bluuebunny/crossref_metadata_2025 huggingface dataset:
Affirmative biopolitics: Social and vocational education for Quechua girls in the postcolonial “affectsphere” of Cusco, Peru
Authors: Lin Chih-Chen Trista , Minca Claudio , Ormond Meghann
Published: January 2018

This paper draws on an affirmative biopolitical framework to analyze the governing of young lives in education and social spaces in Cusco, Peru. We engage with Berlant’s theorization of affect and spatialization of biopolitics in order to discuss youth’s embodied experiences of alternative forms of biopolitical governance. With a case study of a grassroots, non-profit center for residential care and social and educational programs for Quechua-speaking girls, we investigate how the girls sense and respond to the center’s mediation of rural-to-urban projects of “getting ahead,” domestic work, and the tourism and hospitality sector. We reveal the center’s biopoliticization of their lives in an affective manner within the processes of postcolonial educational marginalization, precarity in urban economies, professionalization, and tourism in and beyond Cusco. Our study intends to contribute to an expanded understanding of the production of education, aid, social care, and protection spaces, and to highlight the utility of affective inquiry in examining the contested terrains of (alternative) childhoods/youth.
Austerity urbanism and Olympic counter-legacies: Gendering, defending and expanding the urban commons in East London
Authors: Gillespie Tom , Hardy Kate , Watt Paul
Published: January 2018

This article reflects on an occupation led by single mothers to contest the destruction of social housing in post-Olympics East London. In the process, it argues for a more gendered theorisation of the urban commons. Drawing on auto-ethnography, participant observation and qualitative interviews, the article argues three central points: First, that the occupation demonstrates the gendered nature of the urban commons and the leadership of women in defending them from enclosure; second that the defence of an existing urban commons enabled the creation of a new temporary commons characterised by the collectivisation of gendered socially reproductive activities; and third that this commoning has had a lasting impact on housing activism at the city scale and beyond. This impact is conceptualised as an ‘Olympic counter-legacy’ that is characterised by the forging of new relationships and affinities, the strengthening of networked activism and circulation of tactics between campaign groups.
The University of Vienna Middle Egypt Project at el-Sheikh Fadl - Umm Raqaba: An Introductory Report of the 2014 and 2015 Field Seasons
Authors: Köhler E. Christiana
Published: January 2018

This article provides a summary and first results of the University of Vienna Middle Egypt Project at the necropolis of el-Sheikh Fadl - Umm Raqaba where surveys and rescue excavations have been conducted since early 2014. After a brief introduction of the historical background, aims and methods of the project, the article will give an overview of the main types of tombs encountered so far as well as a discussion of the possible date and archaeological potential of the site.
Eco-environment of reservoirs in China
Authors: Chen Jingan , Wang Jingfu , Guo Jianyang , Yu Jia , Zeng Yan , Yang Haiquan , Zhang Runyu
Published: January 2018

China is home to 97,246 reservoirs, most of which are sub-deep water reservoirs characterized by seasonal stratification and multiple interfaces in the water body. The prominent eco-environmental problems, such as eutrophication and accidental deterioration in water quality, restrict reservoir construction. Compared to natural lakes, reservoirs have specific geologic backgrounds and eco-environmental characteristics, which manifest in the following aspects: (a) the origin of the water environment and ecological system of the reservoir is different from natural lakes; (b) sediment is rich in organic matter and nutrients; (c) water eutrophication and heavy metal pollution are tightly interlocked; (d) multi-interface and seasonal stratification control the key physicochemical and biological processes; (e) the cumulative effect of the material cycle has an important influence on the water environment and ecological security; (f) artificial regulation of water level leads to the ecological degradation of the hydro-fluctuation belt; and (g) the slow response of the aquatic ecosystem to the reduction of external load. Research on the eco-environment of sub-deep water reservoirs trails that of natural lakes in China. After describing the eco-environmental characteristics of reservoirs in China, we address potential challenges and propose future research directions to develop a full understanding of the complex biogeochemical processes prevalent in reservoirs.
Aeroacoustics response of wind turbine blade profiles in normal and icing conditions
Authors: Caicedo Edison H , Virk Muhammad S
Published: January 2018

This article describes a multiphase computational fluid dynamics–based numerical study of the aeroacoustics response of symmetric and asymmetric wind turbine blade profiles in both normal and icing conditions. Three different turbulence models (Reynolds-averaged Navier–Stokes, detached eddy simulation, and large eddy simulation) have been used to make a comparison of numerical results with the experimental data, where a good agreement is found between numerical and experimental results. Detached eddy simulation turbulence model is found suitable for this study. Later, an extended computational fluid dynamics–based aeroacoustics parametric study is carried out for both normal (clean) and iced airfoils, where the results indicate a significant change in sound levels for iced profiles as compared to clean.
Cytokine Removal with a Large Pore Cellulose Triacetate Filter: An Ex Vivo Study
Authors: Uchino S. , Bellomo R. , Goldsmith D. , Davenport P. , Cole L. , Baldwin I. , Panagiotopoulos S. , Tipping P. , Ronco C. , Everard P.
Published: January 2018

Objective

To test the hypothesis that hemofiltration using a new large pore cellulose triacetate hemofilter can achieve effective ultrafiltration of cytokines.

Design

Ex-vivo study.

Setting

Laboratory of Intensive Care Unit in tertiary hospital.

Subjects

Six healthy volunteers.

Interventions

Blood from 6 volunteers was incubated for 4 hours with 1 mg of endotoxin and then circulated through a closed hemofiltration circuit with a large pore cellulose triacetate hemofilter (nominal cut-off point: 60 kilodaltons). Hemofiltration was conducted at 1 L/h or 6 L/h of ultrafiltrate (UF) flow at the start of extra-corporeal circulation, and after 2 and 4 hours. Samples were taken from the arterial, venous and UF sampling ports.

Measurements and main Results

IL-Iβ, IL-6, IL-8, IL-10, TNFα, and albumin were measured. Sieving coefficients (SC) above 0.6 were achieved for IL-Iβ and IL-6 and SCs above 0.3 were achieved for IL-8 and TNF-α at 1 L/h. Sieving coefficients of all cytokines (except IL-10, p=0.22) were reduced when the ultrafiltration rate was increased from IL/h to 6 L/h (p<0.01), but the increase in ultrafiltration rate resulted in an overall increase in the clearance of all cytokines (p<0.001). The highest SC for albumin was 0.07 at 4 hours at 1 L/h, and fell to 0.01 at 6 L/h. The SCs for IL-8 fell at 4 hours (p<0.01), but the SCs for other cytokines did not change. No adsorption of cytokines and albumin was observed.

Conclusion

High volume hemofiltration (HVHF) using a new large pore cellulose triacetate filter achieved cytokine clearances greater than those reported with currently available hemofilters.
Clearance of Quinupristin-Dalfopristin (Synercid®) and their main Metabolites during Continuous Veno-Venous Hemofiltration (CVVH) with or without Dialysis
Authors: Kim M.-K. , Banevicius M.A. , Zhong M. , Shi X. , Hu M. , Nightingale C.H. , Nicolau D.P.
Published: January 2018

Background

Quinupristin-dalfopristin (Q/D) is often utilized in critically ill patients, some of whom require CVVH. This study was undertaken to determine the clearance of Q/D and their main active metabolites (RPR 100391, RP 69012, RP 12536) via CVVH in the swine model.

Methods

Q/D 7.5 mg/kg was intravenously administered over 0.5 h to 12 swine after induction of acute renal failure by ligation of the renal arteries. At 0.5 h post injection, the CVVH procedure was initiated and continued for 8 hours at the following pump rates: (1)100 mL/min, (2)180 rnL/min, and (3)100 mL/min with dialysis (flow rate: 1 L/h). Blood and ultrafiltrate samples were collected at 1 h intervals and assessed by a validated HPLC method.

Results

Plasma analysis suggests rapid metabolism to the main active metabolites which are appreciably cleared as demonstrated by high clearance and sieving coefficient estimates. Mean clearance estimates for RP 69012, RP 100391, and RP 12536 are 729, 777, and 578 mL/h in the 100 mL/min CVVH group, 772, 785, 685 mL/min in the 180 mL/min CVVH group, and 753, 791, 616 mL/min in the 100 mL/min CVVH group with 1L/h dialysis, respectively.

Conclusion

These data reveal that Q/D is rapidly metabolized and the metabolites are cleared to a large extent via CVVH. Due to the considerable contribution of the metabolites to overall in vivo activities, additional studies are required to fully quantify their removal before final dosage modifications for patients undergoing CVVH can be recommended.
Extracorporeal Pressure Monitoring and the Detection of Vascular Access Stenosis
Authors: Kleinekofort W. , Kraemer M. , Rode C. , Wizemann V.
Published: January 2018

Prospective monitoring of static venous pressure is an established tool to detect outflow stenoses in a vascular access. However, with this method it is not possible to identify vascular stenoses which are localized between the arterial and venous dialysis needle. We describe a new approach based on both static arterial and venous extracorporeal pressures. Pressure data of 9 dialysis patients with normal vascular access function and 9 patients with stenotic access were analyzed. Extracorporeal pressure was found to depend on the position of the heart relative to the extracorporeal blood circuit. All patients with venous outflow stenoses had an elevated ratio of arterial and venous intra-access pressure to mean arterial pressure. In case of access stenosis between arterial and venous needle the ratio of venous pressure to mean arterial pressure was normal, and only the arterial pressure ratio was elevated. We conclude that combined arterial and venous intra-access pressure measurement normalized by mean blood pressure detects venous stenosis as well as stenosis between the arterial and venous dialysis needle. To minimize the rate of access thrombosis both arterial and venous intra-access pressure should be monitored.
Development of a Hybrid Artificial Liver Using Polyurethane Foam / Hepatocyte Spheroid Culture in a Preclinical Pig Experiment
Authors: Nakazawa K. , Ijima H. , Fukuda J. , Sakiyama R. , Yamashita Y. , Shimada M. , Shirabe K. , Tsujita E. , Sugimachi K. , Funatsu K.
Published: January 2018

We describe a preclinical study of our original hybrid artificial liver support system (HALSS) for a clinical trial. We designed a HALSS comprising a multi-capillary polyurethane foam packed-bed module (MC-PUF module) containing a total 200 g (2 × 1010 cells) porcine hepatocytes, and an extracorporeal circulation device. Almost all porcine hepatocytes in the MC-PUF module formed many spherical multicellular aggregates (spheroids). This extracorporeal circulation device was improved to promote solute exchange between a living body and a MC-PUF module by including a plasma bypass line in the circulation loop.

The efficacy of the HALSS was evaluated using a 25-kg pig with warm ischemic liver failure by portocaval shunt and ligation of hepatic artery (HALSS group, n=3). As a control experiment, the same system without hepatocytes in the module was used with the same kind of liver failure pig (Control group, n=3). The blood ammonia in the control group was 143 N-μg/dl at the start of circulation, and rapidly increased to 351 N-μg/dl at 2 hours and to 704 N-μg/dl at 6 hours. But the blood ammonia in the HALSS group was completely suppressed, and remained less than the hepatic coma level (over 200 N-μg/dl) during the circulation time. The blood glucose in the control group gradually decreased, and became less than 40 mg/dl within 6 hours of circulation. But the blood glucose in the HALSS group was maintained well, and remained the normal glucose level (50 – 105 mg/dl) for more than 20 hours of circulation. Improvement in blood creatinine and lactate, and the stabilization of vital signs and urinary excretion, were observed in the HALSS group. The survival time of the pigs in the HALSS group was 19.3 hours compared with 8.9 hours in the control group.

In conclusion, our HALSS was effective to stabilize the general conditions of the body in addition to supporting various liver functions. These results suggest that our HALSS has a strong possibility to be used in treating liver failure patients. We have applied for approval of the clinical trial of our HALSS to our institutional ethics committee.
Autologous Cardiomyocyte Transplantation in an Ovine Myocardial Infarction Model
Authors: Kim W.G. , Park J.J. , Chung D.H. , Na C.Y.
Published: January 2018

Background

To evaluate the possibility of autologous cardiomyocyte transplantation, we transplanted cultured autologous cells into an infarct region developed by coronary artery ligation in an ovine model.

Materials and Methods

A chronic heart failure model with a considerable portion of myocardial infarction was created in sheep using sequential ligation of the homonymous artery and its diagonal branch. Autologous cardiomyocytes were cultured and isolated from the right ventricular infundibulum. After a predetermined interval (one animal for two months and the other for three months), the two animals were reanesthetized and a suspension of cultured autologous vetricular cells in 0.3 ml of culture medium (1.2 × 107 cells) was injected into the center of three out of the four sites in the infarcted area using a tuberculin syringe. The same amount of culture medium was injected with an identical procedure into the center of the remaining site, as control. The animals were kept alive for a further month, and then sacrificed for postmortem heart examinations. Light microscopic analysis and immunohistochemical study for myoglobin were done.

Results and Conclusions

On postmortem gross examination, well-demarcated thin-walled anteroseptal infarcts with chamber enlargement were clearly seen in specimens from the two animals. Microscopic analysis showed homogenous fibrosis throughout the infarcted areas. In both animals, one of the three sites of cardiomycyte injection showed an islet of cardiomyocytes in the mid-myocardium, while none were observed in the control site of either animal. A layer of cardiomyocytes was observed in subendocardial regions, as it was in the control areas. In conclusion, cardiomyocyte transplantation into the infarct regions developed by coronary artery ligation in an ovine model was achieved with only limited success. An understanding of why only 33% of cardiomyocyte-injection sites demonstrated viable cardiomyocytes, in the form of tiny cell islets, remains to be elucidated.
Patient Knowledge and Interest on Dialysis Efficiency: A Survey
Authors: Piccoli G.B. , Mezza E. , Pacitti A. , Iacuzzo C. , Bechis F. , Quaglia M. , Anania P. , Garofletti Y. , Martino B. , Peirano G. , Aglì I. , Jeantet A. , Segoloni G.P.
Published: January 2018

Background

Therapeutic compliance is fundamental on dialysis; however following a therapy requires a prior understanding of it. Aim of the study was to assess the need and interest for information on dialysis efficiency and to prepare a dedicated teaching tool.

Methods

72 patients, on hemodialysis in two limited-care satellite units, were given a questionnaire testing knowledge and interest on dialysis efficiency. In a subsequent second phase, following patients' suggestions, a cartoon book was prepared and opinions recorded.

Results

63 patients' returned the questionnaire. 79.4% had basic knowledge on routine blood tests, 30.1% were aware of their specific meaning. All patients asked for further information, preferring books to other media. The book “Kt/V as cartoon” was distributed; 71.2% read it, 93% scored it as good-very good. In the Unit employing flexible dialysis schedules, 22/42 patients increased dialysis time.

Conclusions

Despite insufficient knowledge on dialysis efficiency, patient interest is high. An educational program is feasible and may also give practical results, such as self-increase in dialysis time.
A New Expandable Cannula to Increase Venous Return during Peripheral Access Cardiopulmonary Bypass Surgery
Authors: Jegger D. , Mueller X. , Mucciolo G. , Mucciolo A. , Boone Y. , Seigneul I. , Horisberger J. , Von Segesser L.K.
Published: January 2018

Peripheral cannulation for cardiopulmonary bypass (CPB) is of prime interest in minimally invasive open heart surgery. As CPB is initiated with percutaneous cannulae, venous drainage is impeded due to smaller vessel and cannula size. A new cannula was developed which can change shape in situ and therefore may improve venous drainage.

An in vitro circuit was set-up with a penrose latex tubing placed between the preload reservoir and the cannula, encasing the cannula's inlet and simulating the vena cava. The preload (P) was stabilised at 2 and at 5mmHg respectively. The maximum flow rate was determined for 4 conditions: passive venous drainage (PVD) and assisted venous drainage (AVD) using a centrifugal pump at the 2 preload settings. We compared the results of the prototype cannula to classical femoral venous cannulae: basket 28Fr, a thoracic 28Fr and a percutaneous 27Fr.

Under PVD conditions and a CVP of 2mmHg, the prototype cannula's flow rate outperformed the next best cannula by 14% (p=0.0002) and 13% under AVD conditions (p=0.0001). Under PVD conditions and a CVP of 5mmHg, the prototype cannula outperformed the percutaneous cannula by 19% (p=0.0001) and 14% under AVD conditions (p=0.0002).

The new cannula outperforms the classical percutaneous venous cannulae during all of the four conditions tested in vitro.
The α1-antitrypsin/elastase Complex as an Experimental Model for Hemodialysis in Acute Catabolic Renal Failure, Extracorporeal Blood Circulation and Cardiocirculatory Bypass
Authors: Grano V. , Diano N. , Portaccio M. , Bencivenga U. , De Maio A. , De Santo N. , Perna A. , Salamino F. , Mita D. G.
Published: January 2018

A modified polyethersulphone graft membrane was loaded with antiproteases, with the aim of reducing the active protease blood concentration during hemodialysis in acute catabolic renal failure or cardiopulmonary bypass. As protease/antiprotease system, elastase and α1-antitrypsin were used. The concentration of active elastase in aqueous solutions decreased as function of contact time with the membrane, approaching saturation. A 40% loss of elastase activity was obtained at pH 7.4, which was not due to autolysis, which accounted for 5% of the loss. The highest reduction was achieved at pH 9.0 (25% higher than at pH 7.4). The saturation level of elastase decrease, calculated by means of the Einstein equation, was reached after more than 47 minutes. We speculate that a time reduction might be achieved either increasing the concentration of immobilized antiproteases, or increasing the rate of elastase movement across the membranes by hydraulic, osmotic, or temperature gradients. This technology can be applied to hemodialysis, and in extracorporeal blood circulation to promote elastase release.
In Vitro Blood Damage by High Shear Flow: Human versus Porcine Blood
Authors: Klaus S. , Körfer S. , Mottaghy K. , Reul H. , Glasmacher B.
Published: January 2018

Devices for modern heart support are minimized to reduce priming blood volume and contact area with foreign surfaces. Their flow fields are partly governed by very high velocity gradients. In order to investigate blood damage, porcine and human blood was passed through a narrow Couette type shear gap applying defined high shear rates within the typical range for devices such as blood pumps or artificial heart valves (γ = 1800/s to 110,000/s for 400 ms). Traumatization profiles of both blood species were recorded in terms of hemolysis and platelet count. Sublethal damage in terms of platelet (PF4) and complement activation (C5a) was additionally measured for human blood. Results for porcine and human blood were very similar. Hemolysis was not started until critical shear rates of about 80,000/s. Impact on platelets was severe with drops in cell count of up to 65% (at γ = 55,000/s to 110,000/s) likely to set stronger limits to the design layout of devices than hemolysis. Concentrations of PF4 and C5a clearly increased with shear rate exhibiting stronger gradients where hemolysis started. Due to the similar results of porcine and human blood for hemolysis and platelet drop, porcine blood seems to be suitable for device testing. Selection of blood species would thus depend on handling, availability and analysis demands.
Dialysis Membranes Today
Authors: Bowry S. K.
Published: January 2018

In recent years, hemodialytic therapies have evolved from the simple, diffusion-dependent removal of small molecular weight substances from blood to advanced therapy modalities involving the convective removal of larger uremic sloutes. The clinical benefits of removal of substances such as ß2-microglobulin (ß2-m) have been reported by several authors: elimination of large-molecular weight “uremic toxins” is now widely accepted as being beneficial to the overall quality of life of patients.

This trend would not have been possible without parallel technical developments, especially that of new membranes having more open pore structures resulting in higher sieving coefficients and increased hydraulic permeability. Not all polymer types are suitable for the manufacture of high-flux membranes required for convective therapies in which large fluid volumes are exchanged. Amongst the more important criteria are: the selected polymer must be able to undergo steam sterilisation, have high endotoxin retention capabilities, be versatile for the fabrication of a range of hydraulic permeabilities and, of course, have high blood compatibility.

The aim of this paper is, firstly, to review the major membrane development phases over the last quarter of a century. Secondly, the suitability of current membrane materials to meet the aforementioned requirements will be examined. Thirdly, in view of the recent, rapid proliferation of polysulfone-based membranes, dialysis membranes of the polysulfone ‘family’ are placed under scrutiny; membranes of this class represent a significant portion of the product portfolio of dialyser manufacturers today, yet, few end-users are able to distinguish between the salient features of the respective products because of a combination of confusing membrane nomenclature, classification, tradenames and product claims.
Polymers in Nephrology Characteristics and Needs
Authors: Vienken J.
Published: January 2018

Polymers employed as biomaterials in nephrology serve for different applications: they form membranes for dialysis and plasmapheresis, are used as materials for dialyser housings and as a potting mass for capillary membranes, they make up tubing-systems for extracorporeal circuits and – in the form of beads – act as parts of adsorber columns for hemoperfusion or immunoadsorption.

However, generally speaking, many polymers have not yet been designed for their final application. To date, many polymers are still taken from the chemist's shelf according to their alleged performance properties or to their sterilisability.

When used in medical application, polymers must show a high purity. Uncontrolled leaching of oligomers from the polymer backbone or of additives from or during the manufacturing process must be avoided. Blood and other body fluids are extremely effective in extracting any loosely bound polymers. During long-term application, e.g. in patients suffering from chronic diseases, these effects may lead to an accumulation of these compounds in circulating blood, tissue, or joints. Consequently, polymers should show an excellent biostability and not degrade during their ageing process. The amount of extractable material should be kept low in order to avoid inflammatory reactions. Polymers must have high blood compatibility in terms of minimized cell-and complement activation.

Polymers for medical application should at best be able to stand high temperatures in order to survive steam sterilisation. If this is impossible, their release kinetics for residual quantities of sterilizing agents should be fast.

Finally, protein adsorption should appear under controlled conditions, otherwise a reduced performance through protein adsorption will take place. Further, the uncontrolled activation of biochemical cascades, such as the coagulation, complement or contact phase cascade, following blood/material contact must be minimized. A final aspect has been recently made responsible for adverse patients reactions, the interaction between polymers and medicinal drugs. This drug/material interaction must be low, at best zero, apart form those situations, where a controlled drug-release is wanted.

The chemical variety of polymers for medical application is large. However, all typical requirements cannot be met by one single polymer. Compromises have to be found between properties and application. Polymer selection for application in nephrology has always to be made under the premise of final application.
Acid-Base Balance during Continuous Veno-Venous Hemofiltration: The Impact of Severe Hepatic Failure
Authors: Naka T. , Bellomo R. , Morimatsu H. , Rocktaschel J. , Wan L. , Gow P. , Angus P.
Published: January 2018

Background

Continuous renal replacement therapy (CRRT) affects acid-base balance but the influence of severe hepatic failure (SHF) on this effect is unknown.

Aim

To assess the effect of SHF on acid-base balance in patients receiving CVVH.

Design

Retrospective laboratory investigation.

Subjects

Forty patients with SHF and acute renal failure (ARF) treated with CVVH and 42 critically ill patients with severe ARF but no liver disease also treated with CVVH (controls).

Intervention

Retrieval of clinical and laboratory data from prospective unit and laboratory databases.

Methods

Quantitative acid-base status assessment using the Stewart-Figge methodology. Comparison of findings between the two groups.

Results

Although CVVH had a major effect on acid base balance in both groups, patients with SHF had a higher mean lactate concentrations (4.8 vs. 3.1 mmol/L; p<0.0005), a greater base deficit compared to controls (-1 vs. 4.1 mEq/L; p<0.0001) and a lower PaCO2 tension (36.8 vs. 42.5 mmHg; p<0.0001), despite the use of bicarbonate replacement fluid. The acidifying effect of hyperlactatemia was slightly worsened by an increased strong ion gap (9.3 vs. 4.9 mEq/L; p<0.0001). It was, however, attenuated by an increased strong ion difference apparent (SIDa) (43.6 vs. 41.9 mEq/L; p<0.05) secondary to hypochloremia (96 vs. 100 mmol/L; p<0.0001) and by hypoalbuminemia, although hypoalbuminemia in SHF patients (26 vs. 23; p<0.005) was less pronounced than in controls.

Conclusion

The use of CVVH does not fully correct the independent acidifying effect of liver failure on acid-base status. Increased lactate and strong ion gap values maintain a persistent base deficit despite the alkalinizing effects of hypoalbuminemia and hypochloremia. The correction of acidosis in SHF patients may require more intensive CVVH.
Comparison of Kinetic Characteristics of Amino Acid-Based and Dipeptide-Based Peritoneal Dialysis Solutions
Authors: WeryńSki A. , Waniewski J. , Wang T. , Anderstam B. , Lindholm B. , BergströM J.
Published: January 2018

A mixture of dipeptides (DP) has been proposed as alternatives (to glucose and amino acids, (AA)) osmotic agent in peritoneal dialysis (PD) solutions. DP based solutions may have metabolic and nutritional advantages compared to AA based solutions, as some sources of AA (such as tyrosine) are poorly soluble in water. In a previous study, we compared the kinetic characteristics of DP and AA based solutions; however, the amount of AA differed substantially. The aim of the present study was to compare solutions with almost equal amounts of AA.

Methods

The following solutions were used: (1) amino acid (AA) solution containing leucine, valine, lysine, isoleucine, threonine, phenylalanine and histidine (tyrosine was omitted because of its poor solubility), (2) dipeptide (DP) solution containing leucyl-valine, lysyl-isoleucine, threonyl-phenylalanine and histidyl-tyrosine. Sixteen Sprague-Dawley rats were divided in two groups and were subjected to intraperitoneal injection of either 25 mL of AA (n=8) or DP solution. Dialysate and blood samples were taken frequently postinfusion for measurement of AA and DP concentrations as well as AA from DP.

Results

Kinetic models were developed for estimation of diffusive mass transport coefficient between peritoneal cavity and blood (KBD), DP hydrolysis rate coefficient (KH) and AA clearance in the body (KC). Calculations showed that KH is about ten times lower than KBD. Thus, hydrolysis rate in peritoneal cavity is much lower than the diffusive transport rate of DP. KBD for AA appeared to be similar to KBD for dipeptides. KC was much higher than KBD for AA. This finding explains the rapid clearance of amino acids from blood. Nevertheless, the AA-based solution resulted in much higher peak concentrations of AA in blood after 120 min of the dwell than AA concentrations achieved following the use of the DP-based solution.

Conclusions

Peritoneal transport characteristics of AA and DP were similar; however their kinetics in blood differs substantially. The DP solution resulted in a less pronounced increase in AA concentrations in blood, suggesting that DP solution could provide AA in a more physiological way.
Role of B-Type Natriuretic Peptide in Cardiovascular State Monitoring in a Hemodialysis Patient with Primary Amyloidosis
Authors: Fabbian F. , Stabellini N. , Sartori S. , Molino C. , Russo G. , Russo M. , Cantelli S. , Catizone L.
Published: January 2018

Background

Cardiac involvement occurs in up to 50% of patients with primary or AL amyloidosis (ALA) and is associated with very poor prognosis. B-type natriuretic peptide (BNP) has been proposed as a guide for treatment of heart failure patients and as an index of myocardial dysfunction in patients with ALA. Data about BNP dosage for cardiovascular monitoring of patients with ALA on renal replacement therapy are lacking.

Case

A 64 year old Caucasian man was admitted because of nephrotic syndrome in July 2003. Renal diagnosis was ALA. Melphalan and prednisolone were given but renal function worsened and in April 2004 standard bicarbonate hemodialysis was started. In March 2004 thalidomide was added to his therapy. During the follow-up ejection fraction was stable and was 65% on the contrary E/A ratio gradually increased and overtook 1. BNP plasma levels were increased and the values recorded during the follow-up were: 2505 pg/mL in October 2003 (normal reference values

Conclusion

In ALA patients a powerful prognostic role of BNP has been reported whose expression is increased in ventricular myocytes of patients with cardiac involvement. BNP level monitoring does not appear to be superior to standard echocardiography in evaluating cardiovascular status of uremic patients with ALA.
A New Chemical Etching Process to Improve Endosseous Implant Osseointegration: In Vitro Evaluation on Human Osteoblast-Like Cells
Authors: Giordano C. , Sandrini E. , Busini V. , Chiesa R. , Fumagalli G. , Giavaresi G. , Fini M. , Giardino R. , Cigada A.
Published: January 2018

The development of novel mechanical and chemical surface modification treatments to improve the osteointegration properties of osseointegrated dental implants is nowadays a topic of great applicative interest. The aim of the present study was to analyse the role of surface topography and chemistry of four different surface treatments on titanium by an in vitro human osteosarcoma immortalised cell line model (MG63). The surface treatments considered were (a) machined titanium, (b) chemical etched on machined titanium, (c) sandblasted titanium and (d) chemical etching on sandblasted titanium.

Chemical and physical surface properties were investigated by Scanning Electron Microscopy, Thin Film-X ray Diffraction and by Laser Profilometry. The in vitro biological response was characterised using the MG63 cell line by elution cytotoxicity tests, cell morphology, adhesion, proliferation activity, alkaline phosphatase activity and total DNA content in order to show a relationship between osteoblast response and surface features.

Chemical and physical characterisation showed that the considered treatments differently modify the surface morphology in the micro and sub-micrometric scale. Although some differences in alkaline phosphatase activity were observed in the biological characterisation, depending on the specific material's surface finishing, the results showed that cells were well responsive on all the tested materials and grew and differentiated with similar proliferation rate.
Novel Membrane for Guided Bone Regeneration
Authors: Pirhonen E.M. , Pohjonen T.H. , Weber F.E.
Published: January 2018

Membranes have been clinically used for guided tissue and bone regeneration for decades, but their use in every day clinical practice is rather limited. We developed a biodegradable membrane (InionGTR™) composed of polylactide, polyglycolide and trimethylene carbonate aiming to improve the properties of membrane. Before application the membrane is treated with N-methyl-pyrrolidone (NMP) to achieve a rubber like consistency, to allow easy handling and manageability in the clinical setting. After placing the membrane NMP diffuses out from the polymer phase into the water phase. The loss of NMP in the polymer stiffens the membrane up and allows space maintenance in the defect area. In addition the influx and efflux of NMP creates a porous surface on the membrane leading to an improved integration of tissues into the porous surface layers of the InionGTR™ membrane. Therefore, the use of NMP improves the handling in the clinical setting, and allows tissue integration and space maintenance, both important for the outcome of the treatment.
Quantitative Constitutive Behaviour and Viscoelastic Properties of Fresh Flexor Tendons
Authors: Wu J.J.
Published: January 2018

The objective of this study was to obtain detailed high quality experimental data under well-controlled test conditions in order to quantify tendon viscoelastic behaviour and provide an experimental basis for large deformation mathematical modelling. Eighty-six fresh chicken flexor digitorum profundus (FDP) tendons were mechanically tested using an Instron 5565 universal testing machine and a Bioplus bath containing physiological saline solution. At low strain rates (≤ 0.001s−1), no strain rate dependence was found and the value of the elastic modulus was 324±17 MPa. At medium strain rates (0.003s−1 – 0.1s−1), the elastic stiffness increased with increasing strain rate. For example, the values of the elastic modulus were 427±10, 653±21 and 837±11 MPa for strain rates of 0.006s−1, 0.012s−1 and 0.05s−1 respectively. A series of stress relaxation experiments at different levels of strain were conducted. The higher the initial stress level, the faster the stress relaxed. For all stress relaxation tests, the relationship of normalised relaxation function G(t) against log time (ln(t)) was approximately linear (R2 = 0.935 ± 0.028) and this supports Fung's quasi-linear viscoelasticity (QLV) hypothesis. Some preliminary work on bovine flexor tendons using a video extensometer is also reported.
Attachment and Growth of Fibroblasts on Poly(L-lactide/∊-caprolactone) Scaffolds Prepared in Supercritical CO2 and Modified by Polyethylene Imine Grafting with Ethylene Diamine-Plasma in a Glow-Discharge Apparatus
Authors: Aydin H.M. , TÜRk M. , ÇAlimli A. , PişKin E.
Published: January 2018

In this study, a copolymer of L-lactide and ∊-caprolactone (Mn: 73,523, Mw: 127,990 and PI: 1.74) was synthesized by ring-opening polymerization by using stannous octoate as the catalyst. FTIR, 1H-NMR and DSC confirmed the copolymer formation. The copolymer films were prepared and a novel method was developed to produce highly porous sponges for potential use in tissue engineering. Films were subjected to supercritical CO2 at 3300 psi and 70°C to create porous structures for production of possible tissue engineering scaffolds. The pore sizes were in the range of 40–80 mm. The copolymer films were pre-wetted with polyethylene imine (PEI) and then treated with ethylene diamine (EDA)-plasma in glow-discharge apparatus. Gas plasma surface modification of three-dimensional scaffolds fabricated by supercritical carbon dioxide technique was demonstrated to enhance cell adhesion, proliferation, and differentiation over 6 days in culture using L929 fibroblast cell line. Alkaline phosphatase (ALP) activity and glucose uptake in cell culture medium were followed in the cell culture experiments. Fibroblastic cell attachment and growth on the EDA-plasma treated scaffolds were rather low. However, both cell attachment and growth were significantly increased by PEI pre-treatment before EDA-plasma. The changes in ALP activity and glucose uptake also supported the cell growth behavior on these PEI and EDA-plasma treated scaffolds.
An Experimental Pilot Study on Controlled Portal Vein Arterialization with an Extracorporeal Device in the Swine Model of Partial Liver Resection and Ischemia
Authors: Nardo B. , Montalti R. , Puviani L. , Pacilè V. , Beltempo P. , Bertelli R. , Licursi M. , Pariali M. , Cianciavicchia D.
Published: January 2018

Aim

To determine whether the physiologically oxygenated arterial blood reversed in the portal system by means of portal vein arterialization (PVA) through an extracorporeal device which we have called L.E.O2.NARDO (Liver Extracorporeal Oxygen. NARDO) is effective in treating swine with subtotal hepatectomy leading to acute liver failure (ALF).

Methods

Ten swine with ALF induced by 85–90% liver resection and five minutes of ischemia-reperfusion injury were randomly divided into two groups: five animals received PVA extracoporeal treatment and five swine were not-treated (control group). Blood was withdrawn from the iliac artery and reversed in the portal venous system. An extracorporeal device was interposed between the outflow and the inflow in order to monitoring the hemodynamic parameters. Each treatment lasted 6 hours. Serum and liver samples were collected in both groups. The survival was assessed at 1 week.

Results

The PVA-extracorporeal treatment yielded beneficial effects for subtotal hepatectomy-induced ALF swine with decreased serum ammonia, transaminases and total bilirubin as compared with the untreated group. INR recovered rapidly in the PVA-extracorporeal group remaining significantly lower than in untreated animals. The 7-day survival of PVA-extracorporeal group swine was significantly higher than that of untreated animals, with a statistically significant difference (p<0.05). Four swine in the PVA-extracorporeal group survived at 1 week while none of the swine in the control group were alive at that time; an average time of 144h±13h and 24.4h±5h was observed in the PVA-extracorporeal and control groups, respectively.

Conclusions

Arterial blood supply in the portal system through the extracorporeal device is easily applicable, efficacious, safe and may represent a novel approach for ALF swine induced by subtotal liver resection.
Evaluation of the Effects of Pulse High-Volume Hemofiltration in Patients with Severe Sepsis: A Preliminary Study
Authors: Peng Zhang , Pai Peng , Han-Min Wang , Jun Zhu , Hong-Bao Liu , Rong Li , Chen Huang
Published: January 2018

Objectives

The aim of this study was to evaluate the effects of pulse high-volume hemofiltration (PHVHF) in patients with severe sepsis.

Methods

Twenty-two patients with severe sepsis admitted to XiJing hospital between January 2009 and January 2010 were included in the present study. Patients were randomly divided into the control group (conventional treatment) and the PHVHF group. Patients in the PHVHF group received 72 h of PHVHF treatment in addition to conventional treatment after admission. PHVHF was conducted as follows: HVHF 85 ml/kg per hour for 6 h followed by continuous venovenous hemofiltration 35 ml/kg per hour for 18 h with an AN69 membrane. The hemofilter was replaced every 24 h and PHVHF was performed with 250 to 300 ml/min blood flow rate. The blood samples were taken to measure the changes of plasma cytokines (TNF-α, IL-1, IL-4, IL-6 and IL-10).

Results

With 72 h of PHVHF treatment, there was an improvement in clinical features and hemodynamics variables in PHVHF-treated patients. All plasma cytokines after PHVHF treatment were significantly lower than those at the start of PHVHF treatment (p<0.05). In contrast, there was no significant change in control patients.

Conclusions

Our findings suggest that PHVHF is a feasible adjuvant modality in the treatment of patients with severe sepsis. With the application of PHVHF treatment, plasma cytokines are effectively removed. Considering the lower cost and better feasibility than continuous high-volume hemofiltration (CHVF), PHVHF shows promising prospects for the future.
Percutaneous Vascular Cannulation for Extracorporeal Life Support (ECLS): A Modified Technique
Authors: Grasselli Giacomo , Pesenti Antonio , Marcolin Roberto , Patroniti Nicolò , Isgró Stefano , Tagliabue Paola , Lucchini Alberto , Fumagalli Roberto
Published: January 2018

Purpose

Vascular access and cannulation are crucial issues to maximize the efficiency of extracorporeal circulation techniques and to preserve patients' safety. Techniques of cannulation have changed over the years, from surgical cutdown to percutaneous approaches, which are now considered standard practice. We describe an original modified percutaneous cannulation technique developed in our Department and we report our clinical experience and complications observed.

Methods

A Seldinger technique utilizing 3 guidewires with passage of a dilator over each guidewire was used. Two concentric pursestring sutures, prepared before cannulation, minimize procedure-associated bleeding. Cannulation is performed under direct fluoroscopic control.

Results

From 1997 to 2009, 38 patients (31 VV-ECLS, 7 VA-ECLS) have been cannulated using our technique, resulting in a total of 69 venous cannulations. Average external caliber of venous cannulae was 23 Fr (15–29 Fr). Mean duration of the entire cannulation procedure was 40 minutes (20–60 min). Adverse events occurred in 3 patients.

Conclusions

The technique described is safe and feasible and the incidence of procedure-related complications is very low, but it may require longer time to be performed.
Rapid Identification of Staphylococci from Prosthetic Joint Infections Using MALDI-TOF Mass-Spectrometry
Authors: Harris Llinos G. , El-Bouri Khalid , Johnston Stuart , Rees Eugene , Frommelt Lars , Siemssen Nicolaus , Christner Martin , Davies Angharad P. , Rohde Holger , Mack Dietrich
Published: January 2018

Hospital-acquired infections associated with implanted medical devices are most commonly caused by staphylococci. Current methods of species identification are slow, costly, and sometimes unreliable. We evaluated the ability of a Bruker Daltonics Microflex MALDI-TOF/MS in conjunction with MALDI Biotyper software to identify 158 characterized staphylococcal isolates from prosthetic joint infections, including 36 Staphylococcus aureus, 100 Staphylococcus epidermidis, 10 Staphylococcus capitis, 8 Staphylococcus lugdunensis, 2 Staphylococcus warneri, and 2 Staphylococcus haemolyticus isolates using the extraction method recommended by Bruker Daltonics. The suggested species identification by the MALDI Biotyper software was correct for all isolates, indicating reliable differentiation between S. aureus and coagulase-negative staphylococci. Applying the recommended criteria of the MALDI Biotyper software all 158 isolates gave scores ≥2.0, implying secure genus and probable species identification for all isolates. 34/36 S. aureus, 36/100 S. epidermidis, 5/10 S. capitis, 6/8 S. lugdunensis, 2/2 S. haemolyticus, 0/2 S. warneri displayed scores ≥2.3 implying highly probable species identification. For S. epidermidis 25/100 additional isolates had a score close to 2.3. It appears that additional clinically relevant staphylococcal isolates in the data base might aid in identification at scores implying highly probable species identification. The ability of the MALDI Biotyper software to recognize clonally-related strains within a species group (i.e. sub-typing) was investigated, and showed great potential. In conclusion, the MALDI-TOF/MS MALDI Biotyper system provides a promising rapid and reliable method of identifying clinical isolates from prosthetic joint infections to the species level, and has potential for sub-typing.
Molecular Mechanisms of RIP, an Effective Inhibitor of Chronic Infections
Authors: Lopez-Leban Florencia , Kiran Madanahally Divakar , Wolcott Randall , Balaban Naomi
Published: January 2018

Non-healing bacterial infections are often associated with the formation of a biofilm, where bacteria are more resistant to conventional treatment modalities and to host immune responses. We show here that RNAIII inhibiting peptide (RIP), a linear heptapeptide, is very effective in treating severe polymicrobial infections, including drug-resistant staphylococci like MRSA. By functional genomics studies (microarray analysis) on Staphylococcus aureus, we show here that RIP downregulates the expression of genes involved in biofilm formation and toxin production, and upregulates genes involved in stress response. This pattern of gene regulation may explain why RIP has been so effective in treating severe infections and hopefully through the addition of RIP to existing protocols, a new way of tackling chronic persistent infections will be established.
SEM Evaluation of the Root Canal Walls after Treatment with Tetraclean
Authors: Poggio Claudio , Dagna Alberto , Chiesa Marco , Bianchi Stefano , Arciola Carla Renata , Visai Livia , Giardino Luciano
Published: January 2018

Purpose

In this ex vivo study, the surface cleanliness of root canal walls after shaping with Ni-Ti instruments and irrigating with different endodontic solutions was evaluated by SEM.

Methods

50 single-rooted teeth were divided into 5 groups. All root canals were shaped with Revo-S™ (MICRO-MEGA®, Besancon, France) rotary Ni-Ti instruments and irrigated with NaOCl, varying the final rinse: NaOCl, Tetraclean, 17% EDTA, Cloreximid, Tetraclean liquid not mixed with powder. Specimens were fractured longitudinally and prepared for SEM analysis in order to evaluate the presence/absence of smear layer and the presence/absence of open tubules at the coronal, middle, and apical third of each canal, using a 3-step scale for scores. Numeric data were analyzed using Kruskall-Wallis test and Mann-Whitney U test and significance was predetermined at p<0.05.

Results

This study showed significant differences between the various groups. The 5.25% NaOCl + Tetraclean and 5.25% NaOCl + 17% E.D.T.A. groups had significantly lower scores than other groups (p<0.001), with no significant difference between them.

Conclusions

Final rinse with Tetraclean is effective in removing the smear layer, leaving a high number of opened dentin tubules.