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Scheerlinck T.,Universitair Ziekenhuis Brussel Brussel | Delport H.,AZ Nikolaas | Kiewitt T.,BioMet
Journal of Bone and Joint Surgery - Series A | Year: 2010

Background: The cement mantle within a hip resurfacing head is important for implant survival. Too much cement leads to thermal bone necrosis, whereas not enough cement might cause mechanical failure and particle-induced osteolysis. We evaluated the impact of different cementing techniques on the quality of the cement mantle in hip resurfacing. Methods: Sixty bovine condyles were prepared to fit a size-46 ReCap (Biomet) implant and divided into five groups of twelve specimens each. In two of the groups, a polymeric replica was filled halfway with low-viscosity cement; suction was employed in one of those groups and not used in the other. Medium-viscosity cement was used in the remaining three groups: it was spread out within the implant in one group, it was packed on the bone in another, and a combination of those techniques was used in the third. Half of the sixty specimens had six anchoring holes. The specimens underwent computed tomography and were analyzed with custom-made segmentation software. Results: The cementing technique and anchoring holes influenced the cement quantity within the implant and the thickness of the cement mantle; suction and bone density did not. Both filling techniques involving the use of low-viscosity cement resulted in excessive cement within the implant (filling index, 47.30% to 60.66%) and large cement defects at the base. The combined technique also resulted in large cement quantities (filling index, 46.62% to 54.12%) but fewer cement defects at the base. The filling technique involving the use of medium-viscosity cement decreased the cement quantity (filling index, 43.31% to 45.68%), but cement packing was the best technique (filling index, 29.20% to 31.05%), resulting in the thinnest, most homogeneous cement mantle. However, distal cement defects remained, and the prevalence of proximal cement-implant interfacial gaps was about 10%. Conclusions: The results of this experimental study cannot be extrapolated directly to the in vivo situation, and they apply only to implants with an inner geometry similar to that of the size-46 ReCap resurfacing head and to the cement brands that we used. None of the cementing techniques was "perfect." Both of the filling techniques involving use of low-viscosity cement and the combined technique resulted in excessive cement proximally. The filling technique involving use of medium-viscosity cement was promising, but the cement-packing technique offered the best opportunity to control the quality of the cement mantle. However, the presence of interfacial gaps raised new questions. We suggest that the use of anchoring holes in cancellous bone should be considered with caution in order to avoid overfilling with cement. Clinical Relevance: This study should help the clinician to choose an optimal cementing technique for hip resurfacing. Copyright © 2010 by The Journal of Bone and Joint Surgery, Incorporated. Source

Weil-Olivier C.,University Paris Diderot | van der Linden M.,RWTH Aachen | de Schutter I.,Universitair Ziekenhuis Brussel Brussel | Dagan R.,Ben - Gurion University of the Negev | Mantovani L.,University of Naples
BMC Infectious Diseases | Year: 2012

Background: The burden of invasive pneumococcal disease in young children decreased dramatically following introduction of the 7-valent pneumococcal conjugate vaccine (PCV7). The epidemiology of S. pneumoniae now reflects infections caused by serotypes not included in PCV7. Recently introduced higher valency pneumococcal vaccines target the residual burden of invasive and non-invasive infections, including those caused by serotypes not included in PCV7. This review is based on presentations made at the European Society of Pediatric Infectious Diseases in June 2011.Discussion: Surveillance data show increased circulation of the non-PCV7 vaccine serotypes 1, 3, 6A, 6C, 7 F and 19A in countries with routine vaccination. Preliminary evidence suggests that broadened serotype coverage offered by higher valency vaccines may be having an effect on invasive disease caused by some of those serotypes, including 19A, 7 F and 6C. Aetiology of community acquired pneumonia remains a difficult clinical diagnosis. However, recent reports indicate that pneumococcal vaccination has reduced hospitalisations of children for vaccine serotype pneumonia. Variations in serotype circulation and occurrence of complicated and non-complicated pneumonia caused by non-PCV7 serotypes highlight the potential of higher valency vaccines to decrease the remaining burden. PCVs reduce nasopharyngeal carriage and acute otitis media (AOM) caused by vaccine serotypes. Recent investigations of the interaction between S. pneumoniae and non-typeable H. influenzae suggest that considerable reduction in severe, complicated AOM infections may be achieved by prevention of early pneumococcal carriage and AOM infections. Extension of the vaccine serotype spectrum beyond PCV7 may provide additional benefit in preventing the evolution of AOM. The direct and indirect costs associated with pneumococcal disease are high, thus herd protection and infections caused by non-vaccine serotypes both have strong effects on the cost effectiveness of pneumococcal vaccination. Recent evaluations highlight the public health significance of indirect benefits, prevention of pneumonia and AOM and coverage of non-PCV7 serotypes by higher valency vaccines.Summary: Routine vaccination has greatly reduced the burden of pneumococcal diseases in children. The pneumococcal serotypes present in the 7-valent vaccine have greatly diminished among disease isolates. The prevalence of some non-vaccine serotypes (e.g. 1, 7 F and 19A) has increased. Pneumococcal vaccines with broadened serotype coverage are likely to continue decreasing the burden of invasive disease, and community acquired pneumonia in children. Further reductions in pneumococcal carriage and increased prevention of early AOM infections may prevent the evolution of severe, complicated AOM. Evaluation of the public health benefits of pneumococcal conjugate vaccines should include consideration of non-invasive pneumococcal infections, indirect effects of vaccination and broadened serotype coverage. © 2012 Weil-Olivier et al.; licensee BioMed Central Ltd. Source

Rose M.A.,Goethe University Frankfurt | Christopoulou D.,Pfizer | Myint T.T.H.,Pfizer | De Schutter I.,Universitair Ziekenhuis Brussel Brussel
International Journal of Clinical Practice | Year: 2014

Background Characterisation of risk groups who may benefit from pneumococcal vaccination is essential for the generation of recommendations and policy. Methods We reviewed the literature to provide information on the incidence and risk of invasive pneumococcal disease (IPD) in at-risk children in Europe and North America. The PubMed database was searched using predefined search terms and inclusion/exclusion criteria for papers reporting European or North American data on the incidence or risk of IPD in children with underlying medical conditions. Results Eighteen references were identified, 11 from North America and 7 from Europe, with heterogeneous study methods, periods and populations. The highest incidence was seen in US children positive for human immunodeficiency virus infection, peaking at 4167 per 100,000 patient-years in 2000. Studies investigating changes in incidence over time reported decreases in the incidence of IPD between the late 1990s and early 2000s. The highest risk of IPD was observed in children with haematological cancers or immunosuppression. Overall, data on IPD in at-risk children were limited, lacking incidence data for a wide range of predisposing conditions. There was, however, a clear decrease in the incidence of IPD in at-risk children after the introduction of 7-valent pneumococcal conjugate vaccine into immunisation programmes, as previously demonstrated in the general population. Conclusion Despite the heterogeneity of the studies identified, the available data show a substantial incidence of IPD in at-risk children, particularly those who are immunocompromised. Further research is needed to determine the true risk of IPD in at-risk children, particularly in the post-PCV period, and to understand the benefits of vaccination and optimal vaccination schedules. Linked Comment: Stein. Int J Clin Pract 2014; 68: 2-3. © 2013 The Authors. International Journal of Clinical Practice published by John Wiley & Sons Ltd. Source

Mohades S.G.,Universitair Ziekenhuis Brussel | Struys E.,Universitair Ziekenhuis Brussel | Van Schuerbeek P.,Universitair Ziekenhuis Brussel Brussel | Mondt K.,Flemish Ministry of Education and Training | And 3 more authors.
Brain Research | Year: 2012

The impact of bilingualism on the microstructure of the white matter pathways related to language processing is assessed in elementary school children by magnetic resonance diffusion tensor imaging (MR-DTI). Forty children, 8-11 years old, subdivided into 3 different groups (15 simultaneous bilinguals, 15 sequential bilinguals and 10 monolinguals), were scanned. The hypothesis was that the starting age and the manner of second language acquisition would affect the characteristics of language circuitry. In each subject the mean fractional anisotropy (FA) was obtained for four major white matter pathways: 1 - the left arcuate fasciculus/superior longitudinal fasciculus (lAF/lSLF) that connects Broca's area in the opercular and triangular regions of the left inferior frontal gyrus to the posterior language zone, 2 - the left inferior occipitofrontal fasciculus (lIFOF), connecting anterior regions in the frontal lobe with posterior regions in the temporal occipital lobes, 3 - the bundle arising from the anterior part of the corpus callosum projecting to the orbital lobe (AC-OL) and 4 - the fibers emerging from the anterior midbody (AMB) of the corpus callosum that associate with the premotor and supplementary motor cortices (AMB-PMC). The three groups did not show significant differences in mean FA over the lAF/lSLF or AMB-PMC tracts. In simultaneous bilingual subjects the lIFOF tracts had higher mean FA value compared to monolinguals and also sequential bilinguals, whereas the comparison for the AC-OL fibers yielded a significantly lower mean FA value in simultaneous bilingual subjects compared to monolinguals. In both cases the FA value for sequential bilinguals was intermediate to that of the other two groups. To our knowledge, this study provides the first evidence of bilingualism related adaptation of white matter microstructure in the human brain. © 2011 Elsevier B.V. All rights reserved. Source

Wathlet S.,Vrije Universiteit Brussel | Adriaenssens T.,Vrije Universiteit Brussel | Segers I.,Vrije Universiteit Brussel | Verheyen G.,Universitair Ziekenhuis Brussel Brussel | And 5 more authors.
Human Reproduction | Year: 2011

Background: Cumulus cell (CC) gene expression is suggested as a non-invasive analysis method to predict oocyte competence. There are, however, important between-patient differences in CC gene expression. These can be compensated when expression Results are combined with patient and cycle characteristics using a multiple regression analysis model.MethodsFrom ICSI patients stimulated with GnRH antagonist and recombinant FSH (n 25) or GnRH agonist and highly purified menotrophin (n 20), CC were collected and oocytes were individually fertilized and cultured. CC were analyzed for the expression of Syndecan 4 (SDC4), Prostaglandin-endoperoxide synthase 2 (PTGS2), Versican (VCAN), Activated leukocyte cell adhesion molecule, Gremlin 1, transient receptor potential cation channel, subfamily M, member 7 (TRPM7), Calmodulin 2 and Inositol 1,4,5-trisphosphate 3-kinase A (ITPKA) using quantitative PCR. Results were analyzed in relation to the stimulation protocol. Within-patient variation in gene expression was related to oocyte maturity and developmental potential. Models predictive for normal embryo or blastocyst development and pregnancy in single embryo transfer cycles were developed.ResultsMature oocytes have higher PTGS2 and lower VCAN expression in their cumulus. All genes except VCAN had a positive correlation with good embryo or blastocyst morphology and were used to develop predictive models for embryo or blastocyst development (P< 0.01). Specific models were obtained for the two stimulation protocols. In both groups, better cleavage-stage embryo prediction relied on TRPM7 and ITPKA expression and pregnancy prediction relied on SDC4 and VCAN expression. In the current data set, the use of CC expression for pregnancy prediction resulted in a sensitivity of >70 and a specificity of >90. Conclusions Multivariable models based on CC gene expression can be used to predict embryo development and pregnancy. © 2011 The Author. Source

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