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Biomedical subjects

L Arisz

Publications and source records attributed to L Arisz.

At least 55 records · Page 3Linked to original sources

Compensatory renal response after unilateral partial and whole volume high-dose irradiation of the human kidney.

Renal function was prospectively analysed in 26 patients treated with radiotherapy for various types of malignancies. In patients with gastric non-Hodgkin's lymphoma stage I-II (gNHL, n = 5), the 99mTc-diethylene-triamine-penta-acetic acid (99mTc-DTPA) renal uptake and the relative 99mTc-dimercapto-succinyl acid (99mTc-DMSA) accumulation decreased gradually and concomitantly in the high-dose, whole-volume irradiated left kidney (40 Gy/5, 5 weeks), down to 25 +/- 10% (mean +/- 1 S.E.M.) and 31 +/- 11%, respectively, after 6-9 years. The absolute 99mTc-DMSA uptake in the left kidney declined down to 33 +/- 12% whereas in the low-dose, whole-volume irradiated right kidney (12-13 Gy/3 weeks) it increased up to 187 +/- 11%. When considering renal volume changes with single photon emission computed tomography, the left kidney in the gNHL patients was reduced to 30 +/- 13%, with, surprisingly, a contralateral enlargement up to only 119 +/- 7% (P < 0.05). The overall renal function in this group of patients, as assessed by creatinine clearance and by [125I]iothalamate/[131I]hippuran clearance was reduced to 48-68%. In the Hodgkin's disease patients (HD, n = 7) given 40 Gy in 4 weeks to 30-50% of the left kidney, the 99mTc-DTPA filtration and the relative 99mTc-DMSA uptake in the left kidney was reduced to 75 +/- 4% and 81 +/- 3%, respectively. The absolute 99mTc-DMSA changes were 78 +/- 10% and 135 +/- 13%, respectively. No significant renal functional alterations were observed in patients with either ovarian carcinoma (n = 7) or seminoma (n = 7). These data suggest a significant, compensatory response of the non-irradiated or low-dose irradiated kidney which, however, appears to be incomplete after contralateral, whole-volume, high-dose irradiation. Such compensatory response might be overestimated when considering only relative or absolute changes in radioactivity uptake.

Blood Pressure↗

Effect of dialysate osmolarity on the transport of low-molecular weight solutes and proteins during CAPD.

Osmotic-induced fluid and solute transport was studied in ten stable CAPD patients, who were examined twice within one week, using dialysate with 1.36% glucose on the first and 3.86% glucose on the second day. Peritoneal fluid kinetics were determined using intraperitoneally administered dextran 70 as a volume marker. After a four-hour dwell period, an increase in mean transcapillary ultrafiltration rate (TCUFR) with 3.86% glucose compared to 1.36% glucose was found (3.40 +/- 0.62 ml/min vs. 1.20 +/- 0.57, P < 0.001), but the lymphatic absorption was unchanged (1.32 +/- 0.10 ml/min vs. 1.42 +/- 0.15). The increased TCUFR resulted in a higher clearance of beta 2-microglobulin, but no differences were present in the clearances of albumin, transferrin, IgG, IgA and alpha 2-macroglobulin. This is consistent with the two pore theory for transcapillary transport with a small pore size of less than 40 A. The contribution of osmotic induced convection to the total transport of beta 2-microglobulin was small (6% during 1.36% glucose, 16% during 3.86% glucose), suggesting that macromolecules are mainly transported by diffusion or hydrostatic convection. The peritoneal restriction coefficient was 2.37 +/- 0.04, indicating restricted diffusion for macromolecules. In contrast, the restriction coefficient for low-molecular weight solutes was 1.24 +/- 0.03, in accordance with a process of mainly unrestricted diffusion for solutes smaller than 16 A. Higher values of protein clearances were found during the first hour of dialysis compared with the subsequent hours.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Effect of an increased intraperitoneal pressure on fluid and solute transport during CAPD.

The effect of an increased intraperitoneal pressure on fluid and solute transport was studied in eight stable CAPD patients. Two permeability tests of two hours each with continuous registration of the intraperitoneal pressure were performed while patients were in supine position. The intra-abdominal pressure was raised by means of a tightening girdle with inflatable cuffs in one of the experiments. Intraperitoneally administered dextran 70 was used as a volume marker in order to determine the peritoneal fluid kinetics. The increment in the intra-abdominal pressure of 10.0 +/- 1.0 mm Hg caused a decline in the net ultrafiltration. This was mainly determined by an increase in the lymphatic absorption: 1.07 +/- 0.18 ml/min (without compression) versus 1.86 +/- 0.25 ml/min (with compression; P < 0.01), whereas the transcapillary ultrafiltration rate tended to decrease: 2.02 +/- 0.23 versus 1.73 +/- 0.27 ml/min (P = 0.08). External compression also diminished solute transport from the circulation to the peritoneal cavity. The decline in the mass transfer area coefficient of urea, creatinine, urate and beta 2-microglobulin was 13%, indicating a smaller effective peritoneal surface area caused by external compression probably due to a decrease in the number of the perfused peritoneal capillaries. The fall in the peritoneal protein clearances was more pronounced the higher the molecular weight of the protein, consistent with a decline in the intrinsic permeability of the peritoneum. Kinetic modeling using computer simulations was used to analyse these effects in terms of the pore theory, using a convection model (large pore radius 184 +/- 14 A) and a diffusion model (large pore radius 1028 +/- 218 A) for the transport of macromolecules.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Immuno-effector characteristics of peritoneal cells during CAPD treatment: a longitudinal study.

Peritoneal cells (PC) from 75 patients were immuno-phenotypically and functionally characterized during the first year of CAPD treatment (PCcapd) and compared to PC obtained by laparoscopy of healthy women (control peritoneal cells). Patients were divided, according to their peritonitis incidence (PI), into a high PI (HPI) and a low PI group (LPI). The yield of PCcapd decreased significantly over the year. The differential cell count and immunophenotype of PCcapd remained unchanged in the LPI group, but the percentage of macrophages decreased over the year in the HPI group. Macrophages in the PCcapd, when compared to control peritoneal cells, had a less mature phenotype as measured by RFD7 expression but a higher Fc-receptor expression. The PCcapd showed a higher percentage of B cells, CD4 positive T cells and activated T cells bearing HLA-DR/DQ when compared to the control peritoneal cells. Over the year a decrease in chemotactic activity of the PCcapd towards 10(-8) M N-formylmethionyl-leucyl-phenylalanine and dialysis effluent was observed in LPI patients but not in HPI patients. After one year of treatment, a significantly higher percentage of phagocytosing macrophages in the PCcapd of HPI patients was found when compared to LPI patients. During the year there was an increase of immunophagocytosis of PCcapd independent of PI. In conclusion, the CAPD peritoneal cellular immune system showed signs of both immaturity and activation. The decrease in the yield and in the chemotactic activity of PCcapd suggests an adaptation to the chronic stimulus of the dialysis fluid.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Interleukin-8 production by human peritoneal mesothelial cells in response to tumor necrosis factor-alpha, interleukin-1, and medium conditioned by macrophages cocultured with Staphylococcus epidermidis.

Patients treated with continuous ambulatory peritoneal dialysis (CAPD) may suffer from recurrent peritonitis episodes caused by Staphylococcus epidermidis. Early recruitment of granulocytes from the peripheral blood is important for the peritoneal antibacterial defense of CAPD patients. In this study, human peritoneal mesothelial cells were shown to produce high levels of interleukin-8 (IL-8) in response to IL-1 beta and tumor necrosis factor-alpha (TNF alpha) but not lipopolysaccharide or S. epidermidis. Coculture of peritoneal macrophages with S. epidermidis induced high levels of IL-1 alpha, IL-1 beta, and TNF alpha in 24-h-conditioned medium. Preincubation of this medium with anti-TNF alpha, anti-IL-1 alpha, or anti-IL-1 beta partially blocked stimulation of IL-8 production by mesothelial cells. Added together, these antibodies abolished IL-8 production to a level just above background. Migration of granulocytes to the stimulated mesothelial cell-conditioned medium could be totally blocked with rabbit polyclonal anti-IL-8 antibody. Thus, mesothelial cells are important for the recruitment of granulocytes into the peritoneal cavity.

Cells, Cultured↗

Antigen-presenting capacity of macrophages and dendritic cells in the peritoneal cavity of patients treated with peritoneal dialysis.

In this study the antigen-presenting capacity of human peritoneal cells and the influence of continuous ambulant peritoneal dialysis (CAPD) were studied. On average 6% of the peritoneal cells were dendritic cells (DC), with no difference between CAPD and control peritoneal cells. DC were enriched by selecting for non-adherent, Fc receptor-negative, low density cells. A typical spot-like CD68 positivity was seen in DC, in contrast to the pancytoplasmic staining pattern in macrophages. Peritoneal DC morphologically and functionally showed features of cells belonging to the DC lineage. Peritoneal DC were superior antigen-presenting cells for both allo-antigen, and Candida albicans antigen or purified protein derivative. CAPD peritoneal macrophages were two- to three-fold better stimulator cells for allogeneic T cells compared with control macrophages. The level of integrins/adhesins or MHC class I or II, as measured semi-quantitatively on the FACS, could not account for this phenomenon. In addition, a double chamber system showed that dialysate-activated macrophages produced soluble factors that could enhance DC-induced allogeneic T cell proliferation. In conclusion, human peritoneal cells contain a relatively high percentage of classical DC. CAPD treatment does not impair the antigen-presenting capacity of peritoneal cells, but instead upregulates the allo-antigen-presenting capacity of peritoneal macrophages.

Antigen-Presenting Cells↗

Effect of prednisone on renal function in man.

To clarify the rise in plasma creatinine concentration previously observed during prednisone treatment, we studied changes in renal function in Graves' ophthalmopathy patients before and after 2 weeks of either prednisone 60 mg/day or retrobulbar radiotherapy (controls). Compared to retrobulbar radiotherapy, prednisone treatment was associated with an increase in: (a) plasma creatinine concentration (from 68 +/- 4 to 76 +/- 4 mumol/l), (b) glomerular filtration rate (GFR, from 93 +/- 4 to 102 +/- 5 ml/min/1.73 m2), and (c) urinary creatinine excretion rate (from 510 +/- 40 to 570 +/- 40 mumol/h). We conclude that GFR rises during 2 weeks of high-dose prednisone administration, a rise that is not reflected by a decrease in plasma creatine concentration. On the contrary, both plasma creatinine concentration and urinary creatinine excretion increase, probably as a result of the catabolic effect of prednisone. As established by the present study, prednisone 60 mg/day is associated with protein wasting, also after 14 days of treatment.

Adult↗

The effect of glucose polymers on water removal and protein clearances during CAPD.

Two selected groups of 5 continuous ambulatory peritoneal dialysis (CAPD) patients (3 female, 7 male), mean age 60 years, were studied twice with an interval of 4 weeks. The first study was done with glucose-containing dialysate and the second study with dialysate containing glucose polymers (Dextrin 7.5%) after they had been treated with this solution (night dwell) for 4 weeks. The patients collected night bags for 3 consecutive days during the tests. Protein clearances were determined for beta 2-microglobulin, albumin, IgG, fibronectin, and alpha 2-macroglobulin in both periods to examine the influence of crystalloid-induced convection versus "colloid"-induced convection. Group I normally used 1.50% glucose and was therefore considered to have a "high ultrafiltration";group II was the "low ultrafiltration" group because they needed 4.25% glucose dialysate. For their usual glucose solutions the net ultrafiltration was not different between both groups, but the clearance of beta 2-microglobulin was higher in group II:839 +/- 98 microL/min (group I) and 1135 +/- 131 microL/min (group II) (p = 0.08). For glucose polymers the net ultrafiltration increased in both groups, but this was more pronounced in group II: 657 +/- 104 mL (group I) and 918 +/- 85 mL (group II) (p = 0.06). Also, the clearance of beta 2-microglobulin increased with the glucose polymer solution: 1268 +/- 94 microL/min (for glucose polymer) and 987 +/- 85 microL/min (for glucose) (p < 0.05), but the clearances of the larger serum proteins remained unaffected.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

The effect of amphotericin B on fluid kinetics and solute transport in CAPD patients.

Loss of net ultrafiltration capacity is an important complication in long-term continuous ambulatory peritoneal dialysis (CAPD). It has been reported in animal studies that the drained volumes after a dwell period were larger when amphotericin B had been given intraperitoneally. In this study the effect of intraperitoneally administered amphotericin B on fluid kinetics was evaluated in 3 CAPD patients. The first patient lost 2.5 kg body weight during the first 4 days of treatment, whereas the net ultrafiltration in the second patient was higher in the treatment period compared with the nontreatment period (750 +/- 38 mL/day vs 438 +/- 34 mL/day (mean +/- SEM), p < 0.0001). In the last patient it can be demonstrated that the increase in the net ultrafiltration was caused by an increase in the transcapillary ultrafiltration (570 vs 454 mL/4 hours), but that lymphatic absorption was not different (251 vs 265 mL/4 hours). The higher transcapillary ultrafiltration capacity is probably caused by an increase in the hydraulic permeability. It is likely that this phenomenon is governed by the interaction of amphotericin B with membrane-bound cholesterol leading to the formation of transcellular pores. However, the administration of amphotericin B caused a chemical peritonitis, probably due to its solvent, sodium desoxycholate. Therefore, before amphotericin B can be used for the treatment of CAPD patients with ultrafiltration failure, further investigations are necessary to obtain a solvent for amphotericin B that is nontoxic and causes no chemical peritonitis.

Amphotericin B↗

Acute pancreatitis during CAPD in The Netherlands.

Acute pancreatitis in patients on CAPD treatment is an infrequent, but serious complication. We studied the records of all CAPD patients with acute pancreatitis in the Netherlands from 1979 until May 1992. The incidence of acute pancreatitis during CAPD treatment was 0.46 per 100 treatment-years. In all patients at least one risk factor was present. Hypercalcaemia was the most frequently observed risk factor in our patients. The clinical picture consisted of abdominal pain and vomiting, with normal temperature and normal peristalsis. Plasma amylase was elevated in 18 episodes. Dialysate amylase concentrations exceeded 100 U/l in seven of ten episodes. The dialysate could either be clear, haemorrhagic, or cloudy. Positive dialysate cultures were found in five patients, in most cases with skin flora. No direct correlation with the pancreatitis could be established. Mortality was 58%. Continuation of CAPD or transfer to haemodialysis had no apparent effect on the outcome, but the best prognosis was found in patients with a persistently clear dialysate.

Acute Disease↗

The initial decrease in effective peritoneal surface area is not caused by an increase in hematocrit.

The possible relationship between initial changes in functional characteristics of the peritoneal membrane in time and hemoglobin (Hb) or hematocrit (Ht) was analyzed as part of a prospective longitudinal study. The patients were investigated twice: the first time within 3 months after the start of continuous ambulatory peritoneal dialysis (CAPD), and again 4 months later. Mass transfer area coefficients (MTC) for low molecular weight solutes and net fluid removal were calculated during a 4-hour dwell, glucose 1.36%. Thirty-four patients were analyzed. MTC (mean +/- SD, mL/min/1.73 m2), were higher during the first examination: urea 22.6 versus 19.9, p < 0.05; lactate 15.6 versus 13.8, p < 0.001; creatinine 10.5 versus 9.3, p < 0.05; glucose 9.4 versus 7.9, p < 0.001. Net fluid removal was lower during the first examination: 28 versus 99 mL/min/1.73 m2, p < 0.05. Hb and Ht increased between the two examinations (Hb: 5.4 vs 6.1 mmol/L, p < 0.001: Ht: 0.26 vs 0.29, p < 0.001). No relation was found between the absolute or relative change in Hb or Ht and the absolute or relative change in solute and fluid transport between the same examinations. In conclusion, Hb and Ht increased between the first and second examinations. The simultaneously observed changes in peritoneal transport kinetics could not be attributed to changes in Hb or Ht. Therefore, the changes in transport kinetics during the first months on CAPD are probably due to the recent start of the treatment, possibly by an increase in peritoneal surface area. Local irritation by the dialysate may be the causative mechanism.

Adult↗

Creatinine clearance during cimetidine administration for measurement of glomerular filtration rate.

Creatinine clearance inaccurately estimates true glomerular filtration rate (GFR) because of tubular secretion of creatinine. We studied the ability of oral cimetidine, a blocker of tubular creatinine secretion, to improve the accuracy of measuring creatinine clearance. Clearances of inulin and endogenous creatinine were simultaneously measured in 16 patients with renal disease before administration of cimetidine and during 8 successive 3 h clearance periods with cimetidine 400 mg as priming dose followed by 200 mg every 3 h. At baseline, creatinine relative to inulin clearance (ClC/Cll) ranged from 1.14 to 2.27. With cimetidine, ClC/Cll approached unity in 8 patients (mean 1.02 [SD 0.03]), but considerably exceeded unity in 8 others (1.33 [0.14]). Plasma cimetidine/creatinine ratio was smaller in this second group, due to significantly higher renal clearance of cimetidine (333 [136] vs 165 [89] ml/min, p = 0.01). In a further study, cimetidine dose and, consequently plasma cimetidine concentration, was increased in 6 additional patients who had incomplete inhibited previously. This increased dose completely inhibited tubular creatinine secretion in the third until the sixth hour, so that creatinine clearance equalled GFR. Provided an adequate dose of cimetidine is given, 24 h creatinine clearance during administration of drug measures GFR accurately in patients with renal disease. However, because of the maximum daily dose of cimetidine that is advised, short clearance times (3 h) are recommended.

Adolescent↗

Indirect measurement of lymphatic absorption in CAPD patients is not influenced by trapping.

The disappearance rate of intraperitoneally administered macromolecules is often used to calculate lymphatic absorption during CAPD. The possible contribution of local accumulation (trapping) of such solutes in the tissues surrounding the peritoneal cavity, leading to overestimation of lymphatic flow, was investigated in eight CAPD patients. They were studied twice during a four hour dwell, glucose 1.36%, to which polydisperse neutral dextran 70 1 g/liter had been added for measurement of lymphatic flow. After the test on day 1 dextran 130 mg/kg was given intravenously and also dextran 1 g/liter was added to every following dialysis bag until the second test on day 3. This was done to saturate the tissues surrounding the peritoneal cavity and thereby to create a steady state condition. In one patient the dextran administration was continued until a third study was done on day 5. Dextran in serum during day 3 was 1.3 +/- 0.5 g/liter (mean +/- SD). No difference in peritoneal clearance of dextran was found between day 1 and day 3 (1.11 +/- 0.56 versus 0.97 +/- 0.41 ml/min). Also no difference was found between day 1 (0.32), day 3 (0.62), and day 5 (0.42 ml/min). Trapping would have influenced the first but not the second test, as the second time all tissues were saturated with dextran. As the dextran absorption rate remained the same, this indicates that trapping is of no importance and that lymphatic absorption can be measured by the disappearance of a macromolecular marker.

Absorption↗

Effects of tracer, volume, osmolarity and infection on fluid kinetics during CAPD.

A review is given on various aspects of using the disappearance rate of intraperitoneally administered macromolecules for the determination of fluid kinetics in CAPD patients. The rationale and mathematics for the calculation of transcapillary ultrafiltration and of indirect measurement of lymphatic absorption are described. A comparison is made between autologous haemoglobin, human albumin and dextran 70. Dextran 70 appeared most useful; one brand of human albumin increased solute transport. Lymphatic absorption was higher after the installation of a 3-litre dialysate volume than after a 2-litre one, and also higher during peritonitis than after recovery from infection. A gradual increase in intraperitoneal volume, as obtained with glucose 3.86% dialysate, had no apparent effect on the disappearance rate of dextran 70. It is concluded that intraperitoneally administered dextran 70 is a clinically useful marker for the description of fluid kinetics in CAPD patients under various conditions.

Ascitic Fluid↗