Functional magnetic resonance imaging (fMRI) techniques using the blood-oxygen level-dependent (BOLD) signal have shown great potential as clinical biomarkers of disease. Thus, using these... Show moreFunctional magnetic resonance imaging (fMRI) techniques using the blood-oxygen level-dependent (BOLD) signal have shown great potential as clinical biomarkers of disease. Thus, using these techniques in preclinical rodent models is an urgent need. Calibrated fMRI is a promising technique that can provide high-resolution mapping of cerebral oxygen metabolism (CMRO2). However, calibrated fMRI is difficult to use in rodent models for several reasons: rodents are anesthetized, stimulation-induced changes are small, and gas challenges induce noisy CMRO2 predictions. We used, in mice, a relaxometry-based calibrated fMRI method which uses cerebral blood flow (CBF) and the BOLD-sensitive magnetic relaxation component, R-2 ', the same parameter derived in the deoxyhemoglobin-dilution model of calibrated fMRI. This method does not use any gas challenges, which we tested on mice in both awake and anesthetized states. As anesthesia induces a whole-brain change, our protocol allowed us to overcome the former limitations of rodent studies using calibrated fMRI. We revealed 1.5-2 times higher CMRO2, dependent upon brain region, in the awake state versus the anesthetized state. Our results agree with alternative measurements of whole-brain CMRO2 in the same mice and previous human anesthesia studies. The use of calibrated fMRI in rodents has much potential for preclinical fMRI. Show less
Background The association between spontaneous cerebrospinal fluid (CSF) leak/rhinorrhea and idiopathic intracranial hypertension (IIH) has been increasingly recognized over the last years. However... Show moreBackground The association between spontaneous cerebrospinal fluid (CSF) leak/rhinorrhea and idiopathic intracranial hypertension (IIH) has been increasingly recognized over the last years. However, considerable variability of opinion regarding the assessment, investigations, and management of patients with spontaneous CSF rhinorrhea remains.Methods A consensus group was formed from experts from Europe, Asia, Australia, South and North America. Following literature review and open discussions with members of the panel, a set of 61 statements was produced. A modified Delphi method was used to refine expert opinion with 3 rounds of questionnaires and a consensus group meeting in Santo-Rhino meeting in September 2019.Results Fifty statements (82% of total) on spontaneous CSF leak and IIH reached consensus. In 38 of 50 statements, the median response was 7 (strongly agree) and in the 12 remaining statements the median response was 6 (agree). Eleven statements were excluded because they did not reach consensus and one new statement was added during SantoRhino meeting. The final statements refer to patient history and clinical examination ("History taking should include presence of headache, tinnitus and visual defects"), investigations (role of Thin Slice Computed Tomography and CISS/FLAIR sequences in Magnetic Resonance Imaging), principles of management (watchful waiting or measures to reduce ICP are supplementary but cannot subsitute surgical closure), surgical technique, intraoperative, early postoperative and long term management.Conclusion We present fifty consensus statements on the diagnosis, investigation, and management of spontaneous CSF rhinorrhea based on the currently available evidence and expert opinion. Although by no means comprehensive and final, we believe they can contribute to the standardization of clinical practice. Early diagnosis, prompt surgical closure of the defect, assesment for and treatment of potentially co-existing idiopathic intracranial hypertension in a comprehensive multidisciplinary approach are essential in order to successfully manage spontaneous CSF rhinorrhea, reduce associated morbidity and prevent recurrence. Show less
Background: We previously described that adenoid tissue in children with chronic otitis media (COM) contained more mucosal biofilms than adenoid tissue removed for hypertrophy.Aims/objectives: The... Show moreBackground: We previously described that adenoid tissue in children with chronic otitis media (COM) contained more mucosal biofilms than adenoid tissue removed for hypertrophy.Aims/objectives: The aim of the second part was to characterize nasopharyngeal microbiota and explore virulence of the most common middle ear pathogens.Material and methods: Bacteriological analysis was performed following a culture-based approach on the samples recovered from 30 patients of COM group (15 biofilm-positive and 15 biofilm-negative) and from 30 patients of a control group (15 biofilm-positive and 15 biofilm-negative). Virulence factors of Streptococcus pneumoniae, Streptococcus pyogenes, and Haemophilus influenzae were investigated.Results: The most frequent species were Firmicutes followed by Proteobacteria and Actinobacteria. The presence of biofilm was statistically associated with an increase of the number of bacterial species and Firmicutes phylum regardless of the condition (case/control). No virulence factors associated with invasive isolates were found for the most common middle ear pathogens.Conclusions and significance: This case-control study demonstrated that the presence of COM plus biofilm was associated with a given microbiota which contained more Firmicutes. Our study allows a better understanding of physiopathological mechanisms involved in chronic otitis media and paves the way for further investigations. Show less
Kania, R.; Vironneau, P.; Dang, H.; Bercot, B.; Cambau, E.; Verillaud, B.; ... ; Abbeele, T. van den 2019
BACKGROUND\nMATERIAL AND METHODS\nRESULTS\nCONCLUSIONS AND SIGNIFICANCE\nBiofilms are communities of bacteria embedded in a self-produced glycocalyx matrix. Adenoids have been shown to harbor... Show moreBACKGROUND\nMATERIAL AND METHODS\nRESULTS\nCONCLUSIONS AND SIGNIFICANCE\nBiofilms are communities of bacteria embedded in a self-produced glycocalyx matrix. Adenoids have been shown to harbor bacterial biofilms. Aim/objectives: To compare the prevalence of biofilms in adenoid of children with chronic otitis media (COM) (group1) versus a control group without any COM (group 2) having adenoids removed because of hypertrophy.\nOne hundred and three children were prospectively enrolled in this case-control study, group 1 (n = 52) and group 2 (n = 51). The main outcome measurement was the prevalence of biofilm in adenoidectomy specimens analyzed using confocal laser scanning microscopy. Children in group 1 who had middle ear (ME) effusion and requiring the insertion of a tympanostomy tube underwent biopsy of the ME mucosa and effusion sampling.\nBiofilms were found in adenoids' specimens of both groups and in the ME biopsy and effusion. The biofilm prevalence in adenoids was 63.5% (33/52) in group 1 and 47.1% (24/51) in group 2. Day nursery and previous antibiotics intake were significantly more frequent in group 1 than in group 2.\nThis case-control study demonstrates that adenoid tissue in children with COM contains more mucosal biofilms than adenoid tissue removed for hypertrophy. Biofilm was seen in ME biopsies and effusion. Show less
Kania, R.E.; Lamers, G.E.M.; Laar, N. van de; Dijkhuizen, M.; Lagendijk, E.; Huy, P.T.B.; ... ; Bloemberg, G.V. 2010
The aim of this study was to demonstrate the presence of yeast and bacterial biofilms on the surface of tracheoesophageal voice prostheses (TVPs) by a double-staining technique with confocal laser... Show moreThe aim of this study was to demonstrate the presence of yeast and bacterial biofilms on the surface of tracheoesophageal voice prostheses (TVPs) by a double-staining technique with confocal laser scanning microscopy (CLSM). Biofilms of 12 removed TVPs were visualized by scanning electron microscopy, then stained with ConA-FITC and propidium iodide for CLSM. Microbial identification was by partial 16S rRNA gene analysis and ITS-2 sequence analysis. Microbial biofilms on the TVPs consisted of bacteria and filamentous cells. Bacterial cells were attached to the filamentous and unicellular yeast cells, thus forming a network. Sequence analyses of six voice prostheses identified the presence of a variety of bacterial and yeast species. In vivo studies showed that Klebsiella oxytoca and Micrococcus luteus efficiently attached to Candida albicans. CLSM with double fluorescence staining can be used to demonstrate biofilm formations composed of a mixture of yeast and bacterial cells on the surface of TVPs. Show less
Ruellan, K.; Frijns, J.H.M.; Bloemberg, G.V.; Hautefort, C.; Abbeele, T. van den; Lamers, G.E.M.; ... ; Kania, R.E. 2010
Objective: To investigate the formation of bacterial biofilms on the surface of the electrode array of cochlear implants (CI) explanted because of device failure, without evidence of infection, by... Show moreObjective: To investigate the formation of bacterial biofilms on the surface of the electrode array of cochlear implants (CI) explanted because of device failure, without evidence of infection, by use of scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). Study Design: Prospective study. Setting: Patients from 2 tertiary-care referral centers. Patients and Methods: CIs were explanted from 9 patients because of device failure. Specimens were immediately snapfrozen in cold isopenthane, stored at -80 degrees and examined with SEM and CLSM by 3 investigators. Main Outcome Measure: Presence of bacterial biofilm ascertained by SEM and CSLM. Results: One specimen showed the formation of a bacterial biofilm on the middle ear part of the electrode array. No biofilm formation was found in the inner-ear part of electrode arrays. In the middle-ear part of the electrode array, a cylindrical cover of human muscular tissue was seen plugging the cochleostomy. Conclusion: This is the first study demonstrating that bacterial biofilms may exist on the surface of the electrode array of CIs explanted because of device failure but not infection. We found 1 case of biofilm formation in 9 explanted CIs. Further studies with larger series of CIs are required to investigate biofilm formation on the surface of CI electrode arrays to address both the pathophysiology of bacterial biofilms and prevention of device-related infections in CI patients. Show less
Kania, R.E.; Lamers, G.E.M.; Laar, N. van de; Dijkhuizen, M.; Lagendijk, E.; Tran Ba Huy, P.; ... ; Bloemberg, G.V. 2010
The aim of this study was to demonstrate the presence of yeast and bacterial biofilms on the surface of tracheoesophageal voice prostheses (TVPs) by a double-staining technique with confocal laser... Show moreThe aim of this study was to demonstrate the presence of yeast and bacterial biofilms on the surface of tracheoesophageal voice prostheses (TVPs) by a double-staining technique with confocal laser scanning microscopy (CLSM). Biofilms of 12 removed TVPs were visualized by scanning electron microscopy, then stained with ConA-FITC and propidium iodide for CLSM. Microbial identification was by partial 16S rRNA gene analysis and ITS-2 sequence analysis. Microbial biofilms on the TVPs consisted of bacteria and filamentous cells. Bacterial cells were attached to the filamentous and unicellular yeast cells, thus forming a network. Sequence analyses of six voice prostheses identified the presence of a variety of bacterial and yeast species. In vivo studies showed that Klebsiella oxytoca and Micrococcus luteus efficiently attached to Candida albicans. CLSM with double fluorescence staining can be used to demonstrate biofilm formations composed of a mixture of yeast and bacterial cells on the surface of TVPs. Show less
