bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design Considerations for a Small Bore Vascular Prosthesis
Authors: Underwood C.J. , Tait W.F. , Charlesworth D. 
Published: April 2018

No synthetic prosthesis has yet been found which can satisfactorily be used as a substitute for saphenous veins in vascular surgery. One explanation for the lack of success is that their properties and behaviour do not mimic those of the arteries they replace. The essential features for a successful vascular prosthesis, over and above biocompatibility, are a low friction non-thrombogenic flow surface, mechanical (elastic) behaviour that matches natural artery and dimensions that approximate the host vessels. This will allow a high velocity of flow with low impedance. A prosthesis with this specification would avoid the problems of flow disturbances and reflection at the anastomoses, pulse wave damping and large pressure gradients, all of which reduce pulsatile energy. We have designed a vascular prosthesis based upon the above criteria. It has an internal diameter of 4 mm and a wall thickness of 1 mm. Its geometry makes it kink resistant and a good match for tibial and coronary arteries. The prosthesis is made from Polyurethane and its mechanical properties, which approximate to those of peripheral arteries, are achieved via a mechanism of internal wall compression rather than external circumferential expansion. To assess the in-vivo potential of this prosthesis, 21 grafts were implanted in 11 sheep, replacing a section of carotid artery with a 6 cm long prosthesis. All 21 grafts were patent after 3 months. One graft was removed for histological examination. 16 of the remaining 20 grafts were patent after 7 months. Problems associated with thrombosis were not encountered and we conclude that this prosthesis shows good potential as a small bore vascular substitute.
Morbidity in Valvular Heart Replacement: Risk Factors of Systemic Emboli and Thrombotic Obstruction
Authors: Abdelnoor M. , Hall K.V. , Nitter-Hauge S. , Rostad H. , Risum Ø. 
Published: April 2018

A study on a cohort of 839 patients with valvular heart replacement between June 1977 and May 1985 showed that the linearized rates of systemic emboli and thrombotic obstruction were 1.4/100 pts/year for Aortic Valve Replacement (AVR), 2.2/100 pts./year for Mitral Valve Replacement, and 3.00/100 pts./year for Double Valve Replacement (DVR). The 5-year free-from-thromboembolism (TE) survival was 95% for AVR and 92% for MVR. The hazard function (the instantaneous risk) for TE peaked in the first six months after operation for AVR and MVR. Another analysis using the Cox regression model to estimate risk factors of systemic emboli and thrombotic obstruction pinpointed two factors in the AVR group: presence of aortic regurgitation (AR) and age at operation. In the MVR group the sole predictor covariate was sex of the patients, with a higher hazard for females. Our results underline the importance of patient-related factors besides the type of prosthesis as predictors of morbidity from TE.
A Simplified Method for Purification, Concentration and Freezing of Bone Marrow Cells for Autologous Transplantation
Authors: Wendel S. , Dayawansa T. , Das P.C. , Smit Sibinga C. Th. 
Published: April 2018

Autologous bone marrow (BM) transplantation is being increasingly applied in hematological and oncological patients. However, because of the need to purify and preserve BM requiring high technology, such treatments are virtually concentrated in the “developed” countries. This paper examines methods of BM purification and freezing that could make the technique potentially applicable in developing countries. Hemapheresis is routinely applied for BM purification in our Dutch Centre, where the buffy coats obtained from routine blood donations were utilised in experimental settings. Using DMSO as cryoprotectant, semi-purified white cells were frozen in liquid N2 (LN2), by mechanical freezer or snap-frozen at -55° C. Different types of containers were compared including plastic tubes and ordinary blood bags. After thawing the results show that snap-freezing had a deleterious effect but the cell yields and viability were similar in LN2 or the mechanical freezer where the tubes and the bag were equally effective as containers (86% cell recovery with 90% viability). In the purification/concentration stage, reduction of the volume of the material by extra centrifugation, thus requiring less DMSO, produced better results — 96% cell yield and 90% viability after thawing. This simplified method was applied in a general hospital in Sao Paulo where four oncology patients underwent BM collection. BM was purified and concentrated within a blood bank facility. Hydroxyethyl starch sedimentation and centrifugation of the material in plastic blood bags gave 80% BM cell harvest. After thawing from the mechanical freezer 1 x 108 BM cells/kg were available for reinfusion to patients. There was no immediate untoward reaction. Three of the patients showed signs of bone marrow regeneration by three weeks, but one patient died 16 days after transplantation, of septicemia. We conclude that certain high-technology procedures for ABMT can be adapted for existing facilities in developing countries.
Comparison of Two Hemodialysis Membranes, Polyacrilonitrile and Cellulose Acetate, on Complement and Coagulation Systems
Authors: Moll S. , De Moerloose P. , Reber G. , Schifferli J. , Leski M. 
Published: April 2018

Two hemodialysis membranes, polyacrilonitrile (AN 69) and cellulose acetate (CA), were compared for their effects on complement and hemostasis. Two groups of 5 patients, in dialysis for more than 5 years, were successively dialysed for 4 weeks periods with each type of membrane. We measured C3a (complement activation), platelets and beta-thromboglobulin (platelet activation), thrombin-antithrombin III complexes and fibrinopeptide A (coagulation activation), using C-Reactive Protein as a control for dilution effects. As previously shown, activation of complement was more important with CA than with AN 69 (p < 0.01). In contrast, activation of coagulation (increase in fibrinopeptide A and thrombin-antithrombin III complexes) was more pronounced with AN 69 than with CA. This study emphasizes the need to consider different biological systems when the bioincompatibility of a hemodialysis membrane is evaluated
Treatment of Acute Liver Failure with Hemodetoxification Techniques
Authors: Splendiani G. , Tancredi M. , Daniele M. , Giammaria U. 
Published: April 2018

The exact pathogenesis of hepatic coma is unknown and this fact has stimulated research in the field of hemodetoxification treatment. We studied 31 patients (19 M and 12 F) with acute hepatic failure and used different detoxification techniques such as hemodialysis, hemoperfusion, hemofiltration and plasmaferesis. We evaluated blood tests, degree of coma and serum levels of middle-molecular weight substances (by gel-chromatography) for each patient. Our results show that there was an improvement of consciousness and general clinical state in 40% of patients who underwent HD, in 50% of patients treated with HP, in 37.5% of those treated with PF and 78% of patients treated with HF. Unfortunately, the improvement did not last long. In conclusion we can say that artificial support improves hepatic coma and state of consciousness. This improvement could be due to the better regeneration possibilities of hepatic cells. For this reason hemodetoxification treatment should be started as soon as possible.
Membranes as Substrates for Hepatocyte Adhesion in Liver Support Bioreactors
Authors: Gerlach J. , Stoll P. , Schnoy N. , Bücherl E.S. 
Published: April 2018

Fourteen membranes out of cellulose (CuprophanR), polyamide and polypropylene were compared in a cytocompatibility test using the cytokinetics and cytomorphology of primary hepatatocytes as parameters. Additionally, the impact of coating the membranes with collagen or fibronectin was investigated. Hepatocytes were not able to attach in acceptable amounts on investigated cellulose membranes. On polyamide and polypropylene membranes a sufficient cell seeding was possible. Coating with collagen or fibronectin improves the attachment and spreading on all membranes. Differences between collagen and fibronectin were detected, observing the morphology of the cells: on collagen, most of the cells spread, whilst on fibronectin, most of the cells spread and flattened polygonally. If the adhesion of hepatocytes prolongs their metabolic function, a large adhesion surface in bioreactors is necessary. To reach a high surface area for cell adhesion in bioreactors one possibility is the use of polyamide and polypropylene membranes.
In Vivo Effects of Stroma-Free Hemoglobin and Polyhemoglobin on Coagulation Factors in Rats
Authors: Ning J. , Chang T.M.S. 
Published: April 2018

We studied the effects of rat stroma-free hemoglobin (rSFH), human stroma-free hemoglobin (hSFH), rat polyhemoglobin (rPoly), and human polyhemoglobin (hPoly) on coagulation factors in rats. Albumin and saline infused rats were controls. The infusion volume was 10% of the rat's blood volume. The concentrations of hemoglobin in this study were 7 g/dl. Measurements for prothrombin time (PT) and activated partial thromboplastin time (PTT) were at 5 minutes, 2, 6, 24 and 72 hours after infusion. Factor X, fibrinogen, plasminogen, antithrombin III, and antiplasmin were followed at 24 and 72 hours after infusion. Compared with saline infused rats PT and PTT did not change significantly in those rats infused with Hb preparations. There was a transient increase of PTT from 2 to 24 hours after infusion in albumin infused rats. Factor X, fibrinogen, antithrombin III and antiplasmin showed no significant differences between Hb infused groups and saline infused group. Twenty-four hours and 72 hours after infusion plasminogen decreased in all groups except the albumin infused rats at 24 hours after infusion when compared with normal rat plasma pool. However, there were no significant differences in plasminogen levels between the hemoglobin infused groups and the control saline group. Stroma-free and polyHb solutions (rSFH, hSFH, rPoly and hPoly) did not cause significant changes in prothrombin time and activated partial thromboplastin time in rats. The rats infused with hemoglobin solutions (rSFH, hSFH, rPoly, and hPloy) did not show significant differences in Factor X, fibrinogen, antithrombin III and antiplasmin levels compared with the control group.
Comparison of two Methods for the Estimation of Urea Kinetics and Introduction of a Third Simplified Method
Authors: Vanholder R. , van Trimpont P. , Ringoir S. 
Published: April 2018

It has been claimed that computed urea kinetic (UK) modelling in hemodialysed patients, for the estimation of protein intake, leads to an overestimation of protein catabolic rate (PCR). In the present study, three different methods of kinetic modelling for the determination of PCR and Kt/V are compared in 24 patients. The first method was the direct quantification method (DDQ) based on the collection of all urea eliminated from the body. The first computed method (ICMI) was the urea kinetic modelling method as described by Sargent. Dialyzer clearances were measured directly and not estimated by theoretical extrapolation. The second computed method (ICMII) is based on the indirect calculation of urea distribution volume (Vu), according to Watson, and of dialyzer clearances from this Vu and from pre- and post-dialysis urea concentrations. All three methods resulted in PCR's that were not significantly different (DDQ: 1.03 ± 0.19; ICMI: 1.04 ± 0.22; ICMII: 1.08 ± 0.25 mg/Kg BW.24 hrs; p > 0.05). When the results were correlated, the following results were obtained: ICMI vs ICMII: r = 0.89, p < 0.001; ICMI vs DDQ: r = 0.68, p < 0.01; DDQ vs ICMII: r = 0.78, p < 0.001. Intermutual comparison of Kt/V values resulted in virtually identical results, especially when comparing ICMI and ICMII, where the regression line equalled the identity line. In conclusion, all methods seem equally reliable in determining mean PCR and Kt/V. Our data, obtained with directly measured dialyzer urea clearances, do not confirm the earlier held opinion that computed modelling results in an overstimation of PCR. The newly developed third method (ICMII) appears to be as equally reliable as the two other methods, but is easier to perform and less labour intensive.
Theoretical Model of Blood Flow through Hollow Fibres considering Hematocrit-Dependent, Non-Newtonian Blood Properties
Authors: Lerche D. , Oelke R. 
Published: April 2018

Accounting for the non-Newtonian blood viscosity by the Quemada descriptive viscosity equation, we deduced velocity profiles and volumetric capillary flows from the Navier-Stokes-equation. An arbitrary axial and/or radial hematocrit profile can be chosen. The hematocrit dependence of the intrinsic viscosities ko (H) (characterizing, at least in part, the RBC aggregation) and k∞ (H) (describing orientation/deformation of RBC) was taken into account. Velocity profiles for pressure gradients of 4-4000 Pa/cm show a distinct flattening, if a pronounced axial migration of RBC is assumed. The higher the axial concentration, the higher the flow at the same pressure gradient. Small deviations (≤ 10%) of the capillary number per dialyzer or of the radius of capillaries lead to a strong change of the pressure gradient with the same dialyzer flow. Whereas small hydraulic conductivities do not significantly change this gradient, high conductivities decrease the pressure gradient by about 10%. Impaired blood flow properties (hemoconcentration) result in a slight deviation from the linear axial pressure drop.
Reducing perioperative blood loss in patients undergoing total hip arthroplasty
Authors: D'ambrosio A. , Borghi B. , Damato A. , D'amato G. , Antonacci D. , Valeri F. 
Published: April 2018

In this prospective, randomised, double-blind study, we investigated the effect of epidural anaesthesia and an antifibrinolytic agent, Aprotinin (500,000 KIU in bolus before surgery and 500,000 KIU h-1 in drip form during surgery), on intra and postoperative blood loss and transfusion requirements in total hip arthroplasty. Sixty patients were allocated randomly to four groups (A: epidural + general anesthesia + Aprotinin, B: epidural + general anesthesia + placebo (equal volume), C: general anaesthesia + Aprotinin, D: general anaesthesia + placebo). Postoperative analgesia: epidural analgesia in groups A and B, systemic analgesia with opiates in groups C and D. Blood loss during surgery was monitored and salvaged with the Compact-A Dideco, and postoperative blood loss with the BT 797 Recovery Dideco for the first 24 hours. Perioperative blood loss, frequency and quantity of transfusions were significantly higher in group D (p < 0.0001). Total blood loss was reduced by 31.3% by epidural anaesthesia, 20.4% by Aprotinin and 51.4% using a combination of the two techiniques.
Natural history of longitudinally extensive transverse myelitis in 35 Hispanic patients with systemic lupus erythematosus: good short-term functional outcome and paradoxical increase in long-term mortality
Authors: Flores-Silva F D , Longoria-Lozano O , Aguirre-Villarreal D , Sentíes-Madrid H , Vega-Boada F , Díaz de León-Sánchez E , Murra-Antón S , Morales-Moreno S , Quintanilla-González L , Fragoso-Loyo H , Guraieb-Chaín P , Higuera-Calleja J , Ceballos-Ceballos J , Treviño-Frenk I , González-Duarte A , Dávila-Maldonado L , Cantú-Brito C , Valdés-Ferrer S I 
Published: April 2018

Background and objective Acute transverse myelitis (TM) is an infrequent neurological complication of systemic lupus erythematosus (SLE). Short-term outcome varies widely between cohorts. Little is known about the epidemiology and long-term functional outcome of TM associated to SLE. Methods Patients with SLE and acute TM were identified during hospital admission, visits to the Emergency Room or the Neurology Outpatient Clinic. We evaluated ambispectively those patients with SLE presenting with clinical myelopathy and corroborated with spinal MRI. Cases were divided as partial (non-paralyzing) or complete (paralyzing). We determined long-term functional outcome as well as mortality in those patients with follow-up periods of at least five years. Results We identified 35 patients (partial, n = 15; complete, n = 20) in which complete clinical and imaging data were available (26 with follow-up ≥ 5 years). Patients with complete TM were significantly older than those with partial forms. Positive antiphospholipid antibodies were observed in 80% of patients, suggesting a possible mechanistical role. Surprisingly, functional recovery at one year was in general good; however, we observed a five-year mortality of 31% because of sepsis (in 10 cases) or pulmonary embolism (in one case). Conclusions Short-term outcome of SLE-related TM is generally good, and recurrence rate is low. However, we observed a long-term fatality rate of 31% for reasons unrelated to TM, suggesting that TM is a manifestation of severe immune dysregulation and a predictor of severity and mortality in patients with SLE.
Results of External Fixation and Metatarsophalangeal Joint Fixation With K-Wire in Brachymetatarsia
Authors: Peña-Martínez Víctor Manuel , Palacios-Barajas Dionisio , Blanco-Rivera Juan Carlos , Arnaud-Franco Ángel , Elizondo-Rodríguez Jorge Alberto , Acosta-Olivo Carlos , Vílchez-Cavazos Félix , Morales-Avalos Rodolfo 
Published: April 2018

Background: Brachymetatarsia is a rare foot deformity caused by the premature closure of the metatarsal physis. It may result in functional as well as cosmetic alterations, which may require operative management. Methods: A prospective study examining outcomes of 48 cases of brachymetatarsia with gradual bone lengthening at a rate of 1 mm/d using an external fixator and metatarsophalangeal joint fixation was performed. The difference between the length before treatment and after external fixator removal was measured. The patients were assessed at 2, 4, 6, and 8 weeks postoperatively; at the end of the period of distraction; and 1 year after surgery. The total number of patients was 26, and surgery was performed in 48 metatarsals. The mean age was 17.0 ± 4.1 (range, 11-24) years, and all were female. Results: The fourth metatarsal was the most frequently affected, representing 98% of the cases; the third metatarsal represented the other 2%. The average length gained was 18.6 ± 6.7 mm, and the average length gained as a proportion of the original metatarsal length was 38.2% ± 3.1% (range, 13%-24%). The mean healing time was 71.0 (range, 64-104) days, and the mean healing index (healing time divided by centimeters of length gained [d/cm]) was 38.4 (range, 38.2-50.1) d/cm. Conclusion: Gradual bone lengthening at a rate of 1 mm/d using an external fixator and intramedullary nailing was a safe and efficient method, representing a minimally invasive procedure with a low incidence of complications and satisfactory results for the patient. Level of Evidence: Level IV, retrospective case series.
A survey of mobile phone use in the provision of palliative care services in the African region and priorities for future development
Authors: Allsop Matthew J , Namisango Eve , Powell Richard A 
Published: April 2018

Introduction Palliative care (PC) services in the African region need to adapt to manage rising numbers of patients with cancer or other life-limiting conditions. Mobile phone use in healthcare delivery (mHealth) is at an early stage of development for PC, but may provide new approaches to supporting patients regionally, particularly those with non-communicable diseases. Methods We conducted an online survey of 51 PC providers across 21 countries in the African region to identify: (i) current mHealth use in PC service delivery; (ii) potential barriers to mHealth use; and (iii) provider priorities for research development. Results mHealth approaches were reported across 71.4% of services in which respondents were based. Barriers to mHealth research include patients not having access to phones, mobile network access, and limited access to expertise and hardware required for mHealth. Research priorities were identified which included exploring ways of incorporating mHealth into patient care and ensuring access and relevance of mHealth for patients and health professionals. Discussion mHealth approaches are present across PC services in the African region, but so too are barriers to their use. Further work is required to explore how existing mHealth activities might be further developed and aligned with priority areas for PC development. Crucially, user engagement that seeks to understand the preferences and priorities of patients with PC needs, their caregivers, and those involved in the provision of PC should remain central to these efforts.
The professional experiences and training needs of probation officers in Turkey
Authors: Erdem Gizem , Tuncer Ayşe Esra , Safi Ommay Aiman , Çankaya Banu , Ergin Murat , Aydoğan Ramazan 
Published: April 2018

Summary The current study uses a series of focus groups and participatory methodology to investigate the work experiences and needs of Turkish probation officers and their directors. All participants were employed at an office of Parole and Probation in Istanbul, Turkey. During the concurrent focus groups, officers ( n = 57) discussed their daily work experiences and needs (Phase I). A follow-up focus group was conducted ( n = 25) to discuss potential interpretations of the themes and generate solutions (Phase II), followed by a mini-focus group with the directors ( n = 5) to explore their experiences with the probation system and officer training (Phase III). Findings Officers identified needs for training, improvements of the work environment, professional support, and more thorough risk assessment tools. The follow-up focus group revealed that officers were highly motivated to improve their rehabilitative skills but felt constrained in supervising offenders in the punitive justice system. Several solutions generated through focus groups included mentoring programs to support novice officers, training programs to acquire interviewing skills, and team building activities and events to increase morale. Application The current study bridges the gap between officers and directors in the probation system and generates solutions to the occupational needs of officers. Researchers communicated those needs to the directors, and the study initiated action toward implementing rehabilitative training programs for officers with a particular focus on risk assessment and basic clinical skills. The study has direct implications for the improvement of probation practice and supervision in Turkey.