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PubMed1997

Haemodiafiltration with sorbent-regenerated ultrafiltrate as replacement fluid: a multicenter study.

BACKGROUND: Uncoated adsorbent charcoal may regenerate the ultrafiltrate suggesting its use as an endogenous substitution fluid. The objective of this study was to assess the safety and the long-term clinical results. METHODS: Thirty-three chronic uraemic patients were dialysed for 1 year using two haemodialysers in series in order to separate convection from diffusion. At the outflow of the convective haemofilter, a cartridge containing 130 g of uncoated charcoal was inserted. The regenerated ultrafiltrate was then infused at the entrance of the diffusive dialyser. Ex vivo and in vitro studies were performed to analyse the adsorption characteristics and the release of aluminium, other trace elements, and microparticles. RESULTS: Passage through the charcoal left urea, phosphate, potassium, calcium, and bicarbonate concentrations unchanged. Creatinine, uric acid and beta 2-microglobulin were almost completely absorbed by the charcoal. Aluminium release was dependent upon time of storage, as inferred from studies on inter-lot variability. Washing with bicarbonate buffer (pH 7.0) allowed reduction of aluminium levels to within the pharmacopoeia requirements for intravenous fluids. No significant pre- or post-charcoal differences were observed for several trace elements such as manganese, selenium, arsenic, cadmium, mercury, lead, chromium and zinc. Copper was completely retained in the charcoal. Regenerated ultrafiltrate infused at the entrance of the diffusive dialyser was free of microparticles, bacteria, and endotoxin. Clinical tolerance was excellent and blood pressure control satisfactory. A significant decrease in serum values of beta 2-microglobulin was observed at 6 and 12 months of treatment. CONCLUSIONS: Reinfusion of ultrafiltrate through an uncoated charcoal cartridge proved to be a safe, well-tolerated and simple technique. Further potential benefits of regenerated ultrafiltrate may also include the maintenance of acid-base balance with reinfusion of endogenous bicarbonate.

Adult↗
PubMed2004

Intraperitoneal heparin reduces peritoneal permeability and increases ultrafiltration in peritoneal dialysis patients.

BACKGROUND: Patients on long-term treatment with peritoneal dialysis (PD) suffer from increasing peritoneal permeability and loss of ultrafiltration as a result of persistent inflammation, which may be triggered by bioincompatible dialysis fluids. Heparins have anti-inflammatory and anticoagulant properties. We have examined the effect of intraperitoneal (IP) low-molecular weight heparin (tinzaparin) on peritoneal permeability and ultrafiltration in PD patients. METHODS: By means of a double-blinded cross-over design, 21 PD patients were randomized to receive either placebo or tinzaparin intraperitoneally once a day for two treatment periods of 3 months, separated by a wash-out period. The effect of heparin on peritoneal permeability and ultrafiltration was assessed using the 4 h standard peritoneal equilibration test. RESULTS: IP tinzaparin reduced significantly the dialysate-to-plasma ratios (D/P) of creatinine (P < 0.01), urea (P < 0.01) and albumin (P<0.05). In addition, the ratio of glucose concentration in dialysate at 4 h dwell to that of 0 h dwell (D(4)/D(0)) was increased (P<0.05) along with an increase in ultrafiltration volume (P<0.05). CONCLUSIONS: IP tinzaparin reduces peritoneal permeability to small solutes and increases ultrafiltration in PD patients.

Adult↗
PubMed1996

Vascular reactivity during combined ultrafiltration-haemodialysis: influence of dialysate sodium.

BACKGROUND: It is well known that vascular reactivity is impaired during combined ultrafiltration-haemodialysis as compared to isolated ultrafiltration and haemofiltration, which might be related to differences in plasma osmolality. Therefore vascular reactivity was studied during combined ultrafiltration-haemodialysis in relation to sodium-related differences in plasma osmolality/tonicity. METHODS: With each patient serving as his or her own control, nine stable dialysis patients (23-71 years) were studied during 2 h of combined ultrafiltration-haemodialysis (bicarbonate; UF rate 1.0 l/h)) at two different dialysate sodium concentrations: 134 and 144 mmol/l. Before dialysis as well as every 20 min during dialysis, blood pressure (Dinamap), heart rate (ECG), and forearm vascular resistance and venous tone (strain-gauge plethysmography) were measured. Relative blood volume was monitored continuously by an optical reflection method (Haemoguard 2000), while before and after dialysis blood was obtained for the estimation of plasma prostaglandin E2. RESULTS: High-sodium dialysis resulted in a significantly higher post-dialysis plasma sodium concentration (139. 9 vs 135.0 mmol/l; P<0.01) while the decrease in relative blood volume was significantly smaller as compared to low-sodium dialysis (-8.4 vs -18.4%; P<0.01). There were no significant differences in the different haemodynamic parameters between the two treatment modalities. Both high- and low-sodium dialysis were associated with a significant increase in forearm vascular resistance while venous tone remained unchanged. Although there was no significant difference in plasma PGE2 between the two treatment modalities, PGE2 increased significantly only during low-sodium dialysis. We found no relationship between changes in PGE2 and vascular reactivity. CONCLUSIONS: We conclude that vascular reactivity during combined ultrafiltration-haemodialysis is not directly influenced by sodium-related changes in plasma tonicity. Although not directly studied, the reported improved haemodynamic stability with high-sodium dialysis is probably only mediated through a better preservation of plasma volume. Finally, an increase in plasma PGE2 as observed during low-sodium dialysis does not lead to a decrease in vascular tone.

Adult↗
PubMed1992

Hormonal changes in patients with severe chronic congestive heart failure treated by ultrafiltration.

Plasma atrial natriuretic peptide (ANP), antidiuretic hormone (ADH), plasma renin activity (PRA), and circulatory haemodynamics were studied in five patients with chronic congestive heart failure undergoing ultrafiltration on two consecutive days. The patients were in the New York Heart Association class IV, and were considered candidates for heart transplantation. A mean of 3.3 +/- 0.5 litres of fluid was removed during each ultrafiltration. Plasma ANP concentration remained unchanged during ultrafiltration: 369 +/- 151 pg/ml at start and 316 +/- 116 pg/ml at the end, while plasma ADH concentration and PRA increased from 5.1 +/- 2.1 to 7.5 +/- 3.4 pg/ml (P less than 0.02), and 5.9 +/- 3.0 to 7.7 +/- 3.2 ng/ml (P less than 0.03) respectively (n = 10). After treatment, plasma ADH and PRA declined to baseline values within 1 h. Pulmonary artery, pulmonary capillary wedge, and right atrial pressures decreased significantly, while blood pressure and heart rate remained constant during ultrafiltration. A volume of 3.3 +/- 0.5 litres of fluid was removed, and caused an increase in colloid osmotic pressure from 22.0 +/- 3.0 to 33.7 +/- 3.9 mmHg (P less than 0.02). It was unexpected that plasma ANP concentration did not decline. Due to long-standing severe heart failure the atrial wall may have lost some of its elastic properties, resulting in less ability to adapt to reduced filling pressures. Accordingly, atrial wall stretch remained unchanged, explaining the constant ANP levels. Ultrafiltration treatment caused an increased responsiveness to diuretic therapy, and four patients survived long enough to receive heart transplants.

Adult↗
PubMed2006

In vivo removal of high- and low-molecular-weight compounds in hemodiafiltration with on-line regeneration of ultrafiltrate.

BACKGROUND: Current methods of renal replacement therapy, combining convection and diffusion, are largely unsatisfactory in removing uremic toxins. Adsorption is a third mechanism that has been applied in extracorporeal therapy. This study evaluates the impact of hemodiafiltration with on-line regeneration of ultrafiltrate, a new two-step integrated sorbent system, on in vivo removal of a wide spectrum of solutes with different molecular weights. METHODS: Pre- and post-dialysis concentrations of small, medium-size, and large molecules were determined in ten patients undergoing regular hemodiafiltration treatments with on-line regeneration of the ultrafiltrate. We also analyzed, at different times of the same dialysis session, the inlet and outlet ultrafiltrate; the latter had been regenerated by the sorbent cartridge and was used as reinfusion liquid. The mean dialysis time was 260 +/- 21.2 min with a blood flow of 361 +/- 33.3 ml/min and a reinjection volume of 3.6 +/- 0.2 l/h. RESULTS: Urea, creatinine and phosphate reduction ratio were respectively 69.8 +/- 8.2, 61.9 +/- 5.5, and 40.2 +/- 17.3%. Removal of medium-size markers such as calcitonin, osteocalcin, beta2-microglobulin, cystatin C, myoglobin and prolactin varied between 24 and 60%. The percentage of reduction for retinol binding protein and alpha1-microglobulin was negligible and we were unable to demonstrate any removal of alpha1-acid glycoprotein, pre-albumin, and albumin in the regenerated ultrafiltrate. CONCLUSION: The hemodiafiltration with on-line regeneration of ultrafiltrate is a new hemodialysis system, which allows uremic toxin removal over a wide molecular-weight spectrum.

Aged↗
PubMed2001

Modified ultrafiltration reduces morbidity after adult cardiac operations: a prospective, randomized clinical trial.

BACKGROUND: Extracorporeal circulation contributes to morbidity after open-heart surgery by causing a systemic inflammatory reaction. Modified ultrafiltration is a technique able to remove the fluid overload and inflammatory mediators associated with use of cardiopulmonary bypass. It has been shown to reduce morbidity after cardiac operations in children, but the impact on adult cardiac procedures is unknown. METHODS AND RESULTS: Five hundred seventy-three consecutive adult patients were prospectively randomized to either ultrafiltration after cardiopulmonary bypass (treatment) or to no ultrafiltration (control). Parsonnet score was used to assess the severity of the patients' clinical conditions. Analysis was done with Student's t test or Mann-Whitney U test for continuous variables and Fisher's exact test or Pearson's chi(2) for discrete variables. Hospital mortality was 2.5% (7 of 284) in the treatment group versus 3.8% (11 of 289) in the control group (P=0.357). Hospital morbidity was lower in treated patients (66 of 284 [23.2%] versus 117 of 289 [40.5%], P=0.0001). Cardiac morbidity was similar (26 of 284 [9.1%] versus 35 of 289 [12.1%], P=0.251), whereas significantly lower rates of respiratory (20 of 284 [7.0%] versus 36 of 289 [12.5%], P=0.029), neurological (5 of 284 [1.8%] versus 14 of 289 [4.8%], P=0.039), and gastrointestinal (0 of 284 versus 4 of 289 [1.4%], P=0.044) complications were found in treated patients. Transfusion requirements were also lower in treated patients (1.66+/-2.6 versus 2.25+/-3.8 U/patient, P=0.039). Duration of intensive care (39.9+/-49.2 versus 46.3+/-72.8 hours, P=0.218) and hospital stay (7.6+/-3.5 versus 7.9+/-4.4 days, P=0.372) were comparable. CONCLUSIONS: Modified ultrafiltration after cardiopulmonary bypass is associated with a lower prevalence of early morbidity and lower blood transfusion requirements. The impact on length of hospital stay needs further analysis. Routine application of modified ultrafiltration after adult cardiac operations is warranted.

Adolescent↗
PubMed1974

Dynamics of glomerular ultrafiltration in the rat. V. Response to ischemic injury.

An experimental model of postischemic, acute renal failure has been developed in Wistar rats with surface glomeruli, thereby making possible a direct assessment of the mechanisms responsible for the fall in glomerular filtration rate that characterizes this disorder. Whole kidney and cortical single nephron filtration rates were reduced proportionately, on average by approximately 40%, after 3 h of nearly complete occlusion of the ipsilateral renal artery. The possibility of a significant transtubular leak of inulin was excluded. This decline in filtration rate occurred in the absence of measured changes in mean arterial pressure, mean glomerular transcapillary hydrostatic pressure, or net ultrafiltration pressure at afferent and efferent ends of the glomerular capillary. Net ultrafiltration pressure at the efferent end of the capillary approached zero both before and after ischemic injury, demonstrating that filtration pressure equilibrium was achieved throughout this study. Single nephron filtration fraction remained unchanged, indicating that the fall in filtration rate was accompanied by a proportional decline in glomerular plasma flow. The results indicate that the fall in filtration rate was solely the consequence of this fall in glomerular plasma flow. Since filtration rate per nephron is equal to the product of the ultrafiltration coefficient and mean ultrafiltration pressure, this product must also have fallen in proportion to the decline in glomerular plasma flow. Evidence is presented to indicate that a change in ultrafiltration coefficient is not required to account for the observed fall in filtration rate. The reduction in glomerular plasma flow, occuring in the absence of a concomitant decline in mean glomerular capillary hydrostatic pressure, resulted from large and proportional increases in afferent and efferent arteriolar resistances. These resistance changes appear to play a fundamental role in the pathogenesis of this form of acute renal failure.

Acute Kidney Injury↗
PubMed1993

Serum ultrafiltrable copper, total copper and caeruloplasmin concentrations in gynaecological carcinomas.

Serum copper and caeruloplasmin concentrations are elevated in various carcinomas, but it is not known whether the rise in serum copper is due to elevation of caeruloplasmin alone or whether it is also due to the elevation of 'free' copper. We therefore determined ultrafiltrable copper to answer this question. Serum ultrafiltrate was prepared using the Amicon micropartition system and ultrafiltrable (free) copper was determined by flameless atomic absorption spectrophotometry. Serum total copper was determined by flame atomic absorption spectrometry and caeruloplasmin by rate nephelometry. There was no significant difference in the ultrafiltrable copper concentration between patients with gynaecological tumours and control subjects. However, total copper and caeruloplasmin concentrations were significantly elevated in cancer patients compared with control subjects. In contrast to total copper and caeruloplasmin concentrations, ultrafiltrable copper concentrations showed no significant increase with increase in the stage of the cancer.

Adult↗
PubMed1988

Sexual differences in glomerular ultrafiltration: effect of androgen administration in ovariectomized rats.

The glomerular ultrafiltration rate varies as a function of age and sex. To further elucidate the basis for the sexual difference, an androgen [Deca-Durabolin (DECA)] was administered to female ovariectomized rats, and glomerular hemodynamics were evaluated by renal micropuncture after 6 and 16 weeks of therapy. Results were compared to those in control ovariectomized female rats injected with vehicle. Therapy did not produce significant differences in body weight, but kidney size was modestly increased in DECA-treated rats at 6 weeks (0.68 +/- 0.03 vs. 0.86 +/- 0.03 g wet weight; P less than 0.05); at 16 weeks major differences in renal size were documented (0.69 +/- 0.03 vs. 1.18 +/- 0.05 g wet weight; P less than 0.01). The increase in size was primarily due to tubular hypertrophy, with more modest increases in glomerular size. After 6 weeks of therapy, the single nephron glomerular filtration rate (SNGFR) was increased in DECA-treated ovariectomized rats (24.8 +/- 1.0 vs. 32.9 +/- 1.1 nl/min; P less than 0.01). Whole kidney glomerular filtration rate also rose in proportion to increases in kidney size. The greater SNGFR was attributed to higher rates of nephron plasma flow and a numerical increase in the glomerular ultrafiltration coefficient. However, after 16 weeks of androgen therapy, in spite of marked renal hypertrophy, SNGFR did not further rise in proportion to renal size, and the rate of nephron plasma flow and the glomerular ultrafiltration coefficient actually fell relative to those in control untreated rats. Light microscopic evaluation of renal tissue revealed no abnormalities in DECA-treated rats. Thus, 6-week androgen therapy to ovariectomized female rats increased both glomerular ultrafiltration rates and renal size. However, with prolonged administration a glomerular dysfunction may have ensued whereby glomerular ultrafiltration was dissociated from increases in renal size.

Androgens↗
PubMedDate not supplied

Low molecular weight heparin improves peritoneal ultrafiltration and blocks complement and coagulation.

OBJECTIVES: Clinical studies have demonstrated that the intraperitoneal (IP) complement and coagulation systems are activated in peritoneal dialysis (PD) patients. In animal models, low molecular weight heparin (LMWH) was seen to inhibit peritoneal angiogenesis, and related compounds have increased ultrafiltration volumes after repeated administration to PD patients. The present study evaluated the effects of LMWH on ultrafiltration, coagulation, and complement activation during a single PD dwell. DESIGN: Rats were exposed to a single dose of 20 mL 2.5% glucose-based, filter-sterilized PD fluid, with or without supplementation with LMWH. The PD fluid was administered either as an IP injection or as an infusion through an indwelling catheter. The dwell fluid was analyzed 2 hours later concerning activation of the complement and coagulation cascades, chemotactic activity, neutrophil recruitment, ultrafiltration volume, and glucose and urea concentrations. RESULTS: Exposure to PD fluid induced activation of IP complement [formation of C3a (desArg) and increase of C5a-dependent chemotactic activity] and coagulation (formation of thrombin-antithrombin complex) and recruitment of neutrophils. In the case of IP injection, neutrophil recruitment and complement activation were inhibited by LMWH. In both models, LMWH inhibited thrombin formation, reduced complement-dependent chemotactic activity, and increased the IP fluid volume, indicating an improved ultrafiltration. CONCLUSIONS: The acute inflammatory reaction to PD fluid involves the complement and coagulation cascades. Addition of LMWH to the PD fluid improves ultrafiltration, inhibits formation of thrombin, and potentially blocks C5a activity. The present results motivate further investigations of the IP cascade systems in PD.

Animals↗
PubMed1987

Digoxin-like immunoreactivity eliminated from serum by centrifugal ultrafiltration before fluorescence polarization immunoassay of digoxin.

Digoxin determined in the Abbott "TDx" by fluorescence polarization immunoassay by the manufacturer's recommended method involving precipitation of protein with 5-sulfosalicylic acid (SSA) is subject to interference from endogenous compounds having digoxin-like immunoreactivity. Guided by the work of Graves et al. (Clin Chem 1986;32:1506-9), we eliminated interference caused by digoxin-like immunoreactivity by substituting ultrafiltration for precipitation with SSA to remove protein. Using the manufacturer's method, we quantified digoxin in serum from 53 patients in three clinically defined groups who were receiving no digoxin, finding apparent digoxin in excess of the 200 ng/L detection limit in 24% of the 17 pregnant women, 59% of the 17 renal-dialysis patients, and all of 19 neonatal cord-blood samples examined. No measurable digoxin immunoreactivity was observed by fluorescence polarization immunoassay for any of the 53 clinically defined patients after removal of protein by ultrafiltration. For 22 men for whom digoxin was prescribed, digoxin measurement after protein removal by SSA and by ultrafiltration correlated well (r = 0.98), with good proportionality (slope = 1.04). Analytical recovery of added digoxin from adulterated serum was 115% after SSA, but 100% after ultrafiltration. Thus, before this assay procedure, we recommend ultrafiltration, to remove digoxin-like interference.

Digoxin↗
PubMedDate not supplied

Determination of zinc in serum, blood, and ultrafiltrate fluid from patients on hemofiltration by graphite furnace/atomic absorption spectroscopy or flow injection analysis/atomic absorption spectroscopy.

Two methods were optimized for the determination of zinc in samples of blood, serum, and ultrafiltrate fluid from patients with chronic renal impairment undergoing hemofiltration. In the first procedure, after acid digestion of the samples, Zn in blood and serum is determined by a system coupled to flow injection analysis and atomic absorption spectroscopy. The method is rapid, automated, simple, needs small amounts of sample, and has acceptable analytical characteristics. The analytical characteristics obtained were as follows: determination range of method, 0.05-2.0 ppm of Zn; precision as coefficient of variation (CV), 5.3%; recovery, 95-105%; and detection limit (DL), 0.02 ppm. The second method is optimized for ultrafiltrate fluid because the sensitivity of the first procedure is not suitable for the levels of Zn (ppb or ng/mL) in these samples. The technique chosen was atomic absorption spectroscopy with electrothermal atomization in a graphite furnace. The analytical characteristics obtained were as follows: determination range of method, 0.3-2.0 ppb Zn; CV, 5.7%; recovery, 93-107%; and DL, 0.12 ppb. The methods were used to determine zinc in samples of blood, serum, and ultrafiltrate fluid from 5 patients with chronic renal impairment undergoing hemofiltration to discover whether there were significant differences in the zinc contents of blood, serum, and ultrafiltrate fluid after the hemofiltration process. An analysis of variance of the experimental data obtained from a randomly selected group of 5 patients showed that zinc concentrations in the ultrafiltrate fluid, venous blood, and venous serum do not vary during hemofiltration (p < 0.05), whereas in arterial blood and serum, the time factor has a significant effect.

Flow Injection Analysis↗
PubMed2003

Parameter scanning ultrafiltration: rapid optimisation of protein separation.

High-resolution fractionation of proteins using ultrafiltration is feasible only at highly optimised conditions. Conventional process optimisation methodology demands both time and material. Pulsed sample injection ultrafiltration has been suggested as a rapid process optimisation technique. In the present work the scope of this technique is further extended by "parameter scanning ultrafiltration," which involves continuous change of a process parameter (e.g., pH, salt concentration). The time and material consumption are thus further reduced. The technique was validated using different proteins and membranes. Sieving coefficients at different pH and salt concentration were compared to those obtained in fixed parameter ultrafiltration experiments. As fractionation case studies the separation of monoclonal antibody from bovine serum albumin and separation of human IgG from human serum albumin were examined.

Alemtuzumab↗
PubMed2005

Fractionation of bovine serum albumin and monoclonal antibody alemtuzumab using carrier phase ultrafiltration.

Protein transmission and hence selectivity of separation can be significantly affected by solution pH and ionic strength in protein fractionation using ultrafiltration. Using parameter scanning ultrafiltration, the transmission of bovine serum albumin (BSA) and monoclonal antibody alemtuzumab (Campath-1H) through 300 kDa polyethersulfone (PES) ultrafiltration membranes were studied over a range of pH and salt concentrations, with focus on the likely conditions for achieving "reverse selectivity," i.e., obtaining purified alemtuzumab (approximately 155 kDa) in the permeate. Experimental results demonstrate that the reverse selectivity could be obtained by manipulating the operating conditions such as the solution pH, ionic strength, permeate flux, and system hydrodynamics. With a two-stage batch ultrafiltration process under suitable conditions, the monoclonal antibody alemtuzumab with a purity of > 98% was obtained in the permeate from a feed solution initially containing 0.50 g/l each of BSA and alemtuzumab. Further purity can be expected by selecting more suitable membranes and optimizing operating conditions.

Alemtuzumab↗
PubMed2005

Quantitation and stability of piperacillin and tazobactam in plasma and ultrafiltrate from patients undergoing continuous venovenous hemofiltration by HPLC.

Simple and reproducible HPLC methods for the determination of piperacillin and tazobactam have been developed and a complete stability study carried out. The method for piperacillin plasma samples consisted of protein precipitation with methanol using penicillin G as internal standard. No sample preparation was needed for ultrafiltrate samples. Tazobactam sample preparation involved protein precipitation with acetonitrile and the removal of lipids with dichloromethane. Piperacillin separation was performed on a microBondapack C(18) column (300 x 3.9, 10 microm) and tazobactam on a Novapack C(18) column (150 x 3.9, 4 microm) with UV detection set at 229 and 225 nm, respectively. The mobile phase consisted of phosphate buffer-acetonitrile, delivered at 1.5 mL[sol ]min. Calibration curves determination coefficients were >or=0.999 and response factors CV% < 5%. Intra- and inter-assay precision and accuracy of the quality control and limit of quantification were satisfactory. Plasma and ultrafiltrate samples were stable at -20 and -80 degrees C for 2 months and after three freeze-thaw cycles. In the chromatographic rack, tazobactam ultrafiltrate samples were stable for 24 h and plasma samples for 12 h, piperacillin ultrafiltrate samples for 8 h, but plasma samples for only 4 h. Storage of piperacillin samples at 4 degrees C until analysis is recommended. Piperacillin was stable in the presence of tazobactam.

Anti-Bacterial Agents↗
PubMed1994

Evaluation of ultrafiltration for the free-fraction determination of single photon emission computed tomography (SPECT) radiotracers: beta-CIT, IBF, and iomazenil.

An ultrafiltration system was evaluated for the free-fraction measurement of SPECT radiotracers (beta-CIT, IBF, and iomazenil) used in functional brain imaging. The effect of temperature, storage, centrifugal force, tracer concentration, and percentage filtered demonstrated a relative error of < 9%. As a result of the minimal temperature effect, 25 degrees C was employed for all measurements. A comparison of the ultrafiltration system with equilibrium dialysis revealed < 5% difference for beta-CIT and iomazenil, but 16% for IBF. Additionally, the time and ease of operation considerably favored the ultrafiltration system. The precision quantitated by repetition was < 6% for between-run and within-run variability. In conclusion, ultrafiltration provided rapid results, demonstrated minor analytical errors, revealed generally good correlation with equilibrium dialysis, and allowed excellent precision.

Adsorption↗
PubMed1996

Determination of zinc fractions in human blood and seminal plasma by ultrafiltration and atomic absorption spectrophotometry.

A simple and reliable method is described which combines ultrafiltration technique with atomic absorption spectrophotometry to determine the Zn fractions in human blood plasma and seminal plasma. Ultrafiltrable, loosely bound, and firmly bound Zn can be measured using this method in the presence or absence of ethylenediaminetetraacetic acid (EDTA). The YMT membranes for the ultrafiltration must be rinsed thoroughly before use. In contrast to Zn in blood plasma, a large part of Zn in the seminal plasma was found to be ultrafiltrable. This method can be applied to study the physiologically active part of Zn in body fluids related to various disease states.

Adult↗
PubMed1997

Assessment of a new ultrafiltration blood processing system.

PURPOSE: To report our clinical experience with a new blood processing device which uses ultrafiltration. We assessed safety and efficacy by evaluating: 1 ) the quality and the quantity of intraoperative shed blood processed and reinfused to the patient 2) homologous blood requirements 3) clinical status of the patient post-transfusion. METHODS: With Ethics Committee approval, the ultrafiltration device was used in six consenting patients undergoing major elective spinal surgery. Blood samples for haematology and biochemistry tests were collected from patients post-induction of anaesthesia (baseline), 1 hr and 24 hr post-autotransfusion. Volumes of blood collected and processed, and all autologous and homologous transfusions were recorded. Patients were assessed post-operatively for any adverse effects. RESULTS: Five patients had donated blood preoperatively. One patient required homologous blood products in addition to autologous blood. In two patients, the filtration cartridge became blocked and required changing midprocessing. No patient sustained device-related complications. One patient had postoperative haematuria which resolved spontaneously within two hours. CONCLUSION: The ultrafiltration device was safe and effective in reducing homologous blood requirements in six patients undergoing elective spinal surgery. Further evaluation of the ultrafiltration device will be necessary, especially in view of the blockage of the filtration cartridge.

Blood Transfusion, Autologous↗