Molecular engineering of chiral colloidal liquid crystals using DNA origami

Establishing precise control over the shape and the interactions of the microscopic building blocks is essential for design of macroscopic soft materials with novel structural, optical and mechanical properties. Here, we demonstrate robust assembly of DNA origami filaments into cholesteric liquid crystals, 1D supramolecular twisted ribbons and 2D colloidal membranes. The exquisite control afforded by the DNA origami technology establishes a quantitative relationship between the microscopic filament structure and the macroscopic cholesteric pitch. Furthermore, it also enables robust assembly of 1D twisted ribbons, which behave as effective supramolecular polymers whose structure and elastic properties can be precisely tuned by controlling the geometry of the elemental building blocks. Our results demonstrate the potential synergy between DNA origami technology and colloidal science, in which the former allows for rapid and robust synthesis of complex particles, and the latter can be used to assemble such particles into bulk materials

In vivo genetic manipulation of inner ear connexin expression by bovine adeno-Associated viral vectors

We have previously shown that in vitro transduction with bovine adeno-associated viral (BAAV) vectors restores connexin expression and rescues gap junction coupling in cochlear organotypic cultures from connexin-deficient mice that are models DFNB1 nonsyndromic hearing loss and deafness. The aims of this study were to manipulate inner ear connexin expression in vivo using BAAV vectors, and to identify the optimal route of vector delivery. Injection of a BAAV vector encoding a bacterial Cre recombinase via canalostomy in adult mice with floxed connexin 26 (Cx26) alleles promoted Cre/LoxP recombination, resulting in decreased Cx26 expression, decreased endocochlear potential, increased hearing thresholds, and extensive loss of outer hair cells. Injection of a BAAV vector encoding GFP-tagged Cx30 via canalostomy in P4 mice lacking connexin 30 (Cx30) promoted formation of Cx30 gap junctions at points of contacts between adjacent non-sensory cells of the cochlear sensory epithelium. Levels of exogenous Cx30 decayed over time, but were still detectable four weeks after canalostomy. Our results suggest that persistence of BAAV-mediated gene replacement in the cochlea is limited by the extensive remodeling of the organ of Corti throughout postnatal development and associated loss of non-sensory cells

General and disease-specific quality of life in patients with chronic suppurative otitis media - a prospective study

Background: Chronic suppurative otitis media (CSOM) is frequently associated with symptoms of inflammation like discharge from the ear or pain. In many cases, patients suffer from hearing loss causing communication problems and social withdrawal. The objective of this work was to collect prospective audiological data and data on general and disease-specific quality of life with validated quality of life measurement instruments to assess the impact of the disease on health-related quality of life (HR-QOL). Methods: 121 patients were included in the study. Patients were clinically examined in the hospital before and 6 months after surgery including audiological testing. They filled in the quality of life questionnaires SF-36 and Chronic Otitis Media Outcome Test 15 (COMOT-15) pre-operatively and 6 and 12 months post-operatively, respectively. Results: Complete data records from 90 patients were available for statistical analysis. Disease-specific HR-QOL in patients with CSOM improved after tympanoplasty in all the scales of the COMOT-15. There was no difference in HR-QOL assessment between patients with mesotympanic respectively epitympanic CSOM. However, we did find the outcome to be worse in patients who received revision surgery compared with those receiving primary surgery. Audiometric findings correlated very well with the subscale hearing function from the COMOT-15 questionnaire. General HR-QOL measured with the SF-36 was not significantly changed by tympanoplasty. Conclusions: Tympanoplasty did lead to a significant improvement of disease-specific HR-QOL in patients with CSOM while general HR-QOL did not change. Very well correlations were found between the subscale hearing function from the COMOT-15 questionnaire and audiological findings. Revision surgery seems to be a predictor for a worse outcome

Longitudinal relations between teaching-related motivations and student-reported teaching quality

Teaching-related motivations are often assumed to influence teaching quality; however, the empirical evidence regarding the directionality of such influences is scarce. The present study thus examined the reciprocal links between teaching-related motivations (self-efficacy and enthusiasm for teaching) and student-reported teaching quality (classroom management, learning support, and cognitive activation). Two-level cross-lagged panel analyses across three time points (with an initial sample of 165 secondary- level mathematics teachers and their 4273 students) revealed no significant cross-lagged effects when teachers' stable inter-individual differences are taken into account. Our findings suggest that teachers' motivations are remarkably stable over time

Validierung und Reliabilitätsprüfung des Nijmegen Cochlear Implant Questionnaire in deutscher Sprache

Hintergrund: Der Nijmegen Cochlear Implant Questionnaire (NCIQ) ist ein krankheitsspezifischer Fragebogen zur Erhebung der gesundheitsbezogenen Lebensqualität von Patienten vor und nach Cochleaimplantation. Ziel der Arbeit: Validierung und Reliabilitätsprüfung der deutschen Übersetzung des NCIQ. Material und Methoden: Es wurde eine prospektive Studie an 100 postlingual ertaubten oder hochgradig schwerhörigen Patienten durchgeführt, welche präoperativ sowie 3 und 6 Monate nach einer Cochleaimplantation mittels NCIQ, Abbreviated Profile of Hearing Aid Benefit (APHAB) und Hearing Participation Scale (HPS) untersucht wurden. Als Kontrolle fungierte ein postlingual ertaubtes oder hochgradig schwerhöriges, unbehandeltes Patientenkollektiv (n = 54). Cronbach‑α und Test-Retest-Reliabilität dienten der Reliabilitätsüberprüfung. Es wurde auf Inhalts‑, Übereinstimmungs- und auf diskriminative Validität getestet. Die Konstruktvaliditätsprüfung basiert auf kürzlich veröffentlichen Daten. Als Gütekriterien wurden die Sensitivität und eine ROC("Receiver Operating Characteristic")-Analyse, inklusive AUC("Area Under the ROC Curve")-Betrachtung, eingesetzt. Ergebnisse: Das Test-Retesting ergab nach 3 und 6 Monaten postoperativ stabile NCIQ-Werte. Die Cronbach-α-Werte wiesen auf eine gute interne Konsistenz hin. Der NCIQ diskriminierte valide zwischen behandelten und unbehandelten Patientengruppen. Es ergaben sich statistisch signifikante, wenn auch schwache, Korrelationen zwischen dem NCIQ und dem APHAB (r = -0,22; p = 0,04) und dem HPS (r = 0,30; p = 0,01). Sensitivitäts- und ROC-Analysen zeigten eine gute Messqualität des deutschsprachigen NCIQ. Schlussfolgerung: Die deutsche Übersetzung des NCIQ misst zuverlässig und valide die Lebensqualität vor und nach Cochleaimplantation und kann zur klinischen Erfolgskontrolle nach Cochleaimplantationen verwendet werden.Background: The Nijmegen Cochlear Implant Questionnaire (NCIQ) is a disease-specific questionnaire to determine the health-related quality of life (HRQoL) of patients before and after cochlear implantation. Objective: This study aimed to assess the validity and reliability of the German translation of the NCIQ. Materials and methods: A prospective study was performed in 100 postlingually deaf or severely hearing-impaired patients. HRQoL was assessed using the NCIQ, the Abbreviated Profile of Hearing Aid Benefit (APHAB), and the Hearing Participation Scale (HPS) before as well as 3 and 6 months after cochlear implantation. An untreated group of postlingually deaf or severely hearing-impaired patients (n = 54) served as a control. Cronbach's α and test–retest reliability were measured. The content, discrimination, and agreement validity were tested. The evaluation of construct validity was based on recently published data. Sensitivity and receiver operating curve (ROC) analysis, including consideration of the area under the curve (AUC), were used as quality criteria. Results: The test-retest analysis showed stable NCIQ values 3 and 6 months postoperatively. The Cronbach’s α values indicated good internal consistency. The NCIQ validly discriminated between treated and untreated patient groups. There were statistically significant albeit weak correlations between the NCIQ and the APHAB (r = -0.22; p = 0.04) and the HPS (r = 0.30; p = 0.01). Sensitivity and ROC analyses showed good measurement quality of the German-speaking NCIQ. Conclusion: The German translation of the NCIQ reliably and validly measures HRQoL before and after cochlear implantation and can be used for clinical monitoring after treatment with cochlear implants

Molecular biology of the blood-brain and the blood-cerebrospinal fluid barriers: similarities and differences

Efficient processing of information by the central nervous system (CNS) represents an important evolutionary advantage. Thus, homeostatic mechanisms have developed that provide appropriate circumstances for neuronal signaling, including a highly controlled and stable microenvironment. To provide such a milieu for neurons, extracellular fluids of the CNS are separated from the changeable environment of blood at three major interfaces: at the brain capillaries by the blood-brain barrier (BBB), which is localized at the level of the endothelial cells and separates brain interstitial fluid (ISF) from blood; at the epithelial layer of four choroid plexuses, the blood-cerebrospinal fluid (CSF) barrier (BCSFB), which separates CSF from the CP ISF, and at the arachnoid barrier. The two barriers that represent the largest interface between blood and brain extracellular fluids, the BBB and the BCSFB, prevent the free paracellular diffusion of polar molecules by complex morphological features, including tight junctions (TJs) that interconnect the endothelial and epithelial cells, respectively. The first part of this review focuses on the molecular biology of TJs and adherens junctions in the brain capillary endothelial cells and in the CP epithelial cells. However, normal function of the CNS depends on a constant supply of essential molecules, like glucose and amino acids from the blood, exchange of electrolytes between brain extracellular fluids and blood, as well as on efficient removal of metabolic waste products and excess neurotransmitters from the brain ISF. Therefore, a number of specific transport proteins are expressed in brain capillary endothelial cells and CP epithelial cells that provide transport of nutrients and ions into the CNS and removal of waste products and ions from the CSF. The second part of this review concentrates on the molecular biology of various solute carrier (SLC) transport proteins at those two barriers and underlines differences in their expression between the two barriers. Also, many blood-borne molecules and xenobiotics can diffuse into brain ISF and then into neuronal membranes due to their physicochemical properties. Entry of these compounds could be detrimental for neural transmission and signalling. Thus, BBB and BCSFB express transport proteins that actively restrict entry of lipophilic and amphipathic substances from blood and/or remove those molecules from the brain extracellular fluids. The third part of this review concentrates on the molecular biology of ATP-binding cassette (ABC)-transporters and those SLC transporters that are involved in efflux transport of xenobiotics, their expression at the BBB and BCSFB and differences in expression in the two major blood-brain interfaces. In addition, transport and diffusion of ions by the BBB and CP epithelium are involved in the formation of fluid, the ISF and CSF, respectively, so the last part of this review discusses molecular biology of ion transporters/exchangers and ion channels in the brain endothelial and CP epithelial cells

Variability of an ideal insertion vector for cochlear implantation

© 2015, Otology & Neurotology, Inc. Hypothesis: Based on a three-dimensional analysis, the orientation of the basal turn of the cochlea, the disposition of the basilar membrane, and the characteristics of the hook region - all of which determine the ideal electrode insertion vector during cochlear implantation - might vary among individuals to a greater degree than previously considered. The aim of this study is to assess the variability of an ideal insertion vector among a sample of surgical candidates from a purely anatomical perspective as well as from a more intraoperative-surgical perspective. Background: During cochlear implantation through a cochleostomy or round window approach, the angle or vector of insertion after the first entry point seems to be related to intracochlear damage, which might correlate with anatomical and functional features. Methods: Three-dimensional reconstructions of the temporal bones of 50 cochlear implant candidates (a total of 100 ears) were assessed

General and disease-specific quality of life in patients with chronic suppurative otitis media - a prospective study

Abstract Background Chronic suppurative otitis media (CSOM) is frequently associated with symptoms of inflammation like discharge from the ear or pain. In many cases, patients suffer from hearing loss causing communication problems and social withdrawal. The objective of this work was to collect prospective audiological data and data on general and disease-specific quality of life with validated quality of life measurement instruments to assess the impact of the disease on health-related quality of life (HR-QOL). Methods 121 patients were included in the study. Patients were clinically examined in the hospital before and 6 months after surgery including audiological testing. They filled in the quality of life questionnaires SF-36 and Chronic Otitis Media Outcome Test 15 (COMOT-15) pre-operatively and 6 and 12 months post-operatively, respectively. Results Complete data records from 90 patients were available for statistical analysis. Disease-specific HR-QOL in patients with CSOM improved after tympanoplasty in all the scales of the COMOT-15. There was no difference in HR-QOL assessment between patients with mesotympanic respectively epitympanic CSOM. However, we did find the outcome to be worse in patients who received revision surgery compared with those receiving primary surgery. Audiometric findings correlated very well with the subscale hearing function from the COMOT-15 questionnaire. General HR-QOL measured with the SF-36 was not significantly changed by tympanoplasty. Conclusions Tympanoplasty did lead to a significant improvement of disease-specific HR-QOL in patients with CSOM while general HR-QOL did not change. Very well correlations were found between the subscale hearing function from the COMOT-15 questionnaire and audiological findings. Revision surgery seems to be a predictor for a worse outcome.</p