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PubMed2000

Age and nortriptyline concentrations in plasma ultrafiltrate.

OBJECTIVES: Since plasma protein binding of tricyclic antidepressants may be relevant to treatment effects and can be influenced by age-associated factors, we examined both plasma ultrafiltrate and total concentrations of nortriptyline (NT) in patients and compared these to age. We hypothesized negative associations with age of both ultrafiltrate NT and the ratio of ultrafiltrate NT to total plasma NT. METHODS: Patients with major depression at a psychiatric service treated with a stable dose of NT were studied. Trough plasma ultrafiltrate NT concentrations and total plasma NT concentrations were measured by high performance liquid chromatography. Concentrations were corrected for dose. RESULTS: Eighty-seven patients aged 26 - 88 years were studied. Ultrafiltrate NT concentrations and the ratio of ultrafiltrate NT to total NT concentrations were both significantly negatively associated with age. Total NT concentrations were not significantly associated with age. CONCLUSIONS: Relatively low ultrafiltrate NT concentrations in older patients may reflect lower tissue exposure at a given total plasma NT concentration. This could be relevant to toxic and therapeutic effects. Studies of relationships between non-bound drug concentrations and NT treatment outcomes across the age span are needed.

Adult↗
PubMed1992

Cotinine in an ultrafiltrate of saliva.

BACKGROUND: We have developed a device for the simplified collection of a prepurified sample of saliva in the mouth. METHOD: The device is based on the principle of an osmotic pump and accumulated about 1.2 ml of an ultrafiltrate of saliva within 8 min. We have investigated the ultrafiltrate for its utility as a biological medium in the evaluation of cigarette smoking status. RESULTS: (a) In 58 matched samples from 13 subjects, the correlation coefficient for the cotinine concentration in the saliva and the ultrafiltrate was 0.95; (b) in matched plasma and ultrafiltrate samples from 27 smokers, the correlation coefficient for the cotinine concentrations was 0.96 with plasma containing 1.2 times the ultrafiltrate mean; (c) in a nonsmoker, elevated cotinine levels could be detected in the ultrafiltrate more than 24 hr after smoking 2 cigarettes, and the pattern of rise and decrease reflected that in whole saliva; and (d) in a habitual smoker; the mean cotinine concentration in the ultrafiltrate was 157 ng/ml (SD +/- 25.7 ng/ml) during a period of smoking 15 cigarettes per day and dropped to a mean of 47 ng/ml (SD +/- 10.5) when smoking was reduced to 5 cigarettes per day; after cessation of smoking, detectable concentrations of cotinine persisted for up to 5 days. CONCLUSION: The device facilitated the aesthetic, noninvasive collection of a biological sample useful in the validation of smoking status.

Adult↗
PubMed2005

Early ultrafiltration in patients with decompensated heart failure and diuretic resistance.

OBJECTIVES: We sought to determine if ultrafiltration before intravenous (IV) diuretics in patients with decompensated heart failure and diuretic resistance results in euvolemia and early discharge without hypotension or worsening renal function. BACKGROUND: Heart failure patients with renal insufficiency and diuretic resistance have increased hospital mortality and length of stay. Peripheral veno-venous ultrafiltration may re-establish euvolemia and diuretic responsiveness. METHODS: Ultrafiltration was initiated within 4.7 +/- 3.5 h of hospitalization and before IV diuretics in 20 heart failure patients with volume overload and diuretic resistance (age 74.5 +/- 8.2 years; 75% ischemic disease; ejection fraction 31 +/- 15%) and continued until euvolemia. Re-evaluation was each hospital day, at 30 days, and at 90 days. RESULTS: A total of 8,654 +/- 4,205 ml were removed with ultrafiltration. Twelve patients (60%) were discharged in < or =3 days. One patient was readmitted in 30 days. Weight (p = 0.006), Minnesota Living with Heart Failure scores (p = 0.003), and Global Assessment (p = 0.00003) improved after ultrafiltration and at 30 and 90 days. Median B-type natriuretic peptide levels decreased after ultrafiltration (from 1,230 pg/ml to 788 pg/ml) and at 30 days (815 pg/ml) (p = 0.035). Blood pressure, renal function, and medications were unchanged. CONCLUSIONS: In heart failure patients with volume overload and diuretic resistance, ultrafiltration before IV diuretics effectively and safely decreases length of stay and readmissions. Clinical benefits persist at three months.

Aged↗
PubMed2006

Modified and conventional ultrafiltration during pediatric cardiac surgery: clinical outcomes compared.

OBJECTIVE: This prospective study compared clinical outcomes after heart surgery between three groups of infants with congenital heart disease. One group received dilutional conventional ultrafiltration (group D), another received modified ultrafiltration (group M), and a third group received both dilutional conventional and modified ultrafiltration (group B). We hypothesized that group B patients would have the best clinical outcome. METHODS: Children younger than 1 year undergoing heart surgery for biventricular repair by the same surgeon were randomly allocated to one of the three study groups. Patient management was standardized, and intensive care staff were blinded to group allocation. Primary outcome measure was duration of postoperative mechanical ventilation. Other outcome measures recorded included total blood products transfused, duration of chest tube in situ, chest tube output, and stays in intensive care and in the hospital. RESULTS: Sixty infants completed study protocol. Mean age and weight were as follows: group D (n = 19), 61 days, 4.3 kg; group M (n = 20), 64 days, 4.5 kg; and group B (n = 21), 86 days, 4.4 kg. Preoperative and intraoperative characteristics were similar between groups. Ultrafiltrate volumes obtained were 196 +/- 93 mL/kg in group D, 105 +/- 33 mL/kg in group M, and 261 +/- 113 mL/kg in group B. There were no significant differences between groups for any outcome variable. Technical difficulties prevented completion of modified ultrafiltration in 2 of 41 infants. CONCLUSION: There was no clinical advantage in combining conventional and modified ultrafiltration. Because clinical outcomes were similar across groups, relative risks of the ultrafiltration strategies may influence choice.

Cardiopulmonary Bypass↗
PubMed2003

Continuous ultrafiltration attenuates the pulmonary injury that follows open heart surgery with cardiopulmonary bypass.

BACKGROUND: Pulmonary injury after cardiac surgery is one of the complications of cardiopulmonary bypass. We evaluated the ultrafiltration technique in preventing and relieving the pulmonary injury that can follow open heart surgery with cardiopulmonary bypass (CPB). METHODS: Thirty patients with congenital heart defects were divided into two groups. In the control group conventional cardiopulmonary bypass was used without ultrafiltration. In the treated group, in addition to the same cardiopulmonary bypass procedure, balanced ultrafiltration plus modified ultrafiltration was used throughout cardiopulmonary bypass. Pulmonary function, hematocrit, serum albumin, and some inflammatory mediators were measured. RESULTS: Compared with measurements before anesthesia the pulmonary static compliance at 15 minutes and 6 hours post bypass had decreased by 27.8% and 34.0% in the control group versus 12.6% and 15.4% in the treated group, the airway resistance had increased by 38.0% and 45.2% in the control group versus 9.5% and 4.7% in the treated group, and the alveolar-arterial oxygen difference increased by 73.4% and 62.0% in the control group versus 52.1% and 35.9% in the treated group. Hemodilution from cardiopulmonary bypass caused the hematocrit and serum albumin to decrease by 35.8% and 32.8% in the control group versus 36.1% and 34.5% in the treated group at the termination of CPB. After 10 to 15 minutes modified ultrafiltration the hematocrit and serum albumin increased by 40.0% and 47.6%. At the termination of CPB the serum concentrations of interleukin-6, thromboxane B2, and endothelin-1 were increased by 160%, 265%, and 890% in the control group versus 103%, 208%, and 838% in the treated group compared with those before anesthesia. CONCLUSIONS: The combined use of balanced ultrafiltration and modified ultrafiltration can effectively concentrate the blood, modify the increase of some harmful inflammatory mediators, attenuate the lung edema and inflammatory pulmonary injury, and mitigate the impairment of pulmonary function.

Cardiac Surgical Procedures↗
PubMed1997

Modified ultrafiltration reduces postoperative morbidity after cavopulmonary connection.

BACKGROUND: Modified ultrafiltration reduces the deleterious effects of cardiopulmonary bypass in children. Patients undergoing repair of single-ventricle cardiac anomalies may be particularly sensitive to these adverse effects, and benefit from the use of modified ultrafiltration. METHODS: From January 1995 to June 1996, 120 consecutive cavopulmonary operations were performed at The Children's Hospital of Philadelphia. Procedures included lateral tunnel fenestrated Fontan (n = 50), extracardiac Fontan (n = 5), hemi-Fontan (n = 60), and bidirectional Glenn shunt (n = 5). Modified ultrafiltration was performed after cardiopulmonary bypass in 41 patients, and results were compared by t test with a control group of 79 patients in whom modified ultrafiltration was not used. RESULTS: There was one death for an operative (30-day) mortality of 0.8%. Age, weight, diagnosis, ischemic arrest time, and cardiopulmonary bypass time were similar between the modified ultrafiltration and control groups. Postoperative blood use, chest tube output, the incidence of pleural and pericardial effusions, and hospital stay were all significantly decreased when modified ultrafiltration was used. CONCLUSIONS: By lowering the perioperative morbidity of staged cavopulmonary operations, modified ultrafiltration makes an important contribution to improving outcome after the correction of single-ventricle cardiac anomalies.

Adolescent↗
PubMed1995

Modified ultrafiltration improves cerebral metabolic recovery after circulatory arrest.

Modified ultrafiltration uses hemofiltration of the patient and bypass circuit after separation from cardiopulmonary bypass to reverse hemodilution and edema. This study investigated the effect of modified ultrafiltration on cerebral metabolic recovery after deep hypothermic circulatory arrest. Twenty-six 1-week-old piglets (2 to 3 kg) were supported by cardiopulmonary bypass (37 degrees C) at 100 ml.kg-1.min-1 and cooled to 18 degrees C. Animals underwent 90 minutes of circulatory arrest followed by rewarming to 37 degrees C. After being weaned from cardiopulmonary bypass, animals were divided into three groups: controls (n = 10); modified ultrafiltration for 20 minutes (n = 9); transfusion of hemoconcentrated blood for 20 minutes (n = 7). Global cerebral blood flow was measured by xenon 133 clearance methods: stage I--before cardiopulmonary bypass; stage II--5 minutes after cardiopulmonary bypass; and stage III--25 minutes after cardiopulmonary bypass. Cerebral metabolic rate of oxygen consumption, cerebral oxygen delivery, and hematocrit value were calculated for each time point. At point III, the hematocrit value (percent) was elevated above baseline in the ultrafiltration and transfusion groups (44 +/- 1.8, 42 +/- 1.8 versus 28 +/- 1.7, 30 +/- 0.7, respectively, p < 0.05). Cerebral oxygen delivery (ml.100 gm-1.min-1) increased significantly above baseline at point III after ultrafiltration (4.98 +/- 0.32 versus 3.85 +/- 0.16, p < 0.05) or transfusion (4.59 +/- 0.17 versus 3.89 +/- 0.06, p < 0.05) and decreased below baseline in the control group (2.77 +/- 0.19 versus 3.81 +/- 0.16, p < 0.05). Ninety minutes of deep hypothermic circulatory arrest resulted in impaired cerebral metabolic oxygen consumption (ml.100 gm-1.min-1) at point III in the control group (1.95 +/- 0.15 versus 2.47 +/- 0.07, p < 0.05) and transfusion group (1.72 +/- 0.10 versus 2.39 +/- 0.15, p < 0.05). After modified ultrafiltration, however, cerebral metabolic oxygen consumption at point III had increased significantly from baseline (3.12 +/- 0.24 versus 2.48 +/- 0.13, p < 0.05), indicating that the decrease in cerebral metabolism immediately after deep hypothermic circulatory arrest is reversible and may not represent permanent cerebral injury. Use of modified ultrafiltration after cardiopulmonary bypass may reduce brain injury associated with deep hypothermic circulatory arrest.

Animals↗
PubMed2001

Relationship of ultrafiltration and anastomotic flow in isolated rat lungs.

OBJECTIVE: When arterial and venous pressures are increased to equal values in "stop-flow" studies, perfusate continues to enter the pulmonary vasculature from the arterial and venous reservoirs. Losses of fluid from the pulmonary vasculature are due to ultrafiltration and flow through disrupted anastomotic (bronchial) vessels. This study compared the relative sites of ultrafiltration and anastomotic flows at low and high intravascular pressures. METHODS: Isolated rat lungs were perfused for 10 minutes with FITC-dextran, which was used to detect ultrafiltration. Arterial and venous catheters were then connected to reservoirs containing radioactively labeled dextrans at 20 or 30 cm H2O for 10 minutes. The vasculature was subsequently flushed into serial vials, and ultrafiltration and vascular filling during the equal-pressure interval were calculated. RESULTS: Ultrafiltration equaled 0.43 +/- 0.11 mL at 20 cm H2O and was similar to the volume of fresh arterial and venous perfusate which entered and remained in the pulmonary vasculature during the equal-pressure interval (0.45 +/- 0.10 mL). At 30 cm H2O, 0.80 +/- 0.23 mL entered and remained in the vasculature during the equal-pressure interval, replacing the original perfusate, and calculated transudation (0.56 +/- 0.09 mL) was not significantly more than at 20 cm H2O. Fluid also entered the airspaces at 30 cm H2O but not at 20 cm H2O. CONCLUSIONS: At 20 cm H2O, flow through anastomotic vessels occurs at sites that are at the arterial and venous ends of the microcirculation. Flow in exchange vessels remains minimal, permitting measurements of ultrafiltration and exchange. Losses of perfusate from the pulmonary vessels complicate measurements of ultrafiltration at 30 cm H2O.

Animals↗
PubMed1991

Ascorbate is the principal reductant of chromium (VI) in rat liver and kidney ultrafiltrates.

Chromium (VI) reductase activity was measured in ultrafiltrates of rat liver and kidney after various pretreatments in vitro at 37 degrees C and pH 7.0. Preincubation of ultrafiltrates with L-ascorbate oxidase (EC 1.10.3.3), which specifically eliminated ascorbate, blocked approximately 80% of the Cr(VI) reductase activity. Heat-denatured ascorbate oxidase had no effect on Cr(VI) reductase activity in ultrafiltrates. Preincubation of ultrafiltrates with N-ethylmaleimide, which non-specifically blocked sulfhydryls, including reduced glutathione, decreased Cr(VI) reductase activity by only 20%. Treatment of male Sprague-Dawley rats with phorone decreased non-protein sulfhydryl (NPSH) levels in rat liver by greater than 90% and tripled reduced ascorbate levels 2 h after treatment. Ultrafiltrates of liver prepared from phorone-treated rats had twice the Cr(VI) reductase activity of control ultrafiltrates, and greater than 95% of this activity could be blocked by preincubation with ascorbate oxidase. Treatment of rats with sodium dichromate (20 mg/kg) caused a significant decrease in ascorbate levels in kidney but not liver, and no change in NPSH levels in kidney or liver, 15 min after treatment. We conclude that ascorbate is the major reductant of Cr(VI) in rat liver and kidney ultrafiltrates and may well be the major non-enzymatic reductant of Cr(VI) in rat liver and kidney in vivo.

Animals↗
PubMed1983

Glomerular ultrafiltration coefficient after ischemic renal injury in dogs.

Micropuncture studies of acute renal failure after ischemic renal injury suggest that glomerular ultrafiltration coefficient may remain normal in the period immediately after ischemia and decline significantly during the following 18-24 hours. The present series of in vitro experiments was designed to evaluate glomerular ultrafiltration coefficient and glomerular oncometric and rheological properties in ischemic acute renal failure in dogs. To obtain glomeruli prior to ischemia, a right nephrectomy was performed and glomeruli were isolated for studies of filtration and cell and extracellular spaces. The left renal pedicle then was occluded for 90 minutes; glomeruli isolated from biopsies of this kidney were studied at intervals up to 48 hours after ischemia. Glomeruli were isolated by sieving renal cortical fragments, and filtration was induced by an oncotic gradient. The glomerular ultrafiltration coefficient remained near control levels for the first hour after ischemia, but declined significantly at 24 and 48 hours. Specifically, glomerular ultrafiltration coefficient of glomeruli isolated from normal kidneys was 16.5 +/- 0.9 nl/min per mm Hg (n = 15). Immediately following ischemia, glomerular ultrafiltration coefficient remained essentially unchanged (15.9 +/- 1.1 nl/min per mm Hg, n = 4). At 1 hour, there was a small decrease in glomerular ultrafiltration coefficient (14.4 +/- 1.3 nl/min per mm Hg, n = 4). At 24 hours, glomerular ultrafiltration coefficient was significantly decreased (9.8 +/- 0.5 nl/min per mm Hg, n = 9, P less than 0.01) and remained at that level at 48 hours (9.5 +/- 0.5 nl/min per mm Hg, n = 8, P less than 0.001). In experimental glomeruli, the oncometric response was diminished and erythrocyte movement along glomerular capillaries was impaired. Total water and inulin spaces were measured in glomeruli from control and 48-hour postischemic periods, and glomerular morphology was studied by transmission and scanning electron microscopy at the same time.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Kidney Injury↗
PubMed1970

The effect of dialysates and ultrafiltrates of plasma of saline-loaded dogs on toad bladder sodium transport.

In order to obtain direct evidence for the existence of a natriuretic hormone, dialysates and ultrafiltrates of plasma of dogs expanded with saline were tested for effects on sodium transport by the toad urinary bladder. Dialysate was obtained by dialysis of blood in vivo in a clinical dialyzer and by dialysis in vitro of small volumes of blood using a miniature model of the clinical dialyzer. Ultrafiltrates were prepared using selective molecular filters which permit passage of substances on the basis of molecular weight and three dimensional configuration. Dialysates and ultrafiltrates of hydropenic dogs caused a change in toad bladder potential difference of + 1% and in short circuit current of - 5%. In contrast, dialysates and ultrafiltrates from expanded dogs caused a change in potential difference of - 23% and in short circuit current of - 32%, a highly significant difference. Onset of reduction of short circuit current occurred within 3-5 min, reaching a maximum in 10-20 min. The effect was rapidly reversible, was specific for the serosal surface of the bladder, and could not be explained on the basis of nonspecific alterations in ionic composition or by dilutional effects. Ultrafiltrates of jugular vein plasma caused significantly more reduction of short circuit current than ultrafiltrates of femoral vein plasma. The data indicate the presence in plasma of saline-loaded dogs of a dialyzable inhibitor of toad bladder sodium transport. Ultrafiltrate studies using membranes of appropriate selectivity suggest the factor has a molecular weight of less than 3000.

Animals↗
PubMed1999

Reducing complications during hemodialysis using gradient ultrafiltration with gradient sodium dialysate.

The objective of this study was to determine if patient complications and nursing interventions during hemodialysis could be reduced using gradient ultrafiltration and gradient sodium dialysate. Twenty outpatients who had been on hemodialysis for at least 3 months, and using gradient sodium dialysate for at least 1 month, participated. Patients received either ultrafiltration at a constant hourly rate or gradient ultrafiltration, in which the ultrafiltration rate was set higher initially, then decreased step-wise mid-dialysis. Patients received each protocol for 3 months, using a randomized cross-over design. Both protocols used gradient sodium dialysate (150 mEq/L x 3 hrs, 140 mEq/L x 1 hr). There were significantly fewer complications and interventions using gradient ultrafiltration, as compared to constant ultrafiltration. No differences were found in interdialytic weight gain, intradialytic weight loss, or orthostatic blood pressure. These results indicate that gradient ultrafiltration combined with gradient sodium dialysate enhances patient well-being and reduces nursing interventions during hemodialysis.

Adult↗
PubMed1988

Inhibition of bile secretion in the rat by serum ultrafiltrates and fractions from patients with fulminant hepatic failure.

The effects of serum ultrafiltrates and fractions from patients with fulminant hepatic failure (FHF) on bile production in the rat were investigated. When serum ultrafiltrates (mol. wt less than 10,000) were infused into the portal vein bile flow showed a significant decrease with FHF ultrafiltrate (90.4 +/- s.e. 2.0% of baseline at the end of infusion, n = 4) compared with a small increase on infusion of normal ultrafiltrate (107.9 +/- 3.4%, n = 6, P less than 0.025). Bile acid output was significantly decreased by FHF ultrafiltrate (62.0 +/- 2.3%., P less than 0.005). Chromatography of the ultrafiltrates on Sephadex G-25 gave two fractions from FHF serum which produced similar changes as with whole ultrafiltrate on bile secretion. Thus, toxic substances accumulating in the circulation of patients with FHF could reduce bile flow and impair the recovery of hepatic function.

Adult↗
PubMed2001

Fractionation of biological macromolecules using carrier phase ultrafiltration.

This article discusses a novel mode of operation for ultrafiltration processes termed Carrier Phase Ultrafiltration (CPUF). CPUF is based on a modification of dead-end ultrafiltration. Macromolecular fractionation using ultrafiltration is strongly influenced by operating and physicochemical parameters and requires precise "fine-tuning." CPUF facilitates the fractionation of high value biological macromolecules at optimised conditions and has several advantages over conventional modes of ultrafiltration. In this article the fractionation of two model proteins, lysozyme (MW 14100) and myoglobin (MW 17000), by CPUF using 25-kDa MWCO polysulfone membrane is discussed. Fractionation was carried out using two different CPUF modes, 1) pulse input CPUF and 2) step input CPUF. A high recovery of pure product was obtained in each case. These results are compared with those obtained from "conventional" ultrafiltration experiments.

Chemical Fractionation↗
PubMed1981

Ultrafiltration in serum protein binding determinations.

the ultrafiltration technique was evaluated theoretically and experimentally for use in clinical serum binding determinations. It is apparent from free energy considerations that the ultrafiltrate concentration approaches the true free concentration only as the pressure gradient causing flow reduces to zero. The theory presented accounts for the previously unexplained lower ultrafiltrate concentration observed at higher filtration pressures. Mathematical simulations of the molecular separation show that the ultrafiltrate concentration remains constant during filtration, and, thus, binding equilibria are not disturbed by this procedure, suggesting that an arbitrary restriction on the volume filtered is unnecessary. This finding greatly extends the value of the ultrafiltration technique in clinical binding determinations, especially for strongly bound, potent drugs where assays may be insufficiently sensitive to detect the extremely small free fraction reliably. These theoretical findings were verified experimentally by ultrafiltration of salicylate, ibuprofen, and carprofen in buffer, purified proteins, and whole serum.

Blood Proteins↗
PubMed1983

Resuscitation aspects of ultrafiltration and haemodialysis.

Results of using the method of sequential ultrafiltration with hemodialysis and that of hemodiafiltration in the treatment of 70 patients with acute and chronic renal failure in terminal states are described. The patients were under observation in the course of 202 procedures of hemodiafiltration and 175 sequential ultrafiltration with hemodialysis. Apart from this, 21 procedures of isolated ultrafiltration were carried out in patients with pronounced cardiac failure, irreversible pulmonary edema resulting from acute myocardial infarction and heart diseases. Sequential ultrafiltration and hemodialysis were performed by means of home-produced equipment SGD using Cuprofan dialysis film and capillary dialyzators. The volume of ultrafiltration ranged from 1 to 8 litres/procedure at a rate of 17-500 ml/min, at a transmembrane pressure 100-400 mmHg. It was found that sequential ultrafiltration with hemodialysis was indicated for patients in terminal states complicated by renal failure in the presence of severe fluid retention, pulmonary edema, patients with low tolerance to hemodiafiltration, and those in critical states (including irreversible pulmonary edema) of cardiological genesis.

Acute Kidney Injury↗
PubMed1993

Isolated ultrafiltration in moderate congestive heart failure.

OBJECTIVES: The aim of this study was to evaluate whether ultrafiltration is beneficial in patients with moderate congestive heart failure. BACKGROUND: Ultrafiltration is beneficial in patients with severe congestive heart failure. METHODS: We studied 36 patients in New York Heart Association functional classes II and III in stable clinical condition. Eighteen patients (group A) were randomly selected and underwent a single session of ultrafiltration (venovenous bypass, mean [+/- SEM] ultrafiltrate 1,880 +/- 174 ml, approximately 600 ml/h) and 18 (group B) served as control subjects. RESULTS: Two patients in group A and three in group B did not complete the 6-month follow-up study. In group A, soon after ultrafiltration there were significant reductions in right atrial pressure (from 8 +/- 1 to 3.4 +/- 0.7 mm Hg, pulmonary wedge pressure (from 18 +/- 2.5 to 10 +/- 1.9 mm Hg) and cardiac index (from 2.8 +/- 0.2 to 2.3 +/- 0.2 liters/min). During the follow-up period, lung function improved, extravascular lung water (X-ray score) decreased and peak oxygen consumption (ml/min per kg) increased significantly from 15.5 +/- 1 (day -1) to 17.6 +/- 0.9 (day 4), to 17.8 +/- 0.9 (day 30), to 18.9 +/- 1 (day 90) and to 19.1 +/- 1 (day 180). Oxygen consumption at anaerobic threshold (ml/min per kg) also increased significantly from 11.6 +/- 0.8 (day -1) to 13 +/- 0.7 (day 4), to 13.7 +/- 0.5 (day 30), to 15.5 +/- 0.8 (day 90) and to 15.2 +/- 0.8 (day 180). These changes were associated with increased ventilation, tidal volume and dead space/tidal volume ratio at peak exercise. The improvement in exercise performance was associated with a decrease in norepinephrine at rest, a downward shift of norepinephrine kinetics at submaximal exercise and an increase in norepinephrine during orthostatic tilt. None of these changes were recorded in group B. CONCLUSIONS: In patients with moderate congestive heart failure, ultrafiltration reduces the severity of the syndrome.

Aged↗
PubMed1986

High-performance liquid chromatographic fractionation and partial characterization of cystic fibrosis serum ultrafiltrates.

Analytical separation of serum ultrafiltrates by high-performance liquid chromatography produces a distinctive peak with a retention time of 18.5-21 min (subfraction 18.5) from cystic fibrosis serum ultrafiltrates and obligate heterozygote serum ultrafiltrates, but not in significant concentrations from control or asthmatic serum ultrafiltrates. Semipreparative separation of control serum ultrafiltrates produced a small peak with similar retention time that was approximately 1% of the arbitrary absorbance units found in this cystic fibrosis subfraction. Subfraction 18.5 had biological activity only when separated from cystic fibrosis serum ultrafiltrate, but did not contain measurable amounts of C3a des-arginine and C4a des-arginine. Subfraction 18.5 is a low-molecular-weight material (1000-1400 daltons) that contains 14.9 micrograms orcinol positive material per 50 micrograms protein. The spectrum of subfraction 18.5 indicates that it has to be purified to homogeneity.

Carbohydrates↗