bluuebunny/crossref_metadata_2025 huggingface dataset:
Chitosan-Coated Alginate Membranes for Cultivation of Limbal Epithelial Cells to use in the Restoration of Damaged Corneal Surfaces
Authors: ÖZtüRk E. , ErgüN M.A. , ÖZtüRk Z. , NuröZler A.B. , KeçEci K. , ÖZdemir N. , Denkbaş E.B.
Published: January 2018

Some chemicals or thermal burns may result in abnormal reepithelialization by conjunctival epithelial cells and it causes different types of damage on the cornea surface. When reepithelialization does not occur, chronic inflammation and neovascularization develop, often leading to stroma scarring and/or ulceration. The aim of this study is to restore the human corneal surface with autologous corneal epithelial sheets generated by serial cultivation of the limbal epithelial cells over the different compositions of composite membranes. The composite membranes were prepared by coating the alginate membrane with chitosan. In this method, alginate membrane was prepared by precipitation of the sodium alginate solution in calcium chloride solution. Alginate membranes were washed, dried and immersed into the chitosan solutions to prepare composite membranes. The composite membranes were characterized based on their morphology, hydrophilicity, swellability, and chemical structure. In the last part of the study, composite membranes were used as base matrices for limbal epithelial cell cultivation. The cell cultivation on polymeric membranes was investigated as the in vitro studies. In these studies cell attachment, spreading and growth on polymeric membranes were evaluated.
Multi-Scale Analysis of the Toraymyxin Adsorption Cartridge Part II: Computational Fluid-Dynamic Study
Authors: Fiore G.B. , Soncini M. , Vesentini S. , Penati A. , Visconti G. , Redaelli A.
Published: January 2018

Extracorporeal endotoxin removal by means of the Toraymyxin device is based on the ability of polymyxin B to bind endotoxins with a high specificity. The endotoxins/polymyxin molecular interactions were computationally analyzed in a parallel work (Part I). In this paper we investigate with a multi-scale approach the phenomena involving blood and plasma fluid dynamics inside the device. The macro- and mesoscale phenomena were studied by means of 3D models using computational fluid dynamics. The flow behavior in the sorbent material was focused, modeling the sorbent as a homogeneous porous medium at the macroscale level, or accounting for the realistic geometry of its knitted fibers at the mesoscale level. A microscale model was then developed to analyze the behavior of endotoxin molecules subjected to the competition of flow drag and molecular attraction by fibergrafted polymyxin B. The macroscale results showed that a very regular flow field develops in the sorbent, furthermore supplying the peak velocity to be input in the lower-scale model. The mesoscale analysis yielded the realistic range for wall shear stresses (WSSs) acting on fiber walls. With WSS values in the entire range, the results of the microscale analysis demonstrated that the capability of polymyxin B to capture endotoxin molecules from the flow extends at distances one order of magnitude greater than the characteristic distance of the stable intermolecular bond. We conclude that the use of an integrated, multi-scale analysis allows for a comprehensive understanding of the complex mechanisms involved in endotoxin sorption phenomena with immobilized polymyxin B.
Informed Consent for Therapy and Research in Continuous Renal Replacement Therapy: An International Survey
Authors: Zamperetti N. , Bellomo R. , Ronco C. , Bolgan I. , Ricci Z.
Published: January 2018

Objective

To study the approach of health care workers (HCW) to informed consent for therapy and research in the field of continuous renal replacement therapy (CRRT)

Design

Administration of questionnaire.

Setting

Two International Courses on Critical Care Nephrology (CCN) held in Vicenza and Melbourne.

Participants

Eight hundred and twenty one course participants.

Results

We obtained 349 analysable questionnaires (42.5% of participants). Only 22.5% of responders always obtain informed consent for CRRT; 70.3% just inform patients/relatives without seeking consent, 7.1% never obtain informed consent. In ICU patients, informed consent is considered “good, correct and feasible” for therapy and for research by only 13% and 27% of responders, respectively. Consent for clinical research obtained from the next of kin or legal guardian is considered “good, correct and feasible” by 56.3% of respondents, while 39.1% believe that next of kin or legal guardians can not really make informed decisions. Finally, nearly half of responders think that present rules hamper research in ICU. For many questions, significant variability of responses was found according to profession, speciality and origin of responders.

Conclusions

In the field of CRRT, stated practice, beliefs and currently accepted ethical standards vary greatly according to profession, speciality and origin. A significant disagreement between what is widely promoted to be the “correct” approach and what is currently done is evident.
Design of a Subcutaneous Vascular Access Device Using Ni-Ti SMA Clamps for Hemodialysis
Authors: Choi S.W. , Nam K.W. , Lee J.C. , Yoon K.H. , Kim J.C. , Sun K. , Min B.G.
Published: January 2018

A subcutaneous vascular access device which utilizes an Ni-Ti shape memory alloy (Ni-Ti SMA) spring, has been developed as a new method for subcutaneous vascular access in the treatment of hemodialysis patients. Until now, the connection between the SVAD and needle cannot be externally monitored, and the clamp must be opened and closed with a percutaneous needle by a nephrologist.

The SMA-SVAD accomplishes the opening and closing of its clamp using two Ni-Ti SMA springs, and a transcutaneous energy transmission system (TET) transmits energy to the Ni-Ti SMA springs without the need for percutaneous wires. Two SMA springs open and close the clamp of the SMA-SVAD, without affecting any of the other parts of the system. Wasted thermal energy is reduced to minimal values via electrical regional heating methods. The state of the SMA-SVAD can be monitored according to the amount of power consumed by the external energy transmitter.

In in-vitro experiments, when the clamp was opened and the pressure difference in the hemodialysis machine was set to 50 mmHg, water flow through SMA-SVAD reached 500 ml/min. The maximal surface temperatures of the SVAD and catheter were successfully maintained at proper levels (38~39°C), 2~3 degrees higher than the temperature of the surrounding tissues. The time elapsed from the initiation of energy transmission until the opening of the SMA clamp was 5 seconds.
In Vitro Set-Up of Modified Blalock Taussig Shunt: Vascular Resistance-Flow Relationship
Authors: Bakir I. , Van Tricht I. , Verdonck P. , Meyns B.
Published: January 2018

Background

A modified Blalock-Taussig (mBT) shunt is an anastomosis created between the systemic and pulmonary arterial tree in order to improve pulmonary blood flow in neonates and children with congenital heart disease. The aim of this study was to assess vascular resistance-flow relationship in an in vitro set-up of a modified Blalock Taussig shunt.

Methods

A shunt set-up was constructed with the vessels of a sheep. A modified BT shunt was anastomosed between an innominate (brachiocephalic) and a right pulmonary artery. A Medos pump (ventricular assist device) was used to create pulsatile flow. Three different mean pulmonary artery flow rates (QPA) were applied. Once mean pulmonary and mean aortic flows (QAO) were fixed, shunt flow rates for twelve different pulmonary vascular resistances (Rp) were investigated.

Results

For all three pulmonary flow rates, the shunt flow decreased with increasing pulmonary resistance. In addition, systemic flow decreased compared to pulmonary flow. When pulmonary flow rate was set at 800 ml/min and aorta flow rate at 900 ml/min, the distribution of flow between pulmonary and systemic organs flow rates ranged between 69% - 70% and 30% - 31% respectively. Similarly, when both pulmonary and aorta flow rates were set at 900 ml/min, pulmonary and systemic organ flows ranged between 73% - 77% and 23% - 27% respectively. For pulmonary and aorta flow rates of 1000 ml/min and 900 ml/min, respectively, the distribution of flow between pulmonary and systemic organ flow rates varied between 79% - 83% and 17% - 21% respectively.

Conclusion

Knowledge of the relationship between vascular resistances and flow in this surgically created in vitro mBT shunt set-up may be helpful in the clinical management of the patients whose survival is crucially dependent on the blood flow distribution between the pulmonary and systemic circulation.
Advances in in Vitro and in Vivo Models for Studying the Staphylococcal Factors Involved in Implant Infections
Authors: Harraghy N. , Seiler S. , Jacobs K. , Hannig M. , Menger M.D. , Herrmann M.
Published: January 2018

Implant infections due to staphylococci are one of the greatest threats facing patients receiving implant devices. For many years researchers have sought to understand the mechanisms involved in the adherence of the bacterium to the implanted device and the formation of the unique structure, the biofilm, which protects the indwelling bacteria from the host defence and renders them resistant to antibiotic treatment. A major goal has been to develop in vitro and in vivo models that adequately reflect the real-life situation. From the simple microtiter plate assay and scanning electron microscopy, tools for studying adherence and biofilm formation have since evolved to include specialised equipment for studying adherence, flow cell systems, real-time analysis of biofilm formation using reporter gene assays both in vitro and in vivo, and a wide variety of animal models. In this article, we discuss advances in the last few years in selected in vitro and in vivo models as well as future developments in the study of adherence and biofilm formation by the staphylococci.
Biofilm Related Infections: Is There a Place for Conservative Treatment of Port-Related Bloodstream Infections?
Authors: Del Pozo J.L. , Serrera A. , MartíNez-Cuesta A. , Leiva J. , PenadéS J. , Lasa I.
Published: January 2018

Vascular catheters are the most frequently used indwelling medical devices and have become necessary tools for patients with chronic or critical illness. Surgically or percutaneously placed venous access ports are used to facilitate long-term intravenous therapy. The widespread use of these devices has resulted in a dramatic increase in catheter-related infections. It implies considerable morbidity, occasional mortality, and an increase in medical costs derived from its diagnosis, treatment, and mainly, prolongation of the patient's in-hospital stay. Treatment of such infections is often difficult due to the presence of biofilms on the port inner surface; inside the biofilms, bacteria are less vulnerable to antimicrobial agents. Current diagnostic strategies are suboptimal, and most successful treatment options require removal of the infected device followed by a course of antimicrobial therapy. There are limited data concerning the efficacy of antibiotic treatment of port-related bloodstream infections without catheter removal.
Prevalence and Antibiotic Resistance of 15 Minor Staphylococcal Species Colonizing Orthopedic Implants
Authors: Arciola C.R. , Campoccia D. , An Y.H. , Baldassarri L. , Pirini V. , Donati M.E. , Pegreffi F. , Montanaro L.
Published: January 2018

Several species belonging to Staphylococcus genus (nonSau/nonSep species) exhibit increasing abilities as opportunistic pathogens in colonisation of periprosthesis tissues. Here we report on antibiotic resistance of 193 strains, belonging to nonSau/nonSep species, consecutively collected from orthopedic implant infections in a period of about 40 months. The 193 strains (representing 17% of all staphylococci isolated) were analysed for their antibiotic resistance to 16 different drugs. Five species turned out more prevalent, ranging from 1 to 5%: S. hominis (4.2%), S. haemolyticus (3.7%), S. capitis (2.7%), S. warneri (2.6%), and S. cohnii (1.6%). Among these, the prevalence of antibiotic resistance to penicillins was similar, ranging from 51% to 66%. Conversely, significant differences were observed for all the remaining antibiotics. For S. haemolyticus the resistances to oxacillin and imipenem, the four aminoglycosides and erythromycin were at least twice that of the other three species which were compared. S. warneri was on the contrary the species with the lowest occurrence of resistant strains. Ten species appeared only rarely at the infection sites: S. lugdunensis, S. caprae, S. equorum, S. intermedius, S. xylosus, S. simulans, S. saprophyticus, S. pasteuri, S. sciuri, and S. schleiferi. The behaviours of these species, often resistant to penicillins, were individually analysed. Differences in both the frequencies and the panels of antibiotic resistances observed among the nonSau/nonSep species: i) suggest that horizontal spreading of resistance factors, if acting, was not sufficient per se to level their bio-diversities; ii) highlight and confirm the worrisome appearance within the Staphylococcus genus of emerging “new pathogens”, not homogeneous for their virulence and antibiotic resistance prevalence, which deserve to be recognised and treated individually.
Biocompatibility of Supercritical CO2-Treated Titanium Implants in a Rat Model
Authors: Hill C.M. , Kang Q.K. , Wahl C. , Jimenez A. , Laberge M. , Drews M. , Matthews M.A. , An Y.H.
Published: January 2018

Supercritical phase CO2 is a promising method for sterilizing implantable devices and tissue grafts. The goal of this study is to evaluate the biocompatibility of titanium implants sterilized by supercritical phase CO2 in a rat subcutaneous implantation model. At 5 weeks post implantation titanium implants sterilized by supercritical phase CO2 produce a soft tissue reaction that is comparable to other methods of sterilization (steam autoclave, ultraviolet light radiation, ethylene oxide gas, and radio-frequency glow-discharge), as indicated by the thickness and density of the foreign body capsule, although there were some differences on the capillary density. Overall the soft tissue response to the implants was similar among all methods of sterilization, indicating supercritical phase CO2 treatment did not compromise the biocompatibility of the titanium implant.
A Glance at the Role of Exotoxins in Opportunistic Bacterial Infections
Authors: Montanaro L. , Campoccia D. , Arciola C.R.
Published: January 2018

The production and the mechanism of action of exotoxins from Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa are presented. The attack to the immune host's defenses is the main virulence factor of opportunistic bacteria in implant infections, favoring the invasion and colonization of compromised periprosthesis tissues.
Safety of Citrate Based Hemofiltration in Critically Ill Patients at High Risk for Bleeding: A Comparison with Nadroparin
Authors: Van Der Voort P.H.J. , Postma S.R. , Kingma W.P. , Boerma E.C. , Van Roon E.N.
Published: January 2018

Purpose

To study the incidence and severity of bleeding in high risk critically ill patients during high volume, citrate based continuous veno-venous hemofiltration (CVVH).

Design

A prospective 1-year observational cohort study comparing citrate based CVVH with nadroparin based CVVH.

Procedures

Critically ill patients with multiple organ dysfunction and in need of CVVH were observed for bleeding complications during their CVVH sessions. Pre-defined criteria determined that patients were treated with citrate based CVVH in case of active bleeding or increased risk for bleeding. Otherwise nadroparin was used as anticoagulant.

Statistical and Outcome Methods

The incidence of bleeding complications, the number of transfused blood cell concentrates and the filter-run-time were recorded. Analyses were made by non-parametric tests.

Main Findings

Fifty-five patients received 272 CVVH sessions. In the citrate group 14.8% experienced a bleeding complication compared to 25% in the nadroparin group (p=0.04). The number of transfused red blood cell concentrates was not different between groups. The nadroparin group had a longer filter run time (median 31.5 hours versus 22.5 hours, p=0.0001).

Conclusions

In high risk critically ill patients citrate based anticoagulation for CVVH is safe in terms of bleeding complications and transfusion requirements.
Impedance Cardiography Derived Cardiac Output in Hemodialysis Patients: A Study of Reproducibility and Comparison with Echocardiography
Authors: Karakitsos D.N. , Patrianakos A.P. , Paraskevopoulos A. , Parthenakis F.I. , Tzenakis N. , Fourtounas C. , Daphnis E.K. , Vardas P.E.
Published: January 2018

Background

Hemodialysis patients experience a variety of hemodynamic abnormalities that contribute to cardiovascular disease mortality which is the leading cause of death in these patients. Impedance cardiography has been utilized in order to monitor cardiac hemodynamics with lower cost and inconvenience, but it has not been appropriately validated in the hemodialysis population.

Aim

We repeatedly used impedance cardiography to assess short- (48 hours) and long-term (15 days) reproducibility of cardiac output measurements and we compared baseline impedance cardiography measurements with echocardiographic measurements.

Patients and Methods

We studied 109 stable hemodialysis patients, aged 59.70 ± 11.97 years being on hemodialysis for 67.59 ± 40.15 months, on a non-dialysis day. Cardiac output was obtained with the BioZ impedance cardiography system (Cardiodynamics, San Diego, Ca, USA). Baseline echocardiography was performed using a Hewlett-Packard Sonos 2500 (Andover, Mass., USA).

Results

The values of impedance cardiography derived cardiac output were 5.28 ± 0.79, 5.27 ± 0.75 and 5.25 ± 0.74 l/min at baseline (107 patients), 48 hours (107 patients) and 15 days (98 patients) respectively, showing high reproducibility. Bland and Altman analysis estimated that bias at 48 hours and at 15 days were: −0.013 (95% confidence intervals = −0.045 to 0.019) and 0.028, (95% confidence intervals = −0.044 to 0.101), respectively. In addition baseline impedance cardiography derived cardiac output was significantly correlated with the echocardiographic derived cardiac output (r = 0.9, p < 0.0001).

Conclusion

Impedance cardiography is a simple non invasive technique for cardiac output estimation in hemodialysis patients which has high reproducibility when performed under controlled conditions, and is closely correlated with echocardiographic measurements of cardiac output.
Development of a New Pulsatile Extracorporeal Life Support Device Incorporating a Dual Pulsatile Blood Pump
Authors: Choi S.W. , Nam K.W. , Chung J. , Lee J.C. , Hwang C.M. , Won Y.S. , Sun K. , Min B.G.
Published: January 2018

A new pulsatile extracorporeal life support device (ECLS) has been developed, designed to sustain pulsatile blood flow during emergency cardiopulmonary resuscitations and cardiopulmonary operations. This device features two identical pulsatile pumps that operate alternately and can therefore provide blood inflow in a more uniform manner than similar systems featuring a single-pump configuration. In order to confirm the presumed benefits of this newly-developed dual pulsatile pump configuration, we have conducted a series of in vitro experiments designed to compare the properties of the new system with a single pump system, specifically with regard to pump delivery rate and active filling efficiency. Our results reveal that the dual pump configuration can, indeed, deliver a higher flow than can the single-pump system, and exhibits an active filling efficiency superior to that of the single-pump configuration. We performed a series of animal experiments to measure the pulsatility of the dual-pump configuration in terms of equivalent energy pressure (EEP). In order to measure EEP, we measured femoral arterial pressure and pump outflow. The results of our animal experiments revealed that the newly-developed pulstile ECLS exhibits sufficient pulsatility in terms of the EEP considerations.
Ectopic Cartilage Formation Induced by Mesenchymal Stem Cells on Porous Gelatin-Chondroitin-Hyaluronate Scaffold Containing Microspheres Loaded with TGF-β1
Authors: Fan H. , Hu Y. , Li X. , Wu H. , Lv R. , Bai J. , Wang J. , Qin L.
Published: January 2018

The study aimed to produce a novel porous gelatin-chondroitin-hyaluronate scaffold in combination with a controlled release of TGF-β1 and to evaluate its potentials in ectopic cartilage formation. The gelatin-chondroitin-hyaluronate scaffold was developed to mimic the natural extra cellular matrix of cartilage. Gelatin microspheres loaded with TGF-β1 (MS-TGFβ1) showed a fast cytokine release at initial phase (37.4%) and the ultimate accumulated release was 83.1% by day 18. Then MS-TGFβ1 were incorporated into scaffold. The MSCs seeded on scaffold with or without MS-TGFβ1 were incubated in vitro or implanted subcutaneously in nude mice. In vitro study showed that, compared to the scaffold, the scaffold/MS-TGFβ1 significantly augmented the proliferation of MSCs and GAG synthesis. Three weeks postoperatively histology observation showed that in MSCs/scaffold/MS-TGFβ1 implantation group, cells of newly formed ectopic cartilage were located within typical lacunae and demonstrated morphological characteristics of chondrocytes. Six weeks later the ectopic cartilage grew more and islands of cartilage were observed. The matrix was extensively metachromatic by safranin-O/Fast green staining. Immunohistochemical staining also indicated ectopic cartilage was intensely stained for type II collagen. Instead, in the MSCs/scaffold implantation group, no cartilage-like tissue formed and matrix showed negative or weak positive staining. The percentage of positive staining area was significantly larger in MSCs/scaffold/MS-TGFβ1 group (p<0.05) at each time point. The results indicated that the novel gelatin-chondroitin-hyaluronate scaffold with MS-TGFβ1 could induce the chondral differentiation of MSCs to form cartilage and might serve as a new way to repair cartilage defects.
Virtual Respiratory System for Education and Research: Simulation of Expiratory Flow Limitation for Spirometry
Authors: Golczewski T. , Darowski M.
Published: January 2018

Background

Due to economic and ethical problems, virtual organs may appear more convenient than experiments on animals or limited investigations on patients. In particular, a virtual respiratory system (VRS) may be useful for tasks such as respirators and support methods testing, education, staff (medical and technical) training, (initial) testing of scientific hypotheses.

Methods

A comparative study of simulated and real spirometric results for different patient states (healthy lungs, restrictive lung disease, and obstructive lung disease of different localization and degree) was performed. The volume-flow curve and such standard parameters as FEV1, FEV1%VC, MEF75 etc. were analyzed.

Results

A mathematical description of collapsing bronchi was proposed. All fundamental phenomena present during spirometry also appeared in VRS, especially characteristic dependence between lung volume and air flow for forced expiration. In particular, both airway resistance and the flow limitation were described with one formula derived from commonly known dependence of the resistance on lung volume. Generally there were no significant differences between simulated results and those seen in clinical practice. Only simulation of obstruction in upper airways gave incorrect results, which suggested a different flow limitation mechanism (perhaps wave-speed limitation).

Conclusions

Our VRS can already be used in medical education, e.g. courses of spirometry, and in some other applications. It seems that the significance of the wave-speed criterion has been overestimated.
In Vitro Evaluation of Bio-Functional Performances of Ghimas Titanium Implants
Authors: Gorrieri O. , Fini M. , Kyriakidou K. , Zizzi A. , Mattioli-Belmonte M. , Castaldo P. , De Cristofaro A. , Natali D. , Pugnaloni A. , Biagini G.
Published: January 2018

Titanium is the most widely used material for dental implants. The natural formation, in presence of oxygen, of different oxide films (passivation films) is correlated to titanium implant biocompatibility, resistance to corrosion and is responsible for implant bacteriostatic action. Surface roughness is another surface property of Ti-implants that, affecting implant-to-bone contact, improves integration. In the present study data concerning composition, surface roughness and biocompatibility of Ghimas implants and mini-implants undergoing sandblasting with Calcium Magnesium Carbonate (CaMg(CO3)2) are reported. AFM, SEM/EDX, XRD analyses and morphofunctional tests (MTT and ALP) were performed. Cell actin cytoskeletal modification (fluorescence phalloidin staining) was also observed with confocal laser microscopy (CLSM). Data related to surface geometry and chemical properties, associated with evidence of high purity of all the tested materials (XRD and EDX), highlighted the elevated biocompatibility of tested implants and mini-implants. CLSM investigation confirmed osteoblast features of an active cell behavior able to fit cell to chemico-mechanical stimuli present at the bone/implant interface and suggests an effective implant/alveolar bone integration in vivo.
Surgical Procedures before and after Starting Chronic Hemodialysis in a Predominantly Male Population with High Prevalence of Diabetes
Authors: Martinez Milagros , Last Reuben , Agaba Emmanuel I. , Kassam Hussein , Sun Yijuan , Servilla Karen S. , Murata Glen H. , Tzamaloukas Antonios H.
Published: January 2018

Purpose

The purposes of this study were to analyze changes in the frequency of different categories of surgical procedures after initiation of chronic hemodialysis (HD) and to identify the types of procedures associated with in-hospital postoperative mortality.

Methods

This was a retrospective analysis of surgical procedures performed in an incident HD population of 392 patients followed in the dialysis unit of one hospital over 15 years. Among these patients, 384 were men and 258 had diabetes mellitus. At the start of HD, age of the patients was 66.3 ± 11.2 years and Charlson index 5.35 ± 2.41. Rates of procedures per patient year (n/[pt-yr]), reported as mean (95% Confidence Interval [CI]), were compared by nonparametric methods.

Results

In the whole HD population, the overall rate of procedures increased in the HD period (pre-HD 0.125 [95% CI 0.101–0.149] n/[pt-yr]; HD 0.928 [95% CI 0.795–1.061] n/[pt-yr]; p<0.001). The increase, noted in patients with and without diabetes, reflected increases in the rates for both vascular access and non-vascular access procedures from the pre-HD to the HD period. Amputations and surgery for hip fractures accounted for the increase in the rates of procedures related to non-vascular access. Procedures associated with mortality in the HD period included amputations, hip repair and abdominal surgery for septic conditions.

Conclusions

Rates of surgical procedures for vascular access, amputations, and hip fractures increased after the start of HD. Amputations and hip fractures, both potentially preventable, are associated with mortality in HD patients.
Deceased Donor Renal Transplantation from Older Donors to Increase the Donor Pool
Authors: Kute Vivek B. , Trivedi Hargovind L , Vanikar Aruna V. , Shah Pankaj R. , Gumber Manoj R. , Patel Himanshu V. , Modi Pranjal R. , Shah Veena R.
Published: January 2018

Background

Use of kidneys from donors aged 70 years and older is controversial. Organ shortage has led many transplant centers to accept kidneys from old, suboptimal deceased donors and make increasing use of old-for-old allocation systems. We describe our institutional experience with outcomes from transplanting deceased-donor kidneys from older donors (≥70 years).

Material and methods

20 deceased donor renal transplants (DDRTx) were performed at our center using grafts from deceased donors 70 years and older between June 2004 and September 2011. Kidneys were allocated to dual or single grafting according to pre-transplant biopsy. Mean age of recipients was 47.60 ± 11.38 years, 13 of whom were males. Mean donor age was 76.49 ± 4.9 years; 10 of whom were males. The most common cause of donor death was cerebrovascular/road traffic accidents. Mean dialysis duration pre-transplantation was 19.5 ± 6.5 months. Mean HLA (Human Leukocyte Antigens) match was 1 ± 0.8. Most common recipient diseases leading to ESRD were chronic glomerulonephritis (25%), diabetes (20%), and hypertension (20%). Post-transplant immunosuppression consisted of a calcineurin inhibitor-based regimen.

Results

Over a mean follow-up of 2.8 ± 1.7 years, patient and graft survival rates were 75% (n = 15) and 80% (n = 16), respectively, with a mean serum creatinine of 1.78 ± 0.56 mg/dl; 20% of the patients had biopsy-proven acute rejection episodes. A total of 25% (n = 5) patients died, mainly due to infections.

Conclusions

DDRTx from older donors achieves acceptable graft function with patient/graft survival, provided that organs are allocated to dual or single grafting according to pre-transplant biopsy. These findings encourage the use of this approach even in low-income countries.
Steady State Phosphorus Mass Balance Model during Hemodialysis Based on a Pseudo One-Compartment Kinetic Model
Authors: Leypoldt John K. , Agar Baris U. , Akonur Alp , Gellens Mary E. , Culleton Bruce F.
Published: January 2018

Purpose

Mathematical models of phosphorus kinetics and mass balance during hemodialysis are in early development. We describe a theoretical phosphorus steady state mass balance model during hemodialysis based on a novel pseudo one-compartment kinetic model.

Methods

The steady state mass balance model accounted for net intestinal absorption of phosphorus and phosphorus removal by both dialysis and residual kidney function. Analytical mathematical solutions were derived to describe time-dependent intradialytic and interdialytic serum phosphorus concentrations assuming hemodialysis treatments were performed symmetrically throughout a week.

Results

Results from the steady state phosphorus mass balance model are described for thrice weekly hemodialysis treatment prescriptions only. The analysis predicts 1) a minimal impact of dialyzer phosphorus clearance on predialysis serum phosphorus concentration using modern, conventional hemodialysis technology, 2) variability in the postdialysis-to-predialysis phosphorus concentration ratio due to differences in patient-specific phosphorus mobilization, and 3) the importance of treatment time in determining the predialysis serum phosphorus concentration.

Conclusions

We conclude that a steady state phosphorus mass balance model can be developed based on a pseudo one-compartment kinetic model and that predictions from this model are consistent with previous clinical observations. The predictions from this mass balance model are theoretical and hypothesis-generating only; additional prospective clinical studies will be required for model confirmation.
The Effect of Rat Acute-Liver-Failure Plasma on HepaRG Cells
Authors: Hoekstra Ruurdtje , Nibourg Geert A.A. , Van der Hoeven Tessa V. , Ackermans Mariëtte T. , Hakvoort Theodorus B.M. , Van Gulik Thomas M. , Oude Elferink Ronald P. , Chamuleau Robert A.F.M.
Published: January 2018

Purpose

We recently demonstrated the high liver functionality of the human liver cell line HepaRG, including ammonia eliminating capacity, making it a valuable biocomponent of a bioartificial liver (BAL) to support patients with acute liver failure (ALF). This cell line further gains detoxification properties when cultured with dimethyl sulfoxide (DMSO). In this paper we describe whether its functionality is compromised by the toxic effects of ALF plasma, as has been shown for primary hepatocytes.

Methods

We exposed -DMSO and +DMSO HepaRG cultures during 16 hours to healthy plasma and ALF-rat plasma. The cultures were analyzed for lipid accumulation, cell leakage, apolipoprotein A-1 production, nitrogen metabolism and transcript levels of hepatic genes.

Results

The -DMSO cultures showed increased cell leakage after healthy and ALF plasma exposure in contrast to +DMSO cultures, but otherwise the -DMSO and +DMSO cultures were equally affected by exposure to the plasmas. Exposure to both plasmas caused lipid accumulation and decreased transcript levels of various hepatic genes. ALF plasma decreased urea cycle activity, but increased urea production from arginine by upregulated arginase 2. However, total ammonia elimination was not affected by exposure to either plasma, indicating its predominant elimination by fixation into amino acids. In addition, apolipoprotein A-1 production remained constant.

Conclusions

HepaRG cells are negatively affected by rat plasma, even of healthy origin. However, their ammonia eliminating capacity is relatively resistant, underlining their suitability for BAL application. DMSO pre-treatment may increase their viability in plasma.
The Poor Osteoinductive Capability of Human Acellular Bone Matrix
Authors: Huang Yi-Zhou , Cai Jia-Qin , Xue Jing , Chen Xiao-He , Zhang Chao-Liang , Li Xiu-Qun , Yang Zhi-Ming , Huang Yong-Can , Deng Li
Published: January 2018

Demineralized bone matrix (DBM) has extensive clinical use for bone regeneration because of its osteoinductive and osteoconductive aptitude. It is suggested that the demineralization process in bone matrix preparation is influential in maintaining osteoinductivity; however, relevant investigations, especially into the osteoinductivity of acellular bone matrix, are not often performed. This study addressed the osteoinductive capability of human acellular cancellous bone matrix (ACBM) after subcutaneous implantation in a rat model. The growth and osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (rBM-MSCs) seeded in this material were also studied. Without the demineralization process, the ACBM we obtained had an interconnected porous network and the micropores in the surface were clearly exposed. After the ACBM was subcutaneously implanted for 4 months, new osteoid formation was noted but not typical mature bone formation. rBM-MSCs grew well in the ACBM and kept a steady morphology after continuous culture for 28 days. However, no mineralized nodule formation was detected and the expression levels of genes encoding osteogenic markers were significantly decreased. These results demonstrated that human ACBM possess the structural features of native bone and poor osteoinductivity; nonetheless this material helped to preserve the undifferentiated phenotype of rBM-MSCs. Such insights may further broaden our understanding of the application of ACBM for bone regeneration and the creation of stem cell niches.
Vascular Homograft Use in a Femoropopliteal Rare Bacterial Infection Bypass
Authors: Dainese Luca , Saccu Claudio , Zoli Stefano , Trabattoni Piero , Guarino Anna , Cavallero Annalisa , Spirito Rita
Published: January 2018

We report on a patient with a femoropopliteal bypass infected by Kytococcus sedentarius. Treatment consisted of resection of the infected prosthesis with homograft substitution and antibiotic therapy started postoperatively At 6 months followup, the patient showed no signs of infection and results of laboratory findings were normal.
Accuracy of Ultrasonographic Measurements of Inferior Vena Cava to Determine Fluid Responsiveness: A Systematic Review and Meta-Analysis
Authors: Orso Daniele , Paoli Irene , Piani Tommaso , Cilenti Francesco L. , Cristiani Lorenzo , Guglielmo Nicola
Published: January 2018

Objective:

Fluid responsiveness is the ability to increase the cardiac output in response to a fluid challenge. Only about 50% of patients receiving fluid resuscitation for acute circulatory failure increase their stroke volume, but the other 50% may worsen their outcome. Therefore, predicting fluid responsiveness is needed. In this purpose, in recent years, the assessment of the inferior vena cava (IVC) through ultrasound (US) has become very popular. The aim of our work was to systematically review all the previously published studies assessing the accuracy of the diameter of IVC or its respiratory variations measured through US in predicting fluid responsiveness.

Data Sources:

We searched in the MEDLINE (PubMed), Embase, Web of Science databases for all relevant articles from inception to September 2017.

Study Selection:

Included articles specifically addressed the accuracy of IVC diameter or its respiratory variations assessed by US in predicting the fluid responsiveness in critically ill ventilated or not, adult or pediatric patients.

Data Extraction:

We included 26 studies that investigated the role of the caval index (IVC collapsibility or distensibility) and 5 studies on IVC diameter.

Data Synthesis:

We conducted a meta-analysis for caval index with 20 studies: The pooled area under the curve, logarithmic diagnostic odds ratio, sensitivity, and specificity were 0.71 (95% confidence interval [CI]: 0.46-0.83), 2.02 (95% CI: 1.29-2.89), 0.71 (95% CI: 0.62-0.80), and 0.75 (95% CI: 0.64-0.85), respectively.

Conclusion:

An extreme heterogeneity of included studies was highlighted. Ultrasound evaluation of the diameter of the IVC and its respiratory variations does not seem to be a reliable method to predict fluid responsiveness.
Prognosis of Acute Respiratory Distress Syndrome in Patients With Hematological Malignancies
Authors: Seong Gil Myeong , Lee Yunkyoung , Hong Sang-Bum , Lim Chae-Man , Koh Younsuck , Huh Jin Won
Published: January 2018

Introduction:

The intensive care unit (ICU) admission of patients with hematologic malignancies is gradually increasing. Life-threatening events are common, and acute respiratory distress syndrome (ARDS) is one of the most critical conditions. The aim of this study was to investigate the clinical characteristics and outcomes of ARDS in patients with hematological malignancies admitted to the ICU.

Methods:

A retrospective study was performed on all patients with ARDS with hematological malignancies in a single tertiary teaching hospital between 2008 and 2015. Data on the treatment of and the outcomes of ARDS were collected to determine the clinical characteristics associated with ICU mortality.

Results:

During the 8-year study period, among a total of 821 patients with ARDS admitted to the ICU, all 185 patients with hematological malignancies were included in the analysis. Most of the patients (88.1%) had moderate-to-severe ARDS, and the median PaO2/FiO2 ratio was 122 (interquartile range: 88-157). The overall ICU mortality rate was 57.3% (50.0% for mild, 52.0% for moderate, and 67.7% for severe ARDS). After the univariate and the multivariate logistic regressions, the factors independently associated with a higher ICU mortality were severe ARDS (odds ratio [OR]: 2.47; 95% confidence interval [CI]: 1.17-5.25), identification of carbapenem-resistant gram-negative bacteria (OR: 6.61; 95% CI: 1.31-33.41), the amount of blood product transfusion (OR: 1.25; 95% CI: 1.13-1.38), and the progressive or refractory disease (OR: 3.01; 95% CI: 1.31-6.91). Mortality was independently lower in patients who received the initial low tidal volume ventilation (OR: 0.37, 95% CI: 0.14-0.96).

Conclusion:

The outcome of ARDS in patients with hematological malignancies is associated with the severity of the underlying diseases, the presence of multidrug-resistance pathogens, and the amount of transfusion; however, strict application of low tidal volume ventilation may improve the outcome of these patients at the time of diagnosis.
Psychopathy and Victim Selection: Does Nonverbal Decoding or Empathy Impact Vulnerability Ratings?
Authors: Denardo Roney Julia L. , Falkenbach Diana M. , Aveson Olivia
Published: January 2018

This research examined the role of psychopathic traits in perceptions of victimization and vulnerability. Community-member participants viewed video clips of victims, nonvictims, and victims who studied self-defense, then rated them on vulnerability and perceived history of victimization. Participants were most proficient at identifying nonvictims as nonvictims. Victims who studied self-defense were harder to correctly identify than both victims and nonvictims and were rated by participants as less vulnerable and less likely to be victims than other victims and nonvictims. Moreover, individuals high in psychopathic traits, specifically Factor 2, were more likely than individuals low in psychopathic traits to correctly identify victims who practiced self-defense as victims, as well as nonvictims as victims. Unexpectedly, there was an observed negative relationship between facial affect decoding and identifying self-defense victims. The ability to correctly interpret facial expressions was found to partially mediate the relationship between psychopathy scores and the identification of self-defense victims. The results of this study provide insight into the ability of individuals with psychopathic traits to identify nonverbal cues associated with vulnerability. The results provide evidence that taking self-defense classes may be a meaningful intervention for victims, particularly.
Video-enhanced lesson observation as a source of multiple modes of data for school leadership
Authors: Hidson Elizabeth
Published: January 2018

A growing body of literature recognizes the affordances of video in education, especially in relation to lesson observation and reflection as part of teachers’ initial teacher education and continuing professional development. Minimal attention has been paid to the outcomes of video-enhanced observation as a source of multiple modes of data for reflexive school leadership. This article focuses on the data of three participants from a larger set of nine teachers involved in an over-arching study exploring teachers’ professional knowledge and practices following a recent curriculum change in England. Data from video-stimulated interviews revealed that recorded video can provide school leaders with a window onto the practices and processes of daily school life, illustrated here through a focus on evidence of policy in practice. It is argued that the leadership perspective provides school leaders and managers with the analytical frameworks and competencies for critical interpretation of the data.
Synthesis, characterization and thermal degradation kinetics of azomethine-based halogen-free flame-retardant polyphosphonates
Authors: Vini R , Thenmozhi S , Murugavel SC
Published: January 2018

In this study, azomethine polyphosphonates were synthesized by solution polycondensation of phenylphosphonic dichloride with various azomethine diols such as [4-(4-hydroxy phenyl) iminomethyl] phenol, [(4-(4-hydroxy-3-methoxy phenyl) iminomethyl)] phenol and [4-(4-hydroxy-3-ethoxy phenyl) iminomethyl] phenol using triethylamine catalyst at ambient temperature. The structure of the synthesized polymers was confirmed by Fourier transform infrared and 1H-, 13C- and 31P- nuclear magnetic resonance spectroscopic techniques. Thermal properties of the polymers were studied by thermogravimetric analysis (TGA) and differential scanning calorimetry under nitrogen atmosphere. The TGA data showed that the synthesized polyphosphonates produce high char yield at 600°C due to the presence of phosphorous atom in the polymer chain and hence have good flame-retardant properties. One of the synthesized polyphosphonate was blended with commercial diglycidyl ether of bisphenol-A (DGEBA) resin in various weight percentage and cured with commercial curing agent triethylene tetramine (TETA). The polyphosphonates-blended epoxy thermosets have tensile strength in the range of 5–41 MPa and the percentage of elongation at breaks was 4–18. It was found that the incorporation of polyphosphonates into epoxy thermoset decreased the tensile strength from 41 MPa to 5 MPa, whereas the elongation at break value increased with increase in the weight percentage of polyphosphonate. The influence of polyphosphonates on the flame retardancy of blended thermosets was examined by limiting oxygen index (LOI) and vertical burning (UL-94) tests and found that the polymer samples achieved an increased UL-94 rating and the LOI values were in the range of 24–26. Broido and Horowitz–Metzger methods have been used to study the thermal degradation kinetic parameters.
Search method applied for gear tooth bending stress prediction in normal contact ratio asymmetric spur gears
Authors: Thomas Benny , Sankaranarayanasamy K , Ramachandra S , Suresh Kumar SP
Published: January 2018

Various analytical methods have been developed by designers to predict gear tooth bending stress in asymmetric spur gears with an intention to improve the accuracy of predicted results and to reduce the need for time consuming finite element analysis at the early stages of gear design. Asymmetry in the drive and coast side of asymmetric spur gears poses difficulty in direct application of well-known procedures like American Gear Manufacturers Association and International Organization for Standardization in the prediction of gear tooth bending stress. In earlier works, ISO-6336-3 methodology was suitably modified and adapted to predict asymmetric spur gear tooth bending stress. This approach is based on certain assumptions on the location of critical section which could introduce error in the predicted maximum bending stress. The present work is to analytically predict gear tooth bending stress in normal contact ratio asymmetric spur gears based on a more rigorous analytical approach. This includes a fundamental study on the gear tooth orientation used to define the coordinate system, determination of maximum bending stress by search along the fillet profile and to obtain stress profile along the fillet. Gear tooth bending stress obtained from the present work using Search method is compared against the results obtained from earlier adapted International Organization for Standardization method and Finite Element Analysis. This study recommends a new coordinate system and method for analytical prediction of gear tooth bending stress in normal contact ratio asymmetric spur gears.
Comment on the paper ‘Shape effect of nanosize particles in unsteady mixed convection flow of nanofluid over disk with entropy generation’
Authors: Pantokratoras Asterios
Published: January 2018

The present comment concerns some doubtful results included in the paper ‘Shape effect of nanosize particles in unsteady mixed convection flow of nanofluid over disk with entropy generation’.
Asymptomatic urethral lymphogranuloma venereum: a case report
Authors: Charest Louise , Fafard Judith , Greenwald Zoë R
Published: January 2018

Since 2003, there has been a resurgence of lymphogranuloma venereum (LGV), a variant of Chlamydia trachomatis (CT), among men who have sex with men (MSM) in several urban areas of Europe and North America. LGV infection occurs most often at anal sites causing proctitis. Urethral and oropharyngeal infections are rare. In Quebec, LGV incidence has been increasing exponentially in recent years and the current guidelines support systematic LGV genotype testing among anorectal CT-positive samples only. This case report describes a patient with a urethral LGV infection, remarkable due to its prolonged asymptomatic development prior to the manifestation of an inguinal bubo. Physicians should be vigilant of potential cases of LGV and forward CT-positive samples occurring among individuals with LGV risk factors for genotype testing.