Biomedical subjects

Zheng-Min Wang

Publications and source records attributed to Zheng-Min Wang.

11 recordsLinked to original sources

PubMed2006

An approach for precise three-dimensional modeling of the human inner ear.

For further morphological and physiological research, it is vital to establish precise three-dimensional models of the whole inner ear including the details of the membranous components. With the system of a projector and a high-resolution digital camera, 2 complete serial unstained celloidin sections of fresh human temporal bones were digitized as high-resolution images which were then sorted, calibrated, aligned and segmented using the 3D-Doctor software. Finally, 2 precise three-dimensional models of the inner ear were generated by simple surface rendering. The contours of tiny structures such as the crista ampullaris, the macula utriculi and the macula sacculi could be observed clearly. Our study suggests that it is technically feasible to employ complete serial unstained celloidin sections for precise three-dimensional reconstruction and that this helps reduce errors and laboratory workload. Moreover, the use of a high-resolution digital camera and the autoalignment function of 3D-Doctor further increase the accuracy of the models.

Collodion↗

PubMed2005

Experimental demonstration of an analytic method for image reconstruction in optical diffusion tomography with large data sets.

We report the first experimental test of an analytic image reconstruction algorithm for optical tomography with large data sets. Using a continuous-wave optical tomography system with 10(8) source-detector pairs, we demonstrate the reconstruction of an absorption image of a phantom consisting of a highly scattering medium containing absorbing inhomogeneities.

Algorithms↗

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

[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↗

PubMed2002

Clinical evaluation of 70 degrees and 90 degrees laryngeal telescopes.

OBJECTIVES: Rigid telescopy is widely used in otorhinolaryngology for endolaryngeal visualization. Laryngeal telescopes are made with several angles, including 70 degrees and 90 degrees. In this study, the performances of 70 degrees and 90 degrees telescopes are compared and evaluated on the basis of ability to visualize specific regions of the larynx. METHODS: Each subject (N = 121) received evaluation with both 70 degrees and 90 degrees telescopes. The investigator used the telescopes to attempt to visualize 4 key regions: (1) the subglottic area, (2) the pyriform fossae, (3) the anterior commissure, and (4) the laryngeal surface of the epiglottis. The telescopes were connected to a video camera and videotape recordings were made. The percentage of attempted visualizations that were successful was calculated for both the 70 degrees and the 90 degrees telescopes. RESULTS: The 70 degrees telescope provided successful visualization of the subglottic area in 111 patients (91.7%), of the pyriform fossae in 115 (95.0%), of the anterior commissure in 112 (92.6%), and of the laryngeal surface of the epiglottis in 114 (94.2%). The 90 degrees telescope provided successful visualization of the subglottic area in 103 patients (85.1%), of the pyriform fossae in 112 (92.6%), of the anterior commissure in 100 (82.6%), and of the laryngeal surface of the epiglottis in 102 (84.3%). Differences in rates of visualization were significant for the posterior surface of the epiglottis, the anterior commissure, and the subglottic area. CONCLUSIONS: The 70 degrees telescope provided a significantly higher rate of successful visualization for 3 of the 4 regions studied. This result contributes information that may help the clinical examiner select an instrument of choice.

Adult↗

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↗