Study of morphologic variability of incudostapedial angle and its relation with temporal bone pneumatization

Introduction:Optimal sound transmission across the ossicular chain is dependent on the appropriate alignment of the middle ear ossicles.Incudostapedial joint(ISJ)is conventionally considered to be at right angle.Objective:We intended to study the ISJ anatomy and the impact of temporal bone pneumatization on the same.Methods:In a cadaveric study comprising of 47 human temporal bones,canal wall down mastoidectomy was carried out under microscopic guidance keeping the ossicular chain intact.The morphology of ISJ was recorded and analysed with respect to the pneumatization status of the temporal bone.The data analysis was performed using statistical software Stata version 12.0.Results:The mean ISJ angle for the 47 bones was 90.5^0(SD-15^0;range:54^0-122^0).The mean angle in well pneumatized bones was 93.7^0(SD-16.5;Range:54°-122^0)and in sclerotic mastoids was 88.7^0(SD-14;Range:68°-118^0).The difference in the ISJ angle in these two conditions was not statistically significant(p=0.27).The mean angle was found to be significantly more obtuse in the cases with partially eroded ISJ(111.4^0{SD-8.8;range:100.3^0-221.9^0};p=0.0001)and in the cases with an‘adherent/tilted morphology’of the stapes suprastructure with the promontory(mean-95.8^0(SD-13.8;range:70.7^0-120.4^0);p-<0.00001).Conclusion:The ISJ angle shows considerable variations.This variability needs to be taken into account when undertaking middle ear reconstructive procedures,specifically the ones involving the stapes footplate.The mastoid pneumatization does not appear to have an impact on the ISJ angle.

Positive selection analysis reveals the deep-sea adaptation of a hadal sea cucumber ( Paelopatides sp.) to the Mariana Trench

The Mariana Trench,the deepest trench on the earth,is ideal for deep-sea adaptation research due to its unique characters,such as the highest hydrostatic pressure on the Earth,constant ice-cold temperature,and eternal darkness.In this study,tissues of a the hadal holothurian(Paelopatides sp.)were fi xed with RNA later in situ at~6501-m depth in the Mariana Trench,which,to our knowledge,is the deepest in-situ fi xed animal sample.A high-quality transcript was obtained by de-novo transcriptome assembly.A maximum likelihood tree was constructed based on the single copy orthologs across nine species with their available omics data.To investigate deep-sea adaptation,113 positively selected genes(PSGs)were identifi ed in Paelopatides sp.Some PSGs such as microphthalmia-associated transcription factor(MITF)may contribute to the distinct phenotype of Paelopatides sp.,including its translucent white body and degenerated ossicles.At least eight PSGs(transcription factor 7-like 2[TCF7L2],ETS-related transcription factor Elf-2-like[ELF2],PERQ amino acid-rich with GYF domain-containing protein[GIGYF],cytochrome c oxidase subunit 7a,[COX7A],type I thyroxine 5′-deiodinase[DIO1],translation factor GUF1[GUF1],SWI/SNF related-matrix-associated actin-dependent regulator of chromatin subfamily C and subfamily E,member 1[SMARCC]and[SMARCE1])might be related to cold adaptation.In addition,at least nine PSGs(cell cycle checkpoint control protein[RAD9A],replication factor A3[RPA3],DNA-directed RNA polymerases I/II/III subunit RPABC1[POLR2E],putative TAR DNA-binding protein 43 isoform X2[TARDBP],ribonucleoside-diphosphate reductase subunit M1[RRM1],putative serine/threonine-protein kinase[SMG1],transcriptional regulator[ATRX],alkylated DNA repair protein alkB homolog 6[ALKBH6],and PLAC8 motif-containing protein[PLAC8])may facilitate the repair of DNA damage induced by the high hydrostatic pressure,coldness,and high concentration of cadmium in the upper Mariana Trench.

Heel pain caused by os subcalcis:A case report

BACKGROUND The accessory bones are common bone variations around the feet and ankles,which usually originate from nonunion of the secondary ossification center adjacent to the main bone mass,and most of them remain asymptomatic.Os subcalcis is an accessory bone at the plantar aspect of the calcaneus,which is located just posterior to the insertion of the plantar fascia.Focal bone formation at the calcaneal plantar pole with heel pain has rarely been reported.CASE SUMMARY A 55-year-old man presented to our clinic with left plantar heel pain and a progressive swelling for 8 years.X-ray,computer tomography and magnetic resonance imaging showed a large os subcalcison the plantar side of the calcaneus,located at the insertion of the plantar fascia.He underwent surgical excision of the lesion.Microscopically the bony trabeculae were intermingled with fat and covered with cartilage.CONCLUSION This is a rare case with accessory os subcalcis leading to heel pain.It highlights the awareness of os subcalcis and helps avoid future misdiagnosis of heel pain.

CT virtual endoscopy of the auditory ossicular chain: clinical applications

Objective To evaluate the clinical applications and limitations of CT virtual endoscopy (CTVE) in theauditory ossicular chain.Methods CTVE of the auditory ossicular chain was performed with 1.0 mm collimation at pitch 1.0, bone algorithm, 9.6 cm field of view, and 0.1 - 0.2 mm reconstruction interval in 40 patients with middle ear diseases. 30 cases were confirmed by surgery. Results were compared with the findings of axial high resolution CT (HRCT) and multiplanar reformation (MPR) images and surgery.Results The accuracy of CTVE images in detecting ossicular destruction was 92.6%, significantly higher than that of axial HRCT (83.9%) and multiplanar reformation (76.5%) images. CTVE could also clearty reveal the postoperative condition and congenital dysplasia of the auditory ossicular chain.Conclusions CTVE can clearly demonstrate a three-dimensional image of the auditory ossicular chain and is useful in evaluating diseases of the ear, especially the auditory ossicles. CTVE could not clearly demonstrate abnormal soft tissue within the tympanic cavity, abnormal changes of the tympanic membrane and tympanic walls, and could be easily influenced by artificial factors.

中耳CT仿真内镜成像

CT仿真内镜成像技术作为一种无创立体、直观的影像检查技术越来越成为常规断层影像的有利补充，本文就近年来CTVE在耳科的临床应用情况进行综述。