bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimated versus Predicted Creatinine Generation as an Indicator of Compliance with the Prescribed Dose of Continuous Peritoneal Dialysis
Authors: Tzamaloukas A.H. , Braun M. , Malhotra D. , Murata G.H.
Published: March 2018

The expression (Estimated - Predicted)/Predicted creatinine generation {(E-P)IP} has been proposed as an index of compliance in continuous peritoneal dialysis (CPD). We attempted to define an (E-P)IP value that can be used as a cut-off for non-compliance and to characterize the relation of (E-P)IP to serum albumin. In 324 clearance studies, (E-P)/P had a normal distribution with a mean of +0.094 and an SD of 0.357. In these studies, there was a weak correlation between (E-P)/P and serum albumin (r=0.12, P<0.05), but (E-P)/P was not a predictor of serum albumin by logistic regression. In 34 CPD patients, who had an increase in the dose of CPD resulting in an increase in measured creatinine clearance from 43.8 ± 14.0 to 66.1 ± 17.6 L/1.73 m2 weekly (P<0.001), (E-P)/P increased correspondingly from +0.018 ± 0.284 to +0.153 ± 0.369 (P = 0.018), although all subjects should be in a steady state of creatinine excretion in the second study. The rise in (E-P)/P was statistically significant in the subgroup of 17 subjects who had a decrease in serum albumin, but not in the subgroup of 14 subjects who had an increase in serum albumin from the first to the second clearance study. The (E-P)/P cut-off for a definitive diagnosis of CPD non-compliance may be around +0.400 or +0.500. The findings of this study suggest that non-compliance, as indicated by (E-P)/P, has an adverse effect on serum albumin and that non-compliance increases after a prescribed increase in the dose of CPD.
A New Automatic Cardiac Output Control Algorithm for Moving Actuator Total Artificial Heart by Motor Current Waveform Analysis
Authors: Choi W.W. , Kim H.C. , Min B.G.
Published: March 2018

A new automatic cardiac output control algorithm for an implantable electromechanical total artificial heart (TAH) was developed based on the analysis of motor current waveform without using any transducer. The basic control requirements of an artificial heart can be described in terms of three features: preload sensitivity, afterload insensivity, and balanced ventricular output. In previous studies, transducers were used to acquire information on the hemodynamic states for automatic cardiac output control. However, such a control system has reliability problems with the sensors. We proposed a novel sensorless automatic cardiac output control algorithm (ACOCA) providing adequate cardiac output to the time-varying physiological demand without causing right atrial collapse, which is one of the critical problems in an active filling device. In vitro tests were performed on a mock circulatory system to assess the performance of the developed algorithm and the results show that the new algorithm satisfied the basic control requirements of the cardiac output response.
Effect of ELAD Liver Support on Plasma HGF and TGF–β1 in Acute Liver Failure
Authors: Miwa Y. , Ellis A.J. , Hughes R.D. , Langley P.G. , Wendon J.A. , Williams R.
Published: March 2018

The aim of this study was to investigate the effects of treatment with the extracorporeal liver assist device (ELAD) in patients with acute liver failure (ALF) on plasma hepatocyte growth factor (HGF), the most potent growth factor, and transforming growth factor-β1 (TGF-β1), an inhibitory factor for liver regeneration. Initial plasma HGF, measured by ELISA, was significantly increased in the ALF patients (7.86 ± SEM 1.76 ng/ml) compared with normal subjects (0.10 ± 0.02 ng/ml, p<0.001). After 6 hours of ELAD haemoperfusion, plasma HGF increased further (30.5 ± 6.19 ng/ml, p<0.001), with a subsequent decrease towards the initial value by 48 hours. Initial plasma levels of TGF-β1 determined by ELISA were significantly increased in the ALF patients (43.4 ± 5.9 ng/ml) compared with normal subjects (25.1 ± 2.3 ng/ml, p<0.01), but there was no change in plasma TGF-β1 during the study period in either the ELAD or control ALF group. As HGF is a heparin-binding growth factor and similar changes in HGF were observed during CVVHD, one possible explanation is that heparin administered as anticoagulant for extracorporeal circulation is involved in the effects observed on HGF.
Biocompatibility and Immunology in the Encapsulation of Islets of Langerhans (Bioartificial Pancreas)
Authors: Zekorn T.D.C. , Horcher A. , Mellert J. , Siebers U. , Altug T. , Emre A. , Hahn H-J. , Federlin K.
Published: March 2018

Successful transplantation of encapsulated islets (bioartificial pancreas) would circumvent problems of islet availability and rejection in the treatment of insulin-dependent diabetes with biological organ replacement. Alginates are widely used as a hydrogel matrix or membrane for immunoprotected transplantation. A major problem in the use of diffusion-based devices is the biocompatibility of the material used. The foreign body reaction after implantation of empty microcapsules into different compartments in rats, dogs and pigs is evaluated in this article. However, biocompatibility of the bioartificial pancreas has three different aspects: reaction of the entrapped islet to the encapsulation technique and material; reaction of the recipient against the incorporated device (= foreign body reaction); and finally the reaction of the recipient against the encapsulated islet (= immunology of bioartificial pancreas). It is obvious from different experiments that even if foreign body reactions (reactions against material) are almost abolished the recipient may react against material released from the encapsulated islet. In conclusion, transplantation of encapsulated islets induces various morphological reactions (i.e. inflammation and fibrosis) as a result of a variety of donor and recipient related factors. Therefore, the use of an adequate animal model that reflects the human situation is essential for progress in the development of a bioartificial pancreas.
Intracellular Glutathione in Human Peritoneal Mesothelial Cells Exposed in vitro to Dialysis Fluid
Authors: Breborowicz A. , Rodela H. , Martis L. , Oreopoulos D.G.
Published: March 2018

Effect of peritoneal dialysis fluids on glutathione (GSH/GSSG) level in human peritoneal mesothelial cells was tested in in vitro experiments. To mimic in vivo conditions, cells were initially exposed to dialysis fluids (Dianeal 1.36%, Dianeal 2.27%, Dianeal 3.86%) that subsequently were diluted with dialysate effluent at time intervals. GSH/GSSG concentration in cells initially decreased but returned to normal values thereafter. This decrease in the intracellular concentration of glutathione was less when pH of the tested dialysis fluid was adjusted to 7.3. In further experiments with mesothelial cells exposed to Earle's salts solution supplemented with glucose and/or lactate, we have shown that in the presence of low pH, lactate is the main factor causing depletion of intracellular glutathione. When added to the dialysis solution at a concentration of 0.1 mM, L-2-oxothiazolidine-4-carboxylate, a precursor of glutathione, not only prevents the initial decrease in glutathione concentration but also augments the final intracellular level of this thiol.
The Use of Liquid Perfluorocarbons for Neonatal Lung Ventilation
Authors: Costantino Mi.
Published: March 2018

Over the last years, physiological studies have proved that ventilation with a oxygenated liquid perfluorocarbon (PFC) provides effective gas exchange and acid base balance and improves lung function and recovery Low surface tension and high respiratory gas solubility enable adequate oxygenation and carbon dioxide removal at low insufflation pressure. The elimination of air-liquid interfacial surface tension has recently suggested the adoption of total liquid PFC ventilation as an investigational therapy for severe respiratory distress in human infants. This work is aimed to determine the optimal volumes of PFC to be delivered, the frequency of the ventilatory cycle, the oxygen flow rate and the best circuit set up for neonatal application. The optimisation was obtained through the implementation of a simulation mathematical model of oxygen diffusion in a PFC-ventilated lung and of gas exchange between alveolar environment and pulmonary blood flow. The results show that total liquid ventilation is a valid alternative to traditional gas ventilation, particularly when immature neonates with insufficient or absent production of surfactant are concerned.
Effect of Different Dialysis Membranes on Platelet Function. A Tool for Biocompatibility Evaluation
Authors: De Sanctis L.B. , Stefoni S. , Cianciolo G. , Colì L. , Buscaroli A. , Feliciangeli G. , Borgnino L.C. , Bonetti M. , Gregorini M.C. , De Giovanni P. , Buttazzi R.
Published: March 2018

Intradialytic coagulative and platelet activation, one of the main consequences of blood-membrane contact, was studied in a group of 5 RDT patients with a comparative evaluation of 3 different dialytic membranes: Cuprophan (CU), Polysulfone (PS) and Cellulose Triacetate (CT). Each patient underwent 5 consecutive dialysis sessions with the above mentioned membranes. Intradialytic platelet activation was studied through a morpho-functional evaluation between the mean platelet volume (MPV) and Serotonin (S), ß-Thromboglobulin (ß-TG) and Platelet Factor 4 (PF4) serum levels. These determinations were made before HD (time 0) and after 30', 120’ and 240'. We also checked the intradialytic status of thrombogenesis and fibrinolysis determining aPTT, thrombin time, fibrinogen, antithrombin III (AT III), α-2 antiplasmin and plasminogen, at the same time intervals. All membranes tested (CU, PS, CT) caused appreciable intradialytic platelet activation, above all after 15’ and at the end of dialysis sessions, more marked for CU than PS or CT. In particular MPV showed a decrease throughout the session (-5% at 30’ and -9% at 240') while S, ßTG and PF4 peripheral blood levels showed a significant increase at the same intervals with CU membrane. Lastly coagulative and fibrinolytic parameters showed no significant differences among any of the membranes tested.
Use of Continuous Blood Volume Monitoring to Detect Inadequately High Dry Weight
Authors: Lopot F. , Kotyk P. , Bláha J. , Forejt J.
Published: March 2018

A continuous blood volume monitoring (CBVM) device (Inline Diagnostics, Riverdale, USA) was used to study response to prescribed ultrafiltration during haemodialysis (HD) in 66 stabilised HD patients. Fifty percent of patients showed the expected linear decrease in BV right from the beginning of HD (group 1), 32% exhibited no decrease at all (group 2), while eighteen percent formed the transient group 3 which showed a plateau of varying length after which a decrease occurred. The correct setting of dry weight was verified through evaluation of the ratio of extracellular fluid volume to total body water (VEC/TBW) in 26 patients by means of whole body multifrequency impedometry MFI (Xitron Tech., San Diego, USA) and through measurement of the Vena Cava Inferior diameter (VCID) pre and post HD (in 6 and 5 patients from groups 1 and 3 and from group 2, respectively). The mean VEC/TBW in groups 1 and 3 was 0.56 pre and 0.51 post HD as compared to 0.583 and 0.551 in group 2. VCID decreased on average by 14.1% in groups 1 and 3 but remained stable in group 2. Both findings thus confirmed inadequately high estimation of dry weight. Since CBVM is extremely easy to perform it can be used as a method of choice in detecting inadequately high prescribed dry weight. The status of the cardiovascular system must always be considered before final judgement is made.
Stress Corrosion Cracking in Björk-Shiley Convexo-Concave Prosthetic Heart Valves Due to Random in vivo Electrochemical Pulsing
Authors: Xiao K. , Appleby A.J.
Published: March 2018

Welded downstream struts of Björk-Shiley Convexo-Concave heart valves show failure in vivo, but not in in vitro testing. A pyrolytic carbon pivoting disk occluder closes against a Haynes® 25 alloy ring, which is electrochemically machined from solid with the upstream retaining struts. The weld area is de-alloyed, with residual porosity and carbide inclusions. The valve becomes a short-circuited electrochemical cell when fully open or closed. It is in an aggressive chloride electrolyte, whose high pulsed flow (2 m/s) ensures that supply of oxygen-rich cathode reactant is not mass-transport-limited. During the flight of the occluder, the cell is randomly at open circuit. A random current pulse is applied to the metal parts on circuit closure. Failure is not from simple mechanical fatigue, but from stress-corrosion-cracking and erosion of the less noble weld area caused by these pulses. All welded valves of this type may be susceptible to ultimate in vivo failure.
Preliminary Experimental Study about the Feasibility of Combining Pulsatile Cardiopulmonary Support System and a Membrane Oxygenator
Authors: Nakazawa T. , Shiono M. , Inoue T. , Orime Y. , Shindo S. , Sezai Y.
Published: March 2018

A cardiopulmonary support (CPS) device that incorporated a pneumatic ventricular assist device (VAD) and a membrane oxygenator was developed for the support of patients with profound heart and/or respiratory failure. This device has an advantage of being both a pulsatile assist device and membrane oxygenator. A “triple flow” regulator was included in this system to control the blood flow through the oxygenator. The purpose of this study was to clarify the efficacy of this system in supporting an animal model with combined cardiac and respiratory failure. In vitro tests showed 3.7 L/min of pump flow under 1.6 L/min of oxygen supply to the oxygenator even though there was a 50% clamp of a “triple flow” regulator with sufficient pulsatility. In 14 acute canine experiments, cardiogenic shock and acute respiratory failure were introduced by coronary ligation and mechanical hypoventilation simultaneously. The pump flow was maintaned at 1.95 - 0.6 L/min (average 1.2 L/min) and the driving pressure of the pump was controlled between 200 and 300 mmHg positive pressure and -20 to -50 mmHg negative pressure. The driving rate was fixed at 100 bpm and systolic/diastolic ratio was controlled between 35-50%. The canines were divided into control group (n=4) and pumped group (drained from the right atrium n=7, drained from the left atrium n=3). By using CPS system, flow and aortic pressure recovered to the initial baseline level. Without this support, the canine model could not maintain systemic circulation. In the group drained from right atrium, central venous pressure decreased with the device from 13.9 ± 2.4 to 5.6 ± 1.4 cm H2O (p<0.01), returned to the initial level without this device (p<0.01). In the group drained from left atrium, pulmonary capillary wedge pressure decreased from 37.9 ± 4.6 to 20.8 ± 5.7 mmHg (p<0.01), and returned to the initial level without the device, arterial oxygen tension levels increased (p<0.01), and also arterial oxygen saturation levels recovered (p<0.01). The results suggest that the current model of the pulsatile CPS has a potential to support the animal model with combined cardiac and respiratory failure.
Comparisons of Porcine Hepatocyte Spheroids and Single Hepatocytes in the Non-Woven Fabric Bioartificial Liver Module
Authors: Naruse K. , Sakai Y. , Nagashima I. , Jiang G.X. , Suzuki M. , Muto T.
Published: March 2018

We previously developed a new bioreactor of the bioartificial liver composed of non-woven fabric. We have also experimented with hepatocyte spheroids, with the aim of improving the efficiency of this NWF bioreactor. In this study, we compared the efficiencies of NWF bioreactors employing hepatocyte spheroids versus single hepatocytes. Hepatocytes were isolated from a whole pig liver by Seglen's method. 1.0 × 1010 single hepatocytes were immobilized in the NWF bioreactor. Another 1.0 × 1010 hepatocytes were allowed to form spheroids by 24 hr suspension culture in a 4-L culture vessel, before being immobilized in the bioreactor. Hepatocyte spheroids were found to be functionally superior, on a per-cell basis, to single hepatocytes in the NWF bioreactor. However, the NWF bioreactor employing hepatocyte spheroids exhibited lower efficiency than that employing single hepatocytes, because the total number of the hepatocytes had decreased during the 24 hr suspension culture.
Stimulation of Interleukin-1 ß Production may be Involved in Unresponsiveness to Erythropoietin Therapy
Authors: Takemasa A. , Yorioka N. , Yamakido M.
Published: March 2018

Recombinant human erythropoietin (rHuEPO) can dramatically improve anemia in dialysis patients, but about 20% of patients show a poor response to this agent. It has been reported that cytokines, including interleukin (IL)-1ß, may inhibit the maturation of erythrocytes. To investigate the mechanisms of unresponsiveness to rHuEPO, we isolated peripheral blood mononuclear cells from 12 patients on continuous ambulatory peritoneal dialysis who were receiving maintenance rHuEPO therapy for renal anemia. Cells were cultured with rHuEPO and IL-1 ß production was assessed. In the six patients who did not respond to rHuEPO therapy, there was a marked increase in IL-1 ß during culture with rHuEPO. In contrast, the addition of rHuEPO to cultures of cells from the six responding patients caused little increase in IL-1 ß, and there was a significant difference between the two groups. Induction of IL-1 ß by rHuEPO may be one cause of persistent anemia in dialysis patients.
A Carrier-Mediated Transport of Toxins in a Hybrid Membrane. Safety Barrier between a Patients Blood and a Bioartificial Liver
Authors: Stange J. , Mitzner S.
Published: March 2018

Combination of detoxifying liver support systems with liver cell bioreactors may have additional benefits for the treatment of liver failure due to the replacement of known and unknown metabolic activities of the liver. However, the problem of side effects and possible risks caused by the use of animal hepatocytes or hepatoma cells remains unsolved which underlines the need of a safety barrier between the patients blood and the extracorporeal bioreactor. Passive filters do not meet the requirements of such membranes, because in liver failure desired and undesired molecules in the patients blood share similar physicochemical properties. That challanges the developement of biologically designed separation membranes. A hybrid membrane is formed by implementation of transport proteins into a highly permeable hollow fiber. The transport of free solutes and albumin bound toxins is tested in vitro in comparison with conventional high flux membranes. The transport characteristics for tightly albumin bound toxins are significantly improved for the hybrid membrane. The transport of albumin bound toxins across the membrane is not associated with albumin. The selectivity of the transport is evaluated in vivo. No significant loss of middle molecular weight hormones attached to other carrier proteins was observed. Neither transport of immunologically relevant proteins across the membrane nor loss of valuable proteins was measured. Also in vivo, a significant reduction of protein bound toxins and a transport of metabolically relevant solutes, like amino acids, was shown. The presented hybrid membrane may be used like an “intellegent membrane” as a safety barrier between the patients blood and cell devices.
Pathophysiological and histomorphological evaluation of polyacryloylmorpholine vs polyethylene glycol modified superoxide dismutase in a rat model of ischaemia/reperfusion injury
Authors: Rocca M. , Giavaresi G. , Caliceti P. , Veronese F.M. , Giardino R.
Published: March 2018

Twenty Wistar rats were divided into two groups. Both underwent acute ischaemia followed by reperfusion of the left hind limb. The first group was a control group while the second was treated with PAcM-SOD. The survival percentage of the limb after 10 days was 30% for the first group and 70% for the second. Neither linear regression nor correlation were found between groups as far as the survival percentage of the limb after 10 days and reperfusion pmO2 data were concerned. After ten days the histomorphological analysis was significant regarding the fibre diameter and the percentage of central located nuclei in the specimens of PAcM-SOD treated limbs compared to normal limbs, but not when compared to the muscular fibres of the control group. Comparing these results with others obtained with native SOD and monomethoxypoly (ethylene glycol) modified SOD (mPEG-SOD) used in the same experimental model, we can conclude that the clinical and morphological results were better using mPEG-SOD, and that PAcM-SOD does have a protective effect on ischaemic muscle damage, although it is not as effective as mPEG-SOD in preventing ischaemia/reperfusion injury.
Acquired Renal Cystic Disease and Tumor Markers in Chronic Hemodialysis Patients
Authors: Polenakovic M. , Sikole A. , Dzikova S. , Polenakovic B. , Gelev S.
Published: March 2018

Acquired renal cystic disease (ARCD) is a well documented complication of end-stage renal disease, and it has been related to the duration of dialysis therapy. The association of this condition with renal cell adenoma or carcinoma has already been established. There have also been studies on the concentration of some tumor markers in hemodialysis (HD) patients, clinically free from neoplastic disease, where it was concluded that some tumor markers could be elevated, despite the absence of malignant disease, suggesting their altered metabolism i.e. clearance by the hemodialysis membrane. We compared the pre-dialysis serum concentration of several tumor markers in three groups of chronic HD patients, all of whom had been on maintenance HD treatment for more than 5 years. Group 1 consisted of 16 patients without ARCD with a mean HD treatment duration of 97.06 ± 28.25 months. Group 2 consisted of 32 patients with a mean HD treatment of 105.62 ± 24.4 months, who had ARCD with less than 10 renal cysts detected by ultrasonography. Group 3 consisted of 14 patients with a mean HD duration of 109.92 ± 37.72 months, with ARCD and more than 10 renal cysts. Concentration of the following tumor markers was determined by EIA or ELISA methods: carcinoembryonic antigen (CEA), mucin-like carcinoma-associated antigen (MCA), neuron-specific enolase (NSE), carbohydrate antigen 19-9 (CA 19-9), prostatic specific antigen (PSA), carbohydrate antigen 125 (CA 125), alpha fetoprotein (AFP), cytokeratin 19-fragments 21-1 (CYFRA 21-1). The concentration of all the tumor markers was comparable in all three patient groups, with no statistically significant difference between groups. The mean concentrations of MCA, PSA, CA 125 and AFP were within the normal range. CEA and CYFRA 21-1 had mean values in the upper limit of their normal values, while NSE and CA 19-9 were increased by more than twofold in all three patient groups. We concluded that (i) tumor markers should be used with caution when diagnosing neoplastic diseases in chronic HD patients, because of their altered metabolism, and (ii) that in the follow up of ARCD with possible neoplastic alteration, imaging techniques remain dominant diagnostic tools.
Comparative Evaluation of Different Membranes for the Construction of an Artificial Liver Support System
Authors: Qiang S. , Yaoting Y. , Hongyin L. , Klinkmann H.
Published: March 2018

During the past decades, many technological improvements have been made in the construction of extracorporeal liver support systems. Among these achievements, membranes of artificial capillary system, used as substrates of hepatocyte growth, aroused our interest in their application for the construction of bioreactors. The present paper studied the comparison of hepatocyte growth and function on six different membranes. Four of them are cellulose based membranes, Cuprophan, Hemophan, Cellulose acetate, and Bioflux; two are synthetic polymer SPAN and Polysulphone. Human hepatoma cell line SMMC-7721, with moderately differentiated hepatocyte-specific functions, was inoculated into the hollow fiber cartridges. These cells were allowed to attach and to grow over these membranes. It was found that there existed differences in hepatocyte immobilization and growth among these membranes. They influenced the growth and functions of hepatoma cells in vitro to some extent. These results show that membrane is an important factor in the construction of capillary membrane bioreactors for artificial liver support.
Hemodialysis Associated Hypoxia Extends into the Post-Dialysis Period
Authors: Dhakal M.P. , Kallay M.C. , Talley T.E.
Published: March 2018

To investigate whether hypoxia extends into the post-hemodialysis period, nine clinically stable-end stage renal disease patients were dialyzed against bicarbonate and one against an acetate batch, all with bioincompatible dialyzers. None had clinical evidence of cardiopulmonary overload on the day of the study. Using an oximeter with internal memory, oxygen saturation was monitored continuously at the beginning, during, and for four hours after hemodialysis. Hypoxia was defined as oxygen saturation less than 85%. Three patients had no hypoxia during or after dialysis. Hypoxia occurred in five patients both during and after dialysis, and in two patients only in the post-dialysis period. Episodes of hypoxia were of longer duration and severity in post-dialysis period. We conclude that significant hypoxia can occur in the post-hemodialysis period.
A Comparison of the Dual Lumen and Coaxial Catheters for Temporary Hemodialysis Access
Authors: Walters G.K. , Jescovitch A.J. , Jones H.A. , Jones C.E.
Published: March 2018

Percutaneous central venous catheterization can provide reliable temporary hemodialysis access. The current study compared the hemodynamic performance of 28 coaxial catheters to 27 side by side catheters. A total of 675 dialysis sessions were evaluated to assess the flow characteristics of these two designs. The results demonstrated that the side by side catheter provided greater cumulative blood flow with more favorable venous and arterial pressures. Nevertheless, the coaxial catheter performed satisfactorily and met the minimum standards for these devices.
Case Report of a Patient with Bilateral Renal Cell Carcinoma Successfully Maintained on Continuous Ambulatory Peritoneal Dialysis after Bilateral Nephrectomy
Authors: Nishida Y. , Yorioka N. , Arita M. , Harada S. , Yano A. , Hiromoto N. , Yamakido M.
Published: March 2018

We report on a patient who developed bilateral renal cell carcinoma during continuous ambulatory peritoneal dialysis for chronic renal failure. He was successfully maintained on this type of dialysis after bilateral abdominal nephrectomy.
Multi-Purpose Mechanical Circulatory Device
Authors: Mussivand T.V. , Hendry P.J. , Masters R.G. , Keon W.J.
Published: March 2018

A mechanical circulatory assist device for long term use outside the hospital setting has been developed. The device can be used for left, right or bi-ventricular support, and several of the developed technologies are applicable for total artificial hearts and non-pulsatile flow systems. The totally implantable device is principally designed for left ventricular support with implantation in the left hemithorax. The system utilizes transcutaneous energy and information transfer sub-systems, and has no percutaneous connections. In vitro durability testing has been conducted for periods from 1-4 years. Bovine experiments have been conducted with sustained circulation for periods form 1.5 to 96 hours. The in vitro and in vivo evaluation to date has demonstrated that the system can function effectively as a totally implantable ventricular assist device. The transcutaneous energy and information transfer sub-systems provided the ability to power, monitor and control the device, without the need for percutaneous connections. Design optimization and chronic in vivo evaluation is planned
Non-Invasive Blood Glucose Monitoring by Means of near Infrared Spectroscopy: Methods for Improving the Reliability of the Calibration Models
Authors: Müller U.A. , Mertes B. , Fischbacher C. , Jageman K.U. , Danzer K.
Published: March 2018

The feasibility of using near infrared reflection spectroscopy for non-invasive blood glucose monitoring is discussed. Spectra were obtained using a diode-array spectrometer with a fiberoptic measuring head with a wavelength ranging from 800 nm to 1350 nm. Calibration was performed using partial least-squares regression and radial basis function networks. The results of different methods used to evaluate the quality of the recorded spectra in order to improve the reliability of the calibration models, are presented.
Biomaterials for Orthopedic Surgery in Osteoporotic Bone: A Comparative Study in Osteopenic Rats
Authors: Fini M. , Nicolialdini N. , Gandolfi M.G. , Mattiolibelmonte M. , Giavaresi G. , Zucchini C. , De Benedittis A. , Amati S. , Ravaguoli A. , Krayewski A. , Rocca M. , Guzzardella G-A. , Biagini G. , Giardino R.
Published: March 2018

To evaluate orthopedic devices in pathological bone, an experimental study was performed by implanting Titanium (Ti) and Hydroxyapatite (HA) rods in normal and osteopenic bone. Twenty-four rats were used: 12 were left intact (Control: C) while the other 12 were ovariectomized (OVX). After 4 months all the animals were submitted to the implant of Ti or HA in the left femoral condyle (Ti-C, HA-C, Ti-OVX, HA-OVX). Two months later the animals were sacrificed for histomorphometric, ultrastructural and microanalytic studies. Our results show a significant difference between the Affinity Index (A.I.) of HA-C and Ti-C (77.0 ± 7.4 vs 61.2 ± 9.7) (p < 0.05). No significant differences were observed between the osteointegration of Ti-C and Ti-OVX (61.2 ± 9.7 vs 48.2 ± 6.7). Significant differences also exist between the osteointegration of HA-C and HA-OVX (77.0 ± 7.4 vs 57.6 ± 11.5) (p < 0.01). Microanalysis shows some modifications in Sulphur (S) concentration at the bone/biomaterial interface of the Ti-OVX group. Therefore our results confirmed the importance of biomaterials characteristics and of bone quality in osteointegration processes.
Which Amino-Acids do Serum and Hemofiltrate of Critically Ill Patients with Acute Renal Failure Contain?
Authors: Guth H-J. , Wiersbitzky M. , Ziesche M. , Rose H-J. , Kraatz G.
Published: March 2018

The removal of amino acids during continuous renal replacement therapies induces clinical problems. Previous studies on animals have shown nephroprotective (glycine, alanine) or negative effects (lysine) on renal function in occurrence of acute renal failure. Disturbed metabolism in acute renal failure needs adequate parenteral nutrition. On the other hand, experience with continuous renal replacement therapies of metabolic crises in inborn errors of metabolism indicate a good control of disturbed amino acid metabolism. The aim of our study was to find amino acids, that might play an important role in the pathogenesis, prognosis and detection of acute renal failure and severe illness, so far only estimated by lactic acid. Thirty-three probes (serum and hemofiltrate) were taken from patients, suffering with acute renal failure caused by septic shock, severe pancreatitis and hepatorenal syndrome, one hour after the beginning of extracorporal circulation, the conditions of treatment were standardized. The material was deproteinized and studied by the amino acid analyzer LBK 4251 Apha Plus (Pharmacia, Stockholm, Sweden), while the lactic acid concentration was determined in a standard laboratory. Proline, glycine, alanine, methionine and histidine showed a close relationship to the lactic acid levels, but these amino acids were an essential part of parenteral nutrition. A statistical relationship was also established in (amino acids with amide groups) asparagine, glutamine, citrulline, cystathionine and phosphoethanolamine. The mean values of most of the amino acids were higher than normal, but standard deviations were increased. The presence of these amino acids in hemofiltrate and the good sieving coefficients could mean that the better prognosis of critically ill patients in continuous renal replacement therapies may also be due to continuous control of amino acid levels (especially with amide groups).
Subclavian Vein Stenosis: A Potentially Serious Complication in Chronic Hemodialysis Patients with Permanent Cardiac Pacemakers
Authors: Cavatorta F. , Campisi S. , Zollo A.
Published: March 2018

We report on two hemodialyzed patients in whom subclavian and brachiocephalic vein stenosis secondary to permanent cardiac pacemakers led to massive congestive edema of the same arm after arteriovenous fistula/grafts were created. Therapeutic solutions regarding hemodialysis access are discussed in these patients with permanent pacemakers requiring hemodialysis.
Development of Intracoronary Local Adhesive Delivery Technique
Authors: Sonobe T. , Naganuma S. , Yambe T. , Kobayashi S.I. , Sizuka K. , Katahira Y. , Nitta K. , Nitta S.I.
Published: March 2018

Acute coronary occlusion may occur in weak coronary atherosclerotic lesions, including dissection, ulceration or thrombus. In some cases of occlusion “bail-out” is performed by using recently developed New Devices. However, these have not yet completely solved the problem to this end, we designed a new method of coronary revascularization, the Intracoronary Local Adhesive Delivery Technique, utilizing antithrombotic and absorbable adhesive injected locally into the fragile and morbid arterial wall using a drug delivery PTCA catheter more flexible than the existing New Devices. This adhesive strengthened and hardened the lesions. In this study, we examined the efficacy of making an adhesive cylinder in arteries of similar size to the coronary, through acute animal experiments using the existing clinical adhesives and drug delivery PTCA catheters and 12 femoral arteries of adult goats. We were successful in forming firm tunnels along the inside of six arteries, infused with approximately 0.04 ml Cyanoacrylate. These tunnels were observed with intravascular ultrasound (IVUS) imaging and evaluated microscopically. These results suggest the feasibility of this method as a new approach for making synthetic resinous stents.
Polyurethane Heart Valve Durability: Effects of Leaflet Thickness and Material
Authors: Bernacca G.M. , Mackay T.G. , Gulbransen M.J. , Donn A.W. , Wheatley D.J.
Published: March 2018

A flexible trileaflet polyurethane valve has been made by dip-moulding leaflets directly onto an injection-moulded frame. The durability of this valve is, in part, determined by the thickness of its leaflets. Leaflet thickness is also a major determinant of hydrodynamic function. This study examines valves (n=31) with leaflets made of a polyetherurethane (PEU, n = 22) or a polyetherurethaneurea (PEUE, n = 9), of varying thickness distributions. The valves were subjected to accelerated fatigue test at 37°C and failure monitored. Leaflet thicknesses ranged from 60 to 200 μm. PEU leaflet thickness bore no relationship to durability, which was less than 400 million cycles. PEUE valves, in contrast, exceeded 800 million cycles. Durability in PEUE valves was directly related to leaflet thickness (r = 0.93, p < 0.001), with good durability achieved with median leaflet thicknesses of approximately 150μm. Thus polyurethane valves can be made with good hydrodynamic properties and with sufficient durability to consider potential clinical use.
Blood Trauma in Plastic Haemodialysis Cannulae
Authors: De Wachter D. S. , Verdonck P. R. , De Vos J. Y. , Hombrouckx R.O.
Published: March 2018

To investigate the haemolysis in haemodialysis cannulae, an in-vitro set up is built, using a unipuncture dialysis system. This system is connected to a bag with fresh calf's blood, by the cannula under test, mounted in a large bloodline (5mm diameter). The blood characteristics are kept constant by means of a bicarbonate dialysate in the dialyser. During a 6h period, haematological parameters are regularly sampled. Flow through the cannulae is recorded, which is about 500mUmin. Four different cannulae are tested and compared to the results obtained without any cannula in the circuit. In all cases a linear increase in plasma free haemoglobin levels is found after 6h. The cannulae can be ranked from 8F catheter over 13G, 14G to 16G cannula, the latter producing the highest degree of haemolysis. When using plastic cannulae at high blood flows, their haemolytic effect may not be neglected.
Detection of Hydration Status by Total Body Bioelectrical Impedance Analysis (BIA) in Patients on Hemodialysis
Authors: Oe B. , De Fijter W.M. , De Fijter C.W.H. , Straver B. , Oe P.L. , Stevens P. , De Vries P.M.J.M.
Published: March 2018

The purpose of the present study was to investigate whether total body bioelectrical impedance analysis (BIA) could be appropriate to assess normohydration (i.e. dry weight) in hemodialysis patients. This study is warranted, because the simultaneous assessment of both hydration and nutritional status by BIA requires the presence of a situation of normohydration in order to guarantee valid conclusions about the nutritional analysis. Segmental bioelectrical impedance was performed to classify patients according to their hydration status. BIA measurements revealed significant differences in TBW, ECW and ICW/ECW between three hydration subgroups (under-, normo-, and overhydration), whereas ICW was similar. Therefore, TBW, ECW and ICW/ECW appear appropriate variables to assess hydration status in patients on hemodialysis. Hemodialysis diminished ECW significantly, whereas ICW did not change, suggesting that a decrease of ECW explains the fluid loss during hemodialysis.
Effects of DL-Penicillamine on Cytotoxic Reaction between Baboon Performed Xenoantibodies and Pig Endothelial Cells
Authors: Kwiatkowski P.A. , Puc J. , Rowinski W. , Fiedor P.
Published: March 2018

The purpose of this study was to evaluate effects of DL-Penicillamine (DLP), a compound interrupting S-S bonds (IgM pentamers) on binding and cytotoxicity of adult baboon performed xenoantibodies to pig endothelial cells. Pooled baboon serum was treated with different concentrations of DLP during various periods of time. Complement-mediated cytotoxicity assay was used to determine the reactivity of baboon xenoantibodies to pig aortic endothelial cells (PAEC). To assess IgM and IgG binding to PAEC, ELISA method was applied. Serum treated with DLP revealed significant reduction of cytotoxicity in a dose dependent manner. Cytotoxicity was also reduced during time prolongation of DLP exposure to PAEC. Results indicate that baboon performed IgM and IgG xenoantibodies bind to pig endothelial cells, but only IgM is able to cause degradation of the complement. DLP significantly reduces cytotoxicity and eliminates binding of IgMs to PAEC in spite of continued binding of IgG xenoantibodies to the surface of endothelium.
De novo Membranous Glomerulopathy in a Renal Transplant Patient Treated with FK 506. The First Reported Case
Authors: Lal S.M. , Luger A.M. , Hashefi M. , Ross G.
Published: March 2018

We describe a case of de novo membranous glomerulopathy in the renal allograft of a diabetic patient, treated with the newer immunosuppressive agent FK 506. Twenty-two months later this patient developed nephrotic range proteinuria.
Simultaneous Separate Assessment of the Cardiac and LVAD Output
Authors: Chaus N.I. , Kislukhin V.V. , Smirnov S.S. , Ivanov A.S. , Zhidkov I.L. , Burtsev P. Yu. , Eremenko A.A. , Dzemeshkevich S.L. , Pentalos G. M. , Kolff W. J.
Published: March 2018

The electroimpedance indicators’ dilution (EIID) technique was used to study the possibility of a simultaneous separate assessment of the biological heart and LVAD performance in the position of LVB. The experimental part of the research was performed on 5 dogs; an artificial ventricle of the pulsing type (USA) with cusps was used as a pump. The clinical part of the work was conducted on 5 patients after open-heart surgery who had the clinical picture of postcardiotomy cardiogenic shock; a centrifugal pump “Biopump” (Medtronic, USA) was used. The authors have shown a principally important possibility of applying the EIID, technique for studying the performance curves which are the integral derivatives of the work of a specific hybrid system - “the biological heart - assist device”. From the practical viewpoint the EIID technique permints in the read time mode to control continuously the part of the pumping function which is assumed by the patient's own heart. This information can serve as the basis for making the prognosis and determining the further tactics of treatment; the restoration of the heart performance or its replacement by transplantation.
Estimation of Monomer Content in Polymethyl Methacrylate Contact Lens Materials by Raman Spectroscopy
Authors: Kantarci Z. , Aksoy S. , Hasirci N.
Published: March 2018

Polymethyl methacrylate is the most commonly used contact lens material due to its excellent optical properties. However the presence of residual monomer in the structure alters its transparency as well as its biocompatibility, thus, there is a need to detect any remaining methyl methacrylate. Raman spectroscopy is a rapid, sensitive, and non destructive method as compared to other spectroscopic, chromatographic or polarographic methods. In this study, the spectra of some lens materials (prepared from methyl methacrylate, 2-hydroxy ethyl methacrylate, hexamethyl disiloxane and polypropylene glycol with or without the addition of crosslinker ethylene glycol dimethylacrylate) were obtained by Raman spectroscopy. It was observed that an amount of crosslinker present in the structure proves effective for the unpolymerized monomer content. None of the samples, except those containing hexamethyl disiloxane, demonstrated any monomer residue.
Laser Profiling of Bovine Pericardial Heart Valves
Authors: Donn A.W. , Bernacca G.M. , Mackay T.G. , Gulbransen M.J. , Wheatley D.J.
Published: March 2018

Laser profiling techniques have been used to examine the 2-dimensional and 3-dimensional patterns of leaflet motion in functioning bovine pericardial heart valves (1 normal valve and 1 fatigued/calcified). In the normal valve the general patterns of opening and closing were similar for all leaflets; however, localised variations such as areas of high curvature, retarded motion and high speed motion were identified. In the fatigued/calcified valve significant differences from the normal leaflet motion were observed e.g. increased crimping, gross leaflet lag and irregular deformation. The laser profiling technique was able to reveal changes in the functional dynamics of pericardial valve leaflets not otherwise detectable by conventional hydrodynamic measurements of valve performance.
How to Protect Hypertrophied Myocardium? A Prospective Clinical Trial of three Preservation Techniques
Authors: Bouchart F , Bessou J.P. , Tablet A. , Hecketsweiller B. , Mouton-Schleifer D. , Redonnet M. , Arrignon J. , Soyer R.
Published: March 2018

Protection of the hypertrophied myocardium during heart surgery is still a controversial matter. We prospectively studied 3 currently available preservation techniques in 60 patients operated on for isolated aortic stenosis. Patients were randomly assigned to one of the following groups:

CWB: continuous warm blood cardioplegia

ICB: intermittent cold blood with warm blood controlled reperfusion

Cryst: intermittent cold crystalloid cardioplegia (SLF11, Biosédra Laboratory, Vernon, France).

All groups were matched for age, ejection fraction, NYHA class, aortic valve surface, and operative risk score. There were no deaths. No statistically significant difference was found among the groups in terms of ventilatory support time, ICU stay time, hospitalization or atrial fibrillation occurrence. Blood gases in the coronary sinus at the time of clamp release showed deep acidosis with crystalloid cardioplegia (pH = 7.11 vs 7.39 for CWB and 7.38 for UCB, p < 0.0001) associated with a higher lactate production than in the other groups (1.3 mmol vs 0.5 for CWB and 0.58 for ICB, p < 0.0001). Acidosis was corrected at the end of bypass with no significant differences among groups. CK-MB samples were taken on arrival in ICU, then 6 and 24 hours later. These samples showed much higher levels with cold blood (H6: 70 mcg/l vs 33 for CWB and 45 for Cryst, p = 0.0019). Although the 3 types of cardioplegia may be safely used for isolated aortic stenosis surgery, continuous warm blood cardioplegia appears to be the best choice.
Evaluation of Functional Nerve Recovery after Reconstruction with a New Biodegradable Poly (DL-Lactide-∊-Caprolactone) Nerve Guide
Authors: Meek M.F , Den Dunnen W.F.A. , Robinson P.H. , Pennings A.J. , Schakenraad J.M.
Published: March 2018

The aim of this study was to evaluate functional nerve recovery following reconstruction of a 1 cm gap in the sciatic nerve of a rat, using a new biodegradable p (DLLA-∊-CL) nerve guide. To evaluate both motor and sensory nerve recovery, walking track analysis and electrostimulation tests were carried out after implantation periods, ranging from 3 to 15 weeks post-operatively. The first signs of functional nerve recovery were observed after 3 weeks. After 15 weeks, 70% of the motor - and 90% of the sensory nerve function was re-established. Return of nerve function was better, in comparison with results from other studies. This study demonstrated successful functional nerve recovery after the reconstruction of a 1 cm nerve gap with a biodegradable p(DLLA-∊-CL) nerve guide.
Trace Elements Burden in Geriatric Hemodialysis Patients: A Prospective Multicenter Collaborative Study
Authors: Hung K.Y. , Ho C.Y. , Kuo Y.M. , Lee S.H. , Hseih S.J. , Yang C.S. , Peng C.J. , Wu D.J. , Hung J.T. , Chen P.Y. , Chen J.S. , Chen W.Y.
Published: March 2018

Introduction

Hemodialysis therapy and the aging process bave been reported to interfere with the trace element (TE) status in the body. This multicenter collaborative study on blood levels of TE in geriatric hemodialysis (HD) patients was carried out with an aim to clarify the impact of the aging process and HD therapy on the TE status in such patients.

Methods

One hundred and fifty-one HD patients (65 male, 86 female), all aged over 60 (68.2±3.86 y), and 112 elderly controls (58 male, 54 female) with a mean age of 67.5±3.03 were enrolled. All patients underwent standard HD for at least 6 months. The artificial kidneys used were hollow-fiber dialyzers of cellulose membranes. Water used for HD was prepared by reverse osmosis. Blood was collected in the morning prior to dialysis and after fasting. Atomic absorption spectrophotometry was applied to measure blood levels of Pb, Cd and Hg as well as plasma levels of Cu, Zn and Al. Data are presented as mean ± SEM. Student's t-test and linear regression were applied for statistics.

Results

Our geriatric chronic HD patients showed a marked elevation of blood Al and decreased plasma Zn concentrations. The blood levels of Cu, Cd, Pb and Hg were within normal limits. The blood concentrations of Al, Cu and Pb were significantly higher in HD patients than in the normal elderly controls, whereas Cd and Hg were similar in both groups, and Zn were lower in HD patients. Plasma Zn value decreased as dialysis duration increased, however there was a reversely linear correlation between plasma Zn and age.

Conclusions

This data reported can be regarded as a starting point and may serve as an insight to further studies on TE imbalances in geriatric and chronic HD populations.
Medos®/HIA-assist system: first experiences with mechanical circulatory assist in infants and children
Authors: Herwig V. , Severin M. , Waldenberger F.R. , Konertz W.
Published: March 2018

The Medos®/HIA-System is a new pneumatically driven system for mechanical circulatory assist. The system is characterized by excellent efficiency at high heart rates and is available with three ventricles of 10, 25 and 60ml stroke volume. It can be used as left-, right- or biventricular assist device. Our preliminary experiences with this novel system for support of infants and children are reported.