bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural Changes in Pericardium Tissue Modified with Tannic Acid
Authors: Cwalina B. , Turek A. , Nozynski J. , Jastrzebska M. , Nawrat Z. 
Published: January 2018

Introduction Structural modification of proteins, mainly collagen in connective tissues, is important in the manufacture of tissue-derived biomaterials. Natural compounds like genipin or tannic acid (TA) have been proposed instead of glutaraldehyde which shows cytotoxic effects on the processed tissue. Furthermore, calcification of glutaraldehyde-treated tissue limits the functional lifetime of bioprostheses. TA is known to form numerous hydrogen bonds with proteins. The purpose of our study was to investigate structural changes in porcine pericardium upon chemical modification with tannic acid. Methods Porcine pericardium tissue (PP) was soaked in 2% TA for 4, 24 or 48 hours. Changes in tissue structure were studied using electrophoresis (SDS-PAGE) and histological examination. Structural stability of PP tissue was evaluated by SDS/NaCl extraction method and enzymatic digestion with pancreatin. Results TA-modification of PP caused a time-dependent decrease in the number of peptides extracted from tissue. Microscopic studies revealed no significant morphological differences between native and TA-modified tissues, except for the native pancreatin-digested tissue where lack of both cells and low molecular peptides was observed. Conclusion Modification of PP with TA causes the structural changes leading to an increase in the tissue resistance to SDS/NaCl extraction and enzymatic digestion, providing experimental evidence for the higher structural stability of TA-treated tissue.
Development of a Hybrid (numerical-hydraulic) Circulatory Model: Prototype Testing and Its Response to IABP Assistance
Authors: Ferrari G. , Kozarski M. , De Lazzari C. , Ska K. Górczyń , Tosti G. , Darowski M. 
Published: January 2018

Merging numerical and physical models of the circulation makes it possible to develop a new class of circulatory models defined as hybrid. This solution reduces the costs, enhances the flexibility and opens the way to many applications ranging from research to education and heart assist devices testing. In the prototype described in this paper, a hydraulic model of systemic arterial tree is connected to a lumped parameters numerical model including pulmonary circulation and the remaining parts of systemic circulation. The hydraulic model consists of a characteristic resistance, of a silicon rubber tube to allow the insertion of an Intra-Aortic Balloon Pump (IABP) and of a lumped parameters compliance. Two electro-hydraulic interfaces, realized by means of gear pumps driven by DC motors, connect the numerical section with both terminals of the hydraulic section. The lumped parameters numerical model and the control system (including analog to digital and digital to analog converters) are developed in LabVIEW™ environment. The behavior of the model is analyzed by means of the ventricular pressure-volume loops and the time courses of arterial and ventricular pressures and flows in different circulatory conditions. A simulated pathological condition was set to test the IABP and verify the response of the system to this type of mechanical circulatory assistance. The results show that the model can represent hemodynamic relationships in different ventricular and circulatory conditions and is able to react to the IABP assistance.
A Mathematical Model for the Prediction of Solute Kinetics, Osmolarity and Fluid Volume Changes during Hemodiafiltration with On-Line Regeneration of Ultrafiltrate (HFR)
Authors: Ursino M. , Colì L. , Magosso E. , Capriotti P. , Fiorenzi A. , Baroni P. , Stefoni S. 
Published: January 2018

Hemodiafiltration with on-line regeneration of ultrafiltrate (HFR) is a technique indicated for the treatment of dialysis patients affected by inflammatory syndrome and malnutrition. In the present work, a mathematical model, which describes intradialytic fluid and solute kinetics during standard diffusive dialysis, has been adapted to analyze solutes and fluid dynamics during HFR. The model is an improved version of our previous ones, and represents a good compromise between simplicity and reliability. It considers the intradialytic kinetics of sodium, potassium and urea, and two body fluid compartments: intracellular and extracellular. Moreover, the model includes simple equations to predict the intradialytic time pattern of osmolarity. The model has been experimentally validated by using 9 HFR sessions on 9 patients (one per each patient), comparing the time course of plasma solutes and osmolarity measured every 30 minutes during HFR, with those predicted by the model. Predictions are performed a priori, i.e., without any parameter adjustment, but just starting from knowledge of a few quantities (plasma sodium, potassium, urea, osmolarity and body weight) at the beginning of the session. The average deviations between model and real data (sodium: 1.9 mEq/L; potassium: 0.32 mEq/L; urea: 1.04 mmol/L; osmolarity: 5.02 mosm/L) are of the same order as measurement errors and similar to those obtained using our previous models in standard and profiled hemodialysis. Moreover, the prediction on sodium concentration only scarcely worsens (from 1.9 to 2.02 mEq/L) if default values are used for the initial value of other solutes in blood (i.e., if the algorithm uses only initial body weight and initial sodium concentration in plasma). The results confirm the good predictive capacity of the model in HFR, and suggest its possible innovative use to optimize sodium balance in HFR, from knowledge of only the sodium concentration in the ultrafiltrate. (Int J Artif Organs 2006; 29: 1031–41)
Mobile Telecare System for Intensive Insulin Treatment and Patient Education. First Applications for Newly Diagnosed Type 1 Diabetic Patients
Authors: Ładyżyński P. , WÓJcicki J.M. , Krzymień J. , Foltyński P. , Migalska-Musiał K. , Tracz M. , Karnafel W. 
Published: January 2018

The aim of the work was to develop and to evaluate the clinical efficiency of a mobile telecare system implementing teleconsultations based on the continuous transmission of patient-collected data directly to the physician and to the clinic. The developed TeleMed system consists of the patients' and the diabetologist's mobile units, the diabetologist's clinic and home workstations and the clinical server. The evaluation of the system was performed on a group of 13 newly diagnosed type 1 diabetic patients, during a single-arm study with 3-days run-in period, including a one-day intensive educational program, and 3-week study period, when the intensive insulin treatment was conducted without visits of patients to the clinic. The MBG dropped from 7.2 ± 1.7 mmol/L before the study to 6.1 ± 1.0 mmol/L in the third week of the study (P = 0.02) and the J-index from 30.2±19.2 to 19.7±7.7 (P = 0.04). Hemoglobin A1c decreased from 11.8 ± 3.3% to 8.6 ± 1.2% (P = 0.0002) in one month. The total daily insulin dose declined from 39.9 ± 8.5 U to 20.0 ± 9.6 U (P = 0.000006). The number of hypoglycemia episodes per patient per day decreased by 66% (P = 0.08) and the number of hyperglycemia episodes was reduced by 47% (P < 0.0001). The TeleMed facilitates not only efficient realization of the intensive insulin treatment but also successful remote patient training and education. No formal patient satisfaction study was done. However, some of the findings indicate that the application of the developed system increases patient self-confidence and quality of life. (Int J Artif Organs 2006; 29: 1074–81)
Long-Term Peritoneal Dialysis Experience in Portugal
Authors: Rodrigues A.S. , Matos C.B. , Silva F. , Fonseca I. , Nogueira C. , Santos J. , Silva A.S. , Cabrita A. 
Published: January 2018

Peritoneal dialysis (PD) penetration varies widely. Since the beginning of this therapy, indications have changed and outcomes have improved. In Portugal, PD still remains clearly underutilized. The results of a 20 year PD programme were evaluated: 312 cumulative patients, 48±16 years, 27% >60 years old, 27% diabetic, 59% with prior hemodialysis (HD). The main reason for admission was vascular access failure (48.7%). Admission due to patient preference has increased significantly between first and second decades of the programme (33% vs 47% (P<0.001)); 98 patients (31.4%) were treated with automated PD but this prescription increased to 43% of the active patients. A total of 376 Tenckhoff catheters were surgically implanted, recently by the Popovich-Moncrief technique (77 catheters): the cumulative survival was 82%, 64% and 50% at 1, 3 and 5 years, respectively. A better catheter survival was found in the last decade (85.7%, 69.6%, 54.8% versus 77.3%, 55.5%, 40.2%, at 1, 3 and 5 years, respectively (P=0.007). The patient and technique cumulative survivals were 91, 74, 55% and 85, 67, 41%, at 1, 3, and 5 years, respectively. The main drop-out was to hemodialysis (35.8%), followed by death (23.7%), and transplantation (21.5%). Peritonitis and access-related infections caused 35% of the transfer to HD. Cardiovascular events caused 58% of deaths. The median PD retention was 35.5 months. The rate of peritonitis has decreased to one episode /30 patient months. Hospital admission has also decreased to 4.8 days/patient year. This is a first report on long-term PD experience in Portugal. It has been an effective modality of renal replacement therapy, reflected by the growing patient preference in our PD programme. Experience, knowledge and new technical solutions have improved the outcomes.
Autopsy Findings in Patients on Postcardiotomy Extracorporeal Membrane Oxygenation (ECMO)
Authors: Rastan A.J. , Lachmann N. , Walther T. , Doll N. , Gradistanac T. , Gommert J.F. , Lehmann S. , Wittekind C. , Mohr F.W. 
Published: January 2018

Objectives To assess the clinical sensitivity of causes of death, concomitant diseases and postoperative complications including thromboembolic events in ECMO patients. Methods: Between January 2000 and December 2004 154/202 patients (76.2%) died after postcardiotomy ECMO circulatory support. Autopsy was performed in 78 (50.6%) consecutive patients. Clinical and post-mortem data were prospectively recorded and compared concerning causes of death and postoperative complications including venous and arterial thromboembolisms and significant comorbidities. Results Mean age was 62.1±11.3 years, ejection fraction was 43.4±17.3%. 39.7% were emergency operations including acute coronary syndrome in 25.6% and preoperative cardiogenic shock in 28.2%. Successful ECMO weaning rate was 43.6%. Mean postoperative survival was 11.3 days. Premortem unknown concomitant diseases were found in 63 patients (80.8%) with clinical relevance in 9 patients (11.5%). Clinically unrecognized postoperative complications were found in 59 patients (75.6%) including acute cerebral infarction (n=7), acute bowel ischemia (1), intestinal perforation (3), pneumonia (4), venous thrombus formation (25) and systemic thromboembolic events (24). Clinically based causes of death were cardiac in 62.8%, multi-organ failure in 10.3%, cerebral in 5.1%, respiratory in 10.3%, fatal pulmonary embolism in 2.6%, technical in 5.1%, and others in 3.8%. Unexpected causes of death were found by autopsy in 22 patients (28.2%) including myocardial infarction (n=5), acute heart failure (4), fatal pulmonary embolism (2), pneumonia (2), ARDS (1), lung bleeding (1), fatal cerebrovascular event (4) and multiorgan failure (3). Conclusions In ECMO patients major discrepancies between clinical and post-mortem examination were found. The true incidence of thromboembolic events is highly underestimated by clinical evaluation.
Autonomously Contracting Human Cardiomyocytes Generated from Adult Pancreatic Stem Cells and Enhanced in Co-Cultures with Myocardial Biopsies
Authors: Guldner N.W. , Kajahn J. , Klinger M. , Sievers H.-H. , Kruse C. 
Published: January 2018

Myocardial regeneration with artificially applied cardiomyocytes is emerging as a promising issue of significant scientific and clinical impact. Nevertheless the source of cells for human cardiomyocyte differentiation especially from adult tissue is still unclear. We hypothesized that human pancreatic stem cells may differentiate into cardiomyocyte-like cells and may increase in number when co-cultured with myocardial tissue. Adult stem cells were harvested from pancreatic tissue of patients undergoing operative procedures including the pancreas. The cells were selected, cultured and passaged. To promote self-differentiation into cardiomyocytes, human pancreatic stem cells were co-cultered with biopsies of human myocardium. After co-culture and breeding, cells were phenotyped as well with respect to RNA, protein and cardiomyocyte specificity at the electron-microscopic level. Pancreatic stem cells have already differentiated spontaneously into cardiomyocyte-like cells performing netlike cell clusters with rare but distinct multilocular cellular autonomous contractions with a frequency of about 20 beats per minute. The number of contracting areas however could be enhanced by co-culture with human myocardial biopsies. On RNA and protein levels as well as in electron-microscopy evidence for cardiomyocyte specificity is shown. To the best of our knowledge this is the first report demonstrating the feasibility of generating autonomously contracting cardiomyocyte-like cells from adult human pancreatic stem cells and their enhancement by myocardial co-culture. This procedure might prove to be an alternative source and method for myocardial regenerative medicine.
Hepatitis C Virus Infection in Hemodialyzed Patients
Authors: Vecchi M. LI , La Spada E. , Vecchi V. LI , Montalto G. 
Published: January 2018

In spite of our present improved knowledge of the epidemiology and pathways of contamination of the hepatitis C virus (HCV), infection still remains a public health problem. One category of patients who have suffered greatly from the consequences of HCV infection is certainly that of hemodialysis patients. In the past, in fact, their need for transfusions exposed these patients to infection and, as a result, subjects on dialysis for over 15 years are today paying the price for those inevitable transfusions, as the virus and its pathways of contagion were unknown then. However, still today, albeit at a much lower prevalence, even subjects with a shorter dialysis age present a higher prevalence of anti-HCV than the general population, suggesting that other factors of contamination than the classical ones contribute to keeping this prevalence high. Its clinical course is generally asymptomatic and the biological and virological progression of the disease is quite particular and apparently benign. The mortality rate of infected patients is higher than in non-infected subjects and this is not only due to the liver disease itself but also to cardiovascular disorders. Even anti-viral therapy, after its first timid steps, is now routinely used in patients with a certain degree of liver damage and kidney transplant candidates. The appropriate use of pegylated interferons is expected to improve the percentage of eradication and limit side effects, in parallel with what has been observed in non-dialysis patients. Ribavirin, however, is at present contraindicated due to its toxic effects on red blood cells as hemoglobin content could be dangerously reduced in these patients.
Correlation between HSP-72 Expression and IL-8 Secretion in Human Mesothelial Cells
Authors: Bender T. O. , Riesenhuber A. , Endemann M. , Herkner K. , Witowski J. , JöRres A. , Aufricht C. 
Published: January 2018

Background Cytotoxicity of peritoneal dialysis fluid (PDF) and peritoneal inflammation are currently regarded as the two major culprits for chronic mesothelial injury and peritoneal membrane failure. In this study, we correlated induction of HSP-72, as a marker of the cellular stress response, to secretion of IL-8, as a marker for pro-inflammatory cytokines, in mesothelial cells upon sublethal PDF exposure. Methods Primary omental cell cultures of human mesothelial cells were subjected to sublethal PDF exposure times (CAPD2, Fresenius, Germany). At the end of a 24 hour recovery period, induction of HSP-72 in the cell homogenate and IL-8 secretion in the supernatant was assessed by immunodensitometry and ELISA, respectively. Results PDF exposure times from 15 min to 60 min resulted in progressively increased HSP-72 expression levels (267 vs 320 vs 419% of controls, p<0.05 vs controls) as well as increased IL-8 secretion (323 vs 528 vs 549% of controls, p<0.05 vs controls) with full cell viability (MTT unchanged to control). HSP-72 expression was statistically significantly correlated with IL-8 secretion. Conclusions: The significant correlation between HSP-72 expression and IL-8 secretion suggests that the regulation of pro-inflammatory pathways in mesothelial cells exposed to PDF may represent an integral part of their stress response. Future studies to investigate the cellular regulatory mechanism involved are warranted.
ECG-Triggered Muscular Counterpulsation for Treatment of Low Cardiac Output
Authors: Walpoth B.H. , Aregger C. , Lapanashvili L. , Mettler D. , Carrel T. , Hess O.M. 
Published: January 2018

Background. Skeletal muscular counterpulsation (MCP) has been used as a new non-invasive technique for treatment of low cardiac output. The MCP method is based on ECG-triggered skeletal muscle stimulation. The purpose of the present study was to evaluate acute hemodynamic changes induced by MCP in the experimental animal. Methods. Eight anaesthetized pigs (43±4 kg) were studied at rest and after IV β-blockade (10 mg propranolol) before and after MCP Muscular counterpulsation was performed on both thighs using trains (75 ms duration) of multiple biphasic electrical impulses with a width of 1 ms and a frequency of 200 Hz at low (10 V) and high (30 V) amplitude. ECG-triggering was used to synchronize stimulation to a given time point. LV pressure-volume relations were determined using the conductance catheter. After baseline measurements, MCP was carried out for 10 minutes at low and high stimulation amplitude. The optimal time point for MCP was determined from LV pressure-volume loops using different stimulation time points during systole and diastole. Best results were observed during end-systole and, therefore, this time point was used for stimulation. Results. Under control conditions, MCP was associated with a significant decrease in pulmonary vascular resistance (-18%), a decrease in systemic vascular resistance (-11%) and stroke work index (-4%), whereas cardiac index (+2%) and ejection fraction (+6%) increased slightly. Pressure-volume loops showed a leftward shift with a decrease in end-systolic volume. After β-blockade, cardiac function decreased (HR, MAP, EF, dP/dt max), but it improved with skeletal muscle stimulation (HR +10% and CI +17%, EF +5%). There was a significant decrease in pulmonary (-19%) and systemic vascular resistance (-29%). Conclusions. In the animal model, ECG-triggered skeletal muscular counterpulsation is associated with a significant improvement in cardiac function at baseline and after IV β-blockade. Thus, MCP represents a new, non-invasive technique which improves cardiac function by diastolic compression of the peripheral arteries and veins, with a decrease in systemic vascular resistance and increase in cardiac output.
Hepatitis C Virus Infection and Rituximab Therapy after Renal Transplantation
Authors: Fabrizi F. , Martin P. , Elli A. , Montagnino G. , Banfi G. , Passerini P. , Campise M.R. , Tarantino A. , Ponticelli C. 
Published: January 2018

Background. Rituximab, a chimeric monoclonal antibody, has been successfully given in various diseases including HCV-associated mixed cryoglobulinemia. However, only preliminary data exists on its efficacy and safety after renal transplantation. Methods. We report on a renal transplant recipient with chronic hepatitis C who received rituximab therapy for gastric cancer. Four rituximab infusions of 375 mg/m2 were given. Results. Rituximab therapy was complicated by cholestatic hepatitis C with very high HCV RNA levels; liver insufficiency occurred. The patient developed bacterial pneumoniae and respiratory insufficiency was the cause of death. Although other mechanisms cannot be excluded, we found that rituximab therapy was implicated in the pathogenesis of cholestatic hepatitis C in our patient. Conclusions. We suggest that rituximab therapy may be associated with significant side effects. More experience has to be accumulated before any conclusions on efficacy and safety of rituximab therapy after RT can be drawn.
State of the Art on Autologous Mesothelial Transplant in Animals and Humans
Authors: Di Paolo N. , Sacchi G. , Del Vecchio M.T. , Nicolai G. , Brardi S. , Garosi G. 
Published: January 2018

Sixteen years ago rabbit and human mesothelial cells were successsfully cultured and autoimplanted. The aim of the study was merely to demostrate that mesothelial implant was possible and interesting not only in peritoneal dialysis, but also in the vaster field of medicine and surgery concerning all the mesothelial districts of the body. The aim of this paper is to recollect the steps which have led to autolougous mesothelial transplantation and verify if the tecnique has been validated and adopted by others. Review of the literature published in the last 15 years shows that intraperitoneal transplantation of mesothelial cells has been effective in reducing the formation of peritoneal adhesions, and in remodeling the area of mesothelial denudation. New studies on the mesothelial cell opened the way to costruction of transplantable tissue-engineered artificial peritoneum, to the utilization of mesothelial progenitor cells and to find simple metods to collect autologous mesothelial cells. Finally mesothelial trasnsplantation may represent a new neovascular therapy in the prevention and treatment of ischemic coronaric heart disease.
PIV Validation of Blood-heart Valve Leaflet Interaction Modelling
Authors: Kaminsky R. , Dumont K. , Weber H. , Schroll M. , Verdonck P. 
Published: January 2018

The aim of this study was to validate the 2D computational fluid dynamics (CFD) results of a moving heart valve based on a fluid-structure interaction (FSI) algorithm with experimental measurements. Firstly, a pulsatile laminar flow through a monoleaflet valve model with a stiff leaflet was visualized by means of Particle Image Velocimetry (PIV). The inflow data sets were applied to a CFD simulation including blood-leaflet interaction. The measurement section with a fixed leaflet was enclosed into a standard mock loop in series with a Harvard Apparatus Pulsatile Blood Pump, a compliance chamber and a reservoir. Standard 2D PIV measurements were made at a frequency of 60 bpm. Average velocity magnitude results of 36 phase-locked measurements were evaluated at every 10° of the pump cycle. For the CFD flow simulation, a commercially available package from Fluent Inc. was used in combination with in-house developed FSI code based on the Arbitrary Lagrangian-Eulerian (ALE) method. Then the CFD code was applied to the leaflet to quantify the shear stress on it. Generally, the CFD results are in agreement with the PIV evaluated data in major flow regions, thereby validating the FSI simulation of a monoleaflet valve with a flexible leaflet. The applicability of the new CFD code for quantifying the shear stress on a flexible leaflet is thus demonstrated. (Int J Artif Organs 2007; 30: 640–8)