bluuebunny/crossref_metadata_2025 huggingface dataset:
Serum Sodium Concentration and Body Fluid Distribution during Interdialysis: Importance of Sodium to Fluid Intake Ratio in Hemodialysis Patients
Authors: Kimura G. , Gotch F.A.
Published: April 2018

Changes in the serum Na+ concentration and transcellular body fluid distribution during the interdialytic period were simulated as functions of body weight gain assuming that the effective extracellular osmolality consists only of sodium.

Our model shows that these changes are mainly determined by the relative ratio between sodium intake and weight gain in this period. If the sodium intake-to-net fluid intake ratio is equal to the postdialytic serum [Na+], neither changes in serum [Na+] nor transcellular fluid shifts occur.

When sodium intake is relatively greater than the net water intake, serum [Na+] is increased and transcellular fluid shifts will occur out of the cells. On the other hand, when the net water intake is relatively greater than the sodium intake, serum [Na+] is decreased and fluid is distributed to both the intracellular and extracellular compartments.

The combined application of our models for both the intradialytic interval described previously and the interdialytic interval described here is very useful in quantitatively analyzing the overall sodium and water metabolism in dialyzed patients.
Serum Phosphate Concentration with Relation to the Hematocrit Value in Uremic Patients on Chronic Hemodialysis
Authors: Gonella M. , Fanara G. , Buzzigoli G. , Bartolini V. , Mariani G.
Published: April 2018

The acute effects of hemodialysis on the serum inorganic phosphorus levels (sPi) with relation to the predialysis plasma volume (PV) and the hematocrit (Ht) values were studied in a group of chronic uremic patients on regular hemodialysis.

The results obtained confirmed the close direct correlation between predialysis sPi and fall in sPi induced by hemodialysis. Furthermore, the present fall in sPi induced by hemodialysis was found to be directly correlated to the PV values, and inversely to the HT values. An equation was derived from these data to predict in the individual patients the postdialysis sPi levels, utilizing both the predialysis sPi and the Ht values; this equation showed a better predictive capability than similar expression based on the use of the predialysis sPi value alone.
Granulocyte Transfusion Therapy
Authors: Sciorelli G.A. , Ravagnani F. , Pellegris G.
Published: April 2018

The Autors summarise their experience with the new “early granulocyte transfusion” scheme obtained in cancer patients. The data, based on three trials, clearly point out 1) the importance of early granulocyte transfusion as compared to the traditional one; 2) the efficacy of early granulocyte transfusion in pediatric age and among adult patients in those with good regenerating hemopoietic system.
Pneumocystis Carinii Pneumonia: A Lethal Complication of “Pulse” Methylprednisolone Therapy
Authors: Kozeny G.A. , Quinn J.P. , Bansal V.K. , Vertuno L.L. , Hano E.
Published: April 2018

A previously healthy, HIV-negative, 67-year-old man developed rapidly progressive glomerulonephritis. Following “pulse” methylprednisolone therapy he developed Pneumocystis carinii pneumonia. This complication should be recognized as a potential hazard of “pulse” steroid therapy.
Preserved Respiratory and Phagocytic Functions of Phagocytes Exposed to Flat Sheet Plasmapheresis Equipment
Authors: Jungi T.W. , Aeschbacher B. , Nydegger U.E.
Published: April 2018

Monocytes and polymorphonuclear leukocytes (PMN) were tested for functional integrity after exposure to flat sheet plasmapheresis equipment. Purified PMN were tested for chemiluminescence activity in response to a variety of triggers of the respiratory burst. Monocytes were assessed for their capacity to ingest erythrocytes sensitized with varying amounts of IgG antibodies. Both assays were demonstrated to be sensitive hallmarks of functional modulation. However, no functional differences were noted between phagocytes from blood collected prior to pheresis and those exposed to flat sheet plasmapheresis cylinders. These data suggest that plasmapheresis with the Au-topheresis C system does not influence the respiratory and phagocytic function of phagocytes returned back to the donor and implies that contact of phagocytes with artificial surfaces and/or their exposure to surface-activated plasma factors generated in the collection cylinder are minimal when using this plasmapheresis method.
An Elastic Force-Length Relation for Tympanic Membrane Implants - A Preliminary Report
Authors: Maes M.A. , Boedts D.A.
Published: April 2018

An elastic force-length relation has been recorded for tympanic membrane implants. A model based on the fibre structure of these materials was used to obtain a value for their elastic modulus for tympanic membrane.
Urea Determination in Dialysis, based on a Differential pH Technique
Authors: Bonucchi D. , Castellani A. , Orlandini G.C. , Ripamonti M. , Luzzana M. , Mosca A.
Published: April 2018

The application of a new technique, based on differential measurements of pH, to determine urea concentration in patients of a dialysis center, is reported. Urea in plasma, whole blood or dialysis fluids is measured by an enzymatic reaction, with urease; the procedure, requiring 10 μL of sample, is simple, fast and correlates well with a reference spectrophotometric method, in the 0-300 mg/dL concentration range, according to the equation y = 1.0291 x - 0.0777; r = 0.9991; n = 73.
Increase in P50 with the use of Bicarbonate Hemodialysis
Authors: Ramirez G. , Collice G.L. , James S. , Johns C.C. , Nelson W.P.
Published: April 2018

We studied the effect of bicarbonate and acetate on oxygenation during dialysis in ten male chronic dialysis patients. The dialysis delivery system and dialysate constituents were identical except for the use of either bicarbonate or acetate. We found no hemodynamic differences between the two kinds of dialysis. Blood PO2 fell by a similar amount, but blood PCO2 was higher during bicarbonate dialysis. The blood pH became alkalotic by the second hour of bicarbonate dialysis and remained so throughout the dialysis, whereas blood pH became alkalotic only at the end of acetate dialysis. The P50 increased significantly only during bicarbonate dialysis, but 2.3 DPG concentration did not change. Red cell volume, assessed by the mean corpuscular hemoglobin concentration, was unchanged. Without changes in the red cell volume we cannot explain the observed changes in P50 in the absence of concomitant changes in 2.3 DPG concentration.
Pulmonary Leukosequestration without Hypoxemia during Hemodialysis
Authors: Ross E.A. , Tashkin D. , Chenoweth D. , Webber M.M. , Nissenson A.R.
Published: April 2018

Dialysis-associated hypoxemia is frequently of clinically significant magnitude and is incompletely understood. In order to investigate the hypoxemia directly we labelled a patient's white blood cells with 111Indium-oxine prior to hemodialysis with acetate or bicarbonate baths. Both dialysate buffers were associated with similar degrees of early peripheral neutropenia, complement activation and elevation of lactoferrin levels, with simultaneous lung localization of radionuclide activity. However, there was not widening of the alveolar to arterial oxygen gradient, or increased wasted ventilatory fraction during this early time period. Significant hypoxemia occurred later in the dialysis, was associated with a decreased respiratory exchange ratio and only occurred with the acetate dialysate buffer. Thus, initial pulmonary leukosequestration was documented but did not have an adverse impact on gas exchange. Hypoxemia during acetate dialysis occurred instead as a consequence of alveolar hypoventilation.
Ornithine Decarboxylase Activity and Polyamines level from red Cells Lysate of Uraemic Patients and Normal Healthy Subjects
Authors: Fiocchi O. , Stabellini G. , Caruso A. , Masotti M. , Squerzanti R. , D'Orazi D. , Farinelli A.
Published: April 2018

We studied the ornithine decarboxylase (ODC) activity and polyamines (PAs) content in the red cells lysate before and after haemodialysis of 15 uremic patients and 15 healthy subjects. ODC activity is significantly increased after haemodialysis but the PAs concentrations (particularly spermine and spermidine) do not increase. This could be because of a minimal loss of PAs surplus production. On the contrary the increase of ODC activity could be explained in several ways, e.g. by stimuli during haemodialysis (hypoxia of the first hour of treatment, decrease of plasmatic osmolarity and biological stimulation of the blood during its passage through the filter).
Oxygen free radicals in nephrology
Authors: Canavese C. , Stratta P. , Vercellone A.
Published: April 2018

For living creatures with an aerobic metabolism, the univalent reduction of oxygen can lead to formation within the cell of intermediate products with marked chemical instability and strong potential toxicity. These are the free radicals (FR) superoxide and hydroxyl, hydrogen peroxide and the singlet 1O2. Their toxicity is primarily expressed through the peroxidation of membrane lipids, resulting in mitochondrial, lysosomal and parietal damage. It is enhanced by the presence of metals in trace amounts. Imbalance between the production of FR and the availability of FR scavengers (superoxide dismutase, catalase, glutathione peroxidase, etc.) may underlie different human pathologies. FR have been thought to play a part in inflammation; the aging process, carcinomatous transformations, damage due to recirculation and autoimmune diseases. As far as the kidney is concerned, the intervention of FR has been demonstrated or can be postulated in various contexts in the light of what has been observed in other pathologies: immunological nephritis, toxic nephropathies, microthrombotic and microangiopathic processes, damage caused by post-ischemic reflow, and problems in the preservation and rejection of transplants. FR have also been incriminated in lung lesions following intradialytic leukostasis and some aspects of toxicity ascribable to uremia. Subject to the precautions imposed by the need for theoretical, experimental and clinical verification, FR biochemistry offers new keys to the interpretation of a variety of kidney pathologies and opens up new prospects for treatment, both through a better understanding of the mechanism of action of drugs already known and employed, and with regard to the practical possibility of using alternative or combined forms of therapy.
Heparin-associated Thrombocytopenia in Maintenance Hemodialysis Patients
Authors: Leehey D.J. , Kanak R.J. , Messmore H.L. , Nawab Z.M. , Popli S. , Ing T.S.
Published: April 2018

Thrombocytopenia associated with the presence of a heparin-dependent platelet aggregating factor developed in two patients after hemodialysis with heparin. It resolved in one patient after heparin was stopped; but persisted in the other during a two-week heparin-free period and intermittently thereafter. We suggest that when heparin causes thrombocytopenia in dialysis patients the heparin should be stopped whenever possible, but this may not be necessary in all patients.
Comparison of Four Different Short Dialysis Techniques
Authors: Ronco C. , Fabris A. , Chiaramonte S. , De Dominicis E. , Feriani M. , Brendolan A. , Bragantini L. , Milan M. , Dell'Aquila R. , La Greca G.
Published: April 2018

The goal of shortening dialysis treatment time has stimulated the development of new, highly efficient dialytic strategies. In this study the Authors compared four different short dialysis treatments in terms of efficiency, clinical tolerance, technological investment and costs: 1) Rapid bicarbonate dialysis with 1.5 sq.m. cuprophane membrane; 2) High flux biofiltration with 1.2 sq.m. AN69S hollow fiber membrane; 3) Hemodiafiltration with 1.2-1.9. sq.m. polysulphonic hollow fiber hemodiafilters, and 4) High flux hemodiafiltration with two serial hemodiafilters with AN69s membrane (total 2.4 sq.m.).

Hydraulic properties and solute clearances at different blood flows (300-500 ml/min) were tested for each technique. Once the optimal operative level was established three patients were treated with each technique for at least six months. Since BUN clearance averaged 310 ml/min, the treatment duration varied from 120 to 180 min/session with KT/V always higher than 1. The average protein catabolic rate was 0.9 g/kg/24h. Clinical tolerance was generally good, slightly better in treatments with a high convective component. Despite the greater efficiency of treatment No. 4, the technological requirements and costs are such that the others are currently more feasible and acceptable in clinical routine.

The study demonstrates that reduction of dialysis treatment time is possible in all centres in a selected population with adequate blood access. Treatment No. 1 can even be performed with standard equipment and cuprophan membranes, while bicarbonate in the dialysate is mandatory. The real limit to shortening treatment time seems to be related to the maximal rate of ultrafiltration achievable in the patient during dialysis.
Pyrazinamide and Rifampicin Regimens for Patients on Maintenance Dialysis
Authors: Woo J. , Leung A. , Chan K. , Lai K.N. , Teoh R.
Published: April 2018

We measured pyrazinamide and rifampicin plasma concentrations in five patients with pulmonary tuberculosis and end stage renal failure treated by haemodialysis or continuous ambulatory peritoneal dialysis. Using conventional daily doses of oral pyrazinamide and rifampicin, we found that the drugs were removed efficiently by both dialysis methods, so that plasma levels were sub-optimal for maximal bactericidal action. These findings suggest that in patients with tuberculosis on maintenance dialysis, treatment should be either with higher doses of these two drugs, or with additional replacement doses given after each dialysis. Further detailed pharmacokinetic studies on larger numbers of patients are indicated.
A Portable Pneumatic Driving Unit for a Left Ventricular Assist Device
Authors: Kabei N. , Shimemura E. , Sakurai Y. , Tsuchiya K.
Published: April 2018

The authors developed a portable air driving unit for an artificial heart. As the portable energy source of the driver, a commercially available Ni-Cd battery was used. A linear compressor was selected as a portable size compressor. To reduce the number of parts to be assembled, a new type of pneumatic system was employed. In this system, the pressure level was regulated by varying the output flow rate of the compressor instead of using a pressure regulator and large air reservoirs. A one-board microcomputer and pressure sensors were used to control the pressure level.

The total weight of the unit is 9.5 Kg. After assembling the components into the portable unit, a blood pump was connected to examine the output characteristics of the system. It was confirmed that the unit could drive the blood pump continuously for more than 2 hours under the following conditions: output flow rate of the blood pump = 5 L/min and output pressure — 100 mmHg.
Pharmacokinetics of Paracetamol, Diclofenac and Vidarabine during Plasma Exchange
Authors: Fauvelle F. , Leon A. , Niakate M.T. , Petitjean O. , Guillevin L
Published: April 2018

In order to establish guidelines for prescribing drugs in patients treated with plasma exchange (PE), we studied the pharmacokinetics of paracetamol (5 patients), diclofenac (4 patients) and vidarabine (3 patients) during one or several PE. Results were compared with those obtained without PE. Diclofenac and paracetamol were choosen because they presented different volume distribution and protein binding characteristics. Vidarabine was studied because we use it for the treatment of patients with polyarteritis nodosa related to hepatitis B virus.

Diclofenac (100 mg) and paracetamol (1000 mg) were given 1 hour before PE. Samples were obtained 60 and 30 min before PE, every 15 min during PE and hourly for 2 hours after the end of PE. Vidarabine was given in continuous infusion, 15 mg/kg/d during the first week of treatment and 7.5 mg/kg/d during subsequent weeks. Samples were obtained before PE, 3 times during PE and every 30 min for 4 hours after the end of PE. Paracetamol, diclofenac, vidarabine and hypoxanthine arabinoside were assayed by high performance liquid chromatography. During each PE 60 ml/kg were removed and replaced by albumin.

We found that 17% of diclofenac, 4.3% of paracetamol and 4.9% of vidarabine were removed during each session. Plasmapheresis clearance was 51% of plasma clearance for diclofenac, 15% for paracetamol and 10% for vidarabine.

Drugs which are mainly removed during PE are those which are bound to proteins with a small distribution volume. Those drugs, such as diclofenac, must be administered after the end of each PE session. Drugs which present a large distribution volume and low protein binding can be given before the session. Vidarabine can be administered during PE without loss of effectiveness due to drug removal.
Plasma Collection Using Nafamostat Mesilate and Dipyridamole as an Anticoagulant
Authors: Hiraishi M. , Yamazaki Z. , Ichikawa K. , Kanai F. , Idezuki Y. , Onishi K. , Takahama T. , Inoue N.
Published: April 2018

Nafamostat mesilate (FUT-175) is a strong protease inhibitor and is used as an anticoagulant in extracorporeal circulation. In the present study, we administered FUT and dipyridamole as anticoagulants during donor plasmapheresis, and the additional effect of dipyridamole was examined. In dogs weighing about 15 Kg, donor plasmapheresis was performed using a cellulose triacetate membrane plasmaseparator (PEX-15, Nipro), and 300 ml of filtrated plasma was obtained within 30 minutes. These dogs were divided into two groups, 50 mg/h of FUT alone was infused (group A, n=10), and the same dose of FUT and 25 mg/h of dipyridamole were infused (group B, n=5) during plasmapheresis. Changes of the coagulation system, blood cell counts and complement system were investigated. In clinical cases, an artificial liver support therapy using FUT as an anticoagulant was performed on 8 patients with acute liver failure, and blood compatibility was examined.

In dogs, RBC counts and hematocrits were almost stable, but WBC counts were decreased to about 70% of the previous value. Platelets counts were about 60% and 80% of the previous value, in group A and group B, respectively, at the end of the plasmapheresis (P<0.01). Clotting factor VIII was diminished to about 20% and 35% of the previous value in group A and B, respectively. In clinical cases, all patients received the plasma exchange combined with hemodialysis using FUT as an anticoagulant, and no distinct side effect was observed during plasma exchange.
15 Years of Experience with Renal Replacement Therapy in Patients Starting Therapy before Age 20
Authors: Rubin J. , Bower J.D. , Krueger R.
Published: April 2018

This study retrospectively evaluates the survival on renal replacement therapy among patients starting dialysis before their twentieth birthday. The cohort included all patients starting therapy from 1972 through August, 1987 at the University of Mississippi or Kidney Care, Inc. Fifty-five patients, median age 17 years, range 5-19 years, underwent 335 patient years of therapy. Nineteen initially received CAPD; 12 home hemodialysis, 2 were transplanted prior to dialysis, and the remaining 22 patients were entered into dialysis in a free standing facility. Thirty-one patients received a cadaveric transplant and four patients received a living related transplant. The median transplant survival was 1360 days. There were 10 patients on renal replacement therapy over 10 years and a survival plot projected a 70% survival at 10 years. Nine patients died. Three percent of the time on renal replacement therapy was spent hospitalized. Although the hospitalization rate is significant, the pediatric patient may be expected to have a long survival on renal replacement therapy.
The Effect of Hemodialysis on Whole Blood, Plasma and Erythrocyte Viscosity
Authors: Wink J. , Vaziri N.D. , Barker S. , Hyatt J. , Ritchie C.
Published: April 2018

The effect of hemodialysis (HD) on blood viscosity has not been adequately investigated. We studied blood viscosity during HD employing coneplate viscometry. Ten patients with end-stage renal disease were studied before and immediately after HD. To dissect the possible effects of HD on plasma and red blood cell (RBC) determinants, we measured whole blood, plasma, and reconstituted erythrocyte viscosities. The latter consisted of RBC's suspended in a buffered saline solution (pH = 7.4 units). In addition, serum, electrolytes and hematocrit (HCT) were measured. The results revealed a significant rise in whole blood viscosity after dialysis. Likewise, plasma viscosity rose considerably with dialysis. However, when the RBC's were reconstituted to a constant HCT, no significant difference was noted before and after HD. As expected, body weight, blood urea nitrogen (BUN) and creatinine concentrations fell while HCT and protein concentration rose with HD. A significant correlation was found between the observed rise in HCT, and dialysis-induced rise in whole blood viscosity. Likewise, the observed rises in plasma viscosity after dialysis significantly correlated with the rise in protein concentration. In addition, the change in whole blood and plasma viscosity values correlated with the degree of ultrafiltration (weight loss). In conclusion, whole blood and plasma viscosity rises with hemodialysis. The observed rise in viscosity is primarily due to hemoconcentration.
Beta-2-Microglobulin Adsorption and Release in-Vitro: Influence of Membrane Material, Osmolality and Heparin
Authors: Klinke B. , Röckel A. , Perschel W. , Abdelhamid S. , Fiegel P. , Walb D. , Meairs S.
Published: April 2018

We studied the effects of cuprammonium rayon (CR), polyacrylonitrile (PAN), polysulfone (PS), changes in osmolality, and heparin dosage on beta-2-microglobulin (b2M) handling in an in-vitro model that excluded convective transport and minimized diffusive transport. Both PAN and PS exhibited high adsorption capacity for b2M. Osmolality changes had no effect on b2M adsorption or release. CR membrane adsorption was minimal but increased slightly when higher heparin doses were used. In experiments with CR and high heparin doses (4 U/ml) b2M release occurred during the first 15 minutes of in-vitro dialysis, but this increase was inhibited by removing the leukocytes from the blood, indicating that b2M is released from leukocytes.
A Simplified Procedure to Compute Dialysis Time and Frequency by Means of Urea Kinetics
Authors: Ahrenholz P. , Falkenhagen D. , Klinkmann H.
Published: April 2018

A simplified urea model is presented based on the concept of the time-averaged deviation (TAD) of the blood urea concentration and the introduction of an effective urea generation rate. The increase in the interdialytic blood urea concentration Δc is specific for the individual patient and includes the urea generation rate, distribution volume and residual kidney clearance. By measuring Δc of the largest interdialytic interval of the week the treatment frequency and duration can be calculated. Even for larger residual clearances Kr ≤ 5 ml/min this calculated treatment time does not differ by more than 5 min from the result of the exact urea kinetics. In vivo estimation of the urea clearances versus blood flow for the dialyzer types used is necessary for the application of urea modelling in clinical practice.
Development of Smaller Artificial Ventricles and Valves Made by Vacuum Forming
Authors: Pantalos G.M. , Chaing B.Y. , Bishop D.N. , Perkins P.A. , Yu LS. , Jansen J. , Socha P.A. , Marks J.D. , Riebman J.B. , Burns G.L , Kolff W.J. , Hansen G. , Wildevuur W. , Wurzel D. , Brownstein L. , Kolff J.
Published: April 2018

Implantable prosthetic ventricles and trileaflet valves made by vacuum forming have been developed and implant tested. All components are made from Pellethane®. Recognizing the need for smaller as well as larger ventricles, designs with effective stroke volumes of 50, 85, 100 and 130 cc have been tested with several valve types. The pneumatically driven Utah ventricular assist device (UVAD) can be used as a total artificial heart (TAH) or ventricular assist device (VAD) by using the appropriate inflow and outflow adapters. In vitro durability testing has demonstrated ventricular lifetime beyond two years and valve lifetime to nearly one and one half years. The polymer valves have lower regurgitation than mechanical valves.

Animal implantation experience includes 21 TAH implants and 16 left ventricular assist device (LVAD) implantations. TAH survival ranges from 2 to 210 days. LVAD animals have lived up to 116 days before elective termination. The animal were healthy and grew normally. The devices exhibit a “Starling's Law” response. One TAH animal survived 72 days before successful explantation followed by transplantation. At autopsy, this animal had no renal infarcts. Hematology data has demonstrated the existence of little or no intravascular hemolysis (PF Hb < 5 mg%).

The “Philadelphia” version of the UVAD vacuum formed ventricles are small enough to be implanted without thrombus provoking connectors. Eight animals have received this TAH and survived up to 120 days. Vacuum forming offers a rapid and inexpensive way to produce reliable and effective total artificial hearts and valves for widespread, temporary clinical application in any size adult human.
Heat Dissipation through the Blood Contacting Surface of a Thermally Driven LVAS
Authors: Navarro R.R. , Kiraly R.J. , Harasaki H. , Nasu M. , Nosè Y.
Published: April 2018

A heat exchanger for a totally implantable heat driven LVAD is an essential element in overall system thermal management. The heat exchange is accomplished by supplying cooling water from a pusher-plate driven water pump to the engine and then to the heat exchanger on the pump housing. The temperature of the interface between the blood and pump surface is of critical importance for clinically acceptable operation of the system. Temperatures were measured by instrumenting a pump housing with thermocouples and an electric heater on a mock circulatory loop. Flows were varied from 1 to 8 l/min and heat input was 20 watts. At 1.0 l/min pump flow the maximum inner surface temperature rise is 4.5°C. In vitro tests were conducted to examine the effect of elevated temperature on platelete function. Both platelet aggregation and adhesion were reduced at elevated temperatures of 42 and 478C indicating a potential benefit of reduced thrombogenesis on the heated housing surface.
Hemoglobin Solutions Coupled with Polyethylene Glycol 1900: Preparation, Purification, Quality Control and Pharmacological Trials by Hemorrhagic Shock
Authors: Labrude P. , Mouelle P. , Menu P. , Vigneron C. , Dellacherie E. , Leonard M. , Tayots J.L.
Published: April 2018

The usefulness of hemoglobin solutions as oxygen transporters is limited by their high affinity for oxygen and rapid elimination from the circulation. Various chemical modifications of hemoglobin aimed at overcoming these two handicaps have been suggested. We have developed a conjugate of pyridoxylated human hemoglobin with monomethoxypolyoxyethylene 1900, whose preparation and properties are described. We present comparative results on short-term or definitive survival of Wistar rats which, during hemorrhagic shock due to the loss of 60 or 80% of their blood mass, were given a solution of native or modified hemoglobin, in some cases purified by ion-exchange chromatography to remove non-heme proteins, lipids, and some endotoxins. The more complex the treatment used to improve the properties and the purity of the hemoglobin solutions, the longer the animals survived. The loss of hemoglobin in the urine was greatly reduced after conjugation: after 20 h, less than 6% of the total infused.
The Effects of Hemodialysis with Different Membranes on Middle Molecules and Uremic Neuropathy
Authors: Djukanović L.J. D. , Mimić-Oka J. I. , Potić J. B.
Published: April 2018

Twenty-four hemodialysis patients, 14 with uremic neuropathy and 10 symptom-free, were studied over 12 months. Cuprophan and AN 69 membrane dialyzers were used in their treatment in order to investigate the influence of different membranes on plasma levels of middle molecular weight substances (MMS) and uremic neuropathy. Hemodialysis with the cuprophan membrane caused no significant changes in plasma MMS levels or in the neurological condition of patients. The effect of dialysis with AN 69 membrane depended on initial plasma MMS levels. Initially high plasma MMS levels decreased significantly and significant improvement of neuropathy was achieved. In neuropathic patients with plasma MMS levels similar to those of symptom-free patients, hemodialysis with AN 69 membrane had no effect. These results suggest that hemodialysis with MMS high-permeability membranes may be recommended for neuropathic patients with high plasma MMS levels.
The Effect of Colloid Osmotic Pressure on the Survival of Sheep following Cardiac Surgery
Authors: Barak J. , Einav S. , Tadmor A. , Vidne B. , Austen W.G.
Published: April 2018

The occurrence of late complications in implanted cardiac prosthetic valves has emphasized the need for the development of an animal model in which these complications are reproducible. Sheep constitute an excellent model for chronical and pathological studies of prosthetic devices. In our experience, survival of sheep following implantation of prosthetic valves is closely related to postoperative serum colloid osmotic pressure (C.O.P.). The normal range as measured in 28 healthy sheep was 16.67 ± 0.55 mm Hg. A protocol was developed to maintain the colloid hydrostatic pressure gradient (C.H.P.G.) as close as possible to the normal physiological range, and to delay the extubation until the C.O.P. was within this range, and the C.H.P.G. > 7mm Hg. Using the above protocol, a new tri-leaflet Polyurethane valve was inserted into eight, five to seven month old sheep in place of the mitral and tricuspidal valves. One hour after terminating the extacorporeal circuit, the C.O.P. was measured at 13.10 ± 0.96; but within five to six hours, it rose to 17.1 ± 1.1. During the same period, the C.H.P.G. increased from 3.02 ± 0.96 to 7.6 ± 0.50 mm Hg. The postoperative period was uneventful, and all animals survived. We have thus concluded that the routine measurement and monitoring of C.O.P. constitutes a guide of great clinical importance.
Radiological Features of Dialysis Amyloid Spondyloarthropathy
Authors: Fiocchi O. , Bedani P.L. , Orzincolo C. , Storari A. , Cavazzini P.L. , Malacarne F. , Farinelli A.
Published: April 2018

Nine patients undergoing regular dialytic treatment (RDT) for more than 60 months (mean 125± 33 months) showed clinical and radiological evidence of non-infective destructive spondyloarthropathy (DSA). The cervical spine was the skeletal segment most affected (100% of cases). Three patients were found also to be suffering from discal and bone alterations of the dorsal column, and in two other patients the vertebral bodies L4-L5 were changed. Typical radiological pictures showed a narrowing of intervertebral spaces with the destruction or sclerosis of adjacent subchondral bones, erosions of vertebral body plates and cavitations. CT studies of the altered spines confirmed discal lesions and osteolytic areas with bone condensation at each level. Ligamentous lesions resulting in severe disorders of spinal statics were discovered during autopsy of three patients. Histological study of disc and peridiscal ligaments indicated the presence of large amyloid deposits containing beta-2-microglobulin (B2-m). It is possible that the minor biocompatibility of the cuprophan membrane of dialyzers is the most significant factor responsible for the hyperproduction of B2-m and thus of the osteo-articular deposition of a new type of amyloidosis.
Parameters and Methods for Testing Artificial Heart Valves
Authors: Köhler J.C. , Tech J.G.
Published: April 2018

The report describes the development of heart valve test standards. The aim is comprehensive quality assurance by in vitro tests. The project includes three test fields: general basis, development and definition of test methods and test devices and comparative in vitro assessment of valves for the definition of minimum requirements. A preliminary list of test parameters and test steps has been defined: geometrical, flow, deformation, force, and conditioning parameters. A system of geometrical parameters has been developed for standardized aortic models. Geometrical parameters of 31 valves of six types and different sizes underline a close correlation between geometrical and hemodynamic parameters. The relative ostium cross-section Ae/AT increases with valve size and lies between 0.3 and 0.5. Two new measurement devices with quasi-steady flow are proposed as quick testers for leakage flow and pressure loss.
Velocity and Shear Stress Distribution Downstream of Mechanical Heart Valves in Pulsatile Flow
Authors: Giersiepen M. , Krause U. , Knott E. , Reul H. , Rau G.
Published: April 2018

Ten mechanical valves (TAD 27 mm): Starr-Edwards Silastic Ball, Björk-Shiley Standard, Björk-Shiley Concave-Convex, Björk-Shiley Monostrut, Hall-Kaster (Medtronic-Hall), OmniCarbon, Bicer Val, Sorin, Saint-Jude Medical and Hemex (Duromedics) are investigated in a comparative in vitro study. The velocity and turbulent shear stress profiles of the valves were determined by Laser Doppler anemometry in two different downstream axes within a model aortic root. Depending on the individual valve design, velocity peaks up to 1.5 m/s and turbulent shear stress peaks up to 150 N/m2 were measured during the systolic phase. These shear stress peaks mainly occurred in areas of flow separation and intense momentum exchange. Directly downstream of the valves (measuring axis 0.55.dAorta) turbulent shear stress peaks occurred at peak systole and during the deceleration phase, while in the second measuring axis (1.5.dAorta) turbulence levels were lower. Shear stress levels were high at the borders of the fluid jets. The results are discussed from a fluid-dynamic point of view.
Endothelial Cell Seeding on PTFE Vascular Prostheses Using a Standardized Seeding Technique
Authors: Gerlach J. , Kreusel K.-M. , Schauwecker H.H. , Bücherl E.S.
Published: April 2018

A standardized method was developed for seeding endothelial cells (EC) in tubular vascular grafts. A rotational cell seeding device for tubular prostheses is presented and parameters influencing the kinetics of cell adhesion (rotation speed, graft diameter, cell suspension level, inoculated cell number) are reported. Seeding EC in 14 mm ID PTFE vascular grafts with rotation rate of 10 rph gave an adhesion rate of 80% in a homogeneous monolayer.
Removal of Cephalosporins by Continuous Arteriovenous Ultrafiltration (CAVU) and Hemofiltration (CAVH)
Authors: Lau A.H. , Pyle K. , Kronfol N.O. , Libertin C.R.
Published: April 2018

Cephalosporins are used with increasing frequency for sepsis treatment in patients receiving CAVU and CAVH. The different cephalosporins share the same basic molecular structure, yet they exhibit varied extent of plasma protein binding. Different amounts of the antibiotics may be removed by the ultrafiltration procedure because of these variations of physicochemical properties. We evaluated the sieving of eight new cephalosporins across the hemofilter membrane using an in vitro model. Bovine blood was perfused through polysulfone membranes at blood and ultrafiltrate flow rates of 100 and 20 ml/min respectively. Arterial plasma, venous plasma and ultrafiltrate drug concentrations were used to determine sieving coefficients. The sieving coefficients correlated well with the ultrafiltrate-arterial plasma drug concentration ratio (r= 0.679 - 0.972) but poorly with the extent of protein binding. Factors other than protein binding may therefore affect the drug sieving. Based on the findings, it was predicted that 0.2 - 21.9% of the daily cephalosporin dose may be removed by the CAVU and CAVH treatment. The need to alter drug dosages depends on the techniques of the ultrafiltration and hemofiltration procedure, the kinetics of the cephalosporins in patients, the sensitivity of the pathogen and the nature of the infection.
Early Hematopoietic Reconstitution after Autologous Transplantation with Blood-Derived Stem Cells in a Patient with Advanced Lymphoma
Authors: Iacone A. , Dragani A. , Angelini A. , Accorsi P. , Fioritoni G. , D'Antonio D. , Torlontano G.
Published: April 2018

A 30-year-old man with advanced non-Hodgkin lymphoma underwent repeated leukaphereses for harvesting blood-derived hemopoietic stem cells. Collection was started 8-10 days after the end of L-VAMP therapy (3 cycles). Nine procedures were performed and a total of 65.4× 109 mononuclear cells (0.87× 109/Kg) were collected, processed, cryopreserved and stored in liquid nitrogen. The yields of CFU-GM, BFU-E and CFU-GEMM were respectively 964× 104 (12.4× 104/Kg), 249× 104 (3.2× 104/Kg) and 798× 104 (10.4× 104). The patient received a myeloablative regimen consisting of fractionated total body irradiation (1200 cGy) and cyclophosphamide (120 mg/kg) followed by infusion of his own thawed cells. Early trilineage hematopoietic recovery was first observed on day +8; 1× 109/l WBC were reached on day + 11, 0.5× 109/l PMN on day + 13 and 50× 109/l platelets on day + 11. Course was uneventful and the patient was discharged from hospital on day + 21. Eight months after transplant the patient is in continuous unmaintained complete remission with normal blood cell counts. This reports suggests that complete and sustained engraftment can be achieved with peripheral stem cells recruited after “soft” chemotherapy.
Implant of Autologous Mesothelial Cells in Animals and a Peritoneal Dialysis Patient
Authors: Di Paolo N. , Sacchi G. , Vanni L. , Corazzi S. , Pallini V. , Rossi P. , Gaggiotti E. , Buoncristiani U.
Published: April 2018

Success in culturing human and animal peritoneal mesothelial cells for the purpose of study, led us to determine whether these cells could be autoimplanted in animals and man during peritoneal dialysis in cases of acute and extensive loss of mesothelial surface area. Using an original biopsy technique, we were able to cultivate and characterize from the structural and caryological point of view, human and rabbit peritoneal mesothelial cells. Staphylococcal peritonitis was provoked in 12 rabbits with in-dwelling peritoneal catheters and after 4 days of antibiotic therapy, 6 of them were autoimplanted with cultured mesothelial cells. In the animals sacrificed on the third and sixth days, direct morphological observation and autoradiographic techniques showed that the transplanted cells had taken and revealed a different picture from that in the non-transplanted rabbits.

In a 56 year old female diabetic patient, upon insertion of the first peritoneal catheter, a specimen of mesothelial cells was cultured and then frozen. Seven months later after an episode of peritonitis from Candida which dictated removal of the peritoneal catheter, since there was a sufficient number of cultured mesothelial cells and the patient consented, the implant was performed. Peritoneal biopsy by laparoscopy three and six days later showed that the cells had taken. The purpose of the study was merely to show that autoimplant of mesothelium in man and animals is possible.
Factors Affecting β2-Microglobulin Plasma Concentration during Hemodialysis
Authors: Martin-Malo A. , Mallol J. , Castillo D. , Barrio V. , Burdiel L.G. , Perez R. , Aljama P.
Published: April 2018

We studied ten patients on hemodialysis (HD) treated in sequence with cuprophan (CU), ethylenevinylalcohol (EVAL), polyacrylonitrile (A-69) and polysulphone (PSP) membrane dialyzers. ß2-microglobulin (ß2m) was measured by radioimmunoassay in plasma and dialysate samples. Plasma concentrations were corrected for changes in extracellular volume (ECV). We also studied adsorption in vitro by incubating the above membranes with I-125-labelled ß2m. There were no changes in ß2m plasma concentration after HD with CU dialyzers, but a significant decrease was observed with the other membranes tested. Filtration of ß2m across the dialyzer was absent with CU and minimal with EVAL. However, large amounts were recovered from dialysate with the high-permeability dialyzers, AN-69 and PSP. In vitro studies showed that maximal adsorption capacity was obtained with AN-69 (73%) compared to 9% with CU, 4% with EVAL and 7% with PSP. In summary, ß2m clearance with PSP is achieved through greater removal of this protein by mass transport across the membrane. The mechanism by which ß2m is removed from blood during AN-69 dialysis seems to include both adsorption to and filtration by the membrane itself.
The Effect of Left Ventricular Assist Device (Lvad) on Cardiac Reserve in Dogs
Authors: Matsumoto T. , Mitamura Y. , Shimooka T. , Mikami T.
Published: April 2018

The effect of LVAD on the preservation of cardiac reserve against ischemic damage was studied using Sarnoff's ventricular function curve. An LVAD was implanted between the canine left atrium and the aorta. Left ventricular function was measured by changing the height of the reservoir connected to the left atrium. The left ventricular function curve (LVFC) was drawn by plotting left ventricular stroke work (LVSW) against left atrial pressure (LAP). The coronary artery was occluded under a pump-on (ON group) or pump-off (OFF group). After reperfusion, measurements were repeated and changes in the LVFC caused by ischemia were compared in both groups. The gradient of the LVFC was significantly reduced by ischemia (107± 15ml/beat 80± 14, n= 13) but not in the ON group. LVSW under normal preload did not significantly change in either group. This suggests that the LVAD preserved cardiac reserve against ischemic damage.
Tumor Necrosis Factor, Interleukin-1 and Beta 2-Microglobulin Levels in Chronic Hemodialysis Patients
Authors: Caruana R.J. , Lobel S.A. , Leffell M.S. , Campbell H. , Cheek P.L.
Published: April 2018

We measured tumor necrosis factor (TNFα), interleukin-1 (IL1-B), and beta-2 microglobulin (B2M) levels in 10 chronic hemodialysis patients before and during dialysis with six different dialysate/dialyzer combinations. The mean pre-dialysis serum level of B2M was 23.4 ± 11.1 mg/L (nl < 3 mg/L). There was no significant effect of hemodialysis with any dialysate/dialyzer combination on intradialytic serum B2M levels. Five patients had detectable pre-dialysis serum levels of TNFα (>40 pg/ml) at least once and 2 had detectable levels prior to all dialyses. Six patients had detectable pre-dialysis serum levels of IL1-B (>20 pg/ml) at least once, and 2 had detectable levels prior to all dialyses. Serum TNFα, IL1-B and B2M levels were not significantly correlated with one another. Our data do not support the hypothesis that blood-membrane interactions significantly affect circulating levels of TNFα, IL1-B or B2M. Chronic high level elevations of plasma IL1-B and TNFα are not uniformly observed in hemodialysis patients, arguing against a role for these substances as systemic uremic toxins.
Particle Release from Haemodialysers
Authors: Hoenich N.A. , Thompson J. , McCabe J. , Appleton D.R.
Published: April 2018

Release of particles from eight makes of hollow-fibre and one make of flatplate dialyser have been studied, and the relationship between rinsing volume and particles recovered established. In a supplementary study the effect on the number of particles released was assessed when striking the dialyser header during priming. Particle size distribution indicated that the majority of the particles recovered were less than 5 microns in diameter. A separate analysis of the particles in the 5-30 micron size range showed two different patterns of particle release. In the dialysers containing ethylene vinyl acetate (EVAL) or Cellulate® the number of particles recovered were within the 95% range of the particles in the rinsing fluid and did not alter with increasing rinsing volume. In the dialysers containing Cuprophan® and Hemophan® the initial particle numbers were higher but fell rapidly up to a 450 ml rinse volume; increasing the rinse volume to 1050 ml did not alter particle recovery. Analysis of variance failed to differentiate between individual dialysers. Striking the header during priming resulted in a transient statistically nonsignificant increase in the number of particles recovered.
Internal Jugular Vein Catheterization under Echographic Guidance
Authors: Cavatorta F. , Zollo A. , Campisi S. , Trabassi E. , De Lucia E. , Galli S. , Dolla D.
Published: April 2018

Having examined the various disadvantages of the catheterization of the central veins performed using the Seldinger technique, we report our results of internal jugular vein catheterization under echographic guidance in 38 uremic patients. The echographic guidance technique allows an easier and safer utilization of the internal jugular vein as vascular access in emergency situations.
Contact, Coagulation and Platelet Interaction with Heparin Treated Equipment during Heart Surgery
Authors: Van Der Kamp K.W.H.J. , Van Oeveren W.
Published: April 2018

Heparin coating of an extracorporeal device may reduce blood activation. To evaluate protein and platelet interaction with Duraflo II surface treatment of the cardiopulmonary bypass (CPB) circuit, thirty coronary artery bypass grafting patients were randomly divided into two groups (Duraflo II, n=15 or Control, n=15). Binding of antibodies against factor XII, antithrombin III (ATIII) and platelet receptor GpIb were significantly higher (p<0.01) on the Duraflo II treated surface. Hageman Factor fragment (HFf or factor XIIf)∗ activity observed in the fluid phase tended to be lower in the treated circuits, although complexes of factor XIIf-C1 inhibitor (C1INH) increased by the same extent in both groups. Thrombin was effectively bound on the Duraflo II surface while thrombin-antithrombin III formation was reduced during the first phase of CPB. As expected, this thrombin inhibiting capacity remained higher on the Duraflo II, although in the arterial line a reduction of 10% per hour was observed. This indicated loss of functional bound heparin of the Duraflo II surface. During the second phase of CPB, after release of the aortic crossclamp, factor XII and thrombin were strongly activated in both groups indicated by a sharp increase in concentrations of T/AT complex as well as FPA. Platelet numbers tended to increase more in the control group during CPB than in the Duraflo II group, likely by interaction of platelet Gplb receptors on the Duraflo II treated surface (p<0.01). However, platelet activation assessed by β-TG was similar in both groups of patients. It is concluded that Duraflo II treatment reduced intrinsic clotting activity during CPB by binding of factor XII and thrombin. In cardiac surgery this effect is attenuated after aortic crossclamp release by material-independent stimuli, but the heparin treatment remains functional for more than 3 hours.