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ABSTRACT: This study determines the relationship between interdialytic water retention (IWR) and acid-base homeostasis in uremic patients under regular hemodialysis (HD). To this aim, in 33 regular bicarbonate HD sessions of 11 uremic patients (three HD sessions of 1 week for each patient), blood samples were received from arterial line immediately pre- and post-HD anaerobically in heparinized syringes and the HCO3-, pH, and pco2 were determined. Also in the studied HD sessions, the IWR was estimated and the apparent bicarbonate space percentage (ABS%) pre- and post-HD was calculated by Fernandez et al. (Eq. 1). The mean +/- SD values pre-HD (ABS% = 54.15 +/- 1.49, HCO3- = 18.54 +/- 2.0 mmol/L, pH = 7.32 +/- 0.02, pco2 = 35.44 +/- 3.10 mmHg) and post-HD (ABS% = 49.88 +/- 0.6, HCO3- = 26.33 +/- 1.6 mmol/L, pH = 7.44 +/- 0.02, pco2 = 37.69 +/- 3.00 mmHg) show metabolic acidosis pre-HD and slight alkalosis post-HD. There was a significant positive correlation between IWR and ABS% pre-HD (r = 0.650, p < .0001) and post-HD (r = 0.655, p < .0001), but a significant negative correlation between IWR and HCO3- pre-HD (r = -0.502, p < .003) and post-HD (r = -0.700, p < .001), as well as between IWR and pH pre-HD (r = -0.516, p < .002) and post-HD (r = -0.377, p < .03). In addition, there was a significantly negative correlation between IWR and pco2 post-HD (r = -0.656, p < .001), but not pre-HD (r = 0.0136, PNS). The significantly positive relationship between IWR and ABS% pre- and post-HD, in combination with the significantly negative correlation between HCO3- and pH pre- and post-HD, indicates that the IWR negatively influences the acid-base homeostasis in hemodialysis patients without residual renal function, and may worsen the cardiovascular physiology and tissue oxygenation of these patients.
Renal Failure 01/2005; 27(2):235-8. · 0.82 Impact Factor
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ABSTRACT: The aim of this study was to verify if the degree of pre-HD acidosis and its correction post-HD is related to body fluid expansion during the interdialytic period. Twelve uremic patients without major problems, with stable hematocrit, with regular and similar HD-session characteristics, but widely varying amounts of body fluid expansion in the interdialytic period were included. Blood samples were collected from arterial line pre- and post-HD, anaerobically in heparinized syringes, for determination of HCO3-, pH and PaCO2 (radiometer Copenhagen ABL 300 Acid-Base Laboratory), in two similar HD-sessions for each patient (12 patients, 24 HD-sessions). The percentage (%) of body weight gain in the interdialytic period was also estimated. For each patient, the mean value of parameters studied in the two HD-sessions was used for the evaluation of findings. According to mean values (+/-SD) of HCO3-, pH and PaCO2 Pre-HD (18.26+/-1.99 mmol/L, 7.31+/-0.03, 36.27+/-2.5 mmHg respectively) and post-HD (26.37+/-1.7, 7.43+/-0.03, 38.43+/-2.10 respectively) patients are acidotic pre-HD and slightly alkalemic post-HD. Correlation between the percentage (%) of interdialytic body weight gain (IBWG) and the values of HCO3-, pH and PaCO2, Pre-HD (r=-0.814, p<0.001; r=-0.931, p<0.001; r=0, 100 NS; respectively) and post-HD (r=-0.958, p<0.001; r=-0.937, p<0.001; r=-0.504 NS; respectively) indicates a significant and negative relationship of IBWG% with HCO3- and pH pre- and post-HD, but not with PCO2. In conclusion, the negative relationship of IBWG% with HCO3- and pH pre- and post-HD indicates that the body fluid expansion during the interdialytic period contributes to a dilutional acidosis pre-HD, but not to a contraction alkalosis post-HD, by the elimination of fluid during the HD-session.
The International journal of artificial organs 02/2003; 26(2):135-8. · 1.86 Impact Factor
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ABSTRACT: The purpose of this study was to determine the changes of calcium and potassium content in red blood cells (RBC) from uremic patients during a hemodialysis (HD) session. In 17 uremic patients on HD, the calcium and potassium content of RBC was determined in 3 blood samples collected at 0 min-HD (pre-HD), 45 min-HD, and 240 min-HD (end-HD) during a 4 h HD session. The calcium and potassium content of RBC also was determined in 20 normal subjects (controls). The mean values (+/-SD) of RBC calcium content in patients at 0 min-HD, 45 min-HD, and 240 min-HD were 1.95 +/- 0.34, 2.82 +/- 0.50, and 2. 05 +/- 0.4 microg/ml, respectively, and in controls 0.61 +/- 0.14 microg/ml. These values show that the RBC calcium in patients was generally significantly higher (p < 0.0001) in comparison to that of controls. The RBC calcium at 45 min-HD was significantly higher as compared to that at 0 min-HD and at 240 min-HD (p < 0.0001). The mean values (+/-SD) of RBCs' potassium in uremic patients at the previously mentioned measurements were 95.9 +/- 3.34, 92.5 +/- 4.32, and 93.85 +/- 3.89 mEq/L, respectively, and in controls 98.46 +/- 2. 30 mEq/L. These values show that RBC potassium of patients was generally significantly lower in comparison to controls (0 min-HD: p < 0.01, 45 min-HD and 240 min-HD: p < 0.001). Potassium decrease also was significantly lower at 240 min-HD (p < 0.01) and even lower at 45 min-HD (p < 0.001) compared to that at 0 min-HD. In conclusion, uremic patients during an HD session present a high calcium and a low potassium content of erythrocytes. These changes may prevent swelling of the cells (Gardos effect).
Artificial Organs 09/2000; 24(9):743-5. · 2.00 Impact Factor
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ABSTRACT: It has been reported recently that a number of cytokines, mainly tumor necrosis factor alpha (TNFalpha), interleukin (IL)-1beta, and IL-6, can alter lipid metabolism and produce hyperlipidemia. Studies in hemodialysis (HD) patients have demonstrated increased production of these cytokines during HD. In order to investigate any possible relationship between changes of cytokines and lipid concentrations during HD in the serum of 25 uremic patients on chronic HD using modified cellulose membranes, TNFalpha, IL-1beta, IL-6, total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), lipoprotein a (Lp[a]), and total proteins were measured immediately before (pre-HD) and after HD (post-HD), in one session. The post-HD values were corrected according to the hemoconcentration based on the changes in serum total proteins. Serum TNFalpha and IL-1beta levels were significantly increased from 38.24 +/- 17.85 pg/ml and 2. 60 +/- 3.64 pg/ml pre-HD to 48.86 +/- 25.21 and 3.49 +/- 4.08 pg/ml post-HD, p < 0.001 and p < 0.05 respectively. Also Lp(a) levels presented a statistically significant increase post-HD and were almost doubled (pre-HD: 15.41 mg/dl, to post-HD: 27.39 mg/dl, p < 0. 05). Serum IL-6 as well as serum TC, TG, HDL-C, and LDL-C did not show any statistically significant alterations during HD. A significant positive correlation was detected between TNFalpha and Lp(a) values post-HD (r: 0.413, p: 0.04), but not between pre-HD values. No further relationship between serum cytokines and the other estimated lipid parameters was observed, either between pre- or post-HD values. Our results indicate that release of TNFalpha and IL-1beta during HD have no effect on serum lipids concentration, except on Lp(a). It seems that the acute rise of this lipoprotein during hemodialysis may be related with the TNFalpha overproduction.
Artificial Organs 05/2000; 24(5):329-33. · 2.00 Impact Factor
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A Chryssicopoulos,
D Koutsikos, A Kapetanaki,
B Agroyannis,
H Tzanatos,
G Rammos,
C Fourtounas,
I Kopelias,
B Bossiolis,
M Darema,
P A Zourlas
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ABSTRACT: Two dynamic tests (Gn-RH i.v. and clomiphene citrate-CC p.o.) were used to evaluate the hypothalamic-pituitary axis in hemodialysis patients and renal transplant recipients (recipients). In the Gn-RH test the gonadotropin secretion was maximally decelerated in hemodialysis patients while it was normal in recipients. During the CC test a decrease of gonadotropin secretion, chronically and quantitatively identical for both group, was found; while on the following test days an increase was noted, which was more accelerated in male recipients. In cases with uremia a strong negative feedback dominates at the pituitary level probably owing to testicular inhibin. The estrogenic feedback in uremia was intact, while the antiestrogenic feedback at the level of hypothalamus is partly impaired, owing to altered opioid metabolism.
Renal Failure 12/1996; 18(6):911-21. · 0.82 Impact Factor
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Nephrology Dialysis Transplantation 08/1996; 11(7):1485-6. · 3.40 Impact Factor
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D Koutsikos,
C Fourtounas, A Kapetanaki,
A Dalamanga,
H Tzanatos,
B Agroyannis,
I Kopelias,
B Bosiolis,
G Rammos,
O Bovoleti,
G Sallum,
M Darema
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ABSTRACT: The safety and effectiveness of a low molecular weight heparin (LMWH) of 4500 +/- 1500 Daltons were evaluated in eight hemodialysis (HD) patients, in comparison with unfractionated heparin (UFH). In phase A of the study 3000 +/- 500 anti-factor Xa (AFXa) IU of LMWH were administered in bolus for the three consecutive HD sessions of a week. In phase B, 10000 +/- 2500 IU of UFH were administered to the same patients for the same time. Were observed no significant differences in hematocrit (Ht), platelets (Pt), fibronogen (FG) and prothrombin time (PT). Whole blood activated coagulation time (WBACT) was more prolonged with LMWH, 24 and 48 hours (start of next session) after administration (p < 0.05), and less prolonged at 5, 60, 120, 180, 240 min compared to UFH (p < 0.001). The activated partial thromboplastin time (APTT) and AFXa activity were more prolonged with UFH at 60 and 240 min (p < 0.001). The clinical effectiveness of the two preparations was similar as judged by thrombus formation and compression time. In conclusion, the present study found no real differences between LMWH and UFH, except for prolongation of WBACT 24 and 48 hours after the administration of LWMH. This probably indicates a cumulative effect of the LMWH and needs further investigation.
The International journal of artificial organs 08/1996; 19(8):467-71. · 1.86 Impact Factor
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D Koutsikos,
C Fourtounas, A Kapetanaki,
B Agroyannis,
H Tzanatos,
G Rammos,
I Kopelias,
B Bosiolis,
O Bovoleti,
M Darema,
G Sallum
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ABSTRACT: Abnormal glucose metabolism in uremia may result from a complex interplay between decreased insulin secretion and insulin resistance. Recent studies report beneficial effect of biotin administration in glucose metabolism in diabetic animals and in a small number of patients with diabetes mellitus. The aim of the present study was to evaluate the response of oral glucose tolerance test (OGTT) to the i.v. administration of large doses of biotin in hemodialysis patients. Eleven hemodialysis patients aged 56.90 +/- 11.20 (32-76) years on regular hemodialysis thrice a week for 2.72 +/- 1.79 (1-7) years were studied. Fasting venous plasma glucose, glucosylated hemoglobin (%GH), and plasma glucose concentration 2 h after the administration of a 75-g glucose load were measured before, and 2 weeks and 2 months after administration of 50 mg of biotin i.v. postdialysis, and after a 2-month washout period. During the study, dialysis schedule and patients' medication, diet, and dry weight were kept unchanged. OGTT was abnormal in 4 patients before biotin administration and became normal in 3 patients (75%). Our results offer support to the findings of other studies about the beneficial effect of biotin in experimental or clinical diabetes mellitus, and argue for the involvement of biotin in glucose metabolism.
Renal Failure 02/1996; 18(1):131-7. · 0.82 Impact Factor
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ABSTRACT: The dielectric relaxation of bovine serum albumin (BSA) aqueous solution was studied in various stages of urea denaturation by means of the thermally stimulated depolarization currents (TSDC) technique. A large variation of urea concentration was utilized (0−4 M). Special attention was given for concentrations between 0.006 and 0.050 M, which are comparable to those measured in normal and uremic human serum. The TSDC spectrum consists of two main bands in the temperature range 100−300 K: (1) a broad low-temperature band (A) with two maxima at about 128 and 142 K, which are attributed to the (re)orientation mechanisms of bulk and hydration water molecules, respectively, and (2) an intense band (B), whose position varies in the range between 230 and 245 K and which is attributed to the (re)orientation of protein macromolecules. Two peaks of lower intensity (B1 and B2) are resolved in the rising part of band B and are most likely due to relaxation mechanisms of the side chains of BSA. The activation energies for the last three mechanisms depend on urea concentration, and this fact might be attributed to the conformational changes of BSA upon denaturation. It is of interest to note that the macromolecules' activation energies depend drastically on the concentration of urea up to 0.05 M.
01/1996;
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ABSTRACT: Serum alpha-immunoreactive inhibin was evaluated in 16 male renal transplant recipients with stabilized renal function of mean age 38.5 +/- 10.7 years and was compared to that in sex- and age-matched 17 haemodialyzed patients; 10 patients with chronic renal failure and 26 healthy normal men (controls). Serum LH, FSH, prolactin and testosterone were also measured simultaneously, in the same samples. In renal transplant recipients, inhibin was found significantly higher than that in controls (P<0.001), 25% however of the values were in the normal range. In contrast, all haemodialyzed patients showed highly elevated inhibin values of inhibin were also highly elevated compared to those in normals. A negative correlation was noticed between inhibin and FSH only in controls (r(s) = -0.610, P<0.005). In renal transplant recipients, inhibin showed a strong correlation with serum creatinine (sCr) (r(s) = 0.710, P<0.008), while in the case of graft rejection the rise of sCr was immediately followed by a parallel increase of inhibin. In conclusion, the highly elevated inhibin in uraemic men not improved by haemodialysis and persistent after successful renal transplantation, might be implicated in the pronounced hypergonadotropic hypogonadism of haemodialyzed patients and the remaining dysfunction of hypothalamic-pituitary-testicular axis in renal transplant recipients.
Andrologia 05/1995; 27(5):253-8. · 1.55 Impact Factor
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Nephrology Dialysis Transplantation 02/1995; 10(9):1765-7. · 3.40 Impact Factor
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ABSTRACT: The dielectric relaxation of bovine serum albumin (BSA) aqueous solution was studied in various stages of urea denaturation, by means of the Thermally Stimulated Depolarization Currents (TSDC) technique. A large variation of urea concentration was utilized (0 to 4 M). Special attention was given to concentrations 0.006 and 0.046 M which are comparable to the ones measured in normal and uremic human serum. Three spectral bands were recorded in the temperature range 77 to 300 K which are attributed to the reorientation mechanisms of bulk and hydration water and protein macromolecules. The activation energies for all three mechanisms appear to be dependent on urea concentration and this result is discussed in terms of the conformational changes of albumin upon denaturation
Electrets, 1994. (ISE 8), 8th International Symposium on; 10/1994
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ABSTRACT: The efficacy and safety of acipimox, an antilipolytic agent, were studied in 10 uremic patients under hemodialysis (group A) and in 8 renal transplant recipients with adequate renal function (group B). The medication was given for 20 weeks at a dose of 250 mg daily in both groups. Total serum cholesterol decreased significantly from 218.1 +/- 17.4 to 175.2 +/- 15.2 mg/dL (-19.7%) in group A and from 261.2 +/- 16.5 to 215.3 +/- 26.9 mg/dL (-17.6%) in group B; as did serum triglycerides, from 206.7 +/- 26.9 to 146.9 +/- 17.6 mg/dL (-29%) in group A and from 168.2 +/- 20.6 to 111.3 +/- 12.4 mg/dL (-33.8%) in group B. Low-density lipoprotein (LDL)-cholesterol and very low-density lipoprotein (VLDL)-cholesterol were also decreased significantly (LDL-C by -27% and -25%, and VLDL-C by -29.2% and -33.8% in groups A and B, respectively). Furthermore, the high-density lipoprotein (HDL)-cholesterol was increased significantly, by +29.6% in group A and +18% in group B. The apolipoproteins Apo-A1 and Apo-A2 were decreased in Group A but not in group B. The Apo-B was decreased in group B. Serum CPK (total and muscle fraction), total bilirubin, SGPT, SGOT, alkaline phosphatase, gamma GT, LDL, a-Fp, and creatinine remained unchanged in both groups. Acipimox seems to be effective in the regulation of atherogenic lipid disorders in hemodialysis patients and renal transplant recipients, without any muscular damage or alteration of kidney and liver function.
Renal Failure 02/1994; 16(3):391-405. · 0.82 Impact Factor
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ABSTRACT: Successful renal transplantation has a favourable effect on the development of ocular disorders in periodic haemodialysis patients. Certain complications arise in the eyes of the recipients and are attributed mainly to the immunosuppressive medication. The purpose of our study was the recording of the ocular complications in patients with successful renal transplants after long-term stabilization of renal function and immunosuppressive therapy.
Transplant International 02/1992; 5 Suppl 1:S79-80. · 2.92 Impact Factor
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ABSTRACT: In several studies in humans and animals it has been suggested that high osmolality and ionicity of contrast media are responsible for higher nephrotoxicity. To examine this suggestion, we evaluated the renal effects of three different contrast media--an ionic high osmolar, an ionic low osmolar, and a nonionic--following intravenous and renal arterial administration, in a population of 84 unselected, nondiabetic patients with adequate renal function. The results showed that the nephrotoxicity is minimal and equal for all three contrast media and for both routes of their administration, and it is concluded that in this category of patients the far higher cost of the newer low osmolar ionics and nonionics should be considered seriously in regard to nephrotoxicity.
Renal Failure 02/1992; 14(4):545-54. · 0.82 Impact Factor
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ABSTRACT: We studied the feasibility of treating refractory anemia and post-transfusional serious hemochromatosis in a patient undergoing hemodialysis (3x4 h weekly) for fourteen years, with recombinant human erythropoietin (r-HuEPO) associated with blood-letting. Blood transfusion previously received by the patient at a rate of two units of packed red cells every month for nine years was stopped and r-HuEPO (80 U/kg b.w.) was administered i.v. at the end of each hemodialysis. When Hct increased over 30%, approximately 40 ml of blood was removed per hemodialysis session in an attempt to accelerate iron loss. Excellent control of anemia and hemochromatosis was achieved after seven months of treatment. The patient's general condition and skin pigmentation were significantly improved.
The International journal of artificial organs 08/1991; 14(7):403-6. · 1.86 Impact Factor
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Transplantation Proceedings 09/1990; 22(4):1399-404. · 1.00 Impact Factor
