bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling Indicator Dispersion in Extracorporeal Blood Lines
Authors: Schneditz D. , Wimmer J. 
Published: January 2018

The measurement of indicators such as saline diluted by blood flow provides important information on transport characteristics during extracorporeal blood treatments. When saline is injected and measured using the extracorporeal system, the effects caused by dispersion within the extracorporeal system have to be taken into consideration in order to adequately identify intracorporeal transport characteristics. It was the aim of this study to quantify the extracorporeal contribution and to obtain a transport function for specified sections of the extracorporeal system. The dispersion of saline following an impulsive input was measured in arterial and venous segments of customary extracorporeal blood lines with different distribution volumes (Vt=23–87 mL) using a range of different blood flows (Qb=200–450 ml/min). The dispersion was analyzed using a modified Gamma distribution function characterized by three parameters n, k, and τ, where n is real, positive, and n 1, where k=Q b/Vt*n2, and where trefers to the indicator appearance time at the sampling site. The parameters n, k, and t were identified by fitting the model function to experimental data. The value of n was 2.3±0.5 and largely independent of the type of line segment, Qb, or Vt. τ showed a strong dependence on Vt and Qb which was described by τ= Vt/Qb*(n-1)/n. Thus, with a given n, and when Vt and Qb are known, the transport function for saline in important sections of the extracorporeal circulation can be determined for specific experimental conditions. With this information indicator dilution curves measured in extracorporeal blood lines can be corrected for extracorporeal effects.
Renal Recovery after Severe Acute Renal Failure
Authors: Bagshaw S.M. , Mortis G. , Godinez-Luna T. , Doig C.J. , Laupland K.B. 
Published: January 2018

Background There is limited information about renal recovery to independence from renal replacement therapy (RRT) and about factors associated with its occurrence after severe acute renal failure (ARF). Methods We conducted a population-based surveillance among all adult residents of the Calgary Health Region surviving ICU admission from May 1, 1999 to April 30, 2002. The primary objective was to determine the rate of and the factors associated with 90-day survival and recovery to independence from RRT in critically ill patients with severe ARF. Results At 90 days, 96 patients (40%) were alive. Of these, 72% were RRT independent with most (87%) requiring <4 weeks to recover. Prior to RRT, the median (IQR) serum creatinine and mean (SD) serum urea were 395 (252–517) μmol/L and 29.2 (18) mmol/L, respectively. Oliguria was present in 76%. Intermittent hemodialysis was the initial modality in 46% and continuous renal replacement therapy (CRRT) in 54%. By multivariate analysis, male sex (odds ratio (OR) 7.6, 95% CI, 2.2–27, p=0.01) and a diagnosis of septic shock (OR 3.9, 95% CI 1.02–14.5, p=0.05) were associated with an increased odds of recovery. Conversely, a higher Charlson co-morbidity index score (OR 0.71, 95% CI, 0.6–0.85, p=0.04) and a higher pre-RRT serum creatinine (OR 0.20, 95% CI, 0.05–0.80, p=0.02, p=0.02) were associated with reduced odds of recovery. Chronic kidney disease or the initial modality of RRT were not associated with recovery. Conclusions The majority of severe ARF patients who survive their acute illness are independent of RRT by 90 days. Male sex and a diagnosis of septic shock are independently associated with recovery while a greater co-morbidity score and a higher serum creatinine prior to RRT are predictive of non-recovery. (Int J Artif Organs 2006; 29: 1023–30)
Effect of On-Line Hemodiafiltration with Endogenous Reinfusion (HFR) on the Calcium-Phosphorus Metabolism: Medium-Term Effects
Authors: Bolasco P.G. , Ghezzi P.M. , Ferrara R. , Maxia M. , Pinna M. , Logias F. , Cogoni G. , Cadinu F. , Ghisu T. , Contu B. , Casu D. , Passaghe M. , Pilloni A. , Ganadu M. , Gazzanelli L. 
Published: January 2018

Aim The purpose of the study was to examine the effect of hemodiafiltration with endogenous reinfusion (HFR) compared to hemodialysis (HD) on 28 uremic patients with secondary hyperparathyroidism (2HPT) but positively selected for good and stable control of phosphatemia in order to evaluate the independent effects of dialysis treatments on bone turnover metabolism. Methods: The study was divided into 3 periods of observation: a) HD for three months; b) HFR for three months; c) HFR for a further 3 months. We analysed the trend of: whole PTH, 1–84 PTH, 7–84 PTH, alkaline phosphatase and its bone isoenzyme, total and ionised calcium, phosphatemia, dose of phosphate binder agents, β2-microglobulin, CRP. All the variations found were evaluated through mean values ± SD, t-tests, multivariate analysis. Results We observed a deceleration in bone turnover characterized by a reduction of the total and bone alkaline phosphatase (IU/mL) from 92.3 ± 82.8 and 35.8 ± 49.8 at the end of HD to 63.4 ± 23.9 and 16.0 ± 8.7 at the end of HFR, respectively, and 1–84 PTH from 317.5 ± 264.6 pg/mL at the end of HD to 287.5 ± 258.9 pg/mL at the end of the 3rd month of HFR. β2-microglobulin was reduced from 32.9 ± 16.1 mg/L at the end of HD to 26.4 ± 8.1 mg/L already at the end of the first three months of HFR. CRP was reduced from 2.5 ± 2.6 mg/dL at the beginning of the study to 1.3 ± 1.7 mg/dL at the end of HFR. There were no differences with regard to: dialytic efficiency, nutritional status, calcemia, phosphatemia (maintained in the K-DOQI range for the entire duration of the study), also thanks to more careful use of phosphate chelating agents. Conclusion We are of the opinion that HFR - essentially thanks to the use of ultrapure endogenous infusate - induces a deceleration in bone turnover due to 2PHT. In addition, phosphate substraction in HFR is better compared to HD, thanks to the improvement of the anti-inflammatory conditions by removing the cytokines harmful to bone metabolism and excluding a priori the negative effects related to hyperphosphatemia. (Int J Artif Organs 2006; 29: 1042–52)
Comparison of Specific Adsorbents for Tumor Necrosis Factor-α and Therapeutic Anti-Tumor Necrosis Factor-α Antibodies: An in Vitro Sepsis Model
Authors: Schwanzer-Pfeiffer D. , Mitteregger R. , Rossmanith E. , Falkenhagen D. 
Published: January 2018

Background Tumor necrosis factor alpha (TNF-α), as a key mediator, represents a major point of attack in sepsis. Since it has been shown that systemic anti-TNF-α antibodies do not improve the situation of septic patients, the use of specific adsorption technology in the treatment of sepsis could have beneficial effects. Methods Magnetic beads coated with polyclonal or with monoclonal anti-TNF-α antibodies were investigated in vitro in order to analyze their ability to prevent TNF-α induced adhesion of peripheral blood mononuclear cells (PBMCs) at human umbilical vein endothelial cells (HUVECs). Additionally, therapeutical monoclonal anti-TNF-α antibodies were proofed for inhibitory effects of TNF-α mediated activation of HUVECs. Results We have shown, in vitro, that beads coated with polyclonal or monoclonal anti-TNF-α antibodies were able to significantly reduce monocyte adhesion. It was possible to decrease monocyte adhesion from nearly 9% to 3% within 2 hours and from 18% to 2% within 6 hours of TNF-α treatment by the simultaneous use of beads coated with polyclonal anti-TNF-α antibodies. Beads coated with monoclonal anti-TNF-α antibodies could even prevent monocyte adhesion within the first 2 hours, and reduced monocyte adhesion to 2% during 6 hours of incubation with TNF-α. On the other hand, application of therapeutic anti-TNF-α antibodies showed no significant difference compared to the measured monocyte adhesion values of activated endothelial cells. Conclusion Adsorption techniques using specific adsorbents, possibly used in MDS (Microspheres-Based Detoxification System), are efficient in specific reduction of TNF-α and pathophysiological consequences, since monocyte adhesion at activated HUVECs was shown to be reduced. (Int J Artif Organs 2006; 29: 1140–7)
Tribological Characterization of Surface-Treated Commercially Pure Titanium for Femoral Heads in Total Hip Replacement: A Feasibility Study
Authors: Cotogno G. , Holzwarth U. , Franchi M. , Rivetti S. , Chiesa R. 
Published: January 2018

Most noncemented total hip replacements combine a titanium alloy stem, a CoCrMo femoral head and an ultra-high molecular weight polyethylene (UHMWPE) acetabular cup. In spite of its nickel content of up to 1% and the resulting biocompatibility issues in some clinical situations, the higher cost and some difficulties in machining, CoCrMo alloy is preferred to titanium alloys thanks to its outstanding tribological properties, higher hardness and elastic modulus. Nowadays most of the heads of hip prostheses use CoCrMo as bearing material. The present study investigates the effect of various surface treatments and combinations of treatments, such as electrochemical oxidation (anodization), laser surface melting and barrel polishing, on the tribological properties of commercially pure grade 2 titanium. The aim of the study was to characterize surface treatments capable of improving the tribological properties of titanium surface to the same extent as CoCrMo. The tribological properties were characterized by multidirectional pin-on-flat screening wear tests, using UHMWPE pins as bearing surface. The experiments showed the possibility of improving the wear resistance of titanium to the degree of CoCrMo. Although further efforts will be required to optimize the treatments studied, the results are encouraging enough to warrant pursuing this direction of investigation.
Hemolysis Evaluation of Centrifugal Pumps Using Microcapsule Suspension
Authors: Ootaki Y. , Kamohara K. , Horvath D.J. , Massiello A. , Golding L.A.R. , Lukic B. , Weiss W.J. , Maruyama O. , Fukamachi K. 
Published: January 2018

Objectives Bovine and human blood has been widely used for in vitro hemolysis testing to evaluate centrifugal cardiac assist pumps. However, results from such tests are complicated by variations in the susceptibility of individual red blood cells to shear. The objective of this study was to evaluate the use of microcapsule suspension as an alternative to bovine or human blood for hemolysis testing. Methods Microcapsule suspensions of 100 μm maximal diameter (average 79.1 μm) with a polyurethane membrane were used. Each microcapsule contained a leuco dye, which was used to measure “hemolysis” in the suspension after exposure to mechanical stress. Six centrifugal pumps were used to measure and compare the hemolysis values of microcapsule suspensions, bovine blood and human blood. Results Correlations were significant between the hemolysis values measured using microcapsule suspensions and those using bovine blood (R = 0.965, p = 0.002) and human blood (R = 0.940, p = 0.005). Conclusions Microcapsule suspension can be successfully used instead of blood to compare the relative hemolytic performance of centrifugal blood pumps.
Digoxin Transport by Renal Proximal Tubule Cells is Enhanced by Adhesive Synthetic RGD Peptide
Authors: Ijima H. , Kuroda S. , Ono T. , Kawakami K. 
Published: January 2018

Introduction The dialyzer apparatus has been widely used as an artificial kidney in medical treatment. However, side effects such as amyloidosis have occurred during long-term treatment. Therefore, we focused on developing a hybrid artificial kidney with a filtration and reabsorption apparatus, but it was found that cells spread extensively and it is difficult to maintain a uniform monolayer with a regular cell shape on a collagen-coated substrate. The purpose of this study was to improve cell adhesion, uniform stable monolayer formation and active transport function by immobilization of arginine-glycine-aspartic acid (RGD) on the culture substratum. Materials and Methods Polycarbonate semipermeable membranes were coated with collagen, fibronectin, laminin and synthetic polypeptide, including RGD (Pronectin F). Cell adhesion and digoxin transport were estimated using a renal proximal tubule cell line that overexpressed the P-glycoprotein gene. Results and Discussion Under initial and confluent conditions, immobilized cell density in Pronectin F-coated wells was higher than that under other conditions. Transepithelial electrical resistance and digoxin transport activity on Pronectin F-coated membranes were the highest of all conditions. This might have been caused by uniform cell morphology and high cell density.
In Vitro Evaluation of an Axial Flow Pump: Mock-Pump Interaction and an Approach to Control
Authors: Camus J.M. , Campomar G. , D'Attellis C. , Silvestrini M. , Varela L. , De Forteza E. 
Published: January 2018

Continuous flow pump support has emerged as an alternative therapy in patients with congestive heart failure. For long-term applications, it is important to have a control system that changes the pump function according to the physiological conditions of the patient, thereby preventing risk situations. In the early stages of development, the evaluation of control algorithms for artificial blood pumps can be done in vitro using cardiovascular mock systems. A systemic cardiovascular mock loop was constructed and an axial flow pump was connected to it. The level of pump assistance was estimated using a pulsatility index (IPAo) obtained from the aortic pressure wave. An IPAo proportional-integral control system was implemented and its responses to peripheral resistance and systemic compliance changes were evaluated. IPAo is an indicator of the assistance level of a continuous flow pump operated at constant speed. The IPAo control algorithm responds by increasing the pump speed when peripheral resistance or systemic compliance is reduced. Control system operation around an IPAo fixed value provides a safety point for pump operation by maintaining aortic pressure pulsatility and avoiding ventricular suction. In vitro experimental results show that the IPAo can be taken into consideration in multiobjective control algorithm designs.
Continuous Hemofiltration dose Calculation in a Newborn Patient with Congenital Heart Disease and Preoperative Renal Failure
Authors: Ricci Z. , Polito A. , Giorni C. , Di Chiara L. , Ronco C. , Picardo S. 
Published: January 2018

Objective To report a case of a newborn patient with renal failure due to polycystic kidneys requiring renal replacement therapy, and total anomalous pulmonary venous return requiring major cardiosurgical intervention. Setting Pediatric cardiosurgery operatory room and pediatric cardiologic intensive care. Patient: A 6-day-old newborn child weighing 3.1 kg. Results Renal function (creatinine value and urine output) was monitored during the course of the operation and intraoperative renal replacement therapy was not initiated. Serum creatinine concentration decreased from 4.4 to 3 mg/dL at cardiopulmonary bypass (CPB) start and to 1.5 at the end of surgery: the creatinine decrease was provided by the dilutional effect of CPB priming and the infusion of fresh blood from transfusions together with an adequate filtration rate (800 m/L in about 120 minutes). After the operation, extracorporeal membrane oxygenation (ECMO) for ventricular dysfunction and continuous hemofiltration for anuria refractory to medical therapy were prescribed. The hemofiltration machine was set in parallel with the ECMO machine at a blood flow rate of 60 ml/min and a predilution replacement solution infusion of 600 ml/h (4.5 ml/min of creatinine clearance once adjusted on extracorporeal circuits; 3000 mL/m2 hemofiltration): after a single hemofiltration session lasting 96 hours, serum creatinine reached optimal steady state levels around 0.5 mg/dL on postoperative day 2 and 3. Conclusion Administration of intraoperative continuous hemofiltration is not mandatory in the case of a 3-kg newborn patient with established renal failure needing major cardiosurgery: hemodilution secondary to CPB, transfusion of hemoderivates, and optimal UF rate appear to be effective methods for achieving solute removal. If postoperative continuous hemofiltration is started, however, a “dialytic dose” of 4.5 ml/min allows an adequate creatinine clearance, quick achievement of a steady state of serum creatinine concentration and an eventual acceptable rate of inflammatory mediator removal.
A Pilot Randomized Controlled Crossover Study Comparing Regional Heparinization to Regional Citrate Anticoagulation for Continuous Venovenous Hemofiltration
Authors: Fealy N. , Baldwin I. , Johnstone M. , Egi M. , Bellomo R. 
Published: January 2018

Objective To evaluate the efficacy and safety of a regional heparinization and a regional citrate method of anticoagulation in CVVH. Design Randomized controlled cross-over study Subjects Ten critically ill patients with acute renal failure Setting ICU of tertiary hospital Intervention CVVH was performed with pre-filter fluid replacement at 2000ml/h and a blood flow rate of 150ml/min. Regional heparinization was by the administration of heparin pre-filter at 1500IU/h and protamine post-filter at 15mg/h. Regional citrate anticoagulation was by means of a citrate-based replacement fluid (14 mmol/L) administered pre-dilution. Results We studied nine males and one female. The mean age and APACHE II score were 70.5 and 17 respectively. Median circuit life was 13 hours (IQR 9.28) for the regional heparinization method compared to 17 hours (IQR 12,19.5) for the regional citrate method (p=0.77). There were no episodes of bleeding in either group. Conclusion Regional heparinization and regional citrate anticoagulation achieve similar circuit life in critically ill patients receiving CVVH.
A New Method to Evaluate Patient Characteristic Response to Ultrafiltration during Hemodialysis
Authors: Casagrande G. , Teatini U. , Romei Longhena G. , Miglietta F. , Fumero R. , Costantino M.L. 
Published: January 2018

Background. Several factors are involved in the pathogenesis of dialysis discomfort interfering with optimal fluid removal and reducing the efficacy of the treatment; the most important one is a decrease in blood volume caused by an imbalance between ultrafiltration (UF) and plasma refilling (PR) rates. Objectives. This study is aimed at devising a method to tailor the dialysis therapy to each individual patient, by analyzing the relationship between PR and UF during the sessions in stable patients and widening the knowledge of fluid exchanges during the treatment. Methods. Thirty stable patients undergoing maintenance hemodialysis were enrolled. Three dialysis sessions were monitored for each patient; systemic pressure, blood composition, blood volume % variation, weight loss and conductivity were recorded repeatedly. A Plasma Refilling Index (PRI), defined and calculated by means of parameters measured throughout the dialysis, was introduced as a novel instrument to study plasma refilling phenomena. Results. The PRI provides understanding of patient response (in terms of plasma refilling) to the set UF. In the monitored sessions, the PRI trend is found to be characteristic of each patient; a PRI course that is at variance with the characteristic trend is a signal of inadequate or unusual dialysis scheduling. Moreover, statistical analysis highlights two different PRI trends during the first hour and during the rest of the treatment, suggesting the presence of different treatment phases. Conclusion. The main advantage of the PRI index is that it is non-invasive peculiar to each patient and easy to compute in a dialysis routine based on online data recorded by the monitor. A deviation from the characteristic trend may be a warning for the clinician. The analysis of the PRI trend also suggests how to modulate UF as a function of interstitial to intravascular fluid removal balance during dialysis.
The use of Peritoneal Mesothelium as a Potential Source of Adult Stem Cells
Authors: Gotloib L. , Gotloib L.C. , Khrizman V. 
Published: January 2018

At the dawn of the 21st century, classical curative medicine is being challenged by the fact that efforts to fight and prevent not a few diseases, are in many circumstances, beyond the power of the pharmacological armamentarium of the medical profession. On the other hand, replacement of lost function by mechanical or biophysical devices, or even by organ transplantation, prolongs life but generally derives in new and, at times, unsolvable problems. Regenerative therapy using stem cells began a revolutionary trend that may well change both the therapeutic approach to not a few of the diseases resulting from failing organs, as well as the fate and quality of life of millions of patients. The presence of pluripotent mesenchymal cells in the mesothelial monolayer as well as in the submesothelial connective tissue raises the possibility of using the peritoneal mesothelium in regenerative therapies. This perception of the problem is also based on observations made in humans as well as in laboratory animals showing bone, bone marrow, cartilaginous tissue, glomerular-like structures and creation of blood conducts, pathological situations (mesothelioma, sclerosing peritonitis), or after in vivo or ex vivo experimental interventions. The main concept emerging from this information is that peritoneal mesothelial cells are endowed with such a degree of plasticity that, if placed in the appropriate micro-environment, they have a remarkable potential to generate other mesenchymal-derived cell lines. Intensive research is required to define the best environmental conditions to take advantage of this plasticity and make the peritoneal mesothelium an actual option to be applied in regenerative medicine.
Effect of Two-Hour Daily Hemodialysis and Sham Dialysis on Breath Isoprene Exhalation
Authors: Capodicasa E. , Brunori F. , De Medio G.E. , Pelli M. A. , Vecchi L. , Buoncristiani U. 
Published: January 2018

Background Isoprene, a volatile hydrocarbon produced by the human organism, is currently being extensively investigated because the mechanisms underlying its endogenous origin are unknown and because experiments suggest it is toxic and cancerogenous. Previous reports of increases in breath isoprene concentrations during 4-hour, thrice-weekly hemodialysis, but not during continuous ambulatorial peritoneal dialysis, prompted us to assess the behavior of isoprene in another dialytic modality, i.e., short daily hemodialysis (short DHD). Furthermore, in order to determine whether removal of solutes and/or contact of blood with the dialytic membrane influenced the metabolism of isoprene, we performed a sham short hemodialysis session in a subgroup of 8 patients (sham short HD), i.e., with blood flowing through a dialyzer but without dialysate and ultrafiltration. Methods The present study evaluates the effects of a two-hour short DHD and a two-hour session of sham HD on isoprene breath levels, as determined by gas chromatography before, during and after sessions. Parallel analyses of ambient air and monitoring of blood pressure and heart rate were performed. Results Both short DHD and sham DHD induced an increase in breath isoprene exhalation in all patients without being associated with significant hemodynamic variations. Conclusion These findings suggest that the increase in breath isoprene after a session of hemodialysis is neither a reaction to mevalonate depletion nor to metabolic variations induced by the depurative effect, because these changes do not occur during sham HD. It is not related to hemodynamic changes because none were observed in this experimental model. The isoprene increase seems to be of metabolic origin and appears to be connected in some way with the extracorporeal circuit. These interesting findings provide a further impulse to study the biosynthetic pathways involved and to investigate the medical and biological significance of isoprene in humans. (Int J Artif Organs 2007; 30: 583–8)