically hemodialyzed patients]. / Analiza przyczyn zgonów chorych przewlekle hemodializowanych.

The documentation was analysed of 123 haemodialysed patients dying in the years 1984-1990 in nine extracorporeal dialysis centres in the Provinces of Bielsko, Czestochowa and Katowice. Among the dying haemodialysed patients were 61 men and 62 women. The mean age of these patients was 43.7 +/- 1.0 years. The mean time from starting the haemodialysis therapy to death was 29.2 +/- 3.9 months. Mortality among the haemodialysed patients in individual years ranged from 6.5 to 14.4% and was 9.7% on the average. The most frequent death causes in this group of patient in the studied time period were infections (45.5%) and cardiovascular complications (35%). The results of the analysis of death causes in haemodialysed patients suggest the need of constant monitoring of the risk factors contributing to the development of infections and cardiovascular complications.

[Is it possible to transplant kidneys from donors whose death was caused by ethylene glycol intoxication?]. / Czy mozna przeszczepic nerki pobrane od osób zmarlych po zatruciu glikolem etylenowym?

This paper describes 4 patients with a kidney graft from ethylene glycol intoxicated cadaver donors. Our results suggest usefulness of such donors for transplantation.

KrF laser-pumped dye-laser studies.

Dye-laser efficiency measurements were performed on four Coumarin dyes: C-485, C-498, C-500, and C-503, all operating near 500 nm. They were pumped with a 16-ns pulse-length KrF laser. The most efficient of the Coumarin dyes tested was C-498. The intrinsic efficiency of this dye was found to increase with pump rate. At a pump rate of 2 MW/cm(2), an intrinsic efficiency of > 20% was measured. Longer KrF laser pulses (> 1.2 µs) were also used to pump C-498 and resulted in comparable laser efficiencies at similar pump rates. The temporal relationship between the input KrF laser pump pulse and the output dye-laser pulse was studied and was found to differ significantly for long and short pulses. Significant improvement in long-pulse laser performance was observed when the laser-cavity configuration incorporated a skip mode.

[Treatment of anemia with erythropoietin (rhuEPO) in patients with chronic kidney failure who are not yet in need of dialysis therapy]. / Leczenie niedokrwistosci erytropoetyna (rhuEPO) u chorych z przewlekla niewydolnoscia nerek nie wymagajacych jeszcze dializoterapii.

Eleven uraemic predialysis patients have been selected for the treatment of anaemia with rhuEPO. Administration of rhuEPO was followed by a significant increase of the Hct value and haemoglobin concentration as well as an improvement of well being. The main adverse effects of rhuEPO therapy were the following: increase of blood pressure, reduction of the residual renal function and increase of serum potassium and phosphorous concentration. Monitoring of the iron status in uraemic predialysis patients on rhuEPO therapy seems to be mandatory.

Observation of parametric gain suppression in rotational Raman transitions of N(2) and H(2).

The ratio of forward Raman conversion thresholds for linearly and circularly polarized laser light has been measured in low-Fresnel-number configurations for the strongest rotational Raman transitions of N(2) and H(2). In both cases the ratio is found to be in the range 2.5-3, corresponding to a threshold-suppression factor of 1.7-2 for the linearly polarized laser light. The observed spatial distributions of the Stokes light also confirm the presence of suppression along the direction of propagation of the incident linearly polarized laser light. Numerical calculations are in good agreement with the experimental results.

Measurement of Raman gain of the S(8) transition of N(2).

The ratio of the rotational Raman gain coefficients g of N(2) [S(8), 0.91 amagat] and H(2) [S(1), 0.73 amagat] was determined at 295 K by measuring the 5% conversion threshold for each in the same focused configuration, using a circularly polarized 1054-nm laser. After correcting for dispersion, the optical Stark effect, transient effects, laser-wing Stokes seed injection, and mode-beat intensity modulation, we obtained g(N(2))/g(H(2)) = (8.0 +/- 1.2) x 10(-3), so that g(N(2)) = 4.0 +/- 0.8 cm/TW.