Pediatric morphometric study to guide the optimized implantation of the Osia® 2 implant system.

PURPOSE: Continuous technological advances result in the availability of new bone conduction hearing implants, of which their suitability for pediatric patients is of major concern. The CochlearTMOsia® 2 is a new active osseointegrated steady-state implant system that uses digital piezoelectric stimulation to treat hearing loss. The implant in the United States was approved for patients aged 12 years and above, whereas the CE mark is independent of age, the only requirement is body weight of at least 7 kg. Therefore, further clinical studies are required to assess device characteristics in younger patients. The aim of our study was to perform a morphometric study among 5-12-year-old children, and to develop a surgical protocol for Osia 2 system implantation based on these findings. METHODS: We examined retrospectively cranial CT scans of 5-12-year-old patients from our clinical database. We measured the bone and soft-tissue thickness in the region of interest, and the position of the sigmoid sinus. 3D printed temporal bones were also used for planning. RESULTS: Soft-tissue thickness varied between 3.2 ± 0.5 mm and 3.6 ± 0.6 mm and bone thickness varied between 3.5 ± 1.1 mm and 4.7 ± 0.3 mm. The sigmoid sinus was located 1.3 ± 0.2 cm posterior to the ear canal, and the anterior distance was 4.8 ± 0.9 to 7.1 ± 1.1 mm. CONCLUSIONS: Our morphometric studies showed that patients aged 5-12 have different anatomical dimensions compared to adults, but that implantation of the Osia 2 system is feasible in these patients using an altered implant positioning recommended by our data. The Cochlear™ Osia® 2 is, therefore, an option for hearing rehabilitation in younger pediatrics.

Application field of VOXEL-MAN Tempo 3D virtual reality simulator in surgery of pars petrosa of temporal bone / A VOXEL-MAN Tempo 3D virtuálisvalóság-szimulátor alkalmazása a sziklacsont sebészetében.

Összefoglaló. Bevezetés: Az emberi sziklacsont a halántékcsont része, egy bonyolult és változatos anatómiai felépítésu struktúra. A sziklacsonton végzett beavatkozások elott, a mutéti szövodmények megelozése érdekében, nélkülözhetetlen a biztos anatómiai tudás és kézügyesség megszerzése, valamint az egyes mutéti lépések és mozdulatok begyakorlása. A VOXEL-MAN Tempo 3D fül-orr-gégészeti szimulátor a virtuális valóság és a robotika alkalmazásával nyújt gyakorlási lehetoséget. Célkituzés: A Szegedi Tudományegyetem 2019-ben VOXEL-MAN fül-orr-gégészeti szimulátort helyezett üzembe az Orvosi Készségfejlesztési Központban. A cikk fül-orr-gégész szakorvos szerzoi a VOXEL-MAN Tempo szimulátor megismerését követoen bemutatják a készüléket, és megfogalmazzák a szimulátorral végzett beavatkozásokkal szemben támasztott igényüket. Módszer: A szerzok a megfogalmazott szempontoknak megfeleloen értékelik a VOXEL-MAN Tempo szimulátort, és meghatározzák, milyen szerepet szánnak neki a gyakorlati képzésben. Eredmények: A szimulátor virtuálisan, mégis valósághuen mutatja meg a sziklacsont anatómiai viszonyait, a fontos anatómiai struktúrák valós térbeli elhelyezkedését és egymástól, illetve a sebészi eszköztol mért távolságát. A rendszer lehetové teszi a fülmutétek valósághu elvégzését (kétkezes csontmunka fúróval és szívóval, vérzés szimulálása) taktilis visszacsatolással. Az egy- vagy kétkezes feladatokkal fejleszthetjük a sebészi készségeket. A fülmutétek csontmunkája reprodukálható módon elvégezheto valódi beteg halántékcsontjáról készített rutin, nagy felbontású komputertomográfiás vizsgálat anyagából. Következtetés: Tapasztalataink alapján a szimulátor kiválóan alkalmas az egyes mutéti lépesek begyakorlására. A jövoben fontos szerepet szánunk a virtuális rendszernek a fül-orr-gégészeti graduális és a fülsebészeti posztgraduális képzésben. Orv Hetil. 2021; 162(16): 623-628. INTRODUCTION: The pars petrosa of the human temporal bone is a structure of complex and diverse anatomy. Prior to surgical interventions, in order to prevent surgical complications, it is essential to acquire sound anatomical knowledge and dexterity as well as to practice each surgical step and movement. The VOXEL-MAN Tempo 3D simulator uses virtual reality and robotics to provide an opportunity to practice. OBJECTIVE: In 2019, the University of Szeged installed a VOXEL-MAN Virtual Reality simulator at the Medical Skills Development Center. After learning about the VOXEL-MAN Tempo simulator, the authors present the device and articulate their need for interventions with the simulator. METHOD: The VOXEL-MAN Tempo simulator is evaluated according to the formulated criteria and the role assigned to it in the practical training is determined. RESULTS: The simulator shows the anatomical structure of the temporal bone virtually, yet realistically, the real spatial location of the important anatomical structures and their distance from each other and from the surgical instrument. The system allows ear surgery to be performed realistically (two-handed bone work with a drill and suction) with tactile (vibration) and visual (bleeding) feedback. One can improve surgical skills with one- or two-handed tasks. Bone work in ear surgeries can be performed in a reproducible manner from routine, high-resolution computer tomography of the temporal bone of a real patient. CONCLUSION: With reference to our experience, the simulator is excellent for practicing each surgical step. In the future, we intend to use this virtual system in undergraduate and postgraduate training in otolaryngology. Orv Hetil. 2021; 162(16): 623-628.

The role of microbiological examination in treating peritonsillar abscess based on the retrospective analysis of data from six years / A mikrobiológiai vizsgálatok szerepe a peritonsillaris tályog kezelésében hat év anyagának retrospektív elemzése alapján.

Összefoglaló. Bevezetés és célkituzés: A peritonsillaris tályog a leggyakoribb mély nyaki infekció. Olyan fül-orr-gégészeti kórkép, amely megfelelo kezelés nélkül életveszélyes szövodményekkel járhat. Dönto jelentoségu az empirikus antibiotikumválasztás, melyhez ismerni kell a leggyakoribb kórokozókat és a várható rezisztenciát. Módszerek: A 2012 és 2017 között peritonsillaris tályog miatt kezelt esetek retrospektív feldolgozását végeztük. Összesítettük a sebészi beavatkozás során vett minták aerob és anaerob irányú tenyésztési eredményeit, valamint az empirikusan választott antibiotikumokat. A rutinszeru mikrobiológiai tenyésztés alapján meghatároztuk a leggyakoribb kórokozókat. Az adatokat nemzetközi felmérések eredményeivel hasonlítottuk össze. Eredmények: A vizsgált 6 év során 217 esetben kezeltünk peritonsillaris tályogos beteget. A tenyésztési eredményeket csak 146 esetben tudtuk elemezni. Ebbol 47 esetben került sor Fusobacterium species (ebbol 25 esetben Fusobacterium necrophorum), 31 esetben Actinomyces species és 29 esetben Streptococcus pyogenes izolálására. Az esetek kétharmadában vegyes aerob/anaerob baktériumflórát izolált a laboratórium. Következtetés: A tályogok kezelésében önmagában a sebészi beavatkozás - az anaerob környezet megszüntetésével - jelentos klinikai javulást eredményez. A jól választott antibiotikum meggyorsíthatja a lefolyást, és csökkentheti az esetleges szövodményeket. Nagy jelentosége van a megfelelo mikrobiológiai mintavételnek, nem vagy nehezen gyógyuló esetekben ez teremtheti meg a célzott antibiotikumterápiára történo váltás lehetoségét. Felmérésünk alapján a peritonsillaris tályogok jelentos részét vegyes baktériumflóra okozza, így a szájüregi anaerob baktériumokra is ható amoxicillin-klavulánsav vagy antibiotikum kombinációjának (2. vagy 3. generációs cefalosporinok kombinálva klindamicinnel vagy metronidazollal) alkalmazása javasolt mint empirikus antibiotikumterápia. Orv Hetil. 2020; 161(44): 1877-1883. INTRODUCTION AND OBJECTIVE: Peritonsillar abscess is the most common deep neck infection. Without adequate treatment, this otolaryngological disease pattern can cause life-threatening complications. The empirical choice of antibiotics is crucial which requires knowledge of the most common pathogens and the potential resistance. METHODS: A retrospective analysis of cases treated for peritonsillar abscess was performed between 2012 and 2017. We summarized the aerobic and anaerobic culture results of the surgical samples and the empirically selected antibiotics. The most common pathogens were determined via routine microbiological culture tests. We compared our data with the results of international studies. RESULTS: During the 6-year study at our Clinic, 217 patients with peritonsillar abscess were treated. The microbiological tests were available for analysis in only 146 cases. In 47 cases, Fusobacterium species (including 25 cases with Fusobacterium necrophorum), in 31 cases Actinomyces species and in 29 cases Streptococcus pyogenes were isolated. In 2/3 of the patients, polymicrobial infection was detected. CONCLUSION: In the treatment of peritonsillar abscesses, surgical intervention can result in clinical improvement because of the elimination of the anaerobic milieu. A well-chosen antibiotic can accelerate the healing process and reduce the complication rate. Proper microbiological sampling is of great importance, and in cases of non-recovery or poor recovery, this may create the opportunity to switch for targeted antibiotic therapy. The results of this study show that polymicrobial flora is very important for the development of the peritonsillar abscess, thus the recommended antibiotic therapy is amoxicillin-clavulanic acid or 2nd/3rd generation cefalosporin combined with metronidazol or clindamycin. Orv Hetil. 2020; 161(44): 1877-1883.

[Minimally invasive treatment of postintubation stenosis by use of Ultra Dream Pulse Laser and steroid-mitomycin in a 4-year-old girl]. / Postintubatiós stenosis minimálinvazív mutéti megoldása 4 éves gyermeken ultrapulzációs lézer és szteroid-mitomicin alkalmazásával.

Postintubation stenosis is a frequent complication of long-term endotracheal anesthesia. In the last few decades, its incidence showed an increasing tendency particularly among children and premature infants. It mostly affects the subglottic area and avoidance of a tracheotomy could lead to better life quality of the patient. We present the treatment of a glotto-subglottic stenosis in a 4-year-old girl. Ultra Dream Pulse Laser surgery was performed with mometason (Elocom) and mitomycin (Mitomycin-C) submucosal injections to prevent refibrosis. Minimally invasive operations play a key role in the treatment of laryngotracheal stenosis. Ultra Dream Pulse Laser surgeries could be safely applied in pediatric patients. Patient follow-up revealed wide glottis without any fibrosis. Ultra Dream Pulse Laser intervention completed with steroid-mitomycin infiltration is an efficient method of treating postintubation stenosis. Orv Hetil. 2019; 160(20): 792-796.

Ambiguous splice sites distinguish circRNA and linear splicing in the human genome.

MOTIVATION: Identification of splice sites is critical to gene annotation and to determine which sequences control circRNA biogenesis. Full-length RNA transcripts could in principle complete annotations of introns and exons in genomes without external ontologies, i.e., ab initio. However, whether it is possible to reconstruct genomic positions where splicing occurs from full-length transcripts, even if sampled in the absence of noise, depends on the genome sequence composition. If it is not, there exist provable limits on the use of RNA-Seq to define splice locations (linear or circular) in the genome. RESULTS: We provide a formal definition of splice site ambiguity due to the genomic sequence by introducing equivalent junction, which is the set of local genomic positions resulting in the same RNA sequence when joined through RNA splicing. We show that equivalent junctions are prevalent in diverse eukaryotic genomes and occur in 88.64% and 78.64% of annotated human splice sites in linear and circRNA junctions, respectively. The observed fractions of equivalent junctions and the frequency of many individual motifs are statistically significant when compared against the null distribution computed via simulation or closed-form. The frequency of equivalent junctions establishes a fundamental limit on the possibility of ab initio reconstruction of RNA transcripts without appealing to the ontology of "GT-AG" boundaries defining introns. Said differently, completely ab initio is impossible in the vast majority of splice sites in annotated circRNAs and linear transcripts. AVAILABILITY AND IMPLEMENTATION: Two python scripts generating an equivalent junction sequence per junction are available at: https://github.com/salzmanlab/Equivalent-Junctions. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Direct visualization of the Wntless-induced redistribution of WNT1 in developing chick embryos.

Paracrine Wnt signals are critical regulators of cell proliferation, specification, and differentiation during embryogenesis. Consistent with the discovery that Wnt ligands are post-translationally modified with palmitoleate (a 16 carbon mono-unsaturated fatty acid), our studies show that the vast majority of bioavailable chick WNT1 (cWNT1) produced in stably transfected L cells is cell-associated. Thus, it seems unlikely that the WNT1 signal is propagated by diffusion alone. Unfortunately, the production and transport of vertebrate Wnt proteins has been exceedingly difficult to study as few antibodies are able to detect endogenous Wnt proteins and fixation is known to disrupt the architecture of cells and tissues. Furthermore, vertebrate Wnts have been extraordinarily refractory to tagging. To help overcome these obstacles, we have generated a number of tools that permit the detection of WNT1 in palmitoylation assays and the visualization of chick and zebrafish WNT1 in live cells and tissues. Consistent with previous studies in fixed cells, live imaging of cells and tissues with overexpressed cWNT1-moxGFP shows predominant localization of the protein to a reticulated network that is likely to be the endoplasmic reticulum. As PORCN and WLS are important upstream regulators of Wnt gradient formation, we also undertook the generation of mCherry-tagged variants of both proteins. While co-expression of PORCN-mCherry had no discernible effect on the localization of WNT1-moxGFP, co-expression of WLS-mCherry caused a marked redistribution of WNT1-moxGFP to the cell surface and cellular projections in cultured cells as well as in neural crest and surface ectoderm cells in developing chick embryos. Our studies further establish that the levels of WLS, and not PORCN, are rate limiting with respect to WNT1 trafficking.

Statistical algorithms improve accuracy of gene fusion detection.

Gene fusions are known to play critical roles in tumor pathogenesis. Yet, sensitive and specific algorithms to detect gene fusions in cancer do not currently exist. In this paper, we present a new statistical algorithm, MACHETE (Mismatched Alignment CHimEra Tracking Engine), which achieves highly sensitive and specific detection of gene fusions from RNA-Seq data, including the highest Positive Predictive Value (PPV) compared to the current state-of-the-art, as assessed in simulated data. We show that the best performing published algorithms either find large numbers of fusions in negative control data or suffer from low sensitivity detecting known driving fusions in gold standard settings, such as EWSR1-FLI1. As proof of principle that MACHETE discovers novel gene fusions with high accuracy in vivo, we mined public data to discover and subsequently PCR validate novel gene fusions missed by other algorithms in the ovarian cancer cell line OVCAR3. These results highlight the gains in accuracy achieved by introducing statistical models into fusion detection, and pave the way for unbiased discovery of potentially driving and druggable gene fusions in primary tumors.

Detecting circular RNAs: bioinformatic and experimental challenges.

The pervasive expression of circular RNAs (circRNAs) is a recently discovered feature of gene expression in highly diverged eukaryotes. Numerous algorithms that are used to detect genome-wide circRNA expression from RNA sequencing (RNA-seq) data have been developed in the past few years, but there is little overlap in their predictions and no clear gold-standard method to assess the accuracy of these algorithms. We review sources of experimental and bioinformatic biases that complicate the accurate discovery of circRNAs and discuss statistical approaches to address these biases. We conclude with a discussion of the current experimental progress on the topic.

Statistically based splicing detection reveals neural enrichment and tissue-specific induction of circular RNA during human fetal development.

BACKGROUND: The pervasive expression of circular RNA is a recently discovered feature of gene expression in highly diverged eukaryotes, but the functions of most circular RNAs are still unknown. Computational methods to discover and quantify circular RNA are essential. Moreover, discovering biological contexts where circular RNAs are regulated will shed light on potential functional roles they may play. RESULTS: We present a new algorithm that increases the sensitivity and specificity of circular RNA detection by discovering and quantifying circular and linear RNA splicing events at both annotated and un-annotated exon boundaries, including intergenic regions of the genome, with high statistical confidence. Unlike approaches that rely on read count and exon homology to determine confidence in prediction of circular RNA expression, our algorithm uses a statistical approach. Using our algorithm, we unveiled striking induction of general and tissue-specific circular RNAs, including in the heart and lung, during human fetal development. We discover regions of the human fetal brain, such as the frontal cortex, with marked enrichment for genes where circular RNA isoforms are dominant. CONCLUSIONS: The vast majority of circular RNA production occurs at major spliceosome splice sites; however, we find the first examples of developmentally induced circular RNAs processed by the minor spliceosome, and an enriched propensity of minor spliceosome donors to splice into circular RNA at un-annotated, rather than annotated, exons. Together, these results suggest a potentially significant role for circular RNA in human development.

Concentration-dependent effects of WNTLESS on WNT1/3A signaling.

BACKGROUND: WNTLESS (WLS) is a multi-transmembrane protein that transports Wnt ligands from the Golgi to the cell surface. Although WLS loss-of-function experiments in the developing central nervous system reveal phenotypes consistent with defects in WNT1 and WNT3A signaling, data from complementary gain-of-function experiments have not yet been reported. Here, we report the phenotypic consequences of WLS overexpression in cultured cells and in the developing chick spinal cord. RESULTS: Overexpression of small amounts of WLS along with either WNT1 or WNT3A promotes the Wnt/ß-catenin pathway in HEK293T cells, while overexpression of higher levels of WLS inhibits the Wnt/ß-catenin pathway in these cells. Similarly, overexpressed WLS inhibits the Wnt/ß-catenin pathway in the developing spinal cord, as assessed by cell proliferation and specification. These effects appear to be Wnt-specific as overexpression of WLS inhibits the expression of FZD10, a target of ß-catenin-dependent transcription. CONCLUSIONS: Our results show that overexpression of WLS inhibits Wnt/ß-catenin signaling in the spinal cord. As the activation of the Wnt/ß-catenin pathway in the spinal cord requires WNT1 or WNT3A, our results are consistent with a model in which the relative concentration of WLS to Wnt regulates WNT1/3A signaling in the developing spinal cord.

Frizzled10 mediates WNT1 and WNT3A signaling in the dorsal spinal cord of the developing chick embryo.

BACKGROUND: WNT1 and WNT3A drive a dorsal to ventral gradient of ß-catenin-dependent Wnt signaling in the developing spinal cord. However, the identity of the receptors mediating downstream functions remains poorly understood. RESULTS: In this report, we show that the spatiotemporal expression patterns of FZD10 and WNT1/WNT3A are highly correlated. We further show that in the presence of LRP6, FZD10 promotes WNT1 and WNT3A signaling using an 8xSuperTopFlash reporter assay. Consistent with a functional role for FZD10, we demonstrate that FZD10 is required for proliferation in the spinal cord. Finally, by using an in situ proximity ligation assay, we observe an interaction between FZD10 and WNT1 and WNT3A proteins. CONCLUSIONS: Together, our results identify FZD10 as a receptor for WNT1 and WNT3A in the developing chick spinal cord.