bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and Test of a Hands-Free Tracheostoma Valve to Improve the Rehabilitation Process after Laryngectomy
Authors: Verkerke G.J. , Veenstra A. , Schutte H.K. , Herrmann I.F. , Rakhorst G.
Published: March 2018

The surgical treatment of throat cancer often requires total laryngectomy. The necessary tracheostoma attracts attention, especially during speech, when one must close it manually to force air into the esophagus. To avoid this manual control, several devices have been developed. These must be placed in or around the tracheostoma and possess a valve which closes with a large air flow value. Most devices have a major drawback; coughing calls for manual adaptation, which again attracts attention. A new hands-free tracheostoma valve has been developed. The device consists of two magnetic valves, one which closes the outflow to allow speech, and one which opens to cough. Prototypes were tested in a physical model. Air flow resistance and closing pressures of the speech valve proved to be comparable to those of existing devices. Patients were enthusiastic about the new approach, even though air leakage sometimes occurred.
Amyloid Bone Disease and Highly Permeable Synthetic Membranes
Authors: Boccalatte M. , Pratesi G. , Calabrese G. , Bignazzi A. , Gonella M.
Published: March 2018

The effect of different highly permeable membranes on amyloid bone disease (ABD) was retrospectively evaluated in patients on renal replacement therapy (RRT) in our Unit with a dialytic age of more than 4 years. A group of 36 patients (age 60 ± 12 years) after a variable period (28 ± 29 months) on hemodialysis with cuprophane membrane (CU-HD), were moved to HDF with a reinfusate volume of 22 ± 1 1/session, for a period of 65 ± 26 months using the following membranes: AN69 1.6 m2, PAN 1.8, PMMA 2.1, PS 1.3, polyamide (PA) 1.3 and 1.6. Bone x-rays of wrists, hips and shoulders were taken annually and the presence of ABD was evaluated according to generally accepted criteria. ABD occurred in 4 patients after a period of 73 ± 30 months on CU-HD only; it developed in 4/7 patients an AN69, in 4/6 on PAN, in 3/5 on PMMA, in 3/5 on PS; no patient of the 13 on PA developed ABD. Comparing patients on PA with those on other synthetic membranes, no significant difference was found in dialysis time (73 ± 19 vs 83 ± 28 months) as well as in age (59 ± 13 vs 61 ± 11 years) at ABD on set, when present. These data strongly encourage prospective studies enrolling more patients for a longer period of observation in order to evaluate possible differences on ABD development among various synthetic membranes.
Prevention of Hypovolemia-Induced Hypotension during Hemodialysis by Means of an Optical Reflection Method
Authors: De Vries J.P.P.M. , Donker A.J.M. , De Vries P.M.J.M.
Published: March 2018

In this study protocol we evaluate the clinical value of the continuous monitoring of blood volume (BV) during hemodialysis (HD) by means of an optical reflection method. In the course of a dialysis session the ratio between the ultrafiltration (UF) rate and the patient's refill capacity determines the extent of decrease of BV. A steep fall of BV and, moreover, a remaining absolute BV too low, cause the greater part of hemodialysis-induced complaints. During 23 standard HD sessions BV was monitored by means of the optical method. Nine of the sessions were complicated by hypotension (group H). Comparison of the mean BV graphs of group H with the graphs of non-complicated sessions (non-H) produces several differences. Most important is the fact that BV is better preserved in group non-H, a difference which is already significant during the first ninety minutes of dialysis. By making use of the shape of the monitored BV graph an HD patient, in that way, might be recognized as hypotension-prone during the first third of a dialysis session. To prevent the occurrence of hypovolemia-induced hypotension two strategies can be followed. First, the decrease of BV of a patient prone to hypotension can be triggered to the mean BV decrease according to the BV graph of the non-H group. This can be achieved by interventional methods, e.g. temporary lowering of the UF rate. However, for this intervention the development of a closed-loop circuit is required. Another possibility is to measure a patient's maximal refill capacity each hour of hemodialysis by taking advantage of the displayed BV graph. When the UF rate during ensuing sessions is kept in rate with the measured maximum values the occurrence of hypovolemia-induced hypotension will be minimized.
Tissue Regenerating Capacity of Carbodiimide-Crosslinked Dermal Sheep Collagen during Repair of the Abdominal Wall
Authors: Van Wachem P.B. , Van Luyn M.J.A. , Damink L.H.H. Olde , Dijkstra P.J. , Feijen J. , Nieuwenhuis P.
Published: March 2018

In future, the function of collagen-based biomaterials as temporary scaffolds for the generation of new tissue may be emphasized. In this study the function of dermal sheep collagen (DSC) crosslinked with carbodiimide (ENDSC) as repair material for abdominal wall defects in rats was compared with that of commercial hexamethylenediisocyanate-crosslinked HDSC. The results indicate that early after implantation both ENDSC and HDSC functioned well as a matrix for cellular ingrowth. However during further implantation HDSC soon degraded resulting in herniations, while ENDSC showed a delay in the degradation time of at least 20 weeks. ENDSC thereby enabled collagen new-formation and functioned as a guidance for muscle overgrowth. These results are very promising concerning the problem of the ongoing foreign body reaction with continuing risk of implant rejection observed in clinical practice with non-degradable materials.
Incidence, Possible Causes and Social Aspects of the Symptomatic Introduction of Disinfectant into the Peritoneal Cavity in CAPD
Authors: De Vecchi A. , Scalamogna A. , Castelnovo C. , Artuso K. , Brancadoro A.
Published: March 2018

The frequency and characteristics of episodes of accidental symptomatic introduction of Amuchina in CAPD patients has been retrospectively analyzed in patients treated with three different CAPD systems with disinfectant (two reusable Y set and one disposable Y set). The rate of accidental introduction of Amuchina was 1 episode every 8981 exchanges (1/8620 with the log Baxter Y set, 1/11060 exchanges with the short Baxter Y set and with the Bieffe L3 system). One to 15 fresh dialysis exchanges were required to relief pain due to the introduction of disinfectant. Four patients were hospitalized and one had a long lasting impairment in peritoneal ultrafiltration. There were no significant correlations between the episodes and age, sex or time when the exchange was performed.
Dynamic Pumping Characteristics of the Hemopump®
Authors: Kunst E.E. , Van Alsté J.A. , Arts T. , Boom H.B.K.
Published: March 2018

While pumping blood with the Hemopump® in sheep, the ability of predicting the instantaneous pump flow from the pressure difference over the pump system and pump parameters was investigated. For rotational speed n between 300 and 475 revolutions per second (rps), maximum pump flow QO(n) at zero pressure difference, internal pump resistance R(n), and inertia parameter Lc were found to be suitable parameters for Hemopump® characterization. The instantaneous pump flow could be estimated with an accuracy of approximately 1.0 [ml/s]. The values of the pump source parameters (± sd) were: (the figures in parentheses represent earlier reported values found while pumping water) Lc was a constant of 21.4 ± 6.4 [Pa·s2/ml] (in water: 10.8). QO(n) is linearly related to rotational speed n according to: QO(n) = Qo(ncen) + CQ(n - ncen), with QO(ncen) = 49.4 ± 4.5 [ml/s] (in water: 60.3), CQ = 142 ± 22.4 [10−3 ml] (in water: 146), and ncen = 387.5 [rps]. R(n) is linearly related to rotational speed n according to: R(n) = R(ncen) + CR(n - ncen), with R(ncen) = 556 ± 124 [Pa·s/ml] (in water: 502) and CR = 1.47 ± 0.83 [Pa·s2/ml] (in water: 1.67).
Evaluation of Phospholipidic Surface Coatings ex-vivo
Authors: Von Seg Esser L.K. , Tönz M. , Leskosek B. , Turina M.
Published: March 2018

To evaluate the thromboresistant properties of phospholipidic surface coatings mimicking the lipid surface of blood cells, we studied four different types of phospholipids bound onto PVC tubings in comparison to uncoated as well as heparin bonded controls. The samples analyzed included diacetylenic phospholipid coated as a monomeric treatment (A), diacetylenic phospholipid polymerised prior to being coated (B), and two types of polymeric phospholipids made using methacrylate containing monomers (C and D). A bovine (bodyweight 67 ± 3 kg) left heart bypass model (pump flow 3.2 ±0.1 l/min) was selected and the surfaces were exposed to the blood stream up to 360 min without systemic heparinization. Thereafter another set of samples was exposed to stagnant blood over 20 min. Besides hemodynamic, hematologic and biochemical analyses, the macroscopic appearance of 119 blood exposed surface samples was graded semiquantitatively on a scale of 0 to 10: no macroscopic deposits = grade 0, 1 spot (1 mm diameter) = grade 1, 2 spots = grade 2, 5 or more spots = grade 5, up to 10% of the surface covered with clots = grade 6, 100% covered = grade 10 (p<0.05=∗): mean grade of deposits was 0.0 ± 0.0 for segments perfused and 0.0 ± 0.0 for segments exposed to stagnant blood with surfaces exposing to the blood either heparin, phopholipid A, or phospholipid B (NS). Phospholipids C and D were graded 0.0 ± 0.0 if perfused and 0.7 ± 1.2 if exposed to stagnant blood. Uncoated PVC control tubings however were graded 0.2 ± 0.8 for segments perfused and 2.7 ± 3.0 for segments exposed to stagnat blood (p<0.05 in comparison to all surfaces coated with phospholipids or heparin if perfused and if exposed to stagnant blood). Hence phospholipidic surface coatings expose significant antithrombotic properties which out perform todays standard for tubings in clinical perfusion (uncoated PVC).
Mechanisms of Acid-Base Homeostasis in Acetate and Bicarbonate Dialysis, Lactate Hemofiltration and Hemodiafiltration
Authors: Panichi V. , Parrini M. , Bianchi A.M. , Andreini B. , Cirami C. , Finato V. , Palla R.
Published: March 2018

The different mechanisms of acidosis buffering were investigated in 15 RDT patients dialyzed in cross-over with four depurative techniques: acetate dialysis (AD), bicarbonate dialysis (BD), lactate hemofiltration (LHF) and hemodiafiltration (HDF) with acetate bath and lactate reinfusion fluid. Blood pH, bicarbonate, blood gases, intraerythrocytic pH — on red cell hemolisates — anion gap, L-lactate, pyruvate, adenosinmonophosphate (ADP) and 2-3 Diphosphoglycerate (2-3 DPG) levels were evaluated. During AD the intradialytic buffering is initially achieved by the CO2 fall and later by the acetate metabolism and an important bicarbonate shift from the intra to the extracellular space. A physiological compensation is obtained during BD with bicarbonate administration and a mild ventilatory response to the pCO2 increase. In LHF the massive lactate administration, with plasma levels of 7 mmol/l, strongly alters the Central Nervous System elettroneutrality inducing a hyperventilatory response with a purely pulmonary acidosis buffering. Furthermore the lactate/pyruvate ratio rose as high as 40:1 with ADP increase and cellular energy depletion. In HDF several different mechanisms are associated: the CO2 fixation, the acetate muscular metabolism, the intra-extracellular bicarbonate shift with the pulmonary response driven by lactate Central Nervous System penetration.
Complement Activation in Dialysis: Effects on Cytokines, Lymphocyte Activation and β2 Microglobulin
Authors: Gardinali M. , Calcagno A. , Conciato L. , Agostoni A. , Rosti A. , Cori P. , Vozzo N. , Moroni A. , Anelli A. , Zoni U. , Del Prete M.
Published: March 2018

Anaphylatoxins generated by complement activation by filter membranes are present in plasma during hemodialysis (HD). In the presence of endotoxins which may contaminate the dialysate, they can trigger monocytes to produce interleukin-1 (IL-1) and tumor necrosis factor (TNF), with detrimental effects for the patients. We have investigated whether or not the use of complement activating (cuprophan) and non- (or less-) activating membranes (polysulfone, polymethylmethacrylate or polyacrylonitrile) per se influences cytokine levels in HD patients. Our results indicate that if a sterile bicarbonate solution is used as dialysate, there are no significant increases in IL-1, TNF, interleukin-2 (IL-2) and soluble IL-2 receptors (sIL-2r) throughout HD, even with cuprophan membranes. Moreover even a prolonged use of this membrane (three months) did not change pre-dialysis levels of cytokines and receptors. Use of complement activating membranes also does not influence β2 microglobulin levels.
Dialysate Calcium Loss Using a Calcium Free Dialysate
Authors: Kaye M.
Published: March 2018

Using a dialysate that contained no calcium, we studied the amount of calcium lost and the clearances of urea, creatinine, phosphate and calcium in fifteen different dialyzers at blood flow/min (QB) of 200 and 300. Five of these dialyzers, covering the functional range of the fifteen, were also tested at QB of 100, 150 and 400. The collection period was divided into the first twenty minutes and the remaining 220 minutes. Clearance was calculated using the initial twenty minutes and for all dialyzers the creatinine, phosphate and calcium clearances were linearly related to the measured urea clearnce, r = 0.946, 0.810 and 0.808 respectively. Calcium recovered in the dialysate varied, depending on the dialyzer and QB, however the amount found plateaued at QB 200 and did not increase further, unlike creatinine, phosphate and urea. Total dialysate calcium loss for a four-hour dialysis averaged 49.9 mmol (range 42.2 -63) or almost 2g of elemental calcium for QB of 200 ml/min and 48.9 mmol (range 31.1 -65.5) or 1.95 g of elemental calcium for a QB of 300 ml/min. Decreasing the calcium infusion replacement rate did not decrease the calcium dialysate loss in equal amounts as the blood to dialysate gradient falls leading to a smaller than expected dialysate loss. Measured urea clearance in these fifteen dialyzers was approximately 20% less than specified by the manufacturer and almost 30% less for creatinine and phosphate. This difference is probably due to in vivo measurements with blood whereas most of the specifications are obtained using saline in vitro. The data given provide a basis for calcium replacement when using a calcium free dialysis and a variety of dialyzers and blood flow rates.
Determinants of Drug Removal by Continuous Hemofiltration
Authors: Lau A.H. , Kronfol N.O.
Published: March 2018

Continuous hemofiltration was conducted in vitro to identify parameters that affect drug transport across hemofilter membranes. The removal of seven drugs with different molecular weights and protein binding characteristics was assessed. Sieving coefficients were determined with both blood and saline using polysulfone, polyacrylonitrile and polyamide membranes. Drug sieving coefficients obtained with saline were generally higher than those obtained with blood. Molecular weights of the drugs did not correlate with the magnitude of drug sieving. Sieving coefficients in blood were also predicted from saline data assuming plasma protein binding is responsible for the reduced drug sieving with blood. For drugs that are highly protein bound, protein binding was the primary factor limiting drug sieving. Presence of plasma proteins also had a modest effect on sieving of other drugs. The sieving coefficients obtained with the polyacrylonitrile membrane tend to be different from those obtained with the other hemofilters. Drug-membrane interaction may contribute to the differences in drug transport among the membranes.
Cellulose-Ester as Membrane Materials for Hemodialysis
Authors: Diamantoglou M. , Lemke H.D. , Vienken J.
Published: March 2018

The majority of dialysis membranes are fabricated from regenerated unmodified cellulose. This standard type of cellulosic membrane is frequently under attack because of its alleged lack of biocompatibility. Recent developments, however, have proven that a chemical modification of the reactive surface groups of regenerated cellulose, the hydroxylgroups, limits the complement-activating potential of these materials and thus improves its blood-compatibility. We extended the idea of modifying cellulose for improved blood-compatibility to a series of different cellulose esters. Special focus was directed towards the question whether a variation of the type of substituent and degree of substitution could influence the blood-compatibility pattern of these materials: the analysis of blood-compatibility profiles showed a direct dependency on the type of substituent and the degree of substitution (DS). As an example, it was found that the DS, necessary for a complete reduction of complement activation, decreases with increasing chain lengths of aliphatic substituents. Optimal degrees of substitution are characteristic of the type of substituents and enable us to tailor materials specifically for optimized blood compatibility.
Biomechanical Tissue Properties as an Indicator of Organ Vitality Prior to Transplantations
Authors: Shtengold E. , Godin E. , Affeld K.
Published: March 2018

An organ's vitality prior to transplatation can be evaluated by analysis of its mechanical properties. A new apparatus was designed to measure these properties. The organ to be tested is placed in a reservoir with saline and submitted to the load of a cylindrical element. The load is applied in a stepwise mode and results in a small local deformation of the organ. This deformation is identical to the displacement of the cylinder and is measured as a function of time. This is compared to a theoretical analysis of the deformation of a viscoelastic halfspace. This theory was used to interpret the results of experiments which were carried out on eight rabbit kidneys. The instantaneous modulus of elasticity reaches a maximum within 15 minutes, then decreases and reaches a steady state after 30 minutes of warm ischemia. The method is easy to apply and appears to be useful for the quantification of an organ's vitality and in particular recognizes the level of the organ's edema before transplantation
Effects of dietary therapy on post renal transplant hyperlipidemia. A prospective study
Authors: Lal S.M. , Trivedi H.S. , Van Stone J.C. , Ross G.
Published: March 2018

Hyperlipidemia often occurs after renal transplantation and may contribute to increased cardiovascular morbidity. The National cholesterol education program guidelines (NCEP) recommend dietary modification as the initial therapeutic intervention. We evaluated the effects of the AHA Step I and Step II diets on the serum total cholesterol (TC) and the triglyceride (TG) levels in nondiabetic renal transplant patients. Both the AHA Step I (TC 296 ± 7 vs 294 ± 9 mg/dL, p = ns) and Step II diets (TC 282 ± 8 vs 292 ± 16 mg/dL, p = ns) failed to significantly lower the serum total cholesterol and the triglycerides levels. During this dietary intervention, the patients' body weight and serum creatinine level remained stable. Our data suggest that neither the AHA Step 1 nor the Step II diet are effective in significantly lowering elevated serum lipids in nondiabetic renal transplant recipients.
Well being in patients on CAPD and hemodialysis
Authors: De Vecchi A.F. , Scalamogna A. , Colombini M. , Cesana B. , Cancarini G.C. , Catizone L. , Cocchi R. , Lupo A. , Viglino G. , Salomone M. , Segoloni G.P. , Giangrande A.
Published: March 2018

In the present multicenter study, 120 pts who had been treated by both hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) for at least 6 months each, were invited to answer questions on 34 matters, to compare symptoms and their well-being while on the two treatments. Patients were invited to choose HD or CAPD and indicate the reasons for their choice. For 28 patients the first treatment was HD and for 92 CAPD. The mean time between the change of therapy and the study was 46±35 months. Their final choices were found to be strictly related to the present treatment (p<0.001). The reasons for choice of CAPD were: more free time (21%), more freedom (67%), better well being (44%), less worry (5%); for HD they were: more free time (53%), better well-being (39%), less worry (13%), no need for a peritoneal catheter and fewer clinical complications (19%). The catheter was considered more cumbersome than the A.V. fistula, the time involved was considered to be shorter on HD by 52 patients and on CAPD by 39, thirst and cramps were considered to be more frequent and severe on CAPD by half of the patients. The prevalence and severity of problems and symptoms and choice of treatment were not related to sex, job, education or age.
Production of interleukin 1 receptor antagonist and interleukin 1 during haemodialysis with cellulose membranes
Authors: Frith S.E. , Hoenich N.A. , Redfern C.P.F. , Goodship T.H.J.
Published: March 2018

An in vivo cross-over study has investigated plasma and cellular levels of IL-1 (IL-1α IL-1β and IL-1Ra) when using Cuprophan (C) and cellulose triacetate (CTA) membranes to assess the roles of complement activation and dialysate endotoxin content in the induction of cytokines during the dialysis procedure. The mean C5a level during Cuprophan dialysis was 29.9 ± 0.63 ng/ml (Mean ± SEM), while for the cellulose triacetate dialysis was 3.09 ± 0.7 ng/ml. The endotoxin content of the dialysate was 0.31 ± 0.34 EU/ml and 0.68 ± 1.39 EU/ml. These two factors failed to produce measurable changes in plasma or cellular IL-1α and IL-1β levels during treatment. The plasma IL-1Ra levels pre-dialysis were similar to those for normal controls (CTA 769 ± 156 ng/ml, C739 ± 93, normal controls 635 ± 33) with a considerable day to day variation. A membrane independent fall in plasma IL-1Ra at 15 minutes was noted (CTA 420 ± 92 ng/ml, C 503 ± 139) with a return to pre-dialysis levels by the end of treament. Cellular IL-1Ra levels pre-dialysis were similar to the normal group - (CTA 1904 ± 291 ng/ml, C 1564 ± 292 and normal control 1971 ± 368). However, on average, the values when using cellulose triacetate were 655 ± 623 pg/ml higher than for Cuprophan (p=0.03). These findings indicate that the measurement of plasma cytokine levels is of limited use in the study of cytokine induction by the haemodialysis procedure and that IL-1Ra may be a better indicator of the host response to cytokine stimuli during treatment. However, a considerable inter-patient and intra-treatment variation is present and further studies are required to elucidate the factors involved.
Mechanical ventricular support using pulsatile Abiomed BVS 5000 and centrifugal Biomedicus-pump in postcardiotomy shock
Authors: Minami K. , Posival H. , El-Bynayosy A. , Körner M.M. , Schrofel H. , Murray E. , Körfer R.
Published: March 2018

Since we started using ventricular assist devices (VAD) in July 1987 up to August 1993, 63 of 15,650 (0.4%) patients (pts) who underwent open heart sugery were supported postoperatively by VAD at out institution. Forty-three were male and 20 female, mean age 55.5 years. In 49 pts coronary artery bypass grafting (CABG), in 8 pts valve surgery, in 3 pts combined CABG and valve surgery and in 3 pts corrective procedures for congenital heart disease were performed. Perioperative myocardial infarction was the most frequent indication (73%). In 37 of the 63 pts (58.7%) a centrifugal (Biomedicus pump (group A) was used and in 26 pts (41.3%) a pulsatile Abiomed BVS 5000 (group B). Fourteen of 37 pts (38%) in group A were weaned from the VAD and all of them were discharged. Twenty-three pts were unable to be weaned and 19 of these pts died. The remaining 4 pts were transplanted successfully and subsequently 3 died and 1 was discharged. In all, 15 pts (39%) were long-term survivors. Sixteen of 26 pts (62%) in group B were weaned from VAD and 13 (50%) of them were discharged of whom 3 died. Ten patients were unable to be weaned and 7 of these died. The remaining 3 pts were transplanted successfully. In all, 16 pts (61.5%) were long-term survivors. The shorter the interval between beginning resuscitation and application of VAD the better the outcome. Younger age, VAD installation in OR, support time between 2 and 7 days and Abiomed pump, influence the survival rate positively. Because of higher recovery and survival rates in patients assisted by Abiomed compared to the Biomedicus pump, we recommend the Abiomed pump in postcardiotomy cardiac failure.
Spontaneous fracture of the outlet catheter of a totally implanted catheter system (Port-A-Cath)
Authors: Myint H. , McGregor J. , Edwards R. , Lucie N.P.
Published: March 2018

A case of spontaneous fracture of the outlet catheter of a totally implanted catheter system (Port-A-Cath) is presented. The outlet catheter was fractured at the entrance into the left subclavian vein twenty-one weeks after insertion and the distal part was embolized in the right ventricle. The embolized catheter fragment was retrieved by a ‘goose-neck’ snare via the right femoral vein. The awareness of a possible spontaneous fracture of the outlet catheter of a totally implanted catheter system (Port-A-Cath) is important to prevent accidental spillage of potent cytotoxic substances.
α-Keto acid metabolism by hepatocytes cultured in a hybrid liver support bioreactor
Authors: Fuchs M. , Gerlach J. , Unger J. , Encke J. , Smith M. , Neuhaus P. , Nündel M. , Riedel E.
Published: March 2018

Isolated pig liver cells cultured using a perfusion technique were analyzed over 39 days to test their ability to change the perfusate α-keto acid profile. While the pyruvate concentration in the culture medium decreased as of the first day, the α-ketoglutarate (KG), α-ketoisocaproate (KIC), α-ketoisovalerate (KIV) and α-ketoβ-methyl-n-valerate (KMV) were synthesized immediately and released by the liver cells. The metabolic capacity of the cell culture system increased up to day 10, decreased during the following 5 days and reached a steady state beyond day 15, which was maintained for at least 30 days. The branched chain α-keto acid release, in particular α-ketoisocaproate, reflects an effective transamination capacity of the newly developed culture system and shows an intact protein biosynthesis for at least 30 days in vitro.
Reduction of EDA (+) fibronectin and its clinical importance on cryofiltration
Authors: Kawamura A. , Yonekawa M. , Takahashi M. , Meguro J. , Yanagida N. , Kurauchi N. , Ikeda A. , Kukita K. , Sakashita E.
Published: March 2018

Cryofiltration (CRYO) removes cryogel, which is a combination of fibrinogen (Fbg) and fibronectin (FN), containing pathological substances. The purpose of this study was to measure cryogel EDA(+) FN and study the relationship between EDA(+) FN and clinical symptoms in patients with rheumatoid arthritis, SLE and polymyositis. Cryogel contains 51 times more EDA(+) FN than plasma. The patients with rheumatoid arthritis showed a high level of EDA(+) FN in their plasma, and the EDA(+) FN level in plasma corresponded with changes in joint pain. We calculated the clearance level at several points in cryofiltration, and the reduction enabled us to evaluate the CRYO device. The EDA(+) FN clearance was 23.3 ± 6.4 ml/min, the pFN clearance 16.5 ± 4.1 ml/min, and the Fbg clearance 22.9 ± 5.7 ml/min. As the plasma flow in cryofiltration was 30 ml/min, a clearance of EDA(+) FN and Fbg, approximately 23 ml/min, was obviously high. The study of the plasma level change of EDA(+) FN during cryofiltration revealed a temporary elevation. These results suggest that the EDA(+) FN was most efficiently reduced by cryofiltration, would become a good indicator on plasmapheresis, and might move from other tissues into the blood during cryofiltration.
Lithium Carbonate Decreases Ultrafiltration Rates in an Experimental Model of Pd
Authors: Lal S.M. , Moore H.L. , Groshong T.D. , Nolph K.D.
Published: March 2018

Animal studies have shown increased fluid absorption from the peritoneal cavity following intraperitoneal (ip) vasopressin. Lithium is known to antagonize vasopressin effects on fluid absorption in kidney distal nephrons. The aim of the present study was to see whether lithium-containing exchanges increase the ultrafiltration rates (UF) during peritoneal dialysis (PD) in rats. PD was carried out in 6 Sprague-Dawley rats with 1.5% dextrose-containing PD solution using 15-ml volumes. Each exchange (ex) took 1 min for inflow, 4 mins for outflow and 25 mins for dwell. All rats underwent 9 consecutive half-hourly exs. During exs 4-6 lithium carbonate 2.5 mM was added to the PD solution. During lithium-containing exs significant increases in the glucose absorption rates (3.9 ± 7.8 vs 37.5 ± 8.1 mg/ex; p=0.025) were associated with significnat reductions in the UF (3.03 ± 0.25 vs 1.78 ± 0.12 ml/ex; p=0.005). In conclusion, the isolated increase in glucose absorption without increases in the dialysate protein concentration with ip lithium, may suggest either a selective increase in size of the pores with a mean dimater near that of the glucose molecule or enhanced lymphatic absorption. ip lithium did not increase the UF in a rat model of PD.
Do Different Dialysis-Membranes Affect Beta 2-Microglobulin Kinetics during Chronic Hemodialysis?
Authors: Risler T. , Braun N. , Hanel K.D. , Kuhlmann U. , Skroch D. , Müller G.A.
Published: March 2018

Hemodialysis is not an absolute prerequisite for the formation of β2-microglobulin amyloidosis, but it enhances the progression of this complication related to long-standing renal failure. Thus the clearance and turnover of β2-microglobulin seems to play a major role in this disease. In a prospective multicenter study the β2-microglobulin clearance was studied in 87 patients starting hemodialysis. Serum samples were taken prior to and after the first dialysis session and also before and after dialysis at 4, 6, 12, 16, 26 and 52 weeks. Patients were either treated by cuprophane or a polyacrylonitril membrane. At the start, the mean serum β2-microglobulin level was about 18 mg/L in patients treated with a cuprophane membrane, but the levels increased after hemodialysis and reached a plateau, which was always higher than in those treated with polyacrylonitril, which cleared β2-microglobulin from the serum. However, after 12 months the difference was no longer significant. Thus β2-microglobulin excretion during dialysis differs between the two membranes, but seems to lose its significance for the β2-microglobulin serum level in chronic hemodialysis treatment.
Effect of hematocrit on dialyzer urea and creatinine clearance indices in a hemodialysis patient with erythrocytosis
Authors: Nwosu A.C. , Tzamaloukas A.H. , Malhotra D. , Saddler M.C. , Murata G.H.
Published: March 2018

The association between azotemic index dialyzer clearances and hematocrit was investigated in a 63-year-old dialysis-dependent man with acquired renal cysts. During 43 months of hemodialysis, hematocrit rose from 27.3 to 65.0 vol%, as a consequence of high serum erythropoietin levels. Concomitantly, dry weight also increased from 116.8 to 140.8 kg. Both hematocrit and dry weight correlated with: (a) urea reduction ratio, (b) creatinine reduction ratio (CRR), and (c) KT/V urea. All correlations were negative. Stepwise regression showed that only hematocrit was an independent correlate of the CRR (CRR = 0.662 - 007∗ Hct, R2 = 0.770); whereas, both hematocrit (Hct) and weight (W) were independent correlates of KT/V urea (KT/V = 2.070 - 0.005∗Hct - 0.009∗W, R2 = 0.721). In addition to creatinine clearance, urea clearance through the dialyzer is reduced by a rising hematocrit. The effect of hematocrit on urea clearance is relatively small. Therefore, it requires large changes in hematocrit in order to be detected
The Microspheres based Detoxification System (MDS): A new extracorporeal blood purification technology based on recirculated microspherical adsorbent particles
Authors: Weber C. , Rajnoch C. , Loth F. , Schima H. , Falkenhagen D.
Published: March 2018

Plasma sorption processes have so far been performed with filters and appropriate adsorption columns. In this paper, we introduce a newly developed plasma sorption system, which is based on the high adsorption capacity of microspheres in a recirculation system. The technology has been applied successfully in vitro to eliminate endotoxins, low density lipoproteins (LDL) and barbiturates from human plasma
Removal of antiacetylcholine receptor antibodies by protein-A immunoadsorption in myasthenia gravis
Authors: Berta E. , Confalonieri P. , Simoncini O. , Bernardi G. , Busnach G. , Mantegazza R. , Cornelio F. , Antozzi C.
Published: March 2018

Myasthenia Gravis is an autoimmune disease in which autoantibodies to the acetylcholine receptor interfere with neuromuscular transmission. Plasma exchange is effective in temporarily relieving the symptoms of the disease, but for repeated use the lack of selectivity and need for replacement fluids (which increases the risk of contracting viral diseases) are important drawbacks. Staphylococcal protein A, a potent ligand for immunoglobulins, that interacts negligibly with other plasma proteins, appears to be an optimal candidate for removing antiacetylcholine receptor antibodies, which are mostly IgG. We treated three patients with severe immunosuppression-resistant myasthenia gravis with protein A immunoadsorption. Neurological impairment significantly improved in all patients. After immunoadsorption of 1.5-2 plasma volumes per session, the mean percentage reductions for serum IgG and specific autoantibodies were 71% and 82% respectively. No major side effects occurred. Protein A immunoadsorption appears to be a safe, efficient and effective alternative to plasmaexchange for selected myasthenic patients requiring prolonged apheresis.
Fibroblast proliferation over dialysis membrane: an experimental model for “tissue” biocompatibility evaluation
Authors: Biagini G. , Stefoni S. , Solmi R. , Castaldini C. , Buttazzi R. , Rossetti A. , Belmonte M. Mattioli , Costa A. Nanni , Lannelli S. , Borgnino L.C. , De Sanctis L.
Published: March 2018

The present study reports on a biological model based on fibroblast proliferation applied to 3 different types of flat-plate dialysis membrane, in order to ascertain whether the artificial materials currently used in hemodialysis cause in vitro cellular proliferation. The study plan we followed involved plate membrane isolation from non-used dialyzers and used dialyzers, observed through scanning electron microscopy (SEM) both before and after testing with human fibroblasts by means of cell culture. Fibroblast growth was assessed by phase contrast light microscopy examination and cytometric DNA content evaluation. Our investigations proved that the artificial materials we considered interact with fibroblast cultures. Noticeable proliferative response was observed both after contact with unused material and on mediation by the protein layer absorbed on the membrane surface at the end of dialysis sessions. In this last case fibroblast proliferative activity appeared higher than that observed with unused membranes, showing that the soluble molecules entrapped in the protein layer appeared able to exert a biological activity even in in vitro tests
Hydrodynamic response of a VAD with a compliant cannula: results of in vitro tests
Authors: Antoranz J.C. , Del Cañizo J.F. , Desco M.M.
Published: March 2018

We report on comparative in vitro tests of two ventricular assist devices (VAD) one with a rigid input cannula and the other with a collapsible (compliant) inlet cannula. We show how this compliant cannula yields significant improvements in the hydrodynamic performance of the system.
Evaluation of the BioLogic-DT sorbent-suspension dialyser in patients with fulminant hepatic failure
Authors: Hughes R.D. , Pucknell A. , Routley D. , Langley P.G. , Wendon J.A. , Williams R.
Published: March 2018

The BioLogic-DT sorbent suspension dialyser was developed to remove toxic substances from the blood of patients with liver failure. In the present study a randomised controlled trial was carried out in 10 patients with fulminant hepatic failure who had developed grade 4 encephalopathy to evaluate the safety and biocompatibility of the dialyser in such severely ill patients. A total of 18 treatments were performed in 5 patients. Haemodynamic stability was maintained throughout. There was a significant loss of platelets (163 ± 34 to 101 ± 13 x 109/l) and decrease in plasma fibrinogen (0.53 ± 0.09 to 0.31 ± 0.08 g/l) with a rise in blood activated clotting time (190 ± 17 to 223 ± 22 sec) — not seen in the controls —, which was a result of the dialysis being carried out without the use of heparin as anticoagulant. Removal of metabolites by treatment was limited, with no significant effect on blood ammonia level and further developments of the system will be needed for this very sick group of patients.
Quantitative Estimation of Ideal Body Weight in Uremic Patients
Authors: Nagai T. , Kimura G. , Inoue T. , Nakamura S. , Inenaga T. , Kawano Y. , Matsuoka H. , Omae T.
Published: March 2018

There is no definite way to estimate the ideal body fluid level in uremic patients. We developed a simple method to quantitatively estimate the ideal body weight. Hemofiltration (HF) was performed 9 times in 5 uremic patients. Urea-nitrogen concentration was measured in plasma before and after HF and in total ultrafiltrate mixture. Creatinine concentration was measured in plasma after HF and before the next HF and in urine collected between those two HF therapies. Total body fluid volume, TBF, was obtained, based on urea kinetics principles, as 36.8 ± 1.8 L after HF, assuming that urea is distributed uniformly within total body fluid. Creatinine generation rate, Gcr, was calculated as the sum of urinary creatinine excretion rate, creatinine accumulation rate within body fluids and extra-renal creatinine excretion rate. It is known that solid mass, SM, is related to Gcr and that the TBF to lean body mass (=SM + TBF) ratio is constant under ideal fluid level conditions. Thus, TBF under ideal body fluid level conditions (37.8 ± 3.0 L), SM (13.7 ± 1.1 kg) and fat mass (3.7 ± 2.3 kg) were derived, and finally we found body weight value under ideal fluid level conditions to be 55.1 ± 4.2 kg. The ideal body weight estimated this way was found to be significantly correlated with the dry weight (54.0 ± 3.5 kg) determined clinically by conventional means (r=0.9; p<0.01); no significant difference was found between these body weight values. Our results suggest that the ideal body weight can be estimated simply by applying both urea and creatinine kinetics principles in uremic patients.
Long Term Effects of ACE Inhibitors on the Erythrocytosis in Renal Transplant Recipients
Authors: Lal S.M. , Trivedi H.S. , Ross G.
Published: March 2018

Erythrocytosis is infrequently seen in renal transplant recipients. Both theophylline and angiotensin converting enzyme (ACE) inhibitors have been reported to decrease the elevated hematocrit (Hct) and hemoglobin (Hgb) levels. We studied the efficacy of the ACE inhibitors ramipril (n=6) and enalapril (n=1) in seven stable renal transplant recipients. Although the ACE inhibitors significantly reduced the elevated Hct and Hgb levels during the short and long term (Hct 53 ± 1 vs 48.8 ± 0.7%; Hgb 17.8 ± 0.4 vs 16.7 ± 0.3 vs 16.7 ± 0.3 gm/dl, at 1 year), the clinical significance of these reductions remains unknown. During therapy there were no significant changes in the blood pressure, serum creatinine and potassium levels and the medications were well tolerated.
Chaotic Behavior of Hemodynamics with Ventricular Assist System
Authors: Yambe T. , Nanka S. , Sonobe T. , Naganuma S. , Kobayashi S. , Akiho H. , Kakinuma Y. , Mitsuoka M. , Chiba S. , Ohsawa N. , Haga Y. , Idutsu K. , Nitta S. , Fukuju T. , Miura M. , Uchida N. , Sato N. , Tabayashi K. , Tanaka A. , Yoshizumi N. , Abe K. , Takayasu M. , Takayasu H. , Yoshizawa M.
Published: March 2018

In order to analyze hemodynamic parameters during left ventricular assistance as an entity and not as decomposed parts, non-linear mathematical techniques were utilized. Pneumatically actuated ventricular assist systems (VAS) were implanted as left heart bypasses in acute animal experiments, using healthy adult mongrel dogs. By the use of the non-linear mathematical technique, the arterial blood pressure waveform (AP) was embedded into the four-dimensional phase space and projected into the three-dimensional phase space. The Lyapunov numerical method was used as an adjunct to the graphical analysis of the state space. The phase portrait of the attractor showed a complex structure; a three dimensional solid torus with a screw type structure as a part, suggesting deterministic chaos in the AP without left ventricular assistance. Positive lyapunov exponents confirmed the existence of chaos. During counterpulsation mode left ventricular assistance, the phase portrait of the attractor showed a more complex structure, and positive Lyapunov exponents suggested a greater dimensional deterministic chaos. However, non-structured patterns were seen in the phase space during internal mode VAS driving, suggesting the possibility of dissipative dynamics in the four dimensional phase space. These results suggest that the cardiovascular system with counterpulsation mode VAS driving is in a homeochaotic state, which is thought to be a flexible and intelligent control system. And there is greater dimensional complex dynamics in the circulatory regulatory system with VAD during internal mode assistance.
A Method for Obtaining Monodispersed Cells from Isolated Porcine Islets of Langerhans
Authors: Pueyo M.E. , Darquy S. , Arbet-Engels C. , Poitout V. , Dl Maria S. , Gangnerau M.N. , Reach G.
Published: March 2018

Micro or macroencapsulation of islets of Langerhans have been proposed as a bioartificial pancreas. Encapsulation of dispersed single cells instead of porcine islets should improve the oxygenation of encapsulated tissue. The aim of this work was, therefore, to develop techniques for dissociating porcine islets and test cell viability and function. After islet isolation and purification, islets were dispersed into single cells with collagenase and DNAse in either an extracellular type ionic solution or a UW solution. After culture, islets or cells were perfused with Krebs buffer. Two consecutive stimulations from 2.8 mM to 20 mM glucose were performed. Viability of cells (trypan blue) was higher than 85% after dispersion in ES or UW solutions. Islets or dispersed cells responded similarly to both stimulations with a return to basal rate between stimulations. No difference was found between cell function cultured during 18 hours or 6 days. However, islet function was improved by a long period of culture. In conclusion, this study demonstrates that dissociated cells performed as well as native islets up to six days culture.
Plasma Exchange in Patients with Acute Renal Failure in the Course of Multiorgan Failure
Authors: Stegmayr B.G. , Jakobson S. , Rydvall A. , Björsell-Östling E.
Published: March 2018

Multiorgan failure (MOF) due to intoxication, trauma or sepsis in the progressive late stages always include acute renal failure (ARF). The prognosis of these patients is poor despite adequate dialysis. This study included 27 consecutive patients (20 men and 7 women, age range 15–77 years) with a rapid progress of MOF including ARF, who were treated by plasma exchange as an attempt to reverse the progress of MOF. Twenty-three of the patients suffered from a septic shock. Oliguria or anuria was present in all, dialysis was performed in 16 of them and, mechanical respiratory aid in 17. Plasma exchange was performed 1–10 times and almost exclusively by centrifuge technique, using albumin and/or liquid stored plasma (in a few cases fresh frozen plasma) as colloidal replacement fluid. Twenty-two patients survived (81%) and 5 patients died. The reasons of death were cerebral haemorrhagia, brain abscess, myocardial sudden death, relapsing sepsis from multiple hepatic abscesses and a not drained psoas abscess. All survivors could leave hospital recovered from renal failure with few other sequelae. The plasma exchange technique is easy to perform despite low blood pressures by using a vein to vein access. Plasma exchange, therefore, may be tried to reverse late stages of multiorgan failure.
On Line Echocardiography in Evaluating Left Atrial Changes in Acute Mitral Regurgitation and in Monitoring a Catheter-Mounted Balloon for its Correction
Authors: Chrissos D.N. , Foussas S.G. , Pelekanos E.D. , Theocharis A.G. , Antonatos P.G. , Anthopoulos LP. , Moulopoulos S.D.
Published: March 2018

The purpose of this study was to evaluate changes in the left atrial size in acute mitral regurgitation (AMR) and monitor its correction by a catheter-mounted balloon (B). In 16 dogs, pressure changes in the left atrium (LA) were related to LA size and regurgitant mitral flow after the production of AMR by severing the mitral cusps. TEE was used for evaluating LA area (ALA) and the mitral regurgitation flow area (AMRF). TEE was also used in monitoring the position of a catheter-mounted B inserted through the LV apex and positioned on the mitral ring to relieve AMR. The B was inflated during systole and deflated during diastole. The ALA increased by 4.89 ± 1.21 cm2 (mean ± 1 SD) (p < 0.001) after AMR, the AMRF increased by 3.01 ± 0.85 cm2 (p < 0.001) and the mean atrial pressure (LAP) by 9.38 ± 2.43 mmHg (p < 0.001). In all experiments the position of the B could be confirmed in the 2D image and in 4 the reduction of AMRF by the function of the B was documented by the colour flow Doppler. It is concluded that after AMR the size of the LA increases along with the increase in LA pressure and a phasically inflated balloon and its effect on AMR can be easily identified and monitored by TEE.
Collagen and Fibronectin Immobilization on PHEMA Microcarriers for Hepatocyte Attachment
Authors: Denizli A. , Pişkin E. , Dixit V. , Arthur M. , Gitnick G.
Published: March 2018

Polyhydroxyethylmethacrylate (PHEMA) microcarriers in a size range of 150–250 μm were prepared by a suspension polymerization in an aqueous phase containing magnesium oxide. The hydroxyl groups on the PHEMA microcarriers were activated by cyanogen bromide. In order to improve cell attachment, cell-adhesive proteins, namely, collagen and fibronectin were immobilized onto PHEMA microcarriers. The nonspecific adsorption values for collagen and fibronectin were 0.10 mg collagen/g PHEMA and 0.044 mg fibronectin/g PHEMA, respectively. Collagen and fibronectin immobilization on PHEMA microcarriers were studied at different pH by using single protein solutions containing different amounts of proteins, at a constant temperature of 20° C. The maximum immobilizations were 0.85 mg collagen/g PHEMA (at pH: 9.5) and 0.52 mg fibronectin/g PHEMA (at pH: 7.4). Hepatocyte attachment onto these biologically modified PHEMA microcarriers was studied. Hydrophilic PHEMA microcarriers did not support cell attachment. High hepatocyte attachment yields (up to 75% surface coverage) were observed on collagen and fibronectin immobilized PHEMA microcarriers.