[Analysis of the anatomical features of vestibular nerve canal based on 10 μm otology CT]

Objective: To analysis the anatomical features of normal vestibular nerve canal based on 10 μm otology CT. Methods: Sixty-seven patients (103 ears) underwent 10 μm otology CT examinations in Department of Radiology, Beijing Friendship Hospital, Capital Medical University from September 2020 to March 2021 were retrospectively recruited. There were 24 males and 43 females, aged from 18 to 70 (40±17) years. According to the morphology of the inferior vestibular nerve canal, it can be divided into four types as follows: uniform straight type, curved type, ampullary type and direct connection. The anatomical variables of the superior vestibular nerve canal (external orifice, isthmus and internal orifice widths, canal length, angle with labyrinthine segment of the facial nerve) and inferior vestibular nerve canal (widths of the externaland internal orifice, canal length, angles with long axis of the vestibule and the modiolus) between the different sides, genders and canal morphologies were analyzed and compared, respectively. Results: 100% superior vestibular nerve canals and 75.7% (78/103) inferior vestibular nerve canals are clearly depicted by otology CT. The left-side ear presented with larger internal orifice diameter of the superior vestibular neve canal [(1.46±0.47) mm vs (1.31±0.41) mm], and a smaller angle between the inferior vestibular neve canal and the modiolus [(41.6±16.9)° vs (51.6±21.0)°] than the right-side ear (all P<0.05, respectively), respectively. Compared to females, males demonstrated larger internal orifice of the superior vestibular nerve canal [(1.55±0.37) mm vs (1.28±0.36) mm, P<0.05]. The uniform straight type of the inferior vestibular nerve canal was the most common type (62.1%, 64/103), followed by the direct connection (19.4%, 20/103), and the ampullary type was the least common type (4.9%, 5/103). There were significant differences in external diameter and angles with the long axis of the vestibule and the modiolus between the four morphologies of the superior vestibular nerve canal (all P<0.05, respectively). Conclusion: Ten μm otology CT is capable of depicting normal vestibular nerve canal clearly. Quantitative measurement of the normal vestibular nerve canal can provide references for the imaging diagnosis and preoperative evaluation of lesions in this area.

[Analysis of the imaging characteristics of otosclerosis based on 10 μm otology CT]

Objective: To evaluate the imaging features of otosclerosis based on10 μm otology CT. Methods: Data of 27 patients with otosclerosis (51 sides) in Beijing Friendship Hospital, Capital Medical University from October 2020 to July 2021 were retrospectively collected, including 9 males and 18 females age ffrom 22 to 70 (42±12) years. All patients underwent 10 μm otology CT examination and surgical treatment. The types, amounts and involved sites of otosclerosis were analyzed and the sensitivity of 10 μm otology CT in diagnosing otosclerosis were evaluated. Results: Fenestral type accounted for 49.0% (25/51 sides), and diffuse type accounted for 51.0% (26/51 sides),and he retrofenestral type without fenestral lesion was not seen. Single lesions accounted for 45.1% (23/51 sides) and multiple lesions accounted for 54.9% (28/51 sides). The incidence of involvement of the fissula ante fenestram and annular ligaments were both 100%. The incidence of involvement of stapes footplate, vestibule, cochlea, round window, inner auditory canal wall, facial nerve canal, stapes muscle and semicircular canal was 60.8% (31 sides), 33.3% (17/51 sides), 21.6% (11/51 sides), 17.6% (9/51 sides), 13.7% (7/51 sides), 9.8% (5/51 sides), 7.8% (4/51 sides) and 5.9% (3/51 sides), respectively. The sensitivity of 10 μm otology CT in diagnosis of otosclerosis was 100%. Conclusion: 10 μm otology CT can fully display the imaging features of otosclerosis, and has the potential to be an effective routine method for otosclerosis.

[Study on the relationship between the morphology of the isthmus of the vestibular aqueduct and Meniere's disease based on 10 μm otology CT]

Objective: To evaluate the morphology of isthmus of the vestibular aqueduct (VA) and its relationship with the occurrence, course of Meniere's disease (MD) and the degree of hearing loss based on 10 μm otology CT. Methods: A total of 13 patients with MD in Beijing Friendship Hospital, Capital Medical University from October 2020 to July 2021, including 4 males and 9 females, age from 16 to 77 (56±16) years, were prospectively enrolled. All patients underwent 10 μm otology CT examination. The included lesion side was the MD affected group (14 sides), and the non-lesion side was the MD healthy group (12 sides). According to the 1∶2 side, 16 sex-and side matched cases (28 sides) without external and middle ear disease were included in the control group, including 4 males and 12 females, age from 16 to 77 (56±14) years. The horizontal semicircular canal showed on the largest plane was considered as the standard cross-section, and continuous observation was made on this image. According to the display type of isthmus of the VA, it was divided into Ⅰ to Ⅳ grades. Kruskal Wallis test was used to compare the morphological differences of VA isthmus among the affected group, the healthy group and the control group. The degree of hearing impairment was assessed by pure tone audiometry (PTA) results, which were divided into normal/mild/moderate/moderately severe/severe/extremely severe hearing impairment. Spearman correlation analysis was used to compare the correlation between the morphological rating of VA isthmus on the affected side and age, course of disease and the results of pure tone audiometry (PTA). Results: The proportions of VA isthmic morphology GRADE Ⅰ,Ⅱ,Ⅲ,Ⅳ in the MD affected group were 28.6% (4/14), 42.9% (6/14), 21.4% (3/14), 7.1% (1/14), those in the MD healthy group were 0 (0/12), 33.3% (4/12), 33.3% (4/12), 33.3% (4/12), and those in the control group were 0 (0/28), 7.1% (2/28), 64.2% (18/28), 28.6% (8/28). The VA isthmus scores [M (Q1, Q3)] of MD affected group was lower than that of MD healthy group [2 (1, 3) vs 3 (2, 4)] and control group [2 (1, 3) vs 3 (3, 4)] (all P<0.05, respectively). The morphology of the VA isthmus on the affected side of MD was negatively correlated with age (r=-0.81, P=0.002), and there was no correlation with the course of disease and degree of hearing impairment (r=-0.40, r=-0.26; all P>0.05, respectively). Conclusion: The stenosis of the VA isthmus in MD was a possible anatomical factor for the occurrence of MD.

[Effect of malleostapedotomy procedure on 17 cases of congenital middle ear malformation]

Objective: To conclude the clinical features and the postoperative efficacy of congenital middle ear malformation treated with Malleostapedotomy (MS), and to explore the security and effectiveness of MS surgery. Methods: The clinical data of 17 patients (18 ears) with congenital middle ear malformation undergoing MS procedure were analyzed. There were 10 males (11 ears) and 7 females (7 ears), aged from 7 to 48 years. The imaging examination, pure-tone audiometry, intraoperative findings and postoperative hearing improvement of these patients were analyzed and summarized, and software SPSS23.0 was used for statistical analysis. Rusults All the 17 patients (18 ears) presented with hearing loss since childhood on the affected sides. Preoperative high resolution CT (HRCT) of the temporal bone revealed definite malformations in 9 ears (6 ears with incus long process dysplasia and 3 ears with anterior and posterior crus dysplasia). Before surgery, the mean bone conductive hearing threshold at 500, 1 000, 2 000 and 4 000 Hz was (15.6±10.2) dB HL, the mean air conductive hearing threshold was (60.6±9.7) dB HL, and the mean air-bone gap was (45.0±8.9) dB. During the surgery, all 18 ears were found to be accompanied by absence or hypoplasia of incus long process. 12 ears had stapes fixation, 6 ears had oval window atresia. All patients were treated with MS procedure by using Piston. The patients were followed up for 3 months to 1 year. The mean bone conductive hearing threshold was (14.7±8.8) dB HL. The mean air conductive hearing threshold was (37.7±11.6) dB HL, and the mean air-bone gap was (23.0±8.0) dB. There were statistically significant differences in the mean air conductive hearing threshold and mean air-bone gap before and after surgery (P<0.05). While there were no statistically significant differences in the mean bone conductive hearing threshold before and after surgery (P=0.550). Conclusions: MS procedure is safe and reliable in patients with congenital middle ear malformation of incus long process dysplasia, stapes fixation or oval window atresia. HRCT is useful in evaluating the major deformity of ossicular chain and facial nerve deformity. However, it is not enough to evaluate the joint of incus-stapes and oval window atresia. MS surgery in middle ear malformation requires advanced surgical experience and skills. The hearing improvement can be significant, even though some air-bone gap after surgery exist.

[Clinical analysis of missed diagnostic congenital cholesteatoma]

Objective:The clinical symptoms, imaging features and surgical treatment of congenital cholesteatoma are reported. Method:The clinical data of 20 patients with congenital cholesteatoma diagnosed and treated in our hospital from January 2016 to May 2018 were retrospectively analyzed, including the age of onset, clinical symptoms, signs, audiology, HRCT of temporal bone, surgical methods and so on. Result:In 20 patients with congenital cholesteatoma, the clinical manifestations were hearing loss in the affected ears, including 5 cases with ear fullness and 4 cases with tinnitus. There were 13 cases of local yellow-white shadow of tympanic membrane, 5 cases of normal tympanic membrane and 2 cases of tympanic membrane bombe. Pure tone audiometry showed conductive deafness in 14 cases and mixed deafness in 6 cases. CT scan of temporal bone showed that 15 cases had pneumatic type of mastoid, 4 cases had diploectic type and 1 case had sclerostic type. There were 15 cases of interspersed flocculent shadow and 5 cases of mass shadow. Among the 20 cases of chronic otitis media with cholesteatoma, 6 have cholesteatoma in epitympanum, 4 in tympanic cavity, 3 in tympanic cavity and epitympanum, 2 in mastoid and tympanic antrum, 1 in mastoid, tympanic antrum and tympanic cavity, 1 in tympanic antrum, tympanic cavity and petrous apex, 1 in tympanic cavity, hypotympanum, posterior tympanum and ostium tympanicum tubae auditivae, 1 in aditus ad antrum, epitympanum and posterior tympanum, 1 in tympanic cavity, epitympanum and posterior tympanum. Intact canal wall mastoidectomy and tympanoplasty were performed in 7 cases, open mastoidectomy and tympanoplasty in 5 cases, middle ear exploration and tympanoplasty in 4 cases, atticotomy with reconstruction and tympanoplasty in 3 cases and subtotal temporal bone resection in 1 case. Conclusion:For patients with intact tympanic membrane presenting with hearing loss, the tympanic membranes should be carefully examined, and thin-section CT and MRI of temporal bone should be performed in time to avoid missed diagnosis of congenital cholesteatoma. Once diagnosed, surgery should be performed as soon as possible.

[Experience of revision cochlear implantation]

Objective:To analyse the characteristics of the revision cochlear implantation （RCI）patients，the cause of the cochlear malfunction，and the choice of RCI operative approach. Method:A total of 39 patients with RCI were enrolled in this study. The cochlear use time, cause of failure and reoperation procedure are recorded and analyzed retrospectively. Result:There were 39 patients accepted cochlear reoperation，the ages ranges from 1 to 28，average age was 7.8 years, median age was 5 years old. The cochlear use time ranges from 1 month to 7 years，average was 2.2 years, median time was 1 year. Thirty-seven patients underwent RCI,30 cases right side and 7 cases left side. The reason of RCI contains device failure (28 cases)，infection (5 cases)，incorrect electrode implantation (3 cases)，facial nerve stimulation (2 cases)，and electrode prolapse (1 case).The choice of RCI procedure was dependent on the first operation procedure,contains facial nerve recess approach (35 cases) and mastoid approach (2 cases).Contralateral implantation was performed in 5 cases, the rest were ipsilateral. Conclusion:RCI has a variety causes and the common reason is trauma and device failure，the RCI should be completed as early as possible to avoid the ossified cochlear and hearing or speech stagnation，the electrode implantation through previous approach is the best method.

[Study of cone-beam CT in evaluating the electrode array of cochlear implantation postoperatively]

Objective:To explore ways of evaluating morphological information of cochlea electrode in post cochlear implantation patients, and so as to make sure its value of clinical usage.Method:A series of 52 patients who were diagnosed as severe to profound sensorineural hearing loss and received cochlear implantation were admitted. All the patients had cone-beam CT scanning of the operated side 1 or 2 days after operation. The software of NNT Viewer was used to proceed original DICOM data of CBCT scanning in order to evaluate the morphological information. A comparative study in recognizing the numbers of anatomic structures was carried out between CBCT and X-ray.Result:All the 52 patients successfully received cochlear implantation as well as CBCT scanning.The cochlear implantation was implanted bilaterally at the same time in 3 patients, left side implantation in 13 patients and 36 cases in right side. There are four ways of evaluating the morphological information of electrode in cochlea post-operatively, including mode of Panorex, mode of MPR, mode of 3D-Ceph and 3D-Bone. A comprehensive evaluation can be achieved by the using of these four methods. The numbers of anatomic structures distinguished by CBCT is far more than X-ray.Conclusion:The evaluating methods of CBCT scanning is flexible and diverse, the CBCT scanning have unique values in clinical usage.

[Cochlear implant for elder patients over 75 years old]

Objective: To evaluate the operation safety, hearing as well as speech results of cochlear implantation that were applied in patients over 75 years old. Method: A series of patients who were diagnosed as severe to profound sensorineural hearing loss and received cochlear implantation were admitted. The clinical data and rehabilitation effects of the patients who were over 75 years old were summarized. Result: During this period, in which 7(1.31%) patients aged over 75 at implantation. The age ranged from 75 to 88, with an average of 80 years old. All of the 7 patients received a safe operation under general anesthesia. No major or minor complications happened related to surgery and anesthesia. Only one 84 years old male patient suffered from a transient mild balance problem. Follow up were carried out regularly, ranging from 4-40 months. The average of categories of auditory performance and speech intelligibility rating is 4 and 5 respectively. Conclusion: The cochlear implant surgery and general anesthesia are safe for patients over 75 years old, and these patients can benefit from cochlear implantation.

[Cause analysis of non dry ear after canal wall down mastoidectomy]

Objective:To investigate the possible causes of non dry ear after canal wall down mastoidectomy(CWD).Method:Clinical data of 42 patients undergoing revision CWD in our hospital were analyzed retrospectively,which included history,symptoms,signs,audiological examination,imaging examination, intraoperative findings and postoperative follow-up.All patients underwent CWD and tympanoplasty under general anesthesia.Result:Twenty-six cases were insufficient opened of sinodural angle,36 cases remained mastoid air cell(9 cases is mastoid tip air cell remained),13 cases were inadequate exposured of anterior epitympanic recess, 23 cases were inadequate exposured of posterior tympanum, 25 cases had high facial ridge, posterior facial nerve and labyrinth air cell were 5 cases,3 cases had granulation in round window, 5 cases had dysfunctional eustachian tube, 32 cases had narrow external acoustic meatus. During 3 months,6 months and 1 year follow-up, all 42 cases patients under revision CWD presented with dry ears.Conclusion:Insufficient opened of sinodural angle and mastoid air cell,inadequate exposured of anterior epitympanic recess and posterior tympanum, high facial ridge, narrow external acoustic meatus are all the possible causes of no-dry ear after CWD; As the location of concealment, posterior facial nerve and labyrinth air cell are difficult to clean. The dressing cavity do not be cleaned in time after operation is also the underlying cause of postoperative non-dry ear.

[Middle ear teratoma in infant: report of three cases and review of the literatures]

Objective: To summarize the clinical characteristics and therapeutic experiences of the middle ear teratoma in infants. Methods: Three cases of middle ear teratoma, from 2012-2015 in Beijing Friendship Hospital were analyzed. Results: The three cases all developed slowly and presented unilateral otorrhea and hearing loss. Otoscopy showed the granulation tissue in the external ear canal. Audiological changes varied according to the degree of severity. Imaging features showed the pocket-like occupancy lesions in the Eustachian tube area. The temporal bone CT showed mass with soft tissue density usually involved in the mastoid and tympanic cavity. MRI showed mixed signal intense on both T1 and T2 weighted imaging. All the three cases received neoplasm resection of the middle ear. Only one case received tympanoplasty surgery at the same time. And all the pathology results displayed mature teratoma. The follow-up time was 17 to 54 months. MRI showed complete removal of the tumor. Conclusions: Teratoma are rare in the head and neck neoplasm. When the infants suffer from the unilateral otorrhea, hearing loss, and granulation tissue formed in the external ear canal, it should be vigilant for teratoma. The differential diagnosis is middle ear cholesteatoma, congenital first branchial cyst or fistula, and middle ear carcinoma. Temporal bone CT combined with MRI could improve the accuracy of diagnosis. It should be totally resection as soon as possible if there is no contraindication. Postoperative follow-up and imaging examination are necessary to eliminate tumor recurrence.

[Revisional radical mastoidectomy surgeries--25 cases'experience]

Objective: To analyze the risk factors of failure to dry ear after radical mastoidectomy and discuss key points in revisonal surgery. Methods: Clinical data of 25 patients(32 ears) with revisonal mastoidectomy were analyzed. The preoperative temporal bone CT findings, intra-operative findings, surgical procedures, postoperative operating cavities and aural abilities were recorded and analyzed. Results: All patients received preoperative temporal bone CT followed by revisonal radical mastoidectomy under microscope and general anesthesia. Among the revisonal surgeries, 19 ears(59.4%) presented cholesteatoma and 13 ears(40.6%) had no cholesteatoma. In addition, the inadequate opening for mastoid cavity and incompleted removal of the pathological tissues accounted for 90.6%(29/32), the insufficient drainage of surgical cavity for 90.6%(29/32), the lesions in tympanic ostium of eustachian tube for 31.2%(10/32), the improper operation procedures and selection of incision for 15.6%(5/32). As for the re-operation of the modified canal wall down mastoidectomy, tympanoplasty(Ⅱ) plus plastic repairing of cavity of concha were performed in 14 ears(43.8%), the modified canal wall down mastoidectomy, tympanoplasty(Ⅱ) plus reconstruction posterior bony wall of ear canal in 2 ears(6.2%); the modified canal wall down mastoidectomy, tympanoplasty(Ⅲ) plus plastic repairing of cavity of concha in 10 eras(31.3%), the modified canal wall down mastoidectomy, tympanoplasty(Ⅲ) plus reconstruction posterior boney wall of ear canal in 1 ear(3.1%); the radical mastoidectomy plus plastic repairing of cavity of concha in 5 ears(15.6%). Lodoform gauzes were packed in surgical cavity for 2 weeks and the antibiotic was used for 3 days after surgery. All patients had dressing of ears and their ears were dropped with ofloxacin regularly. The dry ear time ranged from 4 to 8 weeks, the average point was the 5th week. During a period of 6-18 months for follow-up, all patients got dried ears. The epithelialization of the operating cavity was well and the tympanic membranes were integrity. There was not pus in surgical cavities. Neither granulation tissue nor cholesteatoma was found to reoccur. Both pure tone air hearing thresholds and air-bone gap decreased in 27 ears after the revisional surgeries, with statistically significant different in comparison to those before the operation (P<0.05). Conclusions: There are many factors leading to the failure of radical mastoidectomy, including not fully opening of the surgical cavity , incomplete removal of the lesion tissue, poor drainage of surgical cavity, the lesions in the tympanic ostium of eustachian tube, and the improper operation procedures. Treatment strategies were taken according to above factors to obtain dry ear in revisional surgeries.

[Clinical observation on the treatment of intractable otomastoiditis with reconstruction of external auditory canal wall]

Objective:To observe the clinical effect on the treatment of intractable tympanitis with reconstruction of external auditory canal wall.Method:Five cases underwent radical removel of residual lesion and reconsruction of external auditory posterior canal wall using hydroxyapatite ceramic wall with transferred pedicle temporalis fascia covering on it were analyzed. The implement of ossicular chain reconstruction depends on the probing for tympanic cavity intraoperatively. Periodic review were conducted in the 1st, 3rd, 6th, 12th month after surgery.Result:All 5 cases gained dryears within 3 months after surgery, in which hearing of 3 cases improved and ABG were within 20 dB. 1 cases showed no improvement compared to preoperation, and 1 case gained a worse audiology result. Central part of the transplant of 1 case was naked, while peripheral part had been epithelization and external auditory canal gained no accessible to mastoid cavity, the patient were also found recurrence of cholesteatom inside the mastoid cavity when received CT examination during outpatient follow-up one year postoperatively, and underwent correction surgery. 1 case underwent revision operation for a fistula between the reconstructed wall and the skin of the outer auditory canal. No surgical complications like infection or facial paralysis occurred, all patients were satisfied with surgery effect.Conclusion:HA with transferred vascularized temporalis fascia pedicle for the reconstructon of the external auditory canal wall is an effective method for the treatment of intractable tympanitis, and worth promoting.

[Electrically evoked auditory brainstem responses in patients with absence of cochlear modiolus receiving cochlear implantation]

Objective:The purpose of this study was analyzing the characteristic of the electrically evoked auditory brainstem responses (EABR) of cochlear implantation (CI) patients with absence of cochlear modiolus (ACM) and comparing the EABR results in deaf patients with normal anatomic structures. Also we assessed the auditory rehabilitation of ACM patients after cochlear implantation.Method:Twenty-eight profoundly deaf patients were contained, 14 of them were ACM (group A) and the rest were normal anatomic structures (group B). They all received Austria cochlear implants from 2004 to 2015. Postoperative EABR were measured and recorded with No. 2, 6, 11 electrodes in patients receving cochlear implantation. The lead-out rate and threshold of EABR between groups were compared and analyzed. Result:The lead-out rates of EABR in group A was 71.4% and group B was 100%. The thresholds of EABR in group A were higher than group B (P< 0.05). In group A, there were no statistical difference in the thresholds of EABR among electrodes No.2,6 and 11. However, in group B, there were statistical difference in the thresholds of EABR between electrodes No.2 and 11 (P< 0.05), and the thresholds of No.2 was lower than No.11Conclusion:EABR could be used in assessing the objective auditory rehabilitation in ACM patients after cochlear implantation.

[Research advances in the damage and regeneration of mammalian vestibular hair cells]

Vertigo is a common symptom in the clinic and impacts life quality of patients. It is closely related to the damage of vestibular hair cells. So far, there is no available approach which can facilitate abundant regeneration of mammalian vestibular hair cells, so as to recover the impaired vestibular function. Illuminating the mechanisms underlying vestibular hair cell damage and developing potential therapeutic strategies for vestibular hair cell regeneration are of great significance for the prevention and treatment of vertigo. In this study, we summarized research advances in the damage and regeneration of mammalian vestibular hair cells.

Cloning and expression analysis of glucose transporter 4 mRNA in the cold hardiness frog, Rana dybowskii

BACKGROUND

The Rana dybowskii distribute in northeast region of China which have seasonally cold climates. During winter they survival freezing by biosynthesizing carbohydrate cryoprotectants such as high concentrations glucose into blood and all tissues. The essential role of glucose transporter 4 is a high-affinity glucose transporter, which can increase glucose uptake in cells when it stimulated by insulin.

OBJECTIVE

In this study, we analysis the full-length GLUT4 mRNA detect the gene levels of GLUT4 in R. dybowskii main tissues by qPCR during low temperature.

RESULTS

We found in heart, fat body, skeletal muscle and skin four tissues all express GLUT4, and the levels of GLUT4 decreased on initial cold exposure stage, 8~12 hours, followed 24 hours it recovered.

CONCLUSION

This study we firstly indentified and characterized GLUT4 in amphibious, and provide a novel insight into the role of GLUT4 in cryoprotectant synthesis and cell protection in cold hardiness amphibians.

[Related factors of benign paroxysmal positional vertigo:investigation of 310 patients]

Objective:To explore risk factors in the onset of benign paroxysmal positional vertigo(BPPV) by questionnaires and laboratory tests. Method:Three hundred and ten cases of patients with BPPV were conducted. All patients' informations were collected, including age, smoking history, with or without high blood pressure, diabetes, cervical spondylosis, tinnitus, and vertigo. Laboratory tests including pure tone hearing level, electrical diagram of nystagmus,CT, TCD, cervical vertebra X-ray were performed, and data were analyzed. Result:All 310 patients were a total of 215 females (69.4%) and 95 males(30.6%), aged from 20 to 84 years, with a median age of 54. There were 217 cases(70.0%) of PC-BPPV,88 cases(28.4%) of HC-BPPV, and 2 cases（0.6%）of AC-BPPV. Among patients, 106 patients(34.2%) had high blood pressure, 36 patients(11.6%) had diabetes, 123 patients(39.7%) had cervical disease, 91 cases were found cerebral infarction in CT, 152 patients(49.0%) had tinnitus, and 59 patients(19.0%) had history of smoking. Conclusion:Incidence of BPPV is related with gender and ages. Incidences of high blood pressure and brain ischemic change in BPPV patients were higher than that in the general population.

Fractional Quantum Hall States at ν=13/5 and 12/5 and Their Non-Abelian Nature

Topological quantum states with non-Abelian Fibonacci anyonic excitations are widely sought after for the exotic fundamental physics they would exhibit, and for universal quantum computing applications. The fractional quantum Hall (FQH) state at a filling factor of ν=12/5 is a promising candidate; however, its precise nature is still under debate and no consensus has been achieved so far. Here, we investigate the nature of the FQH ν=13/5 state and its particle-hole conjugate state at 12/5 with the Coulomb interaction, and we address the issue of possible competing states. Based on a large-scale density-matrix renormalization group calculation in spherical geometry, we present evidence that the essential physics of the Coulomb ground state (GS) at ν=13/5 and 12/5 is captured by the k=3 parafermion Read-Rezayi state (RR_{3}), including a robust excitation gap and the topological fingerprint from the entanglement spectrum and topological entanglement entropy. Furthermore, by considering the infinite-cylinder geometry (topologically equivalent to torus geometry), we expose the non-Abelian GS sector corresponding to a Fibonacci anyonic quasiparticle, which serves as a signature of the RR_{3} state at 13/5 and 12/5 filling numbers.

Identifying non-Abelian topological order through minimal entangled states

The topological order is encoded in the pattern of long-range quantum entanglements, which cannot be measured by any local observable. Here we perform an exact diagonalization study to establish the non-Abelian topological order for topological band models through entanglement entropy measurement. We focus on the quasiparticle statistics of the non-Abelian Moore-Read and Read-Rezayi states on the lattice models with bosonic particles. We identify multiple independent minimal entangled states (MESs) in the ground state manifold on a torus. The extracted modular S matrix from MESs faithfully demonstrates the Ising anyon or Fibonacci quasiparticle statistics, including the quasiparticle quantum dimensions and the fusion rules for such systems. These findings unambiguously demonstrate the topological nature of the quantum states for these flatband models without using the knowledge of model wave functions.

Abnormal motor reflexes and dormant facial motor neurons in rats with facial-facial anastomosis

After facial nerve injury, some post-paralysis sequelae, such as synkinesis, hemispasm and 'crocodile tears' syndrome appear. The psychosocial impact of these sequelae is unavoidable. Despite recent advances and the growing popularity of this field, the pathophysiological mechanisms of facial nerve injury and regeneration are still not well understood. In this report, an abnormal motor reflex coincident with synkinetic facial movement was examined in a rat model using the blink reflex technique. Some dormant facial motor neurons were found which could not innervate through the suture site but remained alive. These results suggest that such dormant neurons might exert roles distinct from those of re-innervated neurons during facial nerve injury and regeneration. Further study is required to elucidate the biomolecular structure and electrophysiological features of such neurons.

Isoelectric focusing nonporous silica reversed-phase high-performance liquid chromatography/electrospray ionization time-of-flight mass spectrometry: a three-dimensional liquid-phase protein separation method as applied to the human erythroleukemia cell-line

A liquid-phase three-dimensional protein separation method has been developed that is used to separate the cytosolic fraction of a HEL cell lysate via isoelectric focusing (IEF), nonporous silica (NPS) reversed-phase high-performance liquid chromatography (RP-HPLC) and electrospray ionization time-of-flight mass spectrometry (ESI-TOFMS), respectively. Several hundred unique protein molecular weights were observed in a pI range from 4.8 to 8.5 and a mass range from 5 to 85 kDa. Proteins were positively identified by analysis of the pI (+/-0.5 pI units), an intact protein molecular weight (+/-150 ppm), and peptide mass mapping results. Using the molecular weight (MW) and peptide mapping results of identified proteins it was possible to characterize their posttranslational (PTMs) and/or sequence modifications. PTMs were detected on both forms of cytosolic actin, heat shock 90 beta, HINT and alpha-enolase. Sequence modifications or conflicts were observed for beta-and gamma-actin, ATP beta-synthase and heat shock 90 beta. IEF-NPS-RP-HPLC/ESI-TOFMS was used to determine experimental pI, MW and relative hydrophobicity values for each protein detected. This data was used to generate a 2-D pI-MS protein map, where proteins are displayed according to their pI and molecular weight. Protein molecular weight peaks are represented as bands in the 2-D pI-MS image where the gray scale of each band is proportional to the intensity of the protein molecular weight peak. In addition, a third hydrophobicity dimension (%B) was added as the % acetonitrile elution to generate a 3-D pI-MS-%B plot where each protein can be tagged according to three parameters.

Human DNA topoisomerase I-mediated cleavage and recombination of duck hepatitis B virus DNA in vitro

In this study, we report that eukaryotic topoisomerase I (top1) can linearize the open circular DNA of duck hepatitis B virus (DHBV). Using synthetic oligonucleotides mimicking the three-strand flap DR1 region of the DHBV genome, we found that top1 cleaves the DNA plus strand in a suicidal manner, which mimics the linearization of the virion DNA. We also report that top1 can cleave the DNA minus strand at specific sites and can linearize the minus strand via a non-homologous recombination reaction. These results are consistent with the possibility that top1 can act as a DNA endo-nuclease and strand transferase and play a role in the circularization, linearization and possibly integration of viral replication intermediates.

Double-stranded linear duck hepatitis B virus (DHBV) stably integrates at a higher frequency than wild-type DHBV in LMH chicken hepatoma cells

Integration of hepadnavirus DNAs into host chromosomes can have oncogenic consequences. Analysis of host-viral DNA junctions of DHBV identified the terminally duplicated r region of the viral genome as a hotspot for integration. Since the r region is present on the 5' and 3' ends of double-stranded linear (DSL) hepadnavirus DNAs, these molecules have been implicated as integration precursors. We have produced a LMH chicken hepatoma cell line (LMH 66-1 DSL) which replicates exclusively DSL duck hepatitis B virus (DHBV) DNA. To test whether linear DHBV DNAs integrate more frequently than the wild type open circular DHBV DNAs, we have characterized the integration frequency in LMH 66-1 DSL cells by using a subcloning approach. This approach revealed that 83% of the LMH 66-1 DSL subclones contained new integrations, compared to only 16% of subclones from LMH-D2 cells replicating wild-type open circular DHBV DNA. Also, a higher percentage of the LMH 66-1 DSL subclones contained two or more new integrations. Mathematical analysis suggests that the DSL DHBV DNAs integrated stably once every three generations during subcloning whereas wild-type DHBV integrated only once every four to five generations. Cloning and sequencing of new integrations confirmed the r region as a preferred integration site for linear DHBV DNA molecules. One DHBV integrant was associated with a small deletion of chromosomal DNA, and another DHBV integrant occurred in a telomeric repeat sequence.

Loss and acquisition of duck hepatitis B virus integrations in lineages of LMH-D2 chicken hepatoma cells

Hepatocellular carcinoma is the culmination of a series of genetic events which progressively alter the phenotype of a hepatocyte toward malignancy. Hepadnaviral DNA integrations are agents of genetic change which can promote the process of hepatocarcinogenesis. We previously characterized episomally derived duck hepatitis B virus (DHBV) integrations in LMH-D2 cells that replicate wild-type DHBV. In an effort to understand how integrations function as agents of progressive genetic change, we have studied integrations of DHBV DNA in three lineages of LMH-D2 cells through three generations of subclones. Our data have established several features of the integration process. First, single and multiple integrations occur continuously through successive cell generations. Second, the integration frequency can vary dramatically in subclones of the same cell line. Third, integrations can be lost from successive generations of cells and loss of an integration can be accompanied by loss of cellular DNA associated with the integration. Finally, certain subclones which acquire greater plating efficiency have been distinguished by unique new integration patterns. These results provide a basis for DHBV integrations to function as activators of protooncogenes, as well as agents of the loss of tumor suppressor genes during hepatocellular carcinogenesis.

Duck hepatitis B virus integrations in LMH chicken hepatoma cells: identification and characterization of new episomally derived integrations

While the cytoplasmic phase of the hepadnavirus replication cycle is well understood, very little is known about the nuclear phase. In contrast to retroviruses, proviral integration is not required for hepadnavirus replication; however, some of the viral DNAs in the nucleus are diverted into an integration pathway. Under certain conditions these integrations function as carcinogenic agents. In order to study the integration process, we have utilized LMH-D2 cells, which replicate wild-type duck hepatitis B virus (DHBV), to develop the first protocol to detect and characterize integrations of DHBV originating from episomal viral DNAs. Contrary to expectations, our results showed that stable new integrations are readily detectable in subclones of LMH-D2 cells. Complete characterization of one integration revealed a single-genome-length integrant with the structure of double-stranded linear (DSL) DHBV DNAs which are produced by in situ priming during viral replication. The integration contained a terminal redundancy of 6 bp from the r region of the virus DNA minus strand as well as a direct repeat of 70 bp of cellular DNA. On the basis of the structure of the integrant and the cellular DNA target site, we propose a molecular model for the integration mechanism that has some similarities to that of retroviruses. Identification of DSL hepadnavirus DNA integration suggests the possibility that modified DSL viral DNAs may be the precursors to a class of simple, unrearranged hepadnavirus integrations.

Cis- and trans-acting elements involved in amino acid regulation of asparagine synthetase gene expression

We have previously shown that asparagine synthetase (AS) mRNA expression can be dramatically up-regulated by asparagine deprivation in ts11 cells, mutants of BHK hamster cells which encode a temperature-sensitive AS. The expression of AS mRNA was also induced upon starvation for one of several essential amino acids in HeLa cells. We also showed that regulation of AS mRNA expression by amino acid concentration has both transcriptional and posttranscriptional components. Here we report the analysis of the elements in the human AS promoter region important for its basal activity and activation by amino acid starvation. Our results indicate that a DNA fragment spanning from nucleotides -164 to +44 of the AS promoter is sufficient for uninduced and induced gene expression. Mutations in a region located 15 to 30 bp downstream from the major transcription start site that shows good homology to a sequence in the first exon of c-fos implicated as a negative regulatory element resulted in a significant increase in basal gene expression but did not affect regulation. Interestingly, this region binds single-stranded-DNA-binding proteins that are specific for the AS coding strand. Mutations in either one of two putative binding sites for transcription factor Sp1, in a region of approximately 60 bp where many minor RNA start sites are located, or at the major transcription start site decreased promoter activity, but significant induction by amino acid starvation was still observed. Strikingly, mutations centered around nucleotide -68 not only decreased the basal promoter activity but also abolished amino acid regulation. This DNA region contains the sequence 5'-CATGATG-3', which we call the amino acid response element (AARE), that can bind a factor(s) present in HeLa cells nuclear extracts that is not capable of binding to an AS promoter with mutations or deletions of the AARE. This finding is in line with the hypothesis that transcriptional activation of AS gene expression is mediated through the binding of a positive regulatory element. We did not detect changes in the level of binding of this factor to the AARE by using nuclear extracts from HeLa cells grown under starved conditions, suggesting that activation of this factor(s) results from posttranslational modification or complexing with other proteins that do not affect its DNA-binding properties.

Regulation of asparagine synthetase gene expression by amino acid starvation

We have studied the regulation of expression of the asparagine synthetase (AS) gene in ts11 cells, a mutant of BHK hamster cells which encodes a temperature-sensitive AS and therefore does not produce endogenous asparagine at 39.5 degrees C. Incubation of ts11 cells at the nonpermissive temperature drastically increases the level of AS mRNA, and the stimulation of AS mRNA expression is effectively suppressed by the addition of asparagine to the medium. We show here that regulation of AS gene expression involves cis-acting elements which are contained in the mRNA as well as in the 5' genomic region. When a plasmid containing the human AS cDNA under the control of the human AS promoter region was stably transfected into ts11 cells, the expression of human AS RNAs was regulated as that of the endogenous hamster transcripts, indicating that this construct contained all cis elements necessary for regulation. Expression of the AS cDNA in ts11 cells under the control of a constitutive foreign promoter was also regulated by the concentration of asparagine, and this regulation required translation. When we introduced by mutagenesis a number of stop codons in the AS cDNA, the mutant mRNAs with short open reading frames were expressed at low levels that were not increased by asparagine deprivation. Inhibition of protein and RNA synthesis also prevented down-regulation of AS mRNA levels by high concentrations of asparagine. In a parallel series of experiments, we showed that an AS DNA fragment including the promoter and first exon can also regulate RNA expression in response to asparagine concentration. Furthermore, similar increases in the levels of AS RNAs are produced not only by asparagine deprivation in ts11 cells but also by deprivation of human and wild-type BHK cells of leucine, isoleucine, or glutamine. Thus, regulation of AS gene expression is a response to amino acid starvation through mechanisms which appear to involve both changes in RNA stability and change in the rates of transcription initiation or elongation.

A mammalian temperature-sensitive mutation affecting G1 progression results from a single amino acid substitution in asparagine synthetase

ts11 is a temperature-sensitive (ts) mutant isolated from the BHK-21 Syrian hamster cell line that is blocked in the G1 phase of the cell cycle at the non-permissive temperature (39.5 degrees C). We previously showed that the human gene encoding asparagine synthetase (AS) transformed ts11 cells to a ts+ phenotype and that ts11 cells were auxotrophic for asparagine at 39.5 degrees C. We show here that ts11 cells exhibit a ts phenotype for AS activity, and that the ts11 AS was much heat-labile than the wt enzyme. We have isolated AS cDNAs from wt BHK and ts11 cells and found that wt, but not ts11 AS cDNAs were capable of transformation. The deduced amino acid sequence of Syrian hamster AS showed 95% identity to the human protein as well as the same number of residues. The inability of the ts11 AS cDNAs to transform was due to a single base change, a C to T transition, that would result in the substitution of leucine with phenylalanine at a residue located in the C-terminal fourth of the enzyme. Thus the ts11 mutation identifies a mutated, thermolabile AS.

Organization and expression of the cell cycle gene, ts11, that encodes asparagine synthetase

The human ts11 gene was isolated on the basis of its ability to complement the mutation of the BHK cell cycle ts11 mutant, which is blocked in G1 at the nonpermissive temperature. This gene has now been identified as the structural gene for asparagine synthetase (AS) on the bases of sequence homology and the ability of exogenous asparagine to bypass the ts11 block. The ts11 (AS) mRNA has a size of about 2 kilobases and is induced in mid-G1 phase in human, mouse, and hamster cell lines. We have studied the organization and regulation of expression of the ts11 gene. The human ts11 gene consists of 13 exons (the first two noncoding) interspersed in a region of about 21 kilobases of DNA. Transient expression assays using the bacterial chloramphenicol acetyltransferase reporter gene identified two separate promoters: one (ts11 P1) contained in a 280-base-pair region upstream of the first exon and the other (ts11 P2) contained in the first intron. ts11 P1 produced about sixfold more chloramphenicol acetyltransferase activity than did ts11 P2 and had features of the promoters of housekeeping genes: high G + C content, multiple transcription start sites, absence of a TATA box, and presence of putative Sp1 binding sites. ts11 P2 contained a TATA sequence and other elements characteristic of a promoter, but so far we have no evidence of its physiological utilization. The ts11 gene was overexpressed in ts11 cells exposed to the nonpermissive temperature. Addition of asparagine to the culture medium led to a drastic decrease in mRNA levels and prevented G1 induction in serum-stimulated cells, which indicated that expression of the AS gene is regulated by a mechanism of end product inhibition.

Functional anatomy of the simian virus 40 late promoter

We have examined the control sequences for the late promoter function of simian virus 40 (SV40) in COS-1 cells which produce SV40 T antigen constitutively. Plasmids were constructed by cloning mutant late promoter segments upstream from sequences coding for the bacterial chloramphenicol acetyltransferase (CAT) gene, and were converted to "double-origin" type by inserting functional replication origin segments downstream from the CAT gene for replicative competence when necessary. The late promoter activity was determined by transient expression assay of the CAT mRNA and enzyme activity levels following DNA-mediated gene transfer into COS-1 cells. We find that the minimal replication origin and the 21-bp repeat containing T antigen and transcription factor Sp1 binding sites, respectively, are dispensable for late promoter function provided that one copy of the 72-bp repeat enhancer is present. We have mapped within the 72-bp repeat the major late promoter component in a 68-bp fragment (located between nucleotides 205 and 272), and found an overlapping 55-bp fragment (located between nucleotides 179 and 234) to have about one-fifth of the late promoter activity. Both the 68- and 55-bp fragments lack some of the core sequence elements required of the 72-bp repeat for transcriptional enhancer activity, and lack the ability to enhance the activity of the SV40 early promoter. The results suggest that the organization of functional units of the 72-bp repeat required for transcriptional enhancement of the early promoter is different from that required for late promoter function. The 21-bp repeat was found to have some late promoter activity located within the origin-distal copy in the absence of the 72-bp repeat. In association with the 21-bp repeat, the otherwise dispensable origin-proximal 22-bp of the 72-bp repeat containing activator protein AP-1 binding site augmented late promoter activity by three- to fourfold.

Effect of immuno-modulating agents on murine IL-2 production

The effect of two Chinese traditional drugs, Dang Gui injection prepared from Angelica sinensis and C 21 Ester glucoside (GB) extracted from Cynanchus auriculatus on in vitro production of IL-2 has been studied. The IL-2 was produced by Con A stimulation of mouse spleen mononuclear cells. The IL-2 activity was assayed using Con A stimulated blast cells as the target. It was found that Dang Gui increased and GB decreased the production of IL-2. In the control experiments for immuno-modulating effect, prostaglandin E2 (PGE2) was found to suppress and indomethacin to increase IL-2 production. The stimulatory effect of Dang Gui was totally abrogated by PGE2.