bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevention of Nosocomial Transmission of Hepatitis C Infection in a Hemodialysis Unit. A Prospective Study
Authors: Djordjević V. , Stojanović K. , Stojanović M. , Stefanović V.
Published: March 2018

Hepatitis C virus (HCV) infection in hemodialysis patients can be transmitted by transfusions and nosocomially. A high prevalence of HCV infection, over 50%, was demonstrated in our hemodialysis (HD) unit. In order to prevent the nosocomial spread of HCV infection in the HD unit a prospective study was begun separating anti-HCV positive patients from the negative ones. A total of 170 patients (83 anti-HCV positive) started this study in September 1994 and were followed for 4 years. A separate room and dedicated equipment were assigned to anti-HCV positive and anti-HCV negative patients. Of those 170 patients there were 15 hepatitis B virus (HBV) positive patients, 5 of whom were anti-HCV positive, who were treated in a separate room on dialysis equipment for anti-HCV positive or negative patients. Application of general precautions, as recommended by the Center for Disease Control and Prevention (CDC), was reinforced. During the first 12 weeks after implementing the precautions seven more anti-HCV positive patients were detected, and by December 1995 another two HCV infected patients were found. The follow-up included all changes in HD population treated until the end of 1998. The incidence of seroconversion to HCV was 12.9% in 1995, 7.1% in 1996, 5.0% in 1997, and 6.6% in 1998. The higher incidence of seroconversion in September to November 1994 was probably due to the nosocomial infection being in the incubation period at the time of isolation.

This prospective study in a large HD unit with a high prevalence of HCV infection demonstrates a relatively successful prevention of HCV spread. Procedure-related transmission of HCV in hemodialysis could be prevented by rigorous application of universal precautions as recommended by the CDC. As a second line of prevention, in highly burdened dialysis centers, segregation of HCV positive patients can help control nosocomial transmission.
Extracorporeal Circulation in Ewe's Foetus: Towards a Reliable Foetal Cardiac Surgery Protocol a Comparison of two Cases
Authors: Grigioni M. , Carotti A. , Daniele C. , D'avenio G. , Morbiducci U. , Iannace E. , Albanese S.B. , Costa D. , Formigari R. , Ferretti E. , DI Donato R.M.
Published: March 2018

Foetal cardiac surgery is the ultimate goal in the treatment of congenital cardiac malformations. The aim of our research is to elucidate some of the features of the necessarily invasive experimental protocol to be used in an animal model of foetal cardiac surgery. In particular, we assessed the foetal placentar reactivity to prolonged cardiac bypass in steady-flow conditions.

Methods

Two cases were selected to show the outcome of prolonged (> 30 minutes) extracorporeal circulation (ECC) instituted without oxygenator under steady-flow assistance. Following the instrumentation of the animal (placement of pressure, flow and myocardial fiber length transducers) and the baseline recordings, a 60-minute bypass period was established with an axial turbopump (Hemopump 14 Fr), after systemic heparinisation and artero-venous cannulation. At the end of the circulatory assistance, the cannulae were removed and a 90 minute observation period followed. The cardiac function was assessed by means of indirectly obtained P-V loops.

Results

Case A showed a marked reduction in the end-systolic pressure-volume relationship (ESPVR) during ECC, corresponding to a rightward shift of the P-V loop, with a gradual recovery after the assisted circulation. On the contrary, case B was subjected to progressive placental dysfunction, as evidenced by haemogasanalytical data. Consequently, the haemodynamic data also outlined a negative outcome, with high ESPVR values after bypass.

Conclusions

The present study, while confirming the possibility of cardiac intervention in the foetus, underlines the critical role of minimally invasive protocol to limit both foetal stress and placental dysfunction.
Development of New Tracheal Prosthesis: Autogenous Mucosa-Lined Prosthesis Made from Polypropylene Mesh
Authors: Suh S. , Kim J. , Baek C.H. , Kim H.
Published: March 2018

Reliable tracheal or tissue graft has not been developed yet for the reconstruction of large, circumferential tracheal defects. Major limitations were anastomotic dehishence and stenosis, which were attributed to the poor epithelinisation of the prosthetic graft. We developed a new tracheal prosthesis that has a viable lined and well-vasculised mucosa. The prosthesis consists of Prolene® mesh reinforced with polypropylene rings, and is coated with gelatin. In addition, we lined the luminal surface of the prosthesis with transplanted autogenous oral mucosa and wrapped the prosthesis with greater omentum. Animal experiments were performed using 10 adult mongrel dogs. The transplanted mucosa and wrapped greater omentum tightly adhered to the prosthesis to make a single unit within two weeks. The mucosa survived well, was well vasculised by new vessels from greater omentum and showed normal histology. Complete surgical resection and replacement of a thoracic trachea (3 cm in length, 6 tracheal rings) were carried out in 2 dogs, which survived well with normal activity. We concluded that this highly biocompatible tracheal prosthesis could be very useful for step-wise reconstruction of tracheal defects.
Biochemical Assessment and Clinical Evaluation of a Non-Ionic Adsorbent Resin in Patients with Intractable Jaundice
Authors: Pazzi P. , Scagliarini R. , Puviani A.C. , Lodi G. , Morsiani E. , Gullini S.
Published: March 2018

We investigated in vitro and in vivo the ability of a non-ionic adsorbing resin (styrenedivinylbenzene copolymer) to remove bilirubin and bile acids from human plasma. In preliminary experiments, human plasma from healthy donors, enriched in conjugated bile acids and bilirubin, and pooled plasma from jaundiced patients were recirculated through the resin column. The removal of bilirubin and bile acids was evaluated at two different flow rates (200 ml/min and 40 ml/min), and compared to an activated charcoal column. Four patients with severe jaundice were subsequently treated by 4-hour plasmaperfusion through the resin. The in vitro studies showed that after 1 hour the removal of bile acids was almost complete and bilirubin level decreased significantly, reaching a plateau after 4 hours. In the in vivo study, all treatments were well tolerated. After plasmaperfusion, serum bile acid levels decreased by 64.9–94.6% and total bilirubin by 35.3–57.7%. No clinical or biochemical side effects were observed. Our data suggest that plasmaperfusion through this resin is safe and efficient for removal of bilirubin and bile acids in jaundiced patients. Thus, it may serve as a method of artificial liver support in the treatment of cholestatic syndromes.
A Resorbable Biomaterial Shaped as a Tubular Chamber and Containing Stem Cells: A Pilot Study on Artificial Bone Regeneration
Authors: Giardino R. , Aldini N. Nicoli , Torricelli P. , Fini M. , Giavaresi G. , Rocca M. , Martini L.
Published: March 2018

In a previous study, we showed how healing of non-union defects in rabbit radii can be achieved by means of a tubular resorbable chamber, in comparison with untreated defects. In the present study, we placed bone marrow stem cells inside the chamber. Bone marrow was obtained by percutaneous aspiration from the iliac crest in 9 adult New Zealand rabbits. Stem cells were separated by the centrifugation technique. In the same animals, a defect of 10 mm was created in both radii. On the left side, the defect was treated with the poly-DL-Lactide chamber, in which a suspension of autologous cells was injected; on the right side, only autologous cells were used. Radiological and histomorphometric data were compared within this study as well as with the results of our previous study. At 3, 6 and 9 months, there was no healing on the right side. On the left side, progressive bone formation with reunion of the stumps was observed in the chamber. We conclude that stem cells can accelerate bone healing when contained in the tubular chamber.
Comparison of the Quality of Life in Hemodialysed (HD) and Peritoneally Dialysed (CAPD) Patients using the EORTC QLQ-C30 Questionnaire
Authors: Majkowicz M. , Afeltowicz Z. , Lichodziejewska-Niemierko M. , Debska-Slizien A. , Rutkowski B.
Published: March 2018

Background

The aim of the paper was to assess reliability and validity of the QLQ-C30 questionnaire in studying the quality of life in dialysed patients, and then to compare the life quality in patients on hemodialysis (HD), continuous ambulatory peritoneal dialysis (CAPD) and healthy controls. The present study included 65 HD patients, 22 CAPD patients and a group of 76 healthy volunteers.

Methods

Quality of Life Questionnaire (QLQ-C30), Hospital Anxiety and Depression Scale (HADS), Cantrill ladder.

Results

The EORTC QLQ-C30 questionnaire appeared to be a reliable and valid tool for assessing the quality of life in dialysis patients. HD patients had significantly poorer quality of life in the areas of physical, social, cognitive and emotional functioning in comparisons to the controls. CAPD patients were not significantly different life quality-wise from controls, except for their social and professional life.
In vitro and in vivo Uric Acid Lowering by Artificial Cells Containing Microencapsulated Genetically Engineered E. coli DH5 Cells
Authors: Prakash S. , Chang T.M.S.
Published: March 2018

Increase in systemic uric acid occurs in renal insufficiency, gout, chemotherapy, and other diseases. Dialysis can lower this metabolite but is expensive. The use of drugs can, sometime, result in side effects. Therefore, a suitable affordable method for this is required. In this article, for the first time, we report the use of artificial cells containing micro encapsulated genetically engineered E. Coli DH5 cells for lowering uric acid in vitro and in vivo. Results show that this novel approach has the ability to significantly lower uric acid from 84.80±3.40 mg/dl to 9.32±0.05 mg/dl in vitro and from the plasma of the experimental animals from the control levels of 71.00±27.49 mg/dl to 20.33+17.92 mg/dl in vivo. Continued daily oral administration maintained the plasma uric acid concentration of experimental uremic rats to the normal plasma uric acid level range during the entire test period.
Vasoconstrictive Eicosanoid Responses to Extracorporeal Circulation with or without an Oxygenator in Fetal Lambs
Authors: Kim W.G. , Lee J.R. , Kim C.S. , Choi J.Y. , Kim Y.J.
Published: March 2018

Introduction

This study measured levels of vasoconstrictive eicosanoids during ovine fetal cardiac bypass and compared the measurements between two groups: (1) a group in which the placenta functioned as the only source of oxygen supply during the bypass (the placenta group), and (2) a group in which an artificial oxygenator, instead of the placenta, was included in the bypass circuit (the oxygenator group).

Materials and Methods

A total of 16 fetal lambs were randomly assigned into either the oxygenator group or the placenta group. Following anesthesia, the fetal cardiac bypass procedure was performed. The placenta group used a centrifugal pump as the pumping device without an oxygenator during the bypass. The bypass circuit in the oxygenator group consisted of a roller pump and a membrane oxygenator. The fetal cardiac bypass procedure was performed for 30 minutes at normothermia in both groups. For the measurements of thromboxane B2(TXB2) and prostaglandin E2 (PGE2), blood sampels were taken before the bypass, at 5 minutes, 15 minutes, and 30 minutes after the start of cardiac bypass, and at 15 minutes after weaning from the bypass. TXB2 and PGE2 levels were determined by radioimmunoassay with PGE2(125I) and TXB2(125I) assay systems. Hemodynamic observations and arterial blood gas analyses were done every 10 minutes.

Results

The mean arterial pressure and heart rate ranged from 69.8 to 82.6 mmHg and 169 to 182/min during the bypass in the oxygenator group, and from 14.4 to 44.7 mmHg and 64.3 to 75/min in the placenta group. Arterial blood gas analysis showed severe hypercapnia and hypoxemia with acidosis during and after the bypass in the placenta group. Bypass flow rates were maintained at 140.3–164.0 ml/kg/min in the oxygenator group, while flow rates were suboptimal (74.3–97.0 ml/kg/min) in the placenta group. There were no statistically significant differences in PGE2 concentrations before, during, or after bypass, although the placenta group displayed a tendency to higher measurements during bypass, compared to the oxygenator group. The placenta group also showed higher TXB2 measurements than the oxygenator group during the bypass (p=0.0457).

Conclusions

We have demonstrated increase measurements of PGE2 and TXB2 in the placenta group when compared with the oxygenator group in an ovine fetal cardiac bypass model, although the PGE2 difference failed to reach statistical significance.
A Single Institution's Experience (1982–1999) with Plasma-Exchange Therapy in Patients with Fulminant Hepatic Failure
Authors: De Silvestro G. , Marson P. , Brandolese R. , Pittoni G. , Ongaro G.
Published: March 2018

Fulminant hepatic failure is a rare, but often fatal complication of acute viral hepatitis. This condition, in absence of orthotopic liver transplantation (OLTx) surgery, is associated with a high mortality rate, despite the improvement of general intensive care.

Plasma-exchange (PEx) therapy has been long used to treat FHF, in particular by removing toxic substances and correcting the severe coagulopathy.

In this study we describe our experience with PEx treatment of FHF, beginning in 1982. Seventy patients affected with FHF due to various causes (HBV=40; cryptogenic/non-A, non-E=15; Amanita phalloides=8; other=7) were treated with PEx (altogether 348 sessions).

Overall survival rate, comprising patients undergoing OLTx, was 51%, a little higher than what we observed in patients (N=49) treated solely by PEx, i.e., 41%.

The best outcome predictor was FHF aetiology, owing to the good survival rate in patients with Amanita phalloides intoxication and the very poor prognosis of patients suffering from cryptogenic/non-A, non-E FHF. Moreover, the marked increase in prothrombin time and alpha-fetoprotein levels after 48 hours from admission was associated with a good prognosis, whereas the patient's age and coma grade were not clearly predictive of survival. Additionally, lymphocyte subpopulation, resulting in a CD4/CD8 ratio lower than 1.0 along with CD8 activation with HLA-DR strong expression, were associated with a high rate of mortality and morbidity.

Our data indicate that PEx therapy can improve survival in patients with sufficient residual capacity of liver regeneration. Moreover, the identification of certain prognostic factors may be useful for the rational planning of therapeutic strategy in FHF.
Frequent Replacement and Conventional Daily Wear Soft Contact Lens Symptomatic Patients: Tear Film and Ocular Surface Changes
Authors: Versura P. , Bernabini B. , Torreggiani A. , Cellini M. , Caramazza R.
Published: March 2018

We analyzed tear film changes, ocular surface tissue alterations and inflammatory conditions in Frequent Replacement Soft (FRS) Contact Lens (CL) or Conventional Soft (CS)-CL wearers suffering from eye discomfort, by applying complementary diagnostic tests. Our data suggest the following conclusions: i) eye discomfort symptoms begin after 1–3 years of successful wear, mainly in FRS-CL wearers; ii) tear film stability is affected by CL wear, mainly in FRS-CL wearers; iii) CL wear produces a subclinical moderate inflammation based on mononuclear cell recruitment in 3 out of 4 patients of both types of lenses; iv) CL wear induces dry eye conditions, more pronounced in FRS-CL users; v) discomfort symptoms, presence of subclinical inflammation, degree of dryness are not directly related to a clinical presentation of intolerance, mainly in FRS-CL wearers; vi) CL wear-related discomfort symptoms should never be underestimated, since a hidden inflammation or dryness can be present beyond an apparently good clinical picture.
DALI LDL-Apheresis: Anticoagulation with R-Hirudin in a Patient with Heparin-Induced Thrombocytopenia (HIT II)
Authors: Thomas H.-P. , Kassner U. , Schliesser C. , Steinhagen-Thiessen E.
Published: March 2018

A 50-year old male patient with familial hypercholesterolemia and hyperlipoproteinemia (a), who underwent low density lipoprotein-apheresis treatment developed heparin-induced thrombocytopenia type II (HIT II). Because heparin is contraindicated in patients with HIT, an alternative LDL-apheresis system and modified anticoagulation regimen was necessary. Treatment was changed to a new system called DALI (direct adsorption of lipids). After confirmation of the diagnosis HIT II, DALI LDL-apheresis was carried out with recombinant-hirudin (lepirudin) and citrate in order to prevent hypercoagulability. Efficient LDL-apheresis therapy with minimum therapeutic blood levels of lepirudin (1.4 mg/dl) was achieved with an initial intravenous bolus of 0.114 mg/kg of lepirudin followed by continuous lepirudin infusion of 0.350 mg/h. Thrombin-antithrombin III complex production was well controlled and other hemostatic markers showed no abnormalities. LDL-cholesterol and lipoprotein(a) concentrations were effectively reduced. R-hirudin offers a novel anticoagulation strategy and is, at present, the only alternative for patients with HIT II requiring LDL-apheresis on a regular basis.
A Feedback Controller for the Maintenance of FRC during Tidal Liquid Ventilation: Theory, Implementation, and Testing
Authors: Degraeuwe P.L.J. , Dohmen L.R.B. , Geilen J.M. , Blanco C.E.
Published: March 2018

The necessity of controlling functional residual capacity (FRC) during tidal liquid ventilation has been recognized since the first description of this respiratory support technique by Kylstra et al in 1962. We developed a microcomputer feedback system that adjusts the inspired tidal volume (Vt,i) of a liquid ventilator based on the end-expiratory quasi-static alveolar pressure (Pa,ee), in order to maintain a stable FRC. The system consists of three subunits: (1) a tracheal pressure catheter to estimate breath by breath FRC changes, derived from Pa,ee changes, and (2) a roller pump interfaced with (3) a personal computer in which a closed-loop control is implemented. The regulator sets the actual Pa,ee against the corresponding desired value. Any discrepancy is offset by changes in Vt,i and the required change in pump velocity is communicated to the roller pump. The size of any change in pump velocity is determined to both the observed and target or desired Pa,ee (i.e., the error) and the (calibration) pressure-volume curve.

To evaluate the efficacy of the controller, a set of laboratory bench tests were conducted under steady state and transient conditions. Closed-loop control was effective in keeping FRC and Pa,ee near the desired level, with an acceptable oscillatory behaviour. The feedback controller successfully compensated for transient disturbances of PFC liquid balance. The steady state stability was confirmed during a five hour period of liquid ventilation in five preterm lambs.
Changes in Erythrocyte Calcium and Potassium in Patients during HD and CAPD
Authors: Paraskevopoulos A. , Agroyannis B. , Kopelias L. , Tzanatos E. , Tsomi A. , Dalamanga A. , Katsoudas S. , Petras D. , Voudiclari S.
Published: March 2018

The purpose of this study was to determine the changes in calcium and potassium content in the red blood cells (RBC) of uremic patients during a hemodialysis (HD) session and a 6/hrs CAPD exchange. RBC calcium and potassium were determined in 20 patients on HD in three blood samples collected at 0′-HD (pre-HD), 45′-HD and 240′-HD (end-HD), in 20 patients on CAPD, in two blood samples, collected at 0′ time (pre-inflow) and 120′, (solution in peritoneal cavity) during a 6/hrs exchange (4 exchanges / 24 h) and in 20 normal subjects. The mean value (±SD) of RBC calcium in controls was 15.6 ± 3.75 μmol/L, in hemodialysed patients at 0′-HD, 45′-HD and 240′-HD 51.5 ± 8.5, 70.4 ± 12.5 and 51.1 ± 10 μmol/L respectively and CAPD patients at time 0′ and 120 of an exchange 53.6 ± 23.4 and 70.6 ± 9.2 respectively. These values show that RBC calcium in hemodialysed patients is generally significantly higher (p < 0.0001) than in controls. The value at 45′-HD is also significantly higher (p < 0.0001) than at 0′ or 240′-HD. In CAPD patients, at 0′ and 120′ of a 6/hrs exchange, it is significantly higher (p < 0.0001) than in controls, as is the value at 120′ (p < 0.001) in comparison to 0′. The mean value (±SD) of RBC potassium at the aforementioned time measurements were 95.9 ± 3.34, 92.5 ± 4.32 and 93.85 ± 3.89 mmol/L respectively for patients on HD, 95 ± 3.3 and 94.6 ± 5.28 mmol/L respectively for patients on CAPD and 99.1 ± 3.70 mmol/L in controls. These values show that RBC potassium of hemodialysed patients is significantly lower in comparison to that of controls (0′-HD: p < 0.01, 45′-HD and 240′-HD: p < 0.001); also the value at 45′-HD and 240′-HD is significantly lower (p < 0.001, p < 0.01 respectively) when compared to that at 0′-HD. In patients on CAPD, at 0′ time and 120′ during 6/hrs exchange, potassium is significantly lower (p < 0.001) in comparison to that of controls.

In conclusion, uremic patients present high erythrocyte calcium and low potassium with fluctuations during HD-sessions and CAPD 6/hrs exchange.
Conventional Gas Ventilation, Liquid-Assisted High-Frequency Oscillatory Ventilation, and Tidal Liquid Ventilation in Surfactant-Treated Preterm Lambs
Authors: Degraeuwe P.L.J. , Thunnissen F.B.J.M. , Jansen N.J.G. , Dormaar J.T. , Dohmen L.R.B. , Blanco C.E.
Published: March 2018

This study was designed to compare the efficacy and potential protective or injurious effects of tidal liquid ventilation (TLV), liquid-assisted high-frequency oscillatory ventilation (LA-HFOV), and high PEEP conventional mechanical ventilation (CMV) in neonatal respiratory distress syndrome. Preterm lambs (124–126 days gestation), prophylactically treated with natural surfactant, were allocated to one of the treatment modalities or to an untreated fetal control group (F), euthanised after tracheal ligation. LA-HFOV animals received an intratracheal loading dose of 5 mL.kg-1 followed by a continuous intrapulmonary instillation of 12 mL.kg-1;h-1 FC-75 perfluorocarbon liquid. The ventilation strategies aimed at keeping clinically appropriate arterial blood gases for a study period of 5 hours. A histological lung injury score was calculated and semiquantitative morphometry was performed on lung tissue fixed by vascular perfusion.

The alveolar-arterial pressure difference for O2 was significantly lower throughout the study in TLV compared to CMV lambs; at 1, 2, and 5 hours, oxygenation was better in TLV when compared to LA-HFOV. Total lung injury scores in TLV lambs were significantly lower than in either CMV or LA-HFOV animals, but higher when compared to F. CMV and LA-HFOV induced an excess of collapsed and overdistended alveoli, whereas in TLV alveolar expansion was normally distributed around predominantly normal alveoli. CMV and LA-HFOV, but not TLV, were associated with an excess of dilated airways.

Thus, in the ovine neonatal RDS model, TLV compared favourably to either gas ventilation strategy by its more uniform ventilation, reduced lung injury, and improved gas exchange.
Optimized Growth Conditions for Tissue Engineering of Human Cardiovascular Structures
Authors: Hoerstrup S.P. , Zund G. , Schnell A. M. , Kolb S.A. , Visjager J.F. , Schoeberlein A. , Turina M.
Published: March 2018

Optimized in vitro formation of strong tissue is a prerequisite for tissue engineering of cardiovascular structures, such as heart valves and blood vessels. This study evaluates different growth media additives as to cell proliferation, extracellular matrix formation, and mechanical characteristics. Biodegradable polymers were seeded with human vascular myofibroblasts. Group A was cultured with standard medium, groups B, C, and D were in addition supplemented with ascorbate, fibroblast growth factor (bFGF), and both respectively. Analysis included histology, electron microsocopy, mechanical testing, and biochemical assays for cell proliferation (DNA) and extracellular matrix (collagen). DNA content increased in all groups, showing significantly more cells in group C and D after 14d. Collagen increased in all groups, except for C. Morphology showed viable, layered cellular tissue, with collagen fibrils after 2w, most pronounced in B and D. Mechanical properties decreased initially, stabilizing after 2w. In conclusion, standard nutrient media were efficient for seeded human vascular cells cultured on biodegradable meshes. Supplementation with bFGF+ascorbate resulted in enhanced early cell proliferation and structurally more mature tissue formation.
Apligraf – a Living Human Skin Equivalent for the Treatment of Chronic Wounds
Authors: Streit M. , Braathen L.R.
Published: March 2018

Apligraf, a manufactured living human skin equivalent, was the first true composite tissue analog to become commercially available. It has been approved by the FDA for the treatment of venous leg ulcers and diabetic foot ulcers. The tissue engineered bi-layered skin equivalent has both an epidermis and a dermis, which consist of keratinocytes and fibroblasts derived from neonatal foreskin and bovine collagen. The skin equivalent produces a great number of cytokines and growth factors and is immunologically well tolerated. The product is easy to handle in clinical use and can be applied in an outpatient setting.
Autotransfusion during Extracorporeal Membrane Oxygenation
Authors: Tolksdorf B. , Schmeck J. , Osika A. , Bender H.J. , Quintel M.
Published: March 2018

To reduce allogeneic blood transfusion requirements during extracorporeal membrane oxygenation (ECMO) we evaluated an autotransfusion device which processes and retransfuses erythrocytes of changed ECMO-systems. We studied 10 elective changes of ECMO-systems in 7 patients. Hemoglobin levels, the amount of retransfused autologous blood and of transfused allogeneic packed red blood cell units were documented within 48 h after the system change and compared to the measurements obtained from former ECMO-system changes without using any autotransfusion device. We determined the Horrowitz-index, Interleukin 6, 10, TNF-α and endothelin-I concentrations and coagulation parameters during the 48 hours after system change to study the compatibility of this procedure. Allogeneic blood transfusion was reduced from 7 to 2 units of packed red cells using the autotransfusion device. Additionally, no hints of any harmful side effects in these patients was observed.
The Efficacy of Nafamostat Mesilate on the Performance of a Hybrid-artificial Liver using a Polyurethane foam/porcine Hepatocyte Spheroid Culture System in Human Plasma
Authors: Yamashita Y. , Shimada M. , Tsujita E. , Rikimaru T. , Ijima H. , Nakazawa K. , Sakiyama R. , Fukuda J. , Funatsu K. , Sugimachi K.
Published: March 2018

Nafamostat mesilate (FUT) is a protease inhibitor of complement activation. The present study investigates whether FUT protects porcine hepatocytes from being injured by human plasma in a multi-capillary polyurethane foam packed-bed culture system (MC-PUF) such as the hybrid-artificial liver (PUF-HAL). Human plasmas with 1 mM of added ammonia were perfused using a small-scale PUF-HAL with porcine hepatocytes. FUT was continuously infused (10 μ g/ml, 50 μ g/ml,). The ammonia detoxification was maintained in human plasma for 24 hours and for 48 hours with FUT which suppressed the rapid increase of asparaginic acid aminotransferase (AST) and alanine aminotransferase (ALT). After 60 hours of perfusion, hepatocyte spheroids completely collapsed in the human plasma, but a small amount of hepatocyte spheroid was maintained by FUT. The effect of FUT was slightly greater at 50 μ g/ml than at 10 μ g/ml. Our results suggest that FUT has protective effects against porcine hepatocytes in human plasma, and our PUF-HAL using porcine hepatocytes can function in human plasma for about 48 hours with FUT.
Estimation of wall shear stress in bypass grafts with computational fluid dynamics method
Authors: Goubergrits L. , Affeld K. , Wellnhofer E. , Zurbrügg R. , Holmer T.
Published: March 2018

Coronary artery bypass graft (CABG) operation for coronary artery disease with different types of grafts has a large clinical application world wide. Immediately after this operation patients are usually relieved of their chest pain and have improved cardiac function. However, after a while, these bypass grafts may fail due to for example, neointimal hyperplasia or thrombosis. One of the causes for this bypass graft failure is assumed to be the blood flow with low wall shear stress. The aim of this research is to estimate the wall shear stress in a graft and thus to locate areas were wall shear stress is low. This was done with the help of a blood flow computer model. Postoperative biplane angiograms of the graft were recorded, and from these the three-dimensional geometry of the graft was reconstructed and imported into the computational fluid dynamics (CFD) program FLUENT. The stationary diastolic flow through the grafts was calculated, and the wall shear stress distribution was estimated. This procedure was carried out for one native vessel and two different types of bypass grafts. One bypass graft was a saphenous vein and the other one was a varicose saphenous vein encased in a fine, flexible metal mesh. The mesh was attached to give the graft a defined diameter. The computational results show that each graft has distinct areas of low wall shear stress. The graft with the metal mesh has an area of low wall shear stress (< 1 Pa, stationary flow), which is four times smaller than the respective areas in the other graft and in the native vessel. This is thought to be caused by the smaller and more uniform diameter of the metal mesh-reinforced graft.
A new blood donation strategy: Automated blood collection (ABC)
Authors: Menichella G. , Serafini R. , Ciarli M. , Paladini U. , Pierelli L. , Bunkens H. , Leone G.
Published: March 2018

Background

The aim of this study was to find out if Cobe Trima, a blood cell separator that automatically collects RBC, PLT and plasma, is adequate for routine multiple blood donation by apheresis.

Materials and Methods

Eighty donors underwent multiple blood component donations by Cobe Trima. Blood counts were determined on the apheresis products to analyze their quality.

Results

Eighty procedures were performed collecting 193 products. The average platelet yield was 3.5×1011 (± 0.46) in the 54 single product (SP) procedures and 7×1011 (± 0.88) in the 26 double product (DP) procedures. WBC contamination of the PLT products was 1.7 × 105 (1.2–4.2). The mean platelet efficiency was 60 ± 8.35% for SP and 66 ± 9.59% for DP. The hemoglobin (Hb) content per unit was 46.21 g (± 7.84) in 8 DP and 40.82 g (± 6.41) in 34 SP procedures.

Conclusion

The production of standardized blood components with good PLT yield and low WBC contamination plus high efficiency makes Trima one of the best blood cell separators of the new generation.
Excessive weight gain during peritoneal dialysis
Authors: Jolly S. , Chatatalsingh C. , Bargman J. , Vas S. , Chu M. , Oreopoulos D.G.
Published: March 2018

The authors carried out a retrospective chart review in 114 patients treated for at least two years at the Toronto Western Hospital Peritoneal Dialysis Unit and identified eight, who gained an “excessive” amount of weight equal to or greater than 10 kg of their initial weight. These patients had gained an average of 13.1 kg over the preceding two years. They are mostly males and their average age is 51 years. They are well-nourished normotenseive nondiabetics with mostly normal cardiac function. They are adequately dialyzed (per KT/V urea), have little residual renal function and typically have peritoneal membranes characterized by high average transport. According to BIA analysis, this weight gain was likely due to an increase in fat mass accompanied by a trend toward decreasing body-cell mass. This weight gain may be due to increased caloric intake secondary to dialysate glucose absorption in the setting of high average (peritoneal membrane) transport. Such excessive weight gain also may occur if these patients have polymorphism of the UCP-2 gene, which can alter metabolic rate.
Genes of major histocompatibility complex class II influence chronic C hepatitis treatment with interferon in hemodialysis patients
Authors: Dinçer D. , Besisik F. , Oğuz F. , Sever M. Sükrü , Kaymakoglu S. , Çakaloglu Y. , Demir K. , Türkoglu S. , Çarin M. , Okten A.
Published: March 2018

The prevalence of anti-HCV among patients on hemodialysis is consistently higher than in the general population, indicating that patients on hemodialysis programs are at risk of acquiring HCV infection. The response to interferon alpha 2b (IFN -α 2b) therapy in chronic C hepatitis depends on viral and host factors. We treated 22 chronic C hepatitis uremic patients with IFN- α 2b (3 MU three times a week) and compared interferon responsive and unresponsive patients with regard to HLA II genes. HLA II genes were investigated by PCR-SSP low resolution, anti-HCV with ELISA II and HCV-RNA with reverse transcriptase “nested” PCR. Findings: HLA DRB1*13 is 50% positive in the non-responder group (four women, four men, mean age; 28.8±11.9 years) and 7% in the responder group (five women, nine men, mean age; 32.2±7.8 years) (p<0.05). There was no difference with respect to HLA genes between controls (six women, eight men, mean age; 29.5 ± 12.8 years) and patients (nine women, 13 men, mean age; 31.0 ± 9.3 years) (HLA DRB1*13 is 28% and 22% positive, respectively). We conclude that major histocompatibility complex class II genes influence the outcome of chronic C hepatitis treatment with IFN -α 2b.
Isolated hemoperfused heart model of slaughterhouse pigs
Authors: Modersohn D. , Eddicks S. , Grosse-Siestrup C. , Ast I. , Holinski S. , Konertz W.
Published: March 2018

A model of hemoperfused slaughterhouse pighearts is described providing a wide range of applications which leads to a reduction in animal experiments.

The size of a pigheart, heart rate, coronary perfusion, metabolism, etc. are more comparable to conditions in patients than those in hearts of small laboratory animals.

Global heart function can be assessed either by measuring stroke volume, ejection fraction, Emaxetc. in the working model or by measuring intraventricular pressure with balloon catheters in the isovolumetric model. Regional cardiac function can be measured by sonomicrometry and ischemic and non-ischemic areas can be compared. Local metabolic changes are measurable as well with microdialysis.

Cardiac function can be kept on any given functional level by infusion of norepinephrine in spite of the fact that functional parameters are lower without adrenergic drive in vitro than in vivo.

Stable heart function can be maintained for several hours with only 500 to 1000 ml of blood because the blood is permanently regenerated by a special dialysis system. This model can be applied in many research projects dealing with reperfusion injuries, inotropic, antiarrhythmic or arrhythmogenic effects of certain drugs, immunological rejection, evaluation of imaging systems (NMR, echocardiography etc.) or cardiac assist devices.
Lactate dehydrogenase (LD) pattern in serum of calves with a total artificial heart (TAH)
Authors: Šalplachta J. , Nečas J.
Published: March 2018

Serum lactate dehydrogenase (LD) patterns of 16 calves with total artificial heart (TAH) were studied to identify a mean LD pattern in their serum (survival 51–293 days). Evaluations were made by the sum of vectors method (SV). The mean LD pattern was determined from serum LD patterns, interval days of 33 - 49 with TAH. Serum LD patterns of control and mean LD pattern differed significantly (n = 12, P < 0.05) in single isoenzymes and resultant vectors as the representatives of LD patterns. The different tissues with an increased risk of being affected were identified by evaluation of LD patterns in the serum of calves within term without perceptible acute damage and in the terminal stage of experiments. Such identified organs suggest that the organism under study is out of balance and specific treatment is needed.
A new semi-automatic endothelial cell seeding technique for biological prosthetic heart valves
Authors: Laube H.R. , Matthäus M.
Published: March 2018

Background

Until today, tissue heart valve prostheses have been made with biological dead porcine or bovine tissue. However, the durability of this tissue is limited due to degeneration and calcification. Surface seeding with vital human endothelial cells (EC) could improve valve durability and bio-compatibility. A new seeding technique that includes a newly developed special seeding device is presented here.

Methods

The aortic valve, including a cylinder of the aortic root, was prepared from a fresh porcine heart taken from the slaughterhouse. Porcine endothelial cells were removed by surface treatment with chemical detergent solutions. A new seeding device with an integrated CO2-incubator was designed. The device is composed of: the seeding chamber (SC), the rotation unit (RU), and the Control Unit (CU). The porcine aortic root cylinder with the valve leaflets is placed into the SC. A matrix of fibronectin is applied to the acellular valve. The SC is then filled with the endothelial cells suspended in modified Dulbecco's eagle medium (DMEM). Under cell culture conditions, the endothelial cell seeding of the tissue valve is established by rotating the valve around two orthogonal axes simultaneously and independently. This is done following the software controlled preset parameters.

Results

Using initial endothelial cell seeding concentrations of 6×106 endothelial cells/ml DMEM, it was possible to achieve a seeding efficiency of 80–85% within 3–4 hrs. Cell viability tests proved that 90–95% of the seeded endothelial cells are vital after the seeding procedure.

Conclusions

This new seeding technique allows the complex warped surface of a tissue heart valve to be covered with vital endothelial cells to form a confluent endothelial cell monolayer.
Short- and long-term mechanical cardiac assistance
Authors: Berdat P. A. , Gygax E. , Nydegger U. , Carrel T.
Published: March 2018

With the increase in high risk patients undergoing cardiac surgery and the substantial mortality among patients waiting for cardiac transplantation, the need for mechanical circulatory support is growing. Several devices are currently available, ranging from the intra-aortic balloon pump to fully implantable ventricular assist devices. Each system has its own features, and proper patient selection as well as the timing of implantation is sometimes difficult. Algorithms for stepwise management in subgroups of patients remain controversial and the concepts of weaning patients after myocardial recovery during mechanical circulatory support need further evaluation for their long-term effects. Future identification of valuable prognostic and risk factors may help in decision-making and allow for improved survival of these often very ill patients. In this report we review the concepts of mechanical circulatory support at our institution with emphasis on a detailed overview of technical features of extracorporeal life support.
IABP Assistance: A Test Bench for the Analysis of its Effects on Ventricular Energetics and Hemodynamics
Authors: Ferrari G. , Górczyńska K. , Mimmo R. , De Lazzari C. , Clemente F. , Tosti G. , Guaragno M.
Published: March 2018

IABP assistance is frequently used to support heart recovery, improving coronary circulation and re-establishing the balance between oxygen availability and consumption. Hemodynamic and energetic parameters (endocardial viability ratio, ventricular energetics) are used to evaluate its effectiveness which depends on internal (timing, balloon volume and position) and external factors (circulatory conditions). Considering short, medium and long-term effects of IABP, the first depends on its mechanical action, the latter on the changes induced in circulatory parameters. The analysis of the first is important because conditions for the onset of a virtuous cycle able to support ventricular recovery are created. Simulation systems could be helpful in this analysis for the implicit reliability and reproducibility of the experiments, provided that they are able to reproduce both hemodynamic phenomena and energetic relationships. The aim of this paper is to present a system originally developed to test mechanical heart assist devices and modified for IABP testing. Data reported here are obtained from in vitro experiments. A partial verification, obtained from the literature is presented.
A mathematical model of the fetal cardiovascular system based on genetic algorithms as identification technique
Authors: Grigioni M. , Carotti A. , Daniele C. , D'Avenio G. , Morbiducci U. , Di Benedetto G. , Albanese S. , Di Donato R. , Barbaro V.
Published: March 2018

The development of fetal cardiac surgery, considered the ultimate goal in the treatment of congenital cardiac malformations, needs to be supported by detailed knowledge of the blood circulation in the fetal cardiovascular system. The hemodynamic behavior in distal territories is usually inferred from vessel resistance indices, which give limited physiological information. This study presents a mathematical model of the human fetal global cardiovascular system, developed to clarify the relationships and differences existing between upper and lower body circulation. We modelled the heart with two time-varying capacitances, each representing the respective ventricle's pressure-volume relationship. The fetal vascular system was represented using two six-element Windkessel models, for the upper and lower body respectively. We obtained the identification of the set of circuital and elastance function parameters of the model using Genetic Algorithms (GAs), which follow the laws of evolutionary theory.

We compared the results of our numerical study on the model identified with data collected from measurements and literature, to validate the proposed global cardiovascular system model of the human fetus. This model is intended as an instrument to investigate the differences in blood distribution between the different vascular districts in the upper and lower fetal body and the role of the aortic isthmus, the small tract of vessel connecting upper and lower fetal vascular beds; it may also represent a useful tool in the assessment of dynamic balance during mechanical assistance of circulation.
Preparation and characterization of SNO-PEG-hemoglobin as a candidate for oxygen transporting material
Authors: Nakai K. , Togashi H. , Yasukohchi T. , Sakuma I. , Fujii S. , Yoshioka M. , Satoh H. , Kitabatake A.
Published: March 2018

Acellular hemoglobin (Hb) derivates developed as oxygen carriers are known to cause hypertensive reactions due to their nitric oxide (NO) scavenging action. To modulate this undesired activity, we have developed a new Hb derivative, s-nitrosylated polyethylene glycol (PEG)-modified hemoglobin (SNO-PEG-Hb), which can deliver oxygen and NO. After human Hb was modified with PEG to increase its molecular weight, the free sulfhydryl groups of Hb were s-nitrosylated with s-nitrosoglutathione. Administration of unmodified Hb into anesthetized rats caused a hypertensive reaction, while s-nitrosylated Hb derivatives such as SNO-Hb and SNO-PEG-Hb did not raise blood pressure. The plasma half-lives of heme and NO bound to SNO-PEG-Hb were 11.5 and 2.4 hours respectively, indicating that the s-nitrosylated Hb derivative may act as a slow-releasing agent for NO. Based on these findings, SNO-PEG-Hb is a useful candidate for a blood substitute and tool for oxygen therapeutics.
Renal Replacement Therapy: Physical Properties of Hollow Fibers Influence Efficiency
Authors: Düngen H.-D. , Von Heymann C. , Ronco C. , Kox W.J. , Spies C.D.
Published: March 2018

Introduction

Physical properties of filters for continous renal replacement therapy have a great impact on biocompatibility. According to Poiseuille's law, a filter with more and shorter hollow fibers should offer a decreased pressure drop and, therefore, lower transmembrane pressure (TMP). The aim of this study was to study the effect of a new filter configuration in terms of TMP and clotting compared with the standard configuration.

Methods

In a prospective randomized cross-over study 2 polysulphone hollow fiber hemofilters, one handmade, which differed only in length and number of hollow fibers were compared. In each group 12 filters were investigated during continous venovenous hemofiltration in patients with acute renal failure due to septic shock. Pressures were measured every 3 hours and running time until filter clotting was documented. Mediators before and after the filter, at the end of treatment and in filtrate were assessed.

Results

The standard filter with longer hollow fibers had significantly lower TMPs (106 vs.194 mmHg, p=0.02) and longer running times (1276 vs. 851 min, p=0,04). There were no differences in hematocrit, total protein, cellular and plasmatic coagulation or blood temperature. No significant elimination of mediators was shown.

Conclusion

In contrast to our expectations, the filter with the longer hollow fibers had a better performance, as it ran longer and had lower TMP. This may be due to slower blood flow leading to an increase in blood viscosity in a filter with a larger cross section.
Ethylene Glycol Dimethacrylate Cross-linking Anion Exchange Resin as Phosphate Binder: Effects on Rat gut and Digestion by Small Intestine Contents
Authors: Inoue H.
Published: March 2018

In the present study, ethylene glycol dimethacrylate cross-linking 4-vinylpyridinium anion exchange resin (EGDMA-4VP) effectively bound dietary phosphate in normal rats. However, EGDMA-4VP induced more adverse effects in rat gut than cellulose or Dowex 1X2 (both of which have higher water content), and caused damage to the intestine. In order to resolve this seeming paradox, digestion of EGDMA-4VP with rat small intestine content (S-9 fraction) and carboxyl esterase was investigated in vitro to examine the stability of the resin under conditions it would be subjected to as an orally administered medicine. EGDMA-4VP was digested by small intestinal enzymes, with the exception of carboxyl esterase, and the degradation product ethylene glycol (EG) caused reversible relaxation of longitudinal muscle (but not circular muscle) in rat small intestine. Degradation products increased uptake of 3H2O into primary cultured rat small intestinal muscle cells, but the increase was not significant.