Surface properties and osteoblastic cytocompatibility of two blasted and acid-etched titanium implant systems with distinct microtopography

OBJECTIVES: The aim of this study is to compare two commercially available screw-type sandblasted and acid-etched (SLA) Ti implant systems from Eckermann Laboratorium S.L., with similar geometry and distinct microtopography, regarding surface properties and osteoblastic cytocompatibility. MATERIAL AND METHODS: Implant I (referred as a conventional SLA system) and Implant II (a system patented as Eckcyte(®)) were characterized for macro and microtopograpphy, surface roughness and chemical composition. For the cytocompatibility studies, human bone marrow osteoblastic cells were seeded over the implants' surface, and the cell response was assessed for cell adhesion and proliferation, alkaline phosphatase (ALP) activity and matrix mineralization. RESULTS: Implant I presented a rough surface with irregularly shaped and sized cavities among flatter-appearing areas, whereas Implant II exhibited a homogeneous rough microporous surface. Compared to Implant I, Implant II presented higher Ra values (0.8 [SD 0.008] μm and 1.21 [SD 0.15] μm, respectively, P < 0.05) and also increased values of Rz, Rt and Rsm, a more negative value of Rsk, and similar RKu values. XPS showed the expected presence of Ti, O, C and N; Al, Si, F, P and Ca were detected in low concentrations. Implant II exhibited significantly lower Al levels. Both implants supported the adhesion, proliferation and differentiation of osteoblastic cells. Implant II showed a thicker fibrilar cell layer and an earlier onset and more abundant matrix mineralization. CONCLUSIONS: The homogeneous rough and microporous surface of Implant II is most probably a main contributor for its improved cell response

Activation of calpain-1 in human carotid artery atherosclerotic lesions

<p>Abstract</p> <p>Background</p> <p>In a previous study, we observed that oxidized low-density lipoprotein-induced death of endothelial cells was calpain-1-dependent. The purpose of the present paper was to study the possible activation of calpain in human carotid plaques, and to compare calpain activity in the plaques from symptomatic patients with those obtained from patients without symptoms.</p> <p>Methods</p> <p>Human atherosclerotic carotid plaques (n = 29, 12 associated with symptoms) were removed by endarterectomy. Calpain activity and apoptosis were detected by performing immunohistochemical analysis and TUNEL assay on human carotid plaque sections. An antibody specific for calpain-proteolyzed α-fodrin was used on western blots.</p> <p>Results</p> <p>We found that calpain was activated in all the plaques and calpain activity colocalized with apoptotic cell death. Our observation of autoproteolytic cleavage of the 80 kDa subunit of calpain-1 provided further evidence for enzyme activity in the plaque samples. When calpain activity was quantified, we found that plaques from symptomatic patients displayed significantly lower calpain activity compared with asymptomatic plaques.</p> <p>Conclusion</p> <p>These novel results suggest that calpain-1 is commonly active in carotid artery atherosclerotic plaques, and that calpain activity is colocalized with cell death and inversely associated with symptoms.</p

National survey of feasibility of NIV trials for management of children with bronchiolitis.

Background: Bronchiolitis is a major cause of admission to hospital in children. Non-invasive ventilation (NIV) support with continuous positive airway pressure (CPAP) or high-flow nasal cannula (HFNC) oxygen is routinely used for infants in the UK with bronchiolitis. Objective: To establish UK paediatric practice regarding management of bronchiolitis, and to explore issues pertinent to the design of a potential future randomised controlled trial of NIV. Design: Screening logs were completed in hospitals in England capturing information on paediatric bronchiolitis admissions. An online national survey of clinical practice was disseminated to healthcare professionals (HCPs) across the UK to ascertain current management strategies. Results: Screening logs captured data on 393 infants from 8 hospitals. Reasons for admission were most commonly respiratory distress and/or poor fluid intake. Oxygen was administered for 54% of admissions. Respiratory (CPAP and HFNC) and non-respiratory support administered varied considerably. The national survey was completed by 111 HCPs from 76 hospitals. Data were obtained on criteria used to commence and wean NIV, responsibilities for altering NIV settings, minimum training requirements for staff managing a child on NIV, and numbers of trained staff. Most centres were interested in and capable of running a trial of NIV, even out of normal office hours. Conclusions: Respiratory and non-respiratory management of bronchiolitis in UK centres varies widely. A trial of HFNC oxygen therapy in this group of patients is feasible and HCPs would be willing to randomise patients into such a trial. Future work should focus on defining trial eligibility criteria

In vivo measurement of the surface energy of human fingernail plates

The work described in this article was supported by The School of Pharmacy, University of London, and a small part of it was presented at U.K. PharmSci conference, 31 August–2 September 2010, Nottingham, U.K. The authors have no conflict of interest to declare

Giant right coronary artery aneurysm presenting with non-ST elevation myocardial infarction and severe mitral regurgitation: a case report

<p>Abstract</p> <p>Introduction</p> <p>Coronary artery aneurysms are seen in 1.5-5% of patients presenting for coronary angiography, but giant aneurysms, defined as being greater than 2 cm in diameter, are rare. Given the paucity of cases and limited experience in diagnosis and management of the disease, each case is a learning tool in itself.</p> <p>Case presentation</p> <p>We report the rare case of a 78-year-old Caucasian man who presented to a peripheral emergency department with chest pain and was subsequently found to have a giant right coronary artery aneurysm. Following initial investigation and treatment he was referred to our hospital for definitive management.</p> <p>Conclusion</p> <p>The case described illustrates one of the varied presentations and subsequent management of an ill-defined and heterogeneous disease process. Given the limited experience with giant aneurysms in the coronary circulation, this case provides valuable insight into the clinical presentation of the disease and gives an example of the management of the most recent such case at our hospital.</p

Using argument notation to engineer biological simulations with increased confidence

The application of computational and mathematical modelling to explore the mechanics of biological systems is becoming prevalent. To significantly impact biological research, notably in developing novel therapeutics, it is critical that the model adequately represents the captured system. Confidence in adopting in silico approaches can be improved by applying a structured argumentation approach, alongside model development and results analysis. We propose an approach based on argumentation from safety-critical systems engineering, where a system is subjected to a stringent analysis of compliance against identified criteria. We show its use in examining the biological information upon which a model is based, identifying model strengths, highlighting areas requiring additional biological experimentation and providing documentation to support model publication. We demonstrate our use of structured argumentation in the development of a model of lymphoid tissue formation, specifically Peyer's Patches. The argumentation structure is captured using Artoo (www.york.ac.uk/ycil/software/artoo), our Web-based tool for constructing fitness-for-purpose arguments, using a notation based on the safety-critical goal structuring notation. We show how argumentation helps in making the design and structured analysis of a model transparent, capturing the reasoning behind the inclusion or exclusion of each biological feature and recording assumptions, as well as pointing to evidence supporting model-derived conclusions