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Biomedical subjects

L Arisz

Publications and source records attributed to L Arisz.

At least 73 records · Page 4Linked to original sources
PubMed1992

Use of the disappearance rate for the estimation of lymphatic absorption during CAPD.

Several studies are discussed which investigated the usefulness of the disappearance rate of macromolecules from the peritoneal cavity for estimating convective fluid loss from the peritoneal cavity into the peritoneal lymphatic system. It is shown that dextrans are removed from the peritoneal cavity by a size-independent process at a mean rate of 1.37 +/- 0.15 ml/min, whereas the clearance from blood to dialysate of dextrans is size-dependent. The fluid removal rate estimated by the difference in bidirectional transport of inulin (1.79 +/- 0.38 ml/min; p < 0.0005) was of the same order of magnitude as has been found using the removal rate of macromolecules from the peritoneal cavity. Also, the role of local accumulation of macromolecules was studied during continuous administration of dextrans. No differences were found in the dextran disappearance rate before and after saturation of the peritoneal interstitium with dextran (1.1 +/- 0.6 vs. 1.0 +/- 0.4 ml/min). During a study using a hypoosmotic solution we calculated a net transcapillary backfiltration of fluid, whereas the dextran removal rate was in the same order of magnitude as found using commercially available dialysate. In our opinion, the disappearance rate of macromolecules is an estimate of convective fluid loss from the peritoneal cavity into the peritoneal lymphatic system.

Absorption↗
PubMed1992

Residual volume measurements in CAPD patients with exogenous and endogenous solutes.

Accurate residual volume (RV) measurements are needed in studies on fluid kinetics during CAPD. In this study 10 stable CAPD patients were examined twice within 1 week. On both occasions RV after drainage was calculated by the indicator dilution method. Exogenous (dextran 70, inulin) and endogenous (albumin, IgG, urea, creatinine) solutes were used as markers. RV calculated with endogenous solutes (mean +/- SD) were significantly higher than those calculated with dextran (232 +/- 77 mL) and inulin (223 +/- 73): albumin (389 +/- 123), IgG (497 +/- 180), urea (465 +/- 129) and creatinine (429 +/- 109). The relationship between RV calculated with exogenous solutes was much better than between those calculated with endogenous solutes: dextran vs inulin (r = 0.91), albumin vs IgG (r = 0.69) and urea vs creatinine (r = 0.63). Since mass transport of endogenous solutes during rinsing time exceeds mass transport of dextran and inulin, RV was also calculated after corrections had been made for diffusive mass transport of endogenous solutes during the rinsing procedure. After this correction only albumin was similar to exogenous solutes (244 +/- 111 mL) and had an acceptable confidence interval when compared to dextran. No correlation was found between RV on the first and second day, suggesting large intra-individual variability. We conclude that RV should be calculated with dextran or inulin. When no exogenous solutes are used, albumin is the best alternative. However, only rough estimations are obtained when no correction for diffusion is applied.

Adult↗
PubMed1992

Adherence of Staphylococci to plastic, mesothelial cells and mesothelial extracellular matrix.

In this study we have investigated whether mesothelial cells (MC) and mesothelial extracellular matrix (ECM) are suitable substrates for the adherence of Staphylococci. Mesothelial cells were isolated from the peritoneal dialysis effluent by making use of their lack of Fc-receptors and capacity to attach firmly to plastic. After 10 days post-confluency the MC monolayer was removed with 0.1% Triton-X100 and the presence of an ECM shown by enzyme linked immunosorbent assay (ELISA). The ELISA showed the presence of fibronectin and laminin but not of type IV collagen and vitronectin. Bacterial adherence assays with Staphylococcus aureus (N:3 isolates) adhered well to both ECM (33.4%) and MC monolayers (40.2%; ECM vs. MC monolayers p < 0.03). Staphylococcus aureus adhered significantly better to both ECM (p < 0.05) and MC monolayers (p < 0.05) when compared to plastic. Staphylococcus epidermidis (N:3 isolates) showed similar adherence for plastic (22.1%) and MC monolayers (23.5%); mesothelial ECM was a relatively poor substrate for adherence (6.8%, p < 0.03). In conclusion, results obtained sofar do not indicate an increased risk for adherence of Staphylococci when the mesothelial ECM is exposed.

Bacterial Adhesion↗
PubMed1992

Discrepancy between circadian rhythms of inulin and creatinine clearance.

To elucidate the disparity between circadian rhythmicity of inulin and creatinine clearance, we simultaneously measured inulin and creatinine clearances every 3 hours during 1 day in 14 normal subjects and in 8 patients with nephrotic syndrome. All patients and normal subjects had a circadian rhythm for inulin clearance with a maximum during daytime and a relative amplitude of 21% +/- 2%. For creatinine clearance a rhythm was either absent or reduced in relative amplitude (p less than 0.01). In all subjects the rate of tubular creatinine secretion was higher at minimum of inulin clearance (night) than at maximum (day). The fractional clearance (relative to inulin) of creatinine was also higher during the night: normal subjects, 1.28 +/- 0.02 versus 1.10 +/- 0.02; patients, 1.78 +/- 0.08 versus 1.45 +/- 0.05 (p less than 0.005). This demonstrates the inaccuracy of creatinine clearance as a measure of glomerular filtration rate (GFR). By subsequent blocking of the tubular secretion of creatinine with cimetidine in four normal subjects, creatinine clearance became similar to inulin clearance during day and night. This confirms that high tubular secretion of creatinine during the night counteracts the normal rhythmicity of glomerular filtration of creatinine. As a result, plasma creatinine concentration is nearly constant during a 24-hour period. In conclusion, tubular creatinine secretion has a circadian rhythm with a phase opposite to the rhythm of GFR, thus blunting or causing absence of a circadian rhythm for creatinine clearance.

Adult↗
PubMed1991

[Relation between clinical condition and quality of life in patients on hemodialysis, a clinimetric study].

To gain more insight into the quality of life of chronic haemodialysis patients, a clinimetric study was performed in 60 patients treated in a centre for active haemodialysis: Diatel, Amsterdam. The value of a number of objective and subjective test methods was also analysed. The mean age was 52 years, 57% were males and the mean time on dialysis treatment was 68 months. The objective tests were the Karnofsky index, the Active Clinical Problems Score and the Chemistry Abnormality Score. The data were obtained from the physician in charge and the medical record of the patient. The subjective information was gained during an interview based on the following tests: the Complaints score, Affect Balance Scale, Index of Well-being and Nottingham Health Profile. The physical condition of the patients depended on both age and comorbidity and was generally good; 6% of the patients had a Karnofsky score of less than or equal to 60. For the Index of Well-being patients scored lower than healthy people (p less than 0.01). The level of this index depended on age, employment and civil status. The subjective tests were significantly interrelated, the objective tests also but to a lesser extent. No correlations were found between the objective status of the patient and his emotional well-being. In conclusion, active haemodialysis patients appeared to have a fairly good quality of life. Of all tests the Affect Balance Scale, the Index of Well-being and the Complaints score were found to be the most useful, probably also for future longitudinal research.

Adaptation, Psychological↗
PubMed1991

Effect of intraperitoneal administration of two different batches of albumin solutions on peritoneal solute transport in CAPD patients.

The effects of intraperitoneal administration of two different batches of human albumin (batch A and batch B) on peritoneal solute transport and dialysate white cell count were studied in 16 CAPD patients. The studies were done on two separate days during a 4-h dwell, one day without and one day with the intraperitoneal administration of 10 g/l human albumin. Marked differences were found between the two batches. The transport of all measured solutes increased during administration of batch A compared to the control experiments: urea 78% +/- 62%, lactate 51% +/- 38%, creatinine 96% +/- 54%, glucose 67% +/- 55%, inulin 27% +/- 33% IgG 126% +/- 80%, mean +/- SD; P less than 0.02). In the experiments with batch A the white cell count of the test bag was greater than that of the effluent ('night bag') before the test (13 +/- 5 vs 194 +/- 61 mm3/l; P less than 0.02). These effects were also observed when the dialysate was buffered to pH = 7.4 before inflow. Albumin batch B showed no effect on solute transport and white cell count. The effects of solute transport and white cell count are probably caused by the greater concentration of prekallikrein activator in batch A when compared to batch B (30.1 vs 0 U/l). Caution is warranted when human albumin is used for simultaneous measurement of peritoneal fluid and solute kinetics.

Absorption↗
PubMed1991

Effects of renal failure on complement C3d levels.

Elevated plasma concentrations of complement split product C3d have been reported to represent activation of the complement system. In the present study the effect of renal function on C3d concentrations was investigated in patients with various degrees of renal impairment, in patients with chronic renal failure and in CAPD patients. It appeared that elevated plasma C3d concentrations were present in patients with plasma creatinine concentrations in excess of 200 mumol/l regardless of the type of kidney disease. It is very likely that this can be attributed to renal handling (i.e. glomerular filtration, tubular reabsorption and renal catabolism) of C3d in a similar way as has been demonstrated for other low molecular weight proteins. The peritoneal permeability to C3d was slightly less than could be expected on the basis of its molecular weight without evidence of local production of C3d. Renal function should be taken into account in the interpretation of elevated plasma concentrations of C3d.

Complement Activation↗
PubMed1991

Functional characteristics of the peritoneal membrane in long-term continuous ambulatory peritoneal dialysis.

Peritoneal transport characteristics of 20 long-term (LT) patients with a mean duration on continuous ambulatory peritoneal dialysis (CAPD) of 60 months were compared with those of 20 matched patients who recently started (RS) CAPD (mean 39 days, range 11-63). Mass transfer area coefficients (MTC) of creatinine, glucose and inulin were higher in the LT group than in the RS group (12.1 versus 9.2 ml/min, p less than 0.01; 9.9 versus 8.3 ml/min, p less than 0.05; 4.1 versus 3.5 ml/min, p less than 0.05). The MTC of alpha 2-macroglobulin were lower in the LT group (13 versus 25 microliters/min; p less than 0.01). The size selectivity of the membrane for the transport of macromolecules, determined as protein MTC ratios, showed a more restricted passage for macromolecules in the LT group. Net fluid removal using glucose 3.86% was lower in the LT patients (487 versus 826 ml/4 h; p less than 0.001). The results indicate the development of a larger effective peritoneal surface area combined with a less permeable peritoneal membrane after many years of CAPD.

Adult↗
PubMed1991

Metabolic disturbances in CAPD patients.

CAPD is not a physiological condition. The continuous absorption of glucose from the dialysate and the losses of nutrients like protein in it may cause many metabolic abnormalities. This review deals with some effects of CAPD on carbohydrate, lipid and protein metabolism.

Carbohydrate Metabolism↗
PubMed1991

A fast reliable method for the measurement of intraperitoneal dextran 70, used to calculate lymphatic absorption.

The use of intraperitoneally administered dextran 70 was investigated for measurement of lymphatic absorption in CAPD patients. For this purpose a fast, highly accurate HPLC method was developed, that was not influenced by the high glucose concentration in peritoneal dialysate, nor by the inulin that was added to the dialysate for the measurement of residual volume. Pretreatment of the samples consisted of deproteinization with trichloroacetic acid, followed by incubation at 45 degrees C to hydrolyze inulin. This was followed by a further rinsing step using a Sephadex G-25 PD-10 column. The HPLC was performed on a Bio-Gel XL guard column with refractive index detection. Because of the short guard column the chromatographic analysis was only 5 minutes for one sample. With the method described lymphatic absorption rate was measured in 30 CAPD patients and was found to range from 0.1 to 3.5 mL/min, median 1.0 mL/min.

Absorption↗
PubMed1991

Individual characterization of the peritoneal restriction barrier to macromolecules.

The transport of macromolecules such as proteins and dextrans during CAPD is restricted by the permeability of the peritoneum. When its degree is determined by diffusion characteristics of macromolecules, the intrinsic permeability of the peritoneal membrane can be expressed as the relation between clearance of macromolecules and parameters of diffusion velocity. In order to characterize the peritoneal restriction barrier in individual patients, such a relationship has to meet the following conditions: (a) a good fit to linearity, (b) a low inter- and intra individual variability and (c) similarity for proteins and equal sized dextran fractions. In the present study a comparison is made between the reciprocal plot (RP): C-1 = s (esr) + A and the diffusion plot (DP): C = A'. Ds20,w. In these equations C is clearance, esr is Einstein Stokes radius, D20,w is the free diffusion coefficient in water, A and A' are constants, while s is the slope of the regression line and therefore represents intrinsic peritoneal permeability to macromolecules. The 95% confidence interval of the correlation coefficient r was above 0.95 in all studies for the RP and the DP. In general it was somewhat higher for the DP. The inter-individual coefficient of variation was lower in the DP than in the RP. This was also the case for the intra-individual coefficient of variation of the slope for proteins (DP 4% vs RP 27%, p less than 0.01) and for dextrans (DP 18% vs RP 47%, p less than 0.05). The correlation coefficient between dextran slopes and protein slopes was higher for DP (r = 0.68) than for RP (r = 0.50).(ABSTRACT TRUNCATED AT 250 WORDS)

Biological Transport↗
PubMed1991

Day-to-day variability of protein transport used as a method for analyzing peritoneal permeability in CAPD.

The transperitoneal transport of macromolecules is dependent on both effective peritoneal surface area and intrinsic permeability of the peritoneum. For passage of small solutes, the effective surface area is the main determinant. We hypothesized that day-to-day variations in peritoneal clearances are caused by changes in the effective surface area and not in the intrinsic permeability. Four CAPD (continuous ambulatory peritoneal dialysis) patients without peritonitis were investigated on 28 consecutive days. Concentrations of beta-2-microglobulin, albumin, IgG, and alpha-2-macroglobulin were determined daily in dialysate (night bags) and weekly in serum. Clearances and their coefficients of variation were calculated. Mean coefficients of the intraindividual variation of protein clearances increased, the higher the molecular weight: they ranged from 12% for beta-2-microglobulin clearance to 22% for alpha-2-macroglobulin clearance. Correlations were present between the clearances of albumin, IgG, and alpha-2-macroglobulin, but not between any of these and beta-2-microglobulin clearance. In all patients, protein clearance (C) was a power function of the free diffusion coefficient in water (D) according to the equation: C = a. Db in which b represents the restriction coefficient of the peritoneum, and thus intrinsic permeability. The coefficient of variation of the restriction coefficient was low (range 4-6%). This supports our assumption that the intrinsic permeability is fairly constant on the short term. Day-to-day variations in protein clearances are thus mainly caused by alterations in the effective peritoneal surface area. Long-term follow-up of the restriction coefficient in individual patients might identify those at risk for the development of structural changes in the peritoneal membrane.

Adult↗
PubMed1991

Methylprednisolone pulse therapy in rapidly progressive glomerulonephritis.

Twenty-five patients with rapidly progressive glomerulonephritis (RPGN) were treated with methylprednisolone (MP) pulse therapy (1 g intravenously on 3 successive days). In all patients renal biopsy was done before or just after the start of therapy. Pulse therapy was used in all patients in combination with a low oral maintenance dose of prednisone. In 21 patients additional immunosuppressive treatment was given, either cyclophosphamide (n = 19) or azathioprine (n = 2); in 2 patients plasmapheresis was also applied. Sixteen of the 25 patients were dialysis-dependent at presentation; 11 of them improved, an additional 3 had a temporary recovery, but needed maintenance renal replacement therapy after 5-46 months, mean 22 months. Nine of the 25 patients were not dialysis-dependent, 6 of them improved, an additional one had a temporary recovery, but needed chronic dialysis after 35 months. When many irreversible glomerular lesions were present, the effectiveness of MP pulse therapy was limited or only of a temporary character. Serious side effects did not occur. In conclusion MP pulse therapy is a successful treatment with minimal adverse reactions in patients with RPGN and active histological lesions.

Adolescent↗
PubMed1991

Continuous ambulatory peritoneal dialysis (CAPD) in patients with diabetic nephropathy.

A 3-centre study was done to analyse the results of 70 patients with end-stage renal disease caused by diabetic nephropathy and treated with CAPD. Fifty patients had insulin-dependent diabetes (mean age 42, mean duration of diabetes 24 yr); 20 had non-insulin-dependent diabetes (mean age 61, mean duration 15 yr). Total treatment time was 1563 months and ranged from one to 83 months (median 18). Patient survival was 86% at 1 yr and 33% at 4 yr. Technique survival was 87% and 63%. Cox's multiple hazard regression analysis showed that age above 45 yr (relative risk 2.2), systolic hypertension (2.6) and cardiac disease (2.2) at the start of CAPD were associated with shorter patient survival. Metabolic control was good. Haemoglobin rose during the first 3 months. Plasma creatinine concentration increased with time, probably due to the loss of residual renal function. HbA1c levels were in the normal range for 60% of the patients. Mean hospital stay was 42 days per year, 26 as a consequence of vascular complications and 16 due to peritonitis and catheter-related problems. We conclude that CAPD is a good renal replacement modality for patients with diabetic renal failure. The patient survival is dependent on age, systolic hypertension and cardiac disease at the start of CAPD.

Adult↗