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Background Endoscopic endonasal approach to paramedian cranial base implies sacrifice of the nasal structures. Objective The present study aimed to illustrate the anatomy and provide critical anatomical landmarks for the endoscopic prelacrimal recess approach (PLRA) to the paramedian middle cranial base. Methods Anatomical dissections were performed in 10 cadaveric specimens. Results Successful access to the paramedian middle cranial base was achieved in all dissections via the PLRA with the removal of the pterygoid process. For the dissection of the infratemporal fossa and pterygopalatine fossa, the buccal nerve and infraorbital neurovascular bundle can serve as important anatomic landmarks to identify the detailed structures. In the upper parapharyngeal space, the stylopharyngeal aponeurosis can present as anatomical barriers to protect the parapharyngeal segment of the internal carotid artery (PPICA); while the levator veli palatini muscle can be considered as a landmark to locate the PPICA. For the dissection of the Eustachian tube (ET), the isthmus of the ET and ET sulcus can serve as useful landmarks to identify the posterior genu of the ICA and horizontal segment of the petrous ICA respectively. Conclusion The PLRA to the paramedian middle cranial base is anatomically feasible and can facilitate preservation of the integrity of nasal structures. The buccal nerve, infraorbital neurovascular bundle, levator veli palatini muscle, stylopharyngeal aponeurosis, the isthmus of the ET, and ET sulcus can serve as critical anatomic landmarks in their respective region and may facilitate the application of this approach.

To discuss the localization of horizontal segment of petrous internal carotid artery in transnasal endoscopic skull base surgery, and to provide anatomical data for clinical surgery.The horizontal segment of the petrous internal carotid artery of 5 adult cadaveric heads were exposed by endoscopic transnasal and microscopic open approaches respectively, and the relevant data and images were measured and collected.The medial wall of the foramen spinosum is the lateral wall of the isthmus of the eustachian tube, and the thickness of the bone is 0.5 ± 0.2 mm. The medial wall of the isthmus of the eustachian tube is the lateral wall of the posterior genu of the carotid canal and the thickness of the bone is 0.2 ± 0.1 mm. The vidian nerve originates from the anterior genu of the petrous internal carotid artery. The distance from the base of vidian nerve to the isthmus of eustachian tube is 19.2 ± 2.8 mm.The foramen spinosum is the landmark of isthmus of the Eustachian tube. The isthmus of the Eustachian tube is the landmark of the posterior genu of the internal carotid artery. The line between the base of the vidian nerve and the isthmus of the Eustachian tube ioks the landmark of horizontal segment of the petrous internal carotid artery.

To explore the role of DNA methyltransferase 1 (DNMT1) in the development of auditory system using zebrafish as experimental model.Morpholino oligonucleotide was used to induce Dnmt1 deficiency. RNA sequencing, in situ hybridization (ISH), whole genomic bisulfide sequencing (WGBS) and immunostaining were used to investigate the morphologic alterations and mechanisms.We found that downregulation of Dnmt1 induced decreased number of neuromasts and repressed cell proliferation of primordium in the developing posterior lateral line system of zebrafish. The ISH data uncovered that Fgf signalling pathway was inhibited and the expression of chemokine members cxcr4b, cxcr7b and cxcl12a were interfered, while lef1 expression was increased after inhibiting Dnmt1. Additionally, Dnmt1 downregulation led to malformed otoliths and deformed semicircular canals, and hair cell differentiation in utricle and saccule was inhibited severely. The in situ staining of otic placode markers pax2/5 and fgf 3/8/10 was decreased when Dnmt1 downregulated. The WGBS analysis demonstrated that the global methylation status was markedly downregulated, and cell cycle genes were among those most differently expressed between Dnmt1 morphants and the controls. Further ISH analysis confirmed the findings by RNA-seq and WGBS assay that cdkn1a and tp53 were both upregulated after knockdown of Dnmt1.Our results revealed that Dnmt1 is essential for the development of zebrafish auditory organ through regulating cell cycle genes together with Wnt and Fgf signalling pathways.

Rutin is a natural flavonoid, with typical effects including interaction with enzymes and scavenging of free radicals. However, the role of rutin in the auditory system is still unclear. In the present study, we used neonatal organ of Corti explants in vitro to investigate the effects of rutin in cisplatin-induced ototoxicity. The TUNEL assay and the cleaved caspase-3 immunohistochemistry were used to detect the apoptosis of hair cell (HCs) in cochlear explants, and the MitoSox-Red staining was used to detect the difference in mitochondrial superoxide among different groups. Western blot was used to investigate the expression of genes. Confocal microscopy showed that after pretreatment with rutin, the accumulation of reactive oxygen species in HCs caused by cisplatin exposure was significantly reduced. Furthermore, the expression levels of p-P38 and p-JNK were significantly decreased, while ratio of p-AKT/AKT was significantly upregulated. Our study showed that rutin reduced cisplatin-induced HCs death in neonatal cochlear explants in vitro. The potential mechanism involved the alleviation of mitochondrial damage, the scavenging of reactive oxygen species (ROS), the suppression of MAPK signaling pathway, and the activation of PI3K/AKT signaling pathway.

There is emerging evidence indicating that Kinesin family, plays vital roles in influencing the growth of axons, interference with the progression of tumor. However, the function of Kinesin member in the auditory organs remains unknown. SB743921, a kinesin spindle protein (KSP) inhibitor, was applied in mouse organ of Corti and House Ear Institute-Organ of Corti 1 (HEI-OC1) cell line to examine the role of KSP in auditory system with and without cisplatin damage. Cell Counting Kit-8 (CCK-8) and Lactase dehydrogenase (LDH) release assay were conducted to evaluate cell activity and toxicity. Pretreatment with SB743921 increased the sensitivity of HEI-OC1 cells to cisplatin ototoxicity through promoting cell apoptosis and deteriorating superoxide generation mediated damage from cisplatin. SB743921 also enhanced cisplatin induced hair cell damage in explants of mouse cochleae in vitro. Furthermore, the combined N-acetylcysteine (NAC) treatment with cisplatin or with cisplatin and SB743921 both completely rescued the reduced number of hair cells impaired by cisplatin, confirming the strengthening function of superoxide accumulation by SB743921 after cisplatin treatment. Inhibition of kinesin spindle protein enhanced the susceptibility of hair cells to cisplatin induced damage in mouse cochlear explants and HEI-OC1 cells, indicating that kinesin spindle protein might be an unprecedented target to weaken the ototoxicity of platinum medicaments.

Background Kdm6b, a specific histone 3 lysine 27 (H3K27) demethylase, has been reported to be implicated in a variety of developmental processes including cell differentiation and cell fate determination and multiple organogenesis. Here, we regulated the transcript level of kdm6bb to study the potential role in controlling the hearing organ development of zebrafish. Methods A morpholino antisense oligonucleotide (MO) strategy was used to induce Kdm6b deficiency; immunohistochemical staining and in situ hybridization analysis were conducted to figure out the morphologic alterations and embryonic mechanisms. Results Kdm6bb is expressed in the primordium and neuromasts at the early stage of zebrafish embryogenesis, suggesting a potential function of Kdm6b in the development of mechanosensory organs. Knockdown of kdm6bb severely influences the cell migration and proliferation in posterior lateral line primordium, abates the number of neuromasts along the trunk, and mRNA-mediated rescue test can partially renew the neuromasts. Loss of kdm6bb might be related to aberrant expressions of chemokine genes encompassing cxcl12a and cxcr4b/cxcr7b in the migrating primordium. Moreover, inhibition of kdm6bb reduces the expression of genes in Fgf signaling pathway, while it increases the axin2 and lef1 expression level of Wnt/β-catenin signaling during the migrating stage. Conclusions Collectively, our results revealed that Kdm6b plays an essential role in guiding the migration of primordium and in regulating the deposition of zebrafish neuromasts by mediating the gene expression of chemokines and Wnt and Fgf signaling pathway. Since histone methylation and demethylation are reversible, targeting Kdm6b may present as a novel therapeutic regimen for hearing disorders.

Objective: To explain the clinical importance of protecting the superficial temporal artery and introduce a method of protecting the superficial temporal artery.Methods: This study retrospectively analyzed the clinical data of 75 emergency patients undergoing frontotemporal craniotomy. The data was divided into traditional incision group and improved incision group according to the different surgical incision methods.Results: There were 38 cases in the traditional incision group, 13 of which had superficial temporal artery injury. Only 8 cases (21%) underwent the anatomical separation of superficial temporal artery during the operation. Whereas there were 37 cases in the improved incision group, with none showing superficial temporal artery injury. Conclusion: No strong consciousness of protecting the superficial temporal artery was shown in the clinical emergency surgery. The improved incision is a simple and easy way to protect the superficial temporal artery.

N-myc downstream-regulated gene 3 (NDRG3), which belongs to the NDRG family, is believed to play important roles in human cancer. In this present study, one-step quantitative reverse transcription-polymerase chain reaction (qPCR) and western blotting tests with 10 fresh-frozen laryngeal squamous cell carcinoma (LSCC) samples and immunohistochemistry (IHC) analysis in 109 LSCC cases were performed to investigate the relationship between NDRG3 expression and the clinicopathological characteristics of LSCC. Results demonstrated that NDRG3 mRNA and protein expression levels were statistically higher in LSCC tissues than that in non-cancerous tissues (all p0.05). IHC data showed that the NDRG3 protein expression was remarkably correlated with lymph node metastasis (p=0.043). Univariate and multivariate survival analysis implied that high NDRG3 expression (p=0.004), lymph node metastasis (p=0.044) and TNM stage (p=0.020) were independently associated with the unfavourable overall survival of patients with LSCC. The above findings suggested that NDRG3 may be identified as a novel biomarker predicting the prognosis of LSCC.