bluuebunny/crossref_metadata_2025 huggingface dataset:
Blood Pressure after three Different forms of Correction of Anemia in Hemodialysis
Authors: Pascual J. , Teruel J.L. , Marcén R. , Ortuño F. , Liaño J.
Published: March 2018

It is not known whether recombinant human erythropoietin has a direct, clinically apparent pressor effect in hemodialysis patients or whether hypertension developing or aggravated in these patients merely reflects increased hematocrit. We compared blood pressure after three different methods of partial correction of anemia in hemodialysis patients with similar baseline hematocrits (erythropoietin n=12, intravenous iron alone n=10, androgens n=9). Shortly after the start of treatment and with a minimally increased hematocrit, the need for antihypertensive medication increased in the erythropoietin group. No such pressor effect was observed with iron or androgens. These data suggest a direct hypertensive effect of erythropoietin in some patients on hemodialysis.
Can Teledialysis Help in the Clinical Management of Patients on Remote Hemodialysis?
Authors: Montanari A. , Briganti M. , Emiliani G. , Ghiraldi A. , Pirazzoli P. , Fusaroli M.
Published: March 2018

This study investigated whether transmission of the parameters monitored from a remote center to the main center could improve the control of a dialysis session. The parameters of the computer connection module Monitral SC in remote and main centers, were transmitted by means of the Hospal data collection software (Demoplus) by modem, to the host computer. Each remote center can be temporarily disconnected, if necessary, from the telephone line and linked directly to a local computer. We checked 101 hemodialyses. The dialysis was monitored from filter washing to disconnection of the patients and the following parameters were selected: backfiltration during washing and hemodialysis: ultrafiltration, conductivity and temperature. From the sessions recorded (93%) we observed that backfiltration during the filter preparation phase was high (30%) in 28 sessions. Backfiltration during the preparatory phase is the major problem for correct management of dialysis sessions. The high percentage in which ultrafiltration had to be stopped shows that control of this parameter is still not ideal. Finally, the collection of monitor parameters and the comparative analysis of clinical data is useful for improving dialytic management.
Beta 2-Microglobulin Synthesis of Mononuclear Cells in Chronic Dialysis Patients
Authors: Kumano K. , Nanbu M. , Kusakari S. , Sakai T.
Published: March 2018

Beta 2 microglobulin (B2M) has been identified as a major component of amyloid deposits. This study was designed to determine whether changes occur in the synthesis of B2M in dialysis patients. Mononuclear cells (MNC) were isolated in peripheral blood from healthy volunteers, patients on hemodialysis (HD) and on continuous ambulatory peritoneal dialysis (CAPD). MNC were cultured in a medium of RPMI 1640 with or without interleukins IL-1, IL-2 or interferon INF-r. B2M in the cultured cells and supernatant was measured by enzyme immunoassay. IL-2 or INF-r stimulated B2M synthesis 'was significantly lower (25%) in patients on HD than in normal controls regardless of the type of dialysis membranes used, with no change in basal B2M synthesis. No differences were detected between healthy volunteers and CAPD patients. Preincubation of MNC with complement - activating or non-complement - activating membrane had no influence on B2M synthesis. The basal B2M synthesis of MNC significantly increased after a 4-hour HD regardless of the membranes used, and IL-2 and IFN-r stimulated synthesis were both essentially the same before and after HD. It was thus concluded that maximum capacity for B2M synthesis of MNC decreases in hemodialysis patients. This low responsiveness of MNC may be partially the cause for the reduction in cell-mediated immune response in HD patients.
Acute Renal Failure in Hepatitis A
Authors: Chio F. , Bakir A. A.
Published: March 2018

A 21-year-old man developed acute renal failure early in the course of hepatitis A infection and recovered after 17 days. There was no evidence of pre-renal azotemia, the hepato-renal syndrome, ischemic acute tubular necrosis, rhabdomyolysis, or thrombotic microangiopathy. There was, however, transient proteinuria and hypocomplementemia. It would appear that the renal failure resulted from viral-induced injury, either direct or mediated by immune complexes.
A Modular Mock Circulation for Hydromechanical Studies on Valves, Stenoses, Vascular Grafts and Cardiac Assist Devices
Authors: Schima H. , Baumgartner H. , Spitaler F. , Kūhn P. , Wolner E.
Published: March 2018

Devices for hydrodynamic simulation are required in a variety of studies such as device evaluation, cardiovascular modeling and for student training. Most studies today use different, incompatible circuits, which must be redesigned for every new application. To obtain a universal apparatus, a unitized system with standard connectors was developed. Three types of connectors were selected: 1″ flange connectors, ½″ tubing connectors and Luer-connectors with a 2 mm lumen. The complete system consists of reservoirs, throttles, valve holders, adapters for Doppler ultrasound probes, and converters to link these basic diameters. The apparatus can be driven by membrane, centrifugal and geared pumps.

The system has successfully been used in echocardiographic studies of stenosis and valvular insufficiency, for pulse propagation in vascular grafts, and to test the hydraulic performance of cardiac assist devices. Flow rates between 0.1 and 30 l/min and pressure gradients up to 250 mmHg were achieved. In practical use, the system can be adapted to suit various investigations, with minimal expense. Standardization of the parts and connectors results in simple documentation and good reproducibility.
Spontaneous Dialytic Ultrafiltration with Intraperitoneal Reinfusion of the Concentrate versus Large Paracentesis in Cirrhotic Patients with Intractable Ascites: A Randomized Study
Authors: Cadranel J.F. , Gargot D. , Grippon P. , Lunel F. , Bernard B. , Valla D. , Opolon P.
Published: March 2018

Dialytic ultrafiltration of ascites through a hemofilter associated with peritoneal reinfusion (DUF) of the concentrate has been proposed for the treatment of refractory ascites. In five cirrhotic patients, 18 ascites evacuation procedures were randomized either to DUF (n=8) or to large paranceteses (LP) (n=10). The effects of these two methods on hemodynamic and renal function were assessed. After DUF, the protein concentration in ascites increased transiently from 28±7 g/l to 64.8±8 g/l (p<0.04); urinary output increased from day 1 to day 4 (1000±100) VS 1430±140 ml/24h; p<0.02). After LP, ascitic protein concentration and urinary output were unchanged. No side effects were observed with the two methods. The mean amount of albumin infused was 20±15 g after DUF and 15±5 after LP (ns).
Disinfection of Regenerated Dialyzers with Ozone
Authors: Gál G. , Kiss E. , Földes J. , Dombi A.
Published: March 2018

Regenerated, ozone-disinfected dialyzers were use for a total of 190 hemodialyses in 35 patients without the occurence of any complication or pyrogen reactions; the efficiency of hemodialysis was identical with that of new or formalin-disinfected dialyzers. The priming fluid contained in both compartments of ozone-disinfected dialyzers proved to be sterile. The ozone did not damage the dialyzer membrane or the supporting structure of dialyzer. Ozone can effectively substitute formalin and other chemical sterilants as a disinfectant of regenerated capillary dialyzers. The process can also be automated.
Prolonged Extracorporeal Circulation for Acute Myocarditis
Authors: Moreno-Cabral C.E. , Moreno-Cabral R.J. , McNamara J.J. , Dembitsky W.P. , Adamson R.M.
Published: March 2018

Total circulatory support for acute reversible myocardial failure is rarely used in clinical situations outside the postoperative period following cardiac surgery. We treated an 8-year-old girl who suffered acute viral myocarditis and sustained cardiac arrest requiring cardiopulmonary bypass for resuscitation. This was accomplished with the use of the portable cardiopulmonary support system (CPS), which consists of a centrifugal pump and a membrane oxygenator. This patient was placed on CPS in Hawaii and transported after 3 days to San Diego (4200 km) for further mechanical support and possible heart transplantation. Adequate cardiac function returned and CPS was stopped after 6 days. She is alive and well, attending school two and a half years after the event.

Prolonged use of CPS for acute myocardial failure outside the operating room, including long distance transportation, is effective and easily accomplished with currently and widely available equipment, and should be used in acute, reversible catastrophic heart disease
Effect of Recombinant Human Erythropoietin (R-Huepo) Therapy on Plasma Ft3, FT4, TSH, FSH, LH, free Testosterone and Prolactin Levels in Hemodialysis Patients
Authors: Yeksan M. , Tamer N. , Cirit M. , Türk S. , Akhan G. , Akkus I. , Erkul I.
Published: March 2018

The aim of this study was to evaluate the effect of r-HuEPO treatment on free triiodothyronine (FT3), free thyroxine (FT4), thyroid stimulating hormone (TSH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), free testosterone and prolactin levels in uremic hemodialysis patients. Twenty-four uremic hemodialysis patients were given r-HuEPO with a dose 60 U/kg as intravenous bolus injection at the end of each dialysis session. Once the hematocrit value of the patient had reached a range of 30-35%, the dose was adjusted so as to keep the hematocrit levels constant. Twenty uremic dialysis patients were taken as control group. The above-mentioned hormone levels of patients and control group were determined before and 4 months after r-HuEPO treatment. After the treatment, serum prolactin levels significantly decreased in both sexes (36.8 ± 7.8 vs 22.9 ± 6.3 ng/ml and 78.3 ±13.3 vs 37.4 ± 10.4 ng/ml male and female, respectively). FT3 and FT4 significantly increased (1.17 vs 1.67 pg/ml, p<0.05, and 0.64 vs 0.084 ng/dl, p<0.05, respectively). TSH levels increased but those changes were not significant. There was no change in the level of any hormone in the control group. Also, the sexual functions of eight male patients treated with r-HuEPO improved and menstruation started again in four female patients. We concluded that r-HuEPO treatment especially decreases prolactin level in uremic hemodialysis patients. It is conceivable that correction of elevated prolactin levels could improve sexual disorders in these patients.
Nafamostat as Anticoagulant for Membrane Plasmapheresis in high Bleeding risk Patients
Authors: Kinugasa E. , Akizawa T. , Nakashima Y. , Wakasa M. , Koshikawa S.
Published: March 2018

Nafamostat mesilate (NM), an ultrashort-acting multi-enzymatic inhibitor, is a useful anticoagulant in high bleeding risk patients needing hemodialysis. We applied NM as a membrane plasmapheresis (MP) anticoagulant in patients with high bleeding risk. Eleven patients, the majority with hepatic failure and active hemorrhagic foci or severe bleeding diathesis, could be treated with MP 22 times under anticoagulation by 20-40 mg/h/NM by continuous infusion without any trouble. Celite-activated coagulation time (CCT) at the plasma separator inlet and outlet was adequately prolonged during MP, but CCT in systemic blood showed no prolongation throughout the procedure, because NM was rapidly inactivated. There was no observable blood coagulation in the extracorporeal circuit including the plasma separator. No adverse reaction or exacerbation of hemorrhage was noted throughout the MP. NM thus appears to be a useful and safe anticoagulant not only for hemodialysis but also for MP in high bleeding risk patients.
Mayer Waves in Dogs with Total Artificial Heart
Authors: Yambe T. , Nitta S. , Katahira Y. , Sonobe T. , Naganuma S. , Kakinuma Y. , Kobayashi S. , Tanaka M. , Miura M. , Sato N. , Mohri H. , Yoshizawa M. , Izumi K. , Takeda H.
Published: March 2018

To assess the effect of a total artificial heart (TAH) on the autonomic nervous system a power spectral analysis of the hemodynamics in a TAH animal was done by the maximum entropy method. Two pneumatically driven sac-type ventricular assist devices were implanted as total biventricular bypass (BVB) in adult mongrel dogs to compare the differences between natural heart and TAH. Once the BVB was pumping, the natural heart was electrically fibrillated to constitute the BVB-type TAH model. In the arterial pressure waveform in animals with TAH, respiratory waves were not changed (97.7±24.6%) though Mayer waves were significantly decreased (47.5 ± 22.6%) compared with the animal with a natural heart. These results suggest that prosthetic hemodynamics in the TAH animal affect fluctuations in the cardiovascular system.
Effect of Vitamin E Therapy on Sexual Functions of Uremic Patients in Hemodialysis
Authors: Yeksan M. , Polat M. , Türk S. , Kazanci H. , Akhan G. , Erdogan Y. , Erkul I.
Published: March 2018

Twenty-four uremic patients on hemodialysis who had never been treated with vitamin E or related drugs and 12 control patients with normal renal function were studied. Hemodialysis patients were randomly divided into two groups; 12 were treated with oral vitamin E (300 mg/day) for eight weeks and 12 uremic patients and 12 controls were given placebo. Serum vitamin E, prolactin, FSH, LH, and free testosterone levels were measured in all patients before and after treatment. After the vitamin E treatment serum prolactin levels were significantly decreased (50.8 vs 15.4 ng/ml, p<0.01). Vitamin E levels were significantly increased (1.11 vs 1.22 mg/dl, p<0.05). Serum FSH, LH and free testosterone were not affected. In the other two groups there were no significant changes. These results show that vitamin E treatment lowers prolactin levels in uremic hemodialysis patients. This might be due to inhibition of central prolactin secretion. Vitamin E inhibits pituitary gland hypertrophy in vitamin E-deficient rats.
Peritoneal Dialysis Using Conventional, Lactate - Containing Solution Sterilized by Ultrafiltration
Authors: Ing T.S. , Yu A.W. , Thompson K.D. , Ansari A.U. , McShane A.P. , Gandhi V.C. , Filkins J.P.
Published: March 2018

Peritoneal dialysis was performed on 7 end-stage renal failure patients using an I-lactate-containing solution sterilized by ultrafiltration through polyamide filters. The patients tolerated the procedure well while their metabolic acidosis and azotemia improved.
Perforation of the Superior Vena Cava by a Subclavian Hemodialysis Catheter: Early Detection by Angiography
Authors: Kaupke C.J. , Ahdout J. , Vaziri N.D. , Deutsch L.S.
Published: March 2018

A dual-lumen subclavian catheter was placed for temporary dialysis access in a 36-year-old woman. Clinical suspicion for a possible vena caval perforation by the catheter tip was confirmed by injection of contrast through the catheter. This technique allowed rapid diagnosis and prevented further potential complications related to catheter malposition.
High Volume Plasma Exchange in Fulminant Hepatic Failure
Authors: Kondrup J. , Almdal T. , Vilstrup H. , Tygstrup N.
Published: March 2018

We investigated the effect of repeated high volume plasma exchange with fresh donor plasma in 11 patients with fulminant hepatic failure, all initially in stage 3 or 4 encephalopathy. A daily exchange of a volume equal to the extracellular volume (20% of body weight) on three consecutive days was intended. We obtained an average of 2.6 exchanges each with a mean volume equal to 16% of the body weight. Five patients (46%, 95% confidence limits 17%-77%) survived, all with acetaminophen induced liver failure. Four of the 6 non-survivors showed a temporary improvement in cerebral function. Two of the patients woke up completely. The 6 non-survivors maintained a stable condition with a systolic blood pressure >110 mm Hg for a mean of 6.9 days after initiating plasma exchange. Plasma exchange may be considered in acute liver failure in patients with residual liver function before transplantation is finally decided. In addition, plasmapheresis may be used to keep patients with definite liver failure clinically stable until a transplant can be performed.
Dietary Protein Loading and the Oral Adsorbent AST-120 in the Progression of Chronic Renal Failure in the Rat
Authors: Kumano K. , Sakai T. , Kuwao S. , Ise M.
Published: March 2018

Excess protein intake enhances the progression of renal failure. The oral carbonaceous adsorbent, AST-120, was found experimentally and clinically to retard the progression of renal failure. This study was designed to determine whether deterioration of renal function by dietary protein loading can be prevented or mitigated by this oral adsorbent. Rats with uremia induced by partial renal infarction were fed a normal or high-protein diet for 70 days with or without AST-120, in which the inorganic phosphate content was adjusted to the same level. The survival rate deteriorated with the high dietary protein, but was improved from 30% to 100% with AST-120. Dietary protein loading reduced renal function, based on creatinine clearance. AST-120 improved renal function and renal histopathology not only in the normal diet group but in the high-protein group as well. The progression of renal failure induced by protein loading is thus shown to be prevented by oral AST-120. The mechanism for its action remains to be clarified.
Extracellular Matrix Covered Biomaterials for Human Endothelial Cell Growth
Authors: Desgranges P. , Tardieu M. , Loisance D. , Barritault D.
Published: March 2018

The aim of this study is to optimize conditions for growing endothelial cells on vascular biomaterials. Bovine cornea endothelial cells (BCEC), stimulated by basic Fibroblast Growth Factor (bFGF) secrete an extracellular matrix (ECM) similar to the Descemet membrane produced in vivo by these cells. This ECM, obtained by removing BCEC with an hypotonic shock can be used as a substratum for other endothelial cell growth. Human endothelial cells (HEC) were purified from omentum that was digested with a solution of collagenase-dispase, then filtered through nylon meshes. The cells were further purified by centrifugation onto a Percoll gradient. A comparative study on the attachment and growth of HEC on various coatings (laminin, poly-L-lysine, fibronectin or ECM) indicates that ECM is the most performing substratum. The quality of this endothelium was confirmed by the presence of factor VIII, and MHC class I and the absence of class II antigens.
Combined Treatment in Wegener'S Granulomatosis with Crescentic Glomerulonephritis -Clinical Course and Longterm Outcome
Authors: Frascà G.M. , Zoumparidis N.G. , Borgnino L.C. , Neri Lu. , Neri Lo. , Vangelista A. , Bonomini V.
Published: March 2018

This study reports on 9 patients suffering from Wegener's granulomatosis (WG) with crescentic GN and severe systemic manifestations. On admission the mean serum creatinine was 10.9 ± 5.1 mg/dl (4-20 mg/dl); 8 patients were oliguric and required dialysis treatment. Renal biopsy showed crescents in all cases, involving 66 to 100% of glomeruli. Patients were treated with a protocol including: a plasmaexchange (PE) course; methyl-prednisolone; cyclophosphamide; and an antithrombotic agent (defibrotide). Clinical picture and renal function progressively improved in all patients within the first 4 weeks of treatment. After 1 month serum creatinine was 2.7 ± 0.8 mg/dl and dialysis was no longer needed in any patient. Five relapses occurred in 3 patients 12-26 months after the onset of the disease, while they were still receiving immunosuppressive treatment. At follow-up (22 to 112 months: mean 71) all patients were alive with no clinical signs of disease activity. One patient was on regular dialysis while the others had a serum creatinine of 1.2-2.8 mg/dl (mean 1.9). Our results confirm that crescentic GN associated with WG can be successfully treated even when associated with severe clinical picture and suggest that PE can contribute to control the disease without increasing immunosuppression.
Emphysematous Pyelonephritis and Cystitis in a Renal Transplant Recipient - Computed Tomographic Appearance
Authors: Kalra O.P. , Malik N. , Minz M. , Gupta K.L. , Sakhuja V. , Chugh K.S.
Published: March 2018

A 35-year-old nondiabetic renal allograft recipient developed emphysematous pyelonephritis and cystitis emphysematosa necessitating graft nephrectomy. The patient received cyclosporin and prednisolone as immunosuppressive therapy. He developed the first episode of urinary tract infection one week after transplantation and another episode 3 months later. Abdominal CT scan revealed presence of gas in the graft kidney, urinary bladder, and surrounding tissues. Despite appropriate antibiotic therapy, his renal function deteriorated rapidly and he died on the first postoperative day.
Reverse Flux Filtration: A New Mode of Therapy Improving the Efficacy of Heparin - Induced Extracorporeal Ldl Precipitation in Hyperlipidemic Hemodialysis Patients
Authors: Bosch T. , Samtleben W. , Thiery J. , Gurland H.J. , Seidel D.
Published: March 2018

In the steady state after a run-in phase of 3 months, the acute effects of 3 modifications of weekly heparin-induced extracorporeal LDL precipitation (HELP) were studied in 5 ESRD and 2 non-uremic hypercholesterolemic coronary patients. In ESRD patients (n=29 sessions), HELP reduced LDL-cholesterol (LDL-C) (56 ± 7%) and fibrinogen (FIB) (54 ± 10%) by a similar percentage as compared to non-uremic controls (60 ± 4% and 61 ± 3%, resp.; n=5). In order to eliminate the need for extra HELP sessions in addition to the normal dialysis regimen, newly developed hardware was then used to perform combined synchronous HELP/HD (n=12). However, premature precipitate filter plugging probably due to hyperfibrinogenemia in ESRD patients, accentuated by ultrafiltration (UF), decreased the corresponding reductions to 26 ± 9% (LDL-C) and 34 ± 11% (FIB). Therefore, the procedure was modified by reversing the filtrate flux through the precipitate filter membrane after 900 ml of treated plasma (“reverse flux filtration”, RFF; n=11). Thus, in RFF-HELP/HD the LDL/FIB/heparin coprecipitate was deposited on both filter membrane sides which caused a significant enhancement of the filter capacity and improved reductions to 46 ± 14% for LDL-C and 51 ± 15% for FIB. Elution of the precipitate from the precipitate filter after the sessions showed that RFF-HELP/HD had trapped 1733 ± 238 mg LDL-C and 8108 ± 1876 mg FIB in ESRD patients, while HELP eliminated 1890 ± 333 mg LDL-C and only 3663 ± 369 mg FIB in non-uremics. Filter precipitate recoveries (relative to the mass removed from the patient plasma pool) amounted to 97 ± 18% for LDL-C and 158 ± 67% for FIB in the ESRD group treated by RFF-HELP/HD vs. 70 and 76% in the non-uremic HELP group. Probably, passive transport of lipoproteins and FIB from the interstitium into the vascular space caused repletion of this compartment during HELP/HD where an UF induced solvent drag is effective. In summary, the new RFF-HELP/HD procedure effectively reduced LDL-C and FIB in ESRD patients who could not be adequately treated by the conventional HELP/HD system.
Chronic in Vivo Function of a New Ventricular Assist Device: The Extracorporeal Pulsatile Assist Device (Epad)
Authors: Utoh J. , Whalen R.L , Wilkerson B.R. , Fukamachi K. , Harasaki H.
Published: March 2018

An extracorporeal pulsatile assist device (EPAD) is a valveless, single-chambered, pneumatically-actuated blood pump composed of a graft conduit, connecting ring, bladder, and blowmolded housing. This allows a simple and quick surgical procedure and is easily actuated with a conventional intraaortic balloon pumping console if desired. To evaluate in vivo pump functions, the EPAD was tested in calves as a left ventricular assist device for 6-24 days. The EPAD was well synchronized to the natural heart beat up to 130 bpm in the counterpulsation mode with mild systemic heparinization (active clotting time: 200-250 seconds). Heart rate, coronary flow and cardiac output were not significantly changed by on-off testing. However, the pump showed promising diastolic augmentation (10.8% increase in the diastolic pressure time index) in these chronic animal experiments.
Transplantation of Free and Microencapsulated Islets in Rats: Evidence for the Requirement of An Increased Islet Mass for Transplantation into the Peritoneal Site
Authors: Siebers U. , Horcher A. , Bretzel R.G. , Klöck G. , Zimmermann U. , Federlin K. , Zekorn T.
Published: March 2018

Microencapsulation of islets of Langerhans may avoid the necessity of a permanent immunosuppressive drug therapy and opens up new perspectives for xenotransplantation in the treatment of insulin dependent diabetes. In a mouse model we recently showed long-term normoglycemia after microencapsulated xenotransplantation. Since the acceptance of mice to any kind of foreign material is quite high we assume that the rat model better reflects the situation of higher mammalians or even humans. Due to the volume of the transplanted material (i.e. islets + alginate-capsule) only the peritoneal cavity can be used up to now. The quantity of islets necessary to normalize the non-fasting blood glucose level was much higher than expected and free transplants needed even a higher amount of islets than encapsulated ones (3000 encapsulated vs. 2 x 3000 non-encapsulated). Transplantation beneath the kidney capsule was successful with only 1200-1500 islets per rat proving the metabolic potency of the islets. Implantation of empty capsules did not alter the diabetic state. We conclude that the alginate matrix may act as a “spacer” creating a distance between the consuments of a lacking substrate esp. oxygen in an unfavourable environment and perhaps protect it from unspecific mediators released during the postoperative period. Our findings underline the necessity for smaller capsules that would enable us to use other transplantation sites.
A Process for Enhancing Selectivity and Limiting Plugging in Plasmafractionation for Apob Removal
Authors: Legallais C. , Jaffrin M.Y.
Published: March 2018

A new process using pressure and flow pulsations was investigated in the second stage of cascade filtration for ApoB removal. Due to enhanced filtration by the pulsations, the retentate flow vanished naturally without clamping the line, which reduced albumin and ApoA1 losses. The performance of Eval 4A and cellulose PF100 filters in this case were compared with that of classical dead end mode at a plasma flux of 18 ml/(min m2). The apparent sieving coefficient for small proteins (albumin, ApoA1) under pulsed conditions increased with increasing pressure instead of dropping as in dead end mode. In both cases the ApoB sieving coefficients remained below 0.02. These encouraging results were accompanied by a slower rise of transmembrane pressure showing a decrease of membrane plugging. Thus, the recovery of albumin and ApoA1 is increased while ApoB removal remains constant, which improves the selectivity of the fractionation stage.
Serum Alpha-1-Antitrypsin in Hemodialysis Patients with Dialysis Arthropathy
Authors: Docci D. , Bilancioni R. , Baldrati L. , Capponcini C. , Delvecchio C. , Feletti C.
Published: March 2018

Dialysis arthropathy is the most prominent dialysis-related amyloidosis feature. Alpha-1-antitrypsin (alpha-1-proteinase inhibitor) is the major circulating antiprotease. Twenty-three otherwise uncomplicated hemodialysis patients with well-documented dialysis arthropathy had a significantly (p < 0.05) lower serum mean concentration, 1,960 ± 410.4 mg/I of alpha-1-antitrypsin than 47 patients with no joint symptoms who had a mean concentration of 2,256.6 ± 424.5 mg/I. Decreased levels of the substance were detected in 13 (56.5%) of the 23 patients with dialysis arthropathy and in 13 (27.6%) of those 47 with no joint symptoms, the incidence in the former group being significantly (p < 0.05) higher than in the latter. In the dialysis arthropathy group, serum alpha-1-antitrypsin levels correlated inversely (r = −0.54, p < 0.01) with the dialysis duration and directly (r = 0.413, p < 0.05) with the corresponding beta-2-microglobulin determinations. We speculate that reduced antiprotease activity may play a role in amyloidogenesis in the setting of long-term hemodialysis.
Measurement of Oxygen Consumption and Arterial-Venous Oxygen Saturation following Total Artificial Heart Implantation
Authors: Robison P.D. , Pantalos G.M. , Long J.W. , Bliss R.S. , Price D.K. , Everett S.D. , Goldman P. , Goldenberg I. , Olsen D.B.
Published: March 2018

Current algorithms for control of the total artificial heart are directed at maintaining hemodynamic homeostasis. Future control systems will also need to modify cardiac output in response to metabolic needs. This study was undertaken to evaluate oxygen metabolism monitoring as an indicator of the adequacy of organ and tissue perfusion. Following recovery from implantation of the Utah-100 pneumatic total artificial hearts, five calves (85 to 95 kg) underwent placement of fiberoptic oxymetry catheters to determine mixed venous and arterial oxygen saturations. By continuously measuring oxygen consumption with a gas analyzer, oxygen utilization and delivery were determined. In the awake calves, at-rest cardiac output was varied to produce hyperperfused and hypoperfused conditions while the adequacy of tissue perfusion was assessed with continuous mixed venous oxymetry and confirmed with serum lactate (Lact) levels. Inadequate tissue perfusion (Lact > 1.0 mmol/L) was evidenced by a mixed venous oxygen saturation <40%, oxygen delivery of < 200.0 milliliters/minute/m2), and oxygen delivery to utilization ratio of < 1.8 during the hypoperfusion conditions of the experiment. By accounting for oxygen consumption, the ratio of oxygen delivery to oxygen utilization was predictive of the adequacy of tissue perfusion. These results suggest that continuous oxygen metabolism monitoring may be useful as a physiologic control modifier to maintain total artificial heart output sufficient to meet physiologic needs, while avoiding hyperperfusion, unnecessary wear and deterioration of the implanted device due to excessive heart rates.
A Compliant Biological Vascular Prosthesis
Authors: Tu R. , Wang E. , Hata C. , Shen S.H. , Lin D. , Quijano R.C.
Published: March 2018

One requirement of the mechanical parameters for an acceptable vascular prosthesis is compliance. The compliance of a vascular prosthesis is defined as the fractional change in luminal volume per unit change in applied pressure. A compliant prosthesis has been correlated to prosthesis patency and long-term efficacy in an animal study. However, there have been very few reports on how to manufacture a compliant prosthesis. It is the objective of this study to research the processing methods to manufacture a reasonably compliant vascular prosthesis. A new fixative, polyepoxy compound, was used to fix an artery. The arteries were fixed under different degrees of longitudinal retraction. By locking in the collagen micro-structure at an overly relaxed state and then crosslinking said collagen, the resulting biological prosthesis exhibited extreme compliance and pliability. A prosthesis matching its arterial origin in tensile modulus was achieved by crosslinking an artery at its 45% retraction longitudinally. This flexible prosthesis showed a volumetric compliance index of 18.4 ± 0.9 %Δ/100 mmHg and a longitudinal tensile modulus of 942 grams/cm2. Our current study indicated that a prosthesis fixed with polyepoxy compounds has shown more pliability than that with glutaraldehyde. Further animal study to correlate prostheses patency to different degrees of compliance is needed to confirm this proposed manufacturing approach.
Hand Dysfunction in Patients on Chronic Hemodialysis
Authors: Carroll L.L. , Tzamaloukas A.H. , Scremin A.E. , Eisenberg B.
Published: March 2018

We studied hand function by clinical examination (sensory, motor, coordination, activities of daily living), hand roentgenograms, and nerve conduction studies in 26 patients, aged 62 ± 11 (SD) years and dialyzed by hemodialysis for 7 ± 6 years. Multiple sensory deficits were found in 98% of the hands. Motor function and coordination were abnormal in two-thirds of the hands. Roentgenograms were abnormal in 88% of the hands. Metabolic bone disease, joint disease and extraosseous calcifications were detected often. Nerve conduction studies disclosed polyneuropathy and carpal tunnel syndrome, alone or combined, in 90% of the hands. Clinical examination was sensitive, but not specific in detecting neuropathy, and could not distinguish accurately between polyneuropathy and carpal tunnel syndrome. Organic causes of progressive severe hand dysfunction included carpal tunnel syndrome and, in diabetics only, hand gangrene. Disuse led also to hand dysfunction, even in the absence of anatomic hand disease.
Fatal Intracerebral Hemorrhage Associated with Severe Hypertension following Renal Artery Embolization
Authors: Varma P.P. , Malik N. , Khullar D. , Ahmed S. , Sakhuja V. , Chugh K.S.
Published: March 2018

Persistence of gross hematuria for more than three days following renal biopsy merits renal angiography and embolization of the involved branch of renal artery. We report a patient who developed a fatal intracerebral hemorrhage resulting from severe hypertension following embolization of a branch of the left renal artery.
Extracorporeal Liver Perfusion: Applications of an Improved Model for Experimental Studies of the Liver
Authors: Neuhaus P. , Blumhardt G.
Published: March 2018

Long-term extracorporeal liver perfusion of up to 24 hours was achieved with an improved model of pig liver perfusion. Functional and structural integrity of the extracorporeal liver was maintained during the entire duration of extracorporeal perfusion. After 24 hours SGOT was 33.5 (± 6.5) U/L, bile production was 11.5 ml/h. Survival of hepatectomized pigs could be extended to 18.9 (± 3.8) hours with extracorporeal liver perfusion (p < 0.01). The improvement of liver perfusion in our particular model is primarily based on optimised perfusion of the low pressure system of the portal and hepatic vein by the application of sinusoidal pressure profiles. These pressure profiles imitate intra-abdominal conditions and achieve homogeneous perfusion of the low pressure system of the portal vein and complete drainage of hepatic venous blood.
Hepatic Function during General Hypothermia in the Pig: Assessment by Aminopyrine Breath Test
Authors: Schopfer C. , Belenger J. , BüHler L. , Morel PH.
Published: March 2018

We investigated the influence of pre-harvesting general hypothermia on liver metabolic activity by means of Aminopyrine Breath Test (ABT). This study was conducted in pigs which were anesthetized, curarised and cooled on an ice bed. Each animal received labelled aminopyrine and 14CO2 in expired air was measured between 37.5 and 25.5° C. The liver metabolic activity at 31.5° C represents 53.3% of the normothermic value. At 25.5° C, this activity is reduced by 75.1%. The mean decreasing rate is 6.2%/° C for a fall in temperature of 12° C. A change of slope occurred at 31.5° C. The first decreasing rate is 7.47 ± 1.62%/° C and the second one is 4.48 ± 2.27%/° C. Thus, use of general hypothermia during liver harvesting should improve the quality of organ preservation: the important reduction of metabolism should decrease the oxygen debt resulting from anaerobic cold perfusion.
Practical Measures to Control Device-Related Bacterial Infections
Authors: Costerton J.W. , Khoury A.E. , Ward K.H. , Anwar H.
Published: March 2018

Direct examination of medical devices that have been foci of chronic device-related bacterial infections has shown that the causative organisms grow predominantly in slime-enclosed biofilms. These adherent biofilms are inherently resistant to host defences (antibodies, phagocytes) and to conventional antibiotic therapy. Device-related infections can be prevented by careful cleaning and sterilization of the device, and by the avoidance of any manipulations that would allow the formation of even the most rudimentary biofilm prior to implantation. Once a device-related infection has become established, both the Minimum Inhibitory Concentration (MIC) and the Biofilm Eliminating Concentration (BEC) of the causative organism must be determined and therapeutic strategy must aim at the use of the MIC to control the acute phase caused by planktonic bacteria and of the BEC to eliminate the biofilm nidus of infection. The removal of the colonized device should be considered early in the course of treatment if the BEC cannot be delivered to the colonized device. We describe a new bioelectric technology presently in the in vitro stage of development which, if it can be reproduced in vivo, will be very effective in the prevention and control of device-related bacterial infections.
An Assay of Staphylococcus Epidermidis Biofilm Responses to Therapeutic Agents
Authors: Richards G.K. , Gagnon R.F.
Published: March 2018

Implant-associated infections tend to become persistent, resisting host defences and antibiotic therapy. Routine clinical laboratory testing of bacterial isolates in the fluid phase for antibiotic susceptibility may not be predictive of therapeutic outcomes and therefore a number of antibiotic regimes have been formulated empirically. The resistance of implant-associated infections has been ascribed to the production by bacteria, when adherent to the implant surface, of a shielding matrix of polymerized carbohydrates protecting the enclosed bacteria from immune defences and antibiotics. This complex of surface, bacteria and matrix is termed a biofilm. We describe a technique to evaluate the efficacy of antimicrobial agents directed against biofilm-forming strains of Staphylococcus epidermidis (a major cause of implant infections) utilizing standardized biofilm preparations formed on glass. The impact of the antimicrobial agents was assessed quantally using the end-point of permanent cessation of metabolic activity (cell death) of the entire biofilm determined by the loss of ability to reduce 2,3,5-triphenyltetrazolium chloride to a visible red intracellular precipitate of formazan. The relative rate of action of differing antimicrobial agents could be determined by the minimum period of exposure of the biofilm to the agents that is required to bring about sterilization, the clinically relevant marker. A wide range of antimicrobial substances could be evaluated, including chemical disinfectants, immunoreactive substances, antibiotics; singly and in combination; and the modifying effects of interaction with non-antibacterial therapeutic agents and other environmental factors. The technique is simple, inexpensive, reproducible and readily adaptable to the clinical situation where evaluation of therapeutic regimes for individual cases of prosthetic device-associated infection is required routinely with despatch and ease of interpretation.
Phosphate-binding capacities of calcium and aluminum formulations
Authors: Lau A.H. , Kuk J.M. , Franson K.L.
Published: March 2018

Calcium and aluminum phosphate binders are used to treat hyperphosphatemia which is responsible for the development of osteodystrophy commonly seen in patients with end-stage renal disease. The purpose of this study was to determine the phosphate binding capacities of several frequently used calcium and aluminum formulations. The effect of formulation types on phosphate binding was evaluated. Calcium and aluminum phosphate binders were administered to six healthy volunteers after phosphate load on separate study days. Total urine outflow was collected afterwards to determine the amount of phosphate recovered, which indicates the ability of the phosphate binder to reduce gastrointestinal phosphate absorption. The amounts of urinary phosphate recovered were different after administration of the phosphate binders. Calcium acetate resulted in the least amount of phosphate excreted. Calcium carbonate suspension, when compared with the tablet formulation, caused a smaller amount of phosphate excreted in the urine. Different phosphate binders formulations were found to have different phosphate binding capacities. Patients should therefore be closely monitored for efficacy after switching from one phosphate binder to another. (Int J Artif Organs 1998; 21:19–21)
A computer controlled mock circulatory system for mono- and biventricular assist device testing
Authors: Ferrari G. , Lazzarl C. DE , Mimmo R. , Tostl G. , Ambrosi D. , Gorczynska K.
Published: March 2018

The clinical use of heart assist devices for heart recovery, implies the problem of their in vitro testing and training to use. In a mock circulatory system developed to this aim, the main problem is reproducing interaction among the device, the ventricle and the circulatory network. This can be analysed by the position, on the p-v plane, of the working point defined by the intersection between end systolic ventricular (ESPVR) and arterial elastance lines. The system developed on this basis, connectable to mono- and biventricular parallel assist devices, was a closed loop model including systemic and pulmonary circulation. The arterial trees were reproduced by two windkessels with adjustable peripheral resistance, and the Starling's law of the heart by a variable elastance model. The software controls and monitors circulatory parameters and variables. Results showed the behavior of the system with preload or afterload changes. Further, the reproduction of physiological, pathological (obtained by modifying slope and volume intercept of the ESPVR line) and LVAD assisted circulatory conditions was shown. The assistance effect was underlined by the changes in the ventricular work cycle and in hemodynamics variables. The evaluation of the effect of device control strategy on the ventricle and its energetics (on p-v plane) were among the main characteristics of this system, which ought to be further improved to test devices such as the IABP, which requires a different aortic model. (Int J Artif Organs 1998; 21:26–36)
Gait restoration in a spinal cord injured subject via neuromuscular electrical stimulation controlled by an artificial neural network
Authors: Sepulveda F. , Granat M.H. , Cliquet A.
Published: March 2018

Attempts to restore gait in spinal cord injured subjects have stumbled on control difficulties associated to the neuromuscular system's non-linearity and time-variance. Thus, a simple auto-adaptive artificial neural network has been devised to control gait swing generation by means of neuromuscular electrical stimulation. Both theoretical and experimental approaches were taken. The computer-based system consisted of a three-layer artificial neural network that read angular data from the hip, knee and ankle joints. The output signal consisted of variations on the applied stimulation pulse width. Surface electrical stimulation was applied to the femoral and peroneal nerves of one leg. Neural network training included off-line supervised learning schemes. The system was tested on a male subject with an incomplete C6-level lesion. Several tests were run to determine whether the off-line trained neural network could correctly control the motion. The effect of on-line learning upon the control performance was also evaluated.

The system was found to control the motion with success only at times. Control performance was found to improve in response to the application of on-line learning. Learning stability following on-line learning was found to be satisfactory. In a final test, the artificial neural system had appropriate responses to an initial perturbation, which suggests that further research in this area should be pursued. (Int J Artif Organs 1998; 21:49–62)
The “Aachen” keratoprosthesis: A New Approach towards Successful Keratoprosthesis-Surgery
Authors: Von Fischern T. , Langefeld S. , Yuan L. , Völcker N. , Reim M. , Kirchhof B. , Schrage N. F.
Published: March 2018

Background

None of the keratoprostheses available today is absolutely successful in the long term, neither the problems of extrusion, retroprosthetic membrane formation and intraocular pressure rise are yet solved. A new type of keratoprosthesis is required which can show improved ingrowth characteristics and allow intraocular pressure measurements. In order to possibly meet the above mentioned requirements we developed a flexible silicone keratoprosthesis with scleral fixation and chemical surface modification.

Methods

The one-piece keratoprosthesis is made of silicone rubber. Its optical zone has a diameter of 11 mm and is 0.3 mm thick. The surface-modified haptic consists of a scleral rim and eight branches for scleral fixation. A ridge at the back of the keratoprosthesis fitting into the trephination hole shall avoid leakage and retroprosthetic membrane formation. Optical and mechanical qualities are characterised by tensile tests, spectrophotometry and topography.

Results

A method for keratoprosthesis-production was established. The optical quality of the device was improved by submicron lathing of the mould. Spectrophotometry showed high visible and ultraviolet light transmission of the silicone. Mechanical tests with silicone samples revealed high tensile strength and elongation at break. The mechanical properties were not impaired by surface modification.

Conclusions

The production of a flexible silicone keratoprosthesis with high optical and mechanical properties was established. Its use both for the treatment of permanently opacified corneas and as temporary keratoprosthesis seems to be possible.
Polymyxin-B Stimulates Tumor Necrosis Factor-α Production by Human Peripheral Blood Mononuclear Cells
Authors: Jaber B.L. , Sundaram S. , Neto M. Cendoroglo , King A.J. , Pereira B.J.G.
Published: March 2018

Gram-negative bacterial lipopolysaccharide (LPS) is a well known stimulus for cytokine production, particularly interleukin-1 (IL-1) and tumor necrosis tactor alpha (TNFα). Polymyxin B (PMX-B) is a cationic polypeptide that binds to LPS, neutralizing its biological effects. PMX-B also disrupts gram-negative bacterial cell membrane phospholipids but is highly toxic to mammalian cells, therefore is of limited use. PMX-B is used as additive to media, as a way to handle LPS contamination. To derive benefit from the ability of PMX-B to neutralize lipid A in vivo while avoiding its systemic toxicity, PMX-B was covalently bound to polystyrene-derivative fibers, creating a hemoperfusion column (PMX-F) for the selective removal of circulating ET In vitro PMX-F hemoperfusion studies have demonstrated effective ET removal, using either the Limulus amebocyte lysate assay or TNFα production by peripheral blood mononuclear cells (PBMC) as an index of ET removal. However, the question whether PMX-B itself could stimulate human PBMC to produce cytokines has not been adequately addressed. We examined the effect of increasing concentrations of PMX-B on cytokine production by PBMC in vitro. PBMC harvested from healthy volunteers were incubated for 24 hours at 37°C with control (tissue culture media RPMI), or 5 µg/ml, 10 µg/ml, 20 µg/ml or 100 µg/ml PMX-B. At the end of 24 hours, PBMC were subjected to three freeze-thaw cycles, and total TNFα production (pg/2.5x106 PBMC) was measured by radioimmunoassay. Total TNFα production by PBMC was 163 ± 3 pg, 171 ± 9 pg, 164 ± 4 pg, 323 ± 63 pg and 331 ± 58 pg, in the control, PMX-B 5 µg/ml, 10 µg/ml, 20 µg/ml and 100 µg/ml conditions, respectively. Compared to controls (RPMI), the percentage increase in TNFα production by PBMC was 5 ± 6% (P=0.23), 1 ± 3% (P=0.45), 99 ± 40% (P=0.03) and 103 ± 36% (P=0.02) in the presence of 5 µg/ml, 10 µg/ml, 20 µg/ml and 100 µg/ml of PMX-B, respectively. Furthermore, total TNFα production correlated significantly with increasing concentrations of PMX-B (R=0.53, P=0.007). We conclude that the use of PMX-B in in vitro studies as an LPS-neutralizing agent, or in the experimental treatment of endotoxic or septic shock can lead to erroneous interpretations of cytokine production by PBMC, and should be used cautiously in in vitro systems at high concentrations.