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Biomedical subjects

Fang-lu Chi

Publications and source records attributed to Fang-lu Chi.

11 recordsLinked to original sources
PubMed2006

[Clinical research about the distribution of perineural vascular plexus of the facial nerve].

OBJECTIVE: To objectively evaluate the usefulness and the reliability of the perineural vascular plexus as a landmark for facial nerve as well as whether it will be a landmark for identification of the facial nerve in surgery for otology and neurotology by means of investigating the location of the facial nerve for prevention of iatrogenic facial palsy. METHODS: Prospective case series were designed. Three hundred and eleven consecutive patients were studied which required tympanoplasty for chronic otitis media or microsurgery for facial nerve decompression and congenitally malformation of the ear from July 2002 to July 2005. All the patients were operated by the first author. Perineural vascular plexus as a landmark for identification of the facial nerve in surgery were observed to assess the utility. RESULTS: The well recognized perineural vascular plexus were seen on the horizontal mesotympanic segment of the nerve in 95.8% of patients (298 cases), and only in 4.2% of the patients (13 cases), the vessel plexus was difficult to identify. The 95% confidence interval was from 93.6% to 98.0%. CONCLUSIONS: The vascular plexuses around or over the horizontal portion of the facial nerve provide an early and direct indicator of the location of the facial nerve. The perineural vascular plexus could be a dependable and reliable landmark for the identification the horizontal part of the facial nerve in surgery for otology and neurotology.

Adolescent↗
PubMed2006

[Observation of auditory brainstem response and distortion product otoacoustic emission on the animal model of autoimmune auditory neuropathy].

OBJECTIVE: To set up an animal model of autoimmune auditory neuropathy and to observe the auditory brainstem response (ABR) and distortion product otoacoustic emission (DPOAE) in guinea pigs. METHODS: The spiral ganglion and the cochlear nerve were obtained and purified by electrophoresis from 250 normal guinea pigs. The purified cochlear nerve antigen was mixed with an equal volume of complete Freunds adjuvant for immunization. Seventy guinea pigs were divided into three groups: experiment group (50 guinea pigs), control group (10 guinea pigs), normal group (10 guinea pigs). ABR, DPOAE, serum IgG levels, and morphological changes of spiral ganglion cells and the cochlear nucleus were observed. The protein expressions of the antigen were examined by immunohistochemistry and the super-structure of the auditory nerve were observed. RESULTS: The threshold of ABR response increased ranged from 10 to 25 dB in 32% (32/100 ears) of the guinea pigs. The peak latencies of waves I , III and the interpeak latency I approximately III were prolonged in the hearing loss group of guinea pigs. Prolonged peak latency of wave III was noted in hearing loss group at 2 and 3 weeks post immunization and slowly decreased to normal peak latency. The amplitude of DPOAE was no difference in the guinea pigs. The levels of serum IgG increased significantly compared with those of the control group. Inflammatory cell infiltration was observed in the cochlear nerve and the number of spiral ganglion cells detected. On the contrary, inflammatory cell infiltration was not observed in the cochlear nucleus. The cell densities and the across-sectional areas of neurons in anteroventral cochlear nucleus and posteroventral cochlear nucleus were no difference in the guinea pigs. The antigen protein distributed strictly in cochlear nerve and the spiral ganglion. Some demyelinated areas in cochlear nerve was observed in this group. The threshold of ABR response in 68% guinea pigs (68/100 ears) did not increase. The data of DPOAE and the serum IgG levels show no difference compared with the control group. There were not pathological observation in spiral ganglion cells, cochlear nucleus and cochlear nerve. CONCLUSION: An animal model of autoimmune auditory neuropathy has been set up successfully and the character of the ABR and DPOAE was observed.

Animals↗
PubMed2006

[Diagnosis and management of facial nerve neuromas].

OBJECTIVE: To provide the experience for early diagnosis and management of facial nerve neuromas, and to discuss the clinic and imaging feature of facial nerve schwannoma and facial nerve fibroma in 22 cases. METHODS: Twenty cases facial nerve schwannoma and two cases of facial nerve neurofibroma were diagnosed and reviewed retrospectively. Surgical removal were performed through the middle cranial fossa in 2 cases, through intratemporal approach in 8 cases, through intraparotid approach in 2 cases, and combined intra-temporal with out-temporal approaches in 10 cases. Seventeen cases underwent facial nerve graft for repairing a facial nerve defect. Great auricular nerve was used in 3 cases with intratemporal approach and 1 case with intratemporal combined intraparotid approach. Sural nerve graft was used in 5 cases with intratemporal approach and 8 cases with intra-temporal combined intraparotid approach. Two cases were employed two-stage facial muscle flap-plasty. RESULTS: Facial nerve neuromas were totally removed in 21 cases and subtotal neuroma removed in 1 case. In these cases, 20 patients were no recurrence and 1 patient was lost follow-up. One patient with subtotal neuroma removal received Gamma Knife treatment before and after surgery, and this case was no recurrence. The CT imaging of the temporal bone showed that schwannoma was separated "white mass" with smooth margin along the region of facial nerve without intact canal. But neurofibroma locate in enlarge fallopian with intact canal. Magnetic resonance imaging had the advantage of evaluating all segments of the facial nerve and showed continuity of intratemporal and intraparotid mass with the facial nerve. Pathological results indicated that 20 cases were diagnosed as facial nerve schwannoma and 2 cases were neurofibroma. CONCLUSIONS: Although tumors originating from the facial nerve are extremely rare, it is possible to make early diagnosis through finding clinical feature and imaging methods. Generally, systematic surgical approach for tumor removal and facial nerve reconstruction should be considered in the cases with facial neurinoma.

Adolescent↗
PubMed2006

[Preparation of new protein carrier of vaccine against pneumococcal otitis media with genetic engineering technology].

OBJECTIVE: To prepare pneumolysin as a new protein carrier of vaccine against otitis media with genetic engineering technology and establish the base of the study on pneumococcal conjugative vaccines. METHODS: Genomic DNA was isolated from streptococcus pneumoniae. A pair of primers which included two restriction sites was designed based on the published pneumolysin gene sequence. The pneumolysin gene was amplified from pneumococcal DNA with PCR technology. The restriction enzyme digested fragment was linked into the cloning vector PET-28a and the recombinant plasmid DNA containing pneumolysin was then transfected into host cell E. coli JM109 (DE3). RESULTS: DNA fragments were subcloned to construct the complete pneumolysin gene by a conventional coning and PCR. The inserted pneumolysin gene sequence was confirmed by DNA sequencing and the pneumolysin protein was successfully expressed. The relative molecular mass of the expressed product was 52 000. The expressed product amounted to 8% of the total host cell protein. CONCLUSIONS: The pneumolysin gene was successfully cloned into host cell using genetic engineering technology. The recombinant pneumolysin was expressed and purified for preparation. This work laid a foundation of the preparation of pneumococcal conjugative vaccines.

Bacterial Proteins↗
PubMed2006

[Experimental study on facial nerve regeneration by porous silk fibroin conduit].

OBJECTIVE: To evaluate the feasibility of using polyporus silk fibroin as a kind of novel material for facial nerve regeneration. METHODS: The porous silk fibroin conduit was used in the reconstruction of a 5 mm facial nerve gap of SD rat. Chitosan conduit was taken as control group. General observation, electrophysiological study, histological study and image analysis were performed 2, 4, 6 and 8 weeks postoperatively. RESULTS: The facial nerve of SD rat regenerated successfully as time passed through. Mean CAP percentage of regenerated nerve in SF conduit was 24.94% +/- 5.73% 8 weeks postoperatively, which had no statistical significance with that of chitosan conduit group (P = 1.125). And the average number of myelinated myelinated nerve fibers in SF conduit was 62. 5 +/- 6. 3, which had statistical significance with that in chitosan conduit group (P = 0.016). CONCLUSIONS: The porous silk fibroin conduit could effectively repair facial nerve defect and improve peripheral nerve functional recovery.

Animals↗
PubMed2005

[Structure and function influence of cochlear after dexamethasone intratympanic application].

OBJECTIVE: To study the changes of the structure and function of cochlear after dexamethasone intratympanic application. METHODS: Forty-five guinea pigs were divided into three groups as normal group, 0.9% sodium chloride injection group and 0.5% dexamethasone group. By using the auditory brainstem response (ABR), the superoxide dismutase (SOD) activity, the nitric oxide (NO) value and cochlear surface preparation technique, the changes of structure and function of cochlear after intratympanic Dexamethasone application has been investigated in this study. RESULTS: There was not significant difference among three groups in ABR thresholds of wave III (F = 0.5, P = 0.5). There was not significant difference among three groups in SOD activity (F = 2.45, P = 0.96). There was not significant difference among three groups in NO value (F = 3.1, P = 0.3). There was not significant difference among three groups in necrotic values of hair cells on the cochlear surface specimens in 15 mm from basal turn (F = 0.93, P = 0.45). CONCLUSION: There is no change of cochlear construction and function after intratympanic Dexamethasone application.

Administration, Topical↗
PubMed2004

[Quantification of endolymphatic hydrops in experimental animal model].

OBJECTIVE: To investigate a method of quantification of the endolymphatic hydrops in experimental animal model. METHODS: Thirty guinea pigs were divided into three groups at random. In control group, there were ten guinea pigs without operation on both ears. Endolymphatic hydrops was induced by endolymphatic sac obliteration through extradural posterior cranial fossa approach in right ear, including 4-week postoperative group(n = 10) and 8-week postoperative group(n = 10). The area of scala vestibuli (SV) and scala media(SM) of each turn on both cochlear midmodiolar sections was measured, respectively, using auto computer aided design(AutoCAD R14) software combined with digital camera, and then the maximum scala media area(SMA) ratio was calculated and compared. RESULTS: No endolymphatic hydrops was observed in all non-operated ears, however, variety degree of hydrops was present in all operated ears. The average maximum SMA ratio in the 4-week group (2.2231 +/- 0.1996) was greater than that in the control group (1.0971 +/- 0.0644). The average maximum SMA ratio of the 8-week group (4.0142 +/- 0.5218) was greater than that in the 4-weekgroup. There was significant difference between the two groups(P < 0.05). CONCLUSION: It is convenience and reliable to be used to quantify the experimental endolymphatic hydrops with the present method. This study provides a reliable methodological base for the experimental study of Meniere's disease.

Animals↗
PubMed2004

[Connection of efferent neurons and afferent vestibular nuclei in rat].

OBJECTIVE: To study the connection between the efferent and afferent vestibular neurons in the center neural system. METHODS: In the present study, a retrograde neuron tracer horseradish peroxidase (HRP) was injected into the surrounding of efferent vestibular neurons located in the inner side of the facial genu of the rat and after following 48 hours for the retrograde axonal transport of this tracer, then its presence in neurons of the brain stem was demonstrated histochemically. RESULTS: Neurons labeled with HRP were found bilaterally in both Medial vestibular nuclei (MVe) and lateral vestibular nuclei (LVe). Approximately 80% of the neurons in each were located in the MVe on the side ipsilateral to the injection. CONCLUSIONS: There is a direct connection between the efferent and afferent vestibular neurons. These findings suggest that there is an afferent-efferent feedback regulatory mechanism in the vestibular system.

Animals↗
PubMed2003

[Clinical application of posturography with inclinometer and platform with global bottom].

OBJECTIVE: To investigate the efficacy of posturography with inclinometer and platform with global bottom to make the subjects contact the ground almost at one point in the evaluation of body balance function. METHODS: The body balance function of 100 normal persons, 50 males and 50 females, aged 21 approximately 50, and 87 patients with peripheral vertigo due to semicircular canal palsy, aged 20 approximately 60, was measured with a new type of posturograph with inclinometer and platform with global bottom developed by the authors. The subjects with an inclination-sensor being fixed at the waist were asked to adopt four postures during the measurement: standing on the ground with eyes opened (test 1), standing on the ground with the eyes closed (test 2), standing on the platform with the eyes opened (test 3), and standing on the platform with the eyes closed (test 4). RESULTS: The measurement of the normal persons showed the average values of body sway angle velocity were 0.57 +/- 0.24 d/s in test 1, 0.70 +/- 0.18 d/s in test 2, 1.16 +/- 0.32 d/s in test 3, and 2.67 +/- 0.70 d/s in test 4. Sixty-two out of the 87 patients (71.26%) showed abnormality in one or more than one of the 4 tests with a value more than x +/- 2s of the normal value, among them 7 showed abnormal value in test 1, 14 in test 2, 16 in test 16, and 56 in test 4. Two weeks after the onset of vertigo, 55 out of the 87 patients showed abnormal values by this examination. CONCLUSION: Posturography with inclinometer and platform with global bottom is effective on evaluation of balance function, In particular, the test of standing on the platform with the eyes closed effectively reflects the vestibulospinal reflex.

Adult↗