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Fang-Lu Chi

Publications and source records attributed to Fang-Lu Chi.

16 recordsLinked to original sources
PubMed2007

Auricle reconstruction with a nickel-titanium shape memory alloy as the framework.

OBJECTIVE: The objective of this study is to explore the biocompatibility and implantability of a nickel-titanium (NiTi) alloy in auricle reconstruction. METHODS AND MATERIALS: Twelve New Zealand rabbits underwent subcutaneous implantation with a NiTi alloy framework shaped like the human auricle under general anesthesia. The implant was inserted after skin expansion. Implant vascularization was evaluated at months 1, 3, 6, 9, and 12 after implantation by histologic analysis. Immunohistochemical methods were used to examine expression of vascular endothelial growth factor in tissue around the implant. The fibrovascular ingrowth rate of implants was determined by bone scanning using (99m)Tc-PYP. The surface of the NiTi alloy implant was examined microscopically with scanning electron microscopy. RESULT: The implant harvested showed only partial vascularization at 1 month and completely vascularized at 3 months. The amount of vascular endothelial growth factor-positive cells was markedly increased at 6 months and reached the highest number at 3 months. The fibrovascular ingrowth rate of implant was assessed by (99m)Tc-PYP bone scan using ratios of (99m)Tc-PYP activity in placement regions versus the contralateral normal region. One rabbit had exposure of the NiTi alloy framework as a result of overlying skin flap necrosis. It was rescued with animal skin without the complete removal of the framework. All the other rabbits tolerated the implant well, and there were no complications. CONCLUSION: The NiTi alloy implant represents an alternative implant for auricular reconstruction.

Alloys↗
PubMed2006

Dexamethasone pharmacokinetics in Guinea pig inner ear perilymph.

AIM: To study the dexamethasone pharmacokinetics in the inner ear perilymph of guinea pigs using high-pressure liquid chromatography. METHODS: Sixty-five guinea pigs were divided into three groups. In the first group, the drug application protocol used an intra-abdominal dose of 0.5% dexamethasone 4 mg x kg(-1). In the second group, an intratympanic application dose of 0.5% dexamethasone 150 microl was used. The third group was the control group. The concentrations of dexamethasone in inner ear perilymph were determined by high-pressure liquid chromatography. RESULTS: The perilymph concentration-time curves of dexamethasone conformed to a one-compartment open model after an intra-abdominal application. The Cmax was 0.927 +/- 0.008 mg x l(-1), the Tmax 1.47 +/- 0.04 h, the T(1/2K) 2.92 +/- 0.056 h, the AUC 5.533 +/- 0.05 mg x h x l(-1), the T(1/2Ka) 0.47 +/- 0.024 h. After an intratympanic application, the perilymph concentration-time curves of dexamethasone also conformed to a one-compartment open model. The Cmax was 0.201 +/- 0.006 mg x l(-1), the Tmax 0.117 +/- 0.06 h, the AUC 0.868 +/- 0.004 mg x h x l(-1), the T(1/2K) 2.918 +/- 0.089 h, the T(1/2Ka) 0.161 +/- 0.009 h. Compared to the intra-abdominal application, the intratympanic application resulted in similar levels of inner ear perilymph drug concentrations in 30 min. CONCLUSION: Dexamethasone can penetrate the blood-labyrinthine barrier after intra-abdominal application. Dexamethasone can enter into perilymph after intratympanic application. Under the condition of the study, the intratympanic application resulted in a similar level of inner ear perilymph drug concentrations compared to the intra-abdominal application in 30 min.

Animals↗
PubMed2006

Reanimation of paralyzed laryngeal muscles by electrical stimulation synchronized with inspiration.

OBJECTIVE: To determine the effects of electrical stimulation on denervated cat posterior cricoarytenoid (PCA) muscle. STUDY DESIGN AND SETTING: This study was conducted on six cats with PCA muscle denervation. All animals were sacrificed 12 weeks after surgery and the glottal area in the live animals and the fiber diameters of PCA muscle were obtained. RESULTS: Signals synchronized with inspiration were recorded and transmitted to stimulate PCA muscle. The abduction of the paralyzed vocal cord during inspiration was observed; this allows enough flow of air through the larynx to maintain the respiration. The stimulated fiber diameters of PCA muscle were different from that of nonstimulated (P < 0.01). Although all denervated muscles were degenerated, electrical stimulation was used to prevent muscular atrophy. CONCLUSIONS: This study indicates that electrical stimulation of the PCA muscle synchronized with inspiration could restore the abduction of a paralyzed vocal cord and prevent the denervated muscles from atrophying. SIGNIFICANCE: Electrical stimulation synchronized with inspiration may lead to reanimation of paralyzed laryngeal muscles.

Animals↗
PubMed2006

[Landmark of facial nerve in middle ear surgery].

OBJECTIVE: To re-evaluate landmarks for facial nerve in middle ear surgery through temporal bone dissection and facial nerve surgery. METHODS: Some relative landmarks were found through 44 facial nerves dissection in cadaver and 106 cases of facial nerve decompression surgery. RESULTS: (1) Landmarks for vertical segment of the facial nerve: the vertical line in combined point between posterior and middle 1/3 horizontal semicircular canal clews the posterior edge of facial nerve; the prolong line of superior radian of incus short process clues to the anterior edge of the facial nerve, the facial nerve and horizontal semicircular canal are almost in the same plane. (2) Landmarks for horizontal segment of the facial nerve: the facial nerve tracks forward inferior to short process of incus and anterior to horizontal semicircular canal carina in 30 angel. The facial nerve, locating posterior and superior to cochleariform process and parallel with it, forms the step of middle-superior tympanic cavity and tracks forward to geniculate ganglion. (3) location of geniculate ganglion: The same distance prolong line of stapes head to cochleariform process clues to geniculate ganglion. (4) Location of the chorda tympani nerve: chorda tympani nerve, leaving tympanic sulcus at 3 clock of bone canaline left ear and at 9 clock of bone canaline right ear, tracks forward along tympani sulcus and then cross between long process of incus and manubrium. It lies in the border of pars tensa and pars flaccid and is about 5 - 8 mm from the stylomastoid foramen to where the chorda tympani nerve leaves the facial nerve. There is no difference of facial nerve structure in temporal bone dissection and in surgery. CONCLUSIONS: The fixed landmarks of middle ear are the frame of reference of facial nerve, in which horizontal semicircular canal is most invariable; and the safety of surgery will be improved by the reference of the facial nerve.

Ear, Middle↗
PubMed2005

A correlation study of endoneurial fluid pressure and electroneurography of the facial nerve.

OBJECTIVE: The relationship between endoneurial fluid pressure (EFP) and electroneurography (ENoG) of the facial nerve was studied in order to evaluate the pathophysilogical basis of ENoG to serve as the criteria for decompression of the facial nerve. METHODS: While the values of ENoG were recorded by an instrument for physiology on the normal and crushed facial nerves of guinea pigs, EFPs were measured at the same time by a servo-nulling micropipette system. After the elevated EFP was measured, the facial nerves were removed and then fixed properly for examination under the light and electron microscope in order to determine the differences from various periods after injury. RESULTS: With the change of EFP in the facial nerve during the period from day 3 to the third week after crushed injury, the percentage of degenerated facial nerve fiber increased. There was a positive correlation between ENoG and EFP. The coefficient was 0.88 and 0.51 in the second and third week after crushed injury, respectively. Extensive edema in endoneurial and perivascular spaces of the facial nerve could be found at the early stage of injury, while proliferation of numerous Schwann cells appeared at the later stage. CONCLUSION: The change of ENoG could reflect the value of EFP relatively within 3 weeks after crushed injury. Our data indicate that ENoG could be useful to evaluate the pathogenesis underlying facial palsy.

Animals↗
PubMed2005

Modified stapes prosthesis to limit postoperative vertigo.

OBJECTIVE: To investigate the anatomic relationship between utricle, saccule, and stapes footplate, and adapt the stapes prosthesis tip to reduce postoperative vertigo. STUDY DESIGN: Five temporal bones were serially sectioned and stained, and the distance from the inner lining of stapes footplate to saccule and utricle, respectively, were measured. The Fisch prosthesis was modified with a slope of 45 degrees at its tip to adapt to the anatomic configuration of the vestibule. Fisch's original piston or the modified piston was used in 174 ears (Group I) and 108 ears (Group II), randomly. RESULTS: There was no statistically significant difference in hearing improvement between the 2 groups (P > 0.5). However, postoperative vertigo was significantly reduced when the modified prosthesis was inserted (P < 0.005). CONCLUSIONS: The modified piston improved the hearing to the level of the original piston, and the incidence of postoperative vertigo was significantly decreased. SIGNIFICANCE: A modified prosthesis is presented for a patient undergoing stapedotomy.

Adolescent↗
PubMed2005

Functional remobilization evaluation of the paralyzed vocal cord by end-to-side neurorrhaphy in rats.

OBJECTIVE: To investigate the value of end-to-side neurorrhaphy to treat vocal cord paralysis. STUDY DESIGN: A prospective study evaluating the effects of end-to-side neurorrhaphy to treat vocal cord paralysis by means of fiberoptic laryngoscopy and nerve electromyography. METHODS: Thirty Sprague-Dawley rats were divided into experimental group 1, experimental group 2, and a control group randomly. Right recurrent laryngeal nerve (RLN) was incised, and the distal end of the RLN was anastomosed to the right phrenic nerve by end-to-side neurorrhaphy in experimental group 1 or by end-to-end nerve anastomosis in experimental group 2, respectively. The adductor nerve branch of the right RLN was incised and anastomosed to the proximal end of the right ansa cervicalis nerve by end-to-end nerve anastomosis. Fiberoptic laryngoscopy and nerve electromyography were used to examine the vocal cord movement and nerve regeneration. RESULTS: Three months after operation, this effect of end-to-side neurorrhaphy created a significant difference compared with the end-to-end nerve anastomosis (P < .05). The end-to-side neurorrhaphy did not lead to vocal cord movement compared with end-to-end nerve anastomosis. CONCLUSION: Vocal cord paralysis cannot be treated by this microsurgical technique.

Anastomosis, Surgical↗
PubMed2005

[Significance of ceramide from precancerous lesion to carcinoma of larynx].

OBJECTIVE: To investigate the expression of ceramide produced by sphingomyelin in normal laryngeal mucosa, laryngeal precancerous lesion and laryngeal carcinoma. METHODS: One hundred and seventy-eight consecutive patients with leukoplakia larynx were identified from the archived pathology files of Eye Ear Nose and Throat Hospital of Fudan University from 1991 to 2001. Among them, 31 patients developed laryngeal carcinoma. Flow cytometry (FCM) and immunohistochemistry were performed to test DNA content and ceramide expression on normal tissue, precancerous lesions and laryngeal carcinoma RESULTS: Among thirty-one patients with laryngeal carcinoma, thirty-one cases are all aneuploids, diploids in all normal laryngeal mucosa and three diploids, twenty-eight aneuploids in precancerous lesions. Expression of ceramide decreased gradually from normal tissue, precancerous lesions to laryngeal carcinoma Cell staining per high-power field: (400 +/- 30, 180 +/- 20, 10 +/- 10), t test: P < 0.01. The expression of ceramide in DNA diploid cell (400 +/- 20) is more than that in aneuploid cell (150 +/- 10), t test: P < 0.01. CONCLUSIONS: Ceramide, the second messenger in apoptosis, plays a significant role from precancerous lesion to carcinoma of larynx. Reduction of ceramide may be the key factor contribution to laryngeal carcinogenesis.

Aged↗
PubMed2005

[Mutual interaction of vestibular afferent nervous system and vestibular efferent nervous system in vestibular compensation].

OBJECTIVE: To study the mutual interaction of vestibular afferent nervous system and vestibular efferent nervous system in vestibular compensation. METHODS: Build up animal model of vestibular compensation by destroying single side vestibule of wistar rat. In the study the rats were divided into 3 groups: Group A 16 normal rats; Group B 15 rats, after 7 days of left vestibular damage; Group C 7 rats 3 months after left vestibular damage; and Group D 7 rats, after vestibular compensation. Electromyography of the rats was recorded and the expression of calcitonin gene relative peptide (CGRP), choline acetyltransferase (AChT) and Na-K-ATPase were investigated in efferent vestibular nervous system. RESULTS: Electric potential activity of muscles of injury side decreased while that of the opposite side increased. In animals of vestibular compensation electric potential of bilateral musculus longus capitis at quiescent stage recovered symmetrically. CGRP positive cells of efferent vestibular nervous system increased bilaterally, and their activity enhanced, especially obvious at the acute stage. AChT positive cells of injury side of efferent vestibular nervous system decreased, but reaction degree of two sides enhanced. Reaction degree of the opposite side enhanced obviously at the stage of vestibular compensation. Expression of Na-K-ATPase mRNA of the same side was lower, but vestibular signal of the opposite side enhanced, clinically head and neck inclined obliquely by means of medial fasciculus of tractus vestibulospinalis. Months later, vestibular signal of the same side enhanced, and that of the opposite side enhanced also, clinical symptoms improved slightly. At the vestibular compensation stage, expression of Na-K-ATPase mRNA of the same side enhanced, and it was same as that of the opposite side or much higher, clinically it reached vestibular compensation. CONCLUSION: Comprehensive effect of the above results maybe as follows: Efferent vestibular nervous system inhibited afferent signal of the opposite vestibule, and it modulated excitement of vestibular center of the same side, and it worked in the complicated mechanisms of vestibular compensation. CGRP may have facilitation function to the vestibular afferent signal of injury side. While Ach improved vestibule compensation by means of inhibition of vestibule excitement of the healthy side.

Afferent Pathways↗
PubMed2004

Study on ceramide expression and DNA content in patients with healthy mucosa, leukoplakia, and carcinoma of the larynx.

OBJECTIVE: To investigate the expression of ceramide produced by sphingomyelin and DNA content in patients with healthy laryngeal mucosa, leukoplakia, and laryngeal carcinoma. DESIGN: A retrospective review of the clinical and surgical records of 178 patients with leukoplakia of the larynx; 23 of them developed laryngeal carcinoma. SETTING: University medical center. PATIENTS: One hundred seventy-eight consecutive patients with leukoplakia of the larynx were identified from the archived pathology files of the Eye Ear Nose and Throat Hospital of Fudan University from January 1, 1990, to December 30, 2001. Among them, 23 developed laryngeal carcinoma. Flow cytometry and immunohistochemistry were performed to test DNA content and ceramide expression in healthy tissue, tissue with leukoplakia, and tissue with laryngeal carcinoma from the same patient. RESULTS: Among 23 patients with leukoplakia, 20 had aneuploidy and 3 had diploidy. The healthy tissues were all diploids, and the tissues with laryngeal carcinoma were all aneuploids. The expression of ceramide decreased gradually from healthy tissue to tissue with leukoplakia to tissue with laryngeal carcinoma (0, no staining; 1+, weak staining; 2+, mild staining; 3+, moderate staining; 4+, strong staining; and 5+, the highest staining intensity). The expression of ceramide in DNA diploid cells is stronger than in aneuploid cells. CONCLUSIONS: Ceramide, the second messenger in apoptosis, may associate with the progress of leukoplakia to carcinoma of the larynx. The reduction of ceramide may contribute to laryngeal carcinogenesis.

Aneuploidy↗
PubMed2004

Spontaneous healing of various tympanic membrane perforations in the rat.

OBJECTIVES: To investigate the spontaneous healing process of various types of perforation and the location of the epithelial generation center in the tympanic membrane of rats. MATERIAL AND METHODS: Various types of perforation were made in the ears of 50 rats and the healing process was observed using light and electron microscopy. RESULTS: Epithelia hyperplasia could not be seen at the edge of the perforations, but occurred in the annulus and handle of malleus regions during the early stage of healing. There was no correlation between the healing time and the size of the perforations. When one ear was perforated, no changes were observed in the intact ear on the other side. The epithelium did not migrate into the tympanic cavity in the posterior marginal perforations. All the perforations healed, although the manubria of the malleus were damaged. CONCLUSIONS: The perforations healed by means of epithelial migration. The epithelial generation center was located near the annulus and the handle of the malleus, and therefore protection of these two regions is very important in middle ear surgery.

Animals↗
PubMed2004

Effects of hyperbaric therapy on function and morphology of Guinea pig cochlea with endolymphatic hydrops.

OBJECTIVE: The objective of this study was to investigate the effect on experimental endolymphatic hydrops in guinea pigs after hyperbaric therapy. BACKGROUND: The histopathologic character of Ménière's disease is the presence of endolymphatic hydrops. Endolymphatic hypertension could be one of the factors resulting from endolymphatic hydrops. Some treatments of Ménière's disease are aimed toward preventing the endolymphatic hypertension. Exposure to pressure change has risen in recent years. METHODS: Thirty-two guinea pigs were operated on the right ears to induce endolymphatic hydrops by obliterating the endolymphatic sac through an extradural posterior cranial fossa approach. After 5 weeks' survival, 12 guinea pigs were put into a chamber with an absolute atmospheric pressure of 2.2 for 3 weeks (90 minutes once a day 5 times a week). We observed the morphologic and functional changes in guinea pig cochleae of the pressure group, 4-week hydrops group (n = 10), 8-week hydrops group (n = 10), and the normal group (n = 10). We measured the hearing threshold of the auditory brainstem response, the 70-dB SPL action potential (AP) latency, the ratio of 70-dB SPL summating potential magnitude to action potential magnitude (-SP/AP) of the electrocochleogram, and the maximum scala media area (SMA) ratio, respectively. RESULTS: The average 70-dB SPL-SP/AP magnitude of right ears (0.29 +/- 0.09) and the average maximum SMA ratio (2.23 +/- 0.20) in the pressure group were significantly less than that in the 8-week hydrops group (0.69 +/- 0.15 and 4.04 +/- 0.52, respectively) with the same survival time (p < 0.05). The results in the pressure group were almost as similar as that in the 4-week hydrops group (0.29 +/- 0.13 and 2.22 +/- 0.20, respectively) (p > 0.05). The average hearing threshold of ABR of right ears in the pressure group (36.67 +/- 14.30-dB SPL) was lower than that of the 8-week hydrops group (44 +/-1 4.30-dB SPL), but the difference was insignificant (p > 0.05). The average 70-dB SPL AP latency of right ears in the pressure group was not significantly different from those of the 8-week hydrops group, the 4-week hydrops group, or the normal group (p > 0.05). CONCLUSIONS: Our findings suggest hyperbaric therapy can significantly suppress the development of endolymphatic hydrops and improve cochlear function in guinea pigs. This study provided strong evidence for the development of pressure treatment of Ménière's disease without destroying the inner ear.

Animals↗
PubMed2004

The quantification of endolymphatic hydrops in an experimental animal model with guinea pigs.

To better quantify endolymphatic hydrops in experimental guinea pigs, endolymphatic hydrops was induced by endolymphatic sac obliteration through an extradural posterior cranial fossa approach in the right ear. The area of the scala vestibuli and scala media of each turn on both cochlear midmodiolar sections was measured, using an automated computer-aided design (AutoCAD R14) software combined with a digital camera. No endolymphatic hydrops was observed in all nonoperated ears; however, various degrees of hydrops were present in all operated ears. The average maximum SMA (scala media area) ratio in the 4-week group (2.22 +/- 0.20) was greater than that in the control group (1.10 +/- 0.06). The average maximum SMA ratio of the 8-week group (4.04 +/- 0.52) was greater than that of the 4-week group (p < 0.05). This study provides a reliable methodologic base for the experimental study of Ménière's disease.

Animals↗
PubMed2002

Apoptosis and expression of BCL-2 in facial motoneurons after facial nerve injury.

BACKGROUND: Apoptosis has been implicated in neuronal degeneration after optic and sciatic nerve injury. The mechanisms contributing to facial motoneuron death are poorly understood. This study investigated the mechanisms underlying facial motoneuronal death and the expression of BCL-2 in facial motoneurons after facial nerve injury. METHODS: Morphologic changes in the facial motoneurons were examined by light and transmission electron microscopy, and TdT-mediated dUTP-biotin nick end labeling (TUNEL) methods was used. Expression of BCL-2 was studied by immunohistochemistry and in situ hybridization after facial nerve injury. RESULTS: Cell shrinkage, condensed cytoplasm, and apoptotic bodies were demonstrated in numerous cells under light microscopy. The chromatin was condensed and localized to the nuclear envelope, forming a crescent or cap, and the endoplasmic reticulum was still visible but appeared swollen under electron microscopy. In vivo TUNEL staining displayed positive facial motoneurons 7 days after facial nerve transsection. The BCL-2 expression in facial motoneurons declined and reached its lowest level on the fifteenth day (p < 0.05). The reduction in BCL-2 expression after facial nerve transsection close to the facial motoneuron nucleus was greater than that of facial nerve transsection far away from the facial motoneuron nucleus (p < 0.05). BCL-2 expression after crushing of the facial nerve was found to be more intense in comparison with that after nerve transsection at the stylomastoid foramen (p < 0.05). CONCLUSIONS: These findings indicated that motoneuron death induced by facial nerve transsection was consistent with the process of apoptosis. The endogenous BCL-2 in these motoneurons may protect facial motoneurons from axotomy-induced cell death.

Animals↗
PubMed2002

Isolated sphenoid sinus disease: an analysis of 122 cases.

Isolated sphenoid sinus disease (ISSD) is a relatively uncommon disease. The present study is a retrospective review of 122 patients with ISSD who were treated at the Department of Otolaryngology, Eye, Ear, Nose and Throat Hospital at Shanghai Medical University over a 25-year period. The diagnosis of ISSD was made on the basis of history and physical examination, signs and symptoms, nasal endoscopy, and computed tomography (CT) and magnetic resonance imaging (MRI). The final diagnosis of ISSD was confirmed by histopathologic and microbiological examinations of the surgical specimens. The pathological findings in this study included sphenoid cyst (47 cases), sphenoid sinusitis (31 cases), fungal disease (19 cases), inverted papilloma (4 cases), sphenochoanal polyp (1 case), foreign body (8 cases), malignant tumors (8 cases), and others (4 cases). The most common initial symptom was headache, followed in decreasing order by visual changes, cranial nerve palsies, and nasal symptoms. The more frequent use of routine CT and MRI scanning, as well as endoscopy, in the diagnosis of sinus disease has led to an increase in the early diagnosis of ISSD. The recent advances in endoscopic sphenoidotomy has allowed for relatively safe and immediate treatment of ISSD, preventing late extension into adjacent vital structures, which is commonly fatal. Endoscopic surgery also enables the surgeon to make a precise pathological diagnosis.

Adolescent↗