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Ying Chen

Publications and source records attributed to Ying Chen.

At least 199 records · Page 11Linked to original sources

Application of CT angiography of complex cerebrovascular lesions during surgical decision making.

Helical computed tomographic angiography (CTA) is a relatively new noninvasive volumetric imaging technique. Since early reports in the 1990s, CTA has rapidly improved image resolution and scan volume. Cerebral arteries can be imaged clearly, which is advantageous in the diagnosis of vascular diseases such as cerebral aneurysms, arteriovenous malformations, and cerebrovascular occlusive disease. Before attacking a cerebrovascular lesion near or in the skull base, precise preoperative knowledge of anatomic relationships between the bony and neurovascular structures is critical for obtaining successful outcomes. The sensitivity of CTA for the detection of cerebral aneurysms < or = 5 mm in diameter may be higher than that of digital subtraction angiography (DSA), with equal specificity and high interoperator reliability. With minor modification to the technique, paraclinoid vascular lesions can be depicted using CTA. We present our experience using CTA in addition to DSA to obtain important anatomic information about skull base vascular lesions that assisted in the clinical decision-making process.

Journal Article↗

Diets containing soy protein isolate increase hepatic CYP3A expression and inducibility in weanling male rats exposed during early development.

Hepatic CYP3A enzymes were studied in weanling male Sprague-Dawley rats exposed to diets from gestational d 4 in which the sole protein source was either casein (CAS) or soy protein isolate (SPI). At age 25 d, rats were gavaged with corn oil or one of the CYP3A inducers, dexamethasone (DEX) and clotrimazole (CLT), at a dose of 50 mg/kg. Little CYP3A1 (CYP3A23), CYP3A2, or CYP3A9 mRNA was observed in CAS-fed weanling rats but CYP3A18 mRNA was readily detectable in Northern blots. In contrast, consumption of SPI without inducer treatment resulted in the expression of CYP3A1 (CYP3A23), and CYP3A2 mRNAs, expression of CYP3A apoprotein in hepatic microsomes, and a 2-fold greater turnover of the CYP3A substrate midazolam (P < 0.05). DEX induced CYP3A1, CYP3A2, and CYP3A9 (P < 0.05), but not CYP3A18 mRNA expression in rats fed both diets. Hepatic CYP3A apoprotein expression and midazolam 4-hydroxylation in SPI-fed rats was greater than that of CAS-fed rats after DEX treatment (P < 0.05). CLT also induced CYP3A2 mRNA 2-fold in rats fed both diets but CYP3A apoprotein expression in microsomes from SPI-fed CLT rats was double that of CLT-treated rats fed CAS (P < 0.05). The elevation of CYP3A apoprotein due to SPI and the CYP3A apoprotein induction by DEX and CLT treatment yielded no significant diet x inducer interaction. Analysis of heterologous nuclear RNA expression by RT-PCR using intron-specific primers for CYP3A1 revealed a 14-fold increase in RNA transcription in CAS-fed rats after treatment with DEX (P < 0.05) but no increase in rats fed SPI compared with rats fed CAS even though CYP3A1 mRNA and CYP3A apoprotein were significantly elevated. These data demonstrate that exposure to SPI during early development can increase CYP3A expression via post-transcriptional mechanisms and suggest that early soy consumption has potential effects on the metabolism of a wide variety of CYP3A substrates.

Animals↗

Dual functional roles of Tie-2/angiopoietin in TNF-alpha-mediated angiogenesis.

Inflammation and angiogenesis are associated with pathological disorders. TNF-alpha is a major inflammatory cytokine that also regulates angiogenesis. TNF-alpha has been shown to regulate Tie-2 and angiopoietin (Ang) expression, but the functional significance is less clear. In this study, we showed that TNF-alpha induced a weak angiogenic response in a mouse cornea assay. Systemic overexpression of Ang-1 or Ang-2 dramatically increased corneal angiogenesis induced by TNF-alpha. In the absence of TNF-alpha, neither Ang-1 nor Ang-2 promoted corneal angiogenesis. Low doses (0-25 ng/ml) of TNF-alpha increased vascular branch formation of cultured endothelial cells. Overexpression of Ang-1 or Ang-2 enhanced the effects of TNF-alpha. These data suggest that Tie-2 signaling synergistically amplifies and participates in TNF-alpha-mediated angiogenesis. In addition, high doses (>/=50 ng/ml) of TNF-alpha induced apoptosis in endothelial cells, but addition of Ang-1 or Ang-2 significantly reduced cell death. Enhanced endothelial cell survival was correlated with Akt phosphorylation. Collectively, our data reveal dual functional roles of Tie-2: low doses enhance TNF-alpha-induced angiogenesis, and high doses attenuate TNF-alpha-induced cell death. The study provides evidence supporting a role for Tie-2 in inflammatory angiogenesis.

Angiopoietin-1↗

Identification of RDH10, an All-trans Retinol Dehydrogenase, in Retinal Muller Cells.

PURPOSE: To investigate the expression of RDH10, an all-trans retinol dehydrogenase identified in the retinal pigment epithelium (RPE), in retinal Muller cells. METHODS: The RDH10 protein levels in mouse eyecups and bovine tissues were examined by Western blot analysis using a polyclonal antibody against RDH10. The cellular localization in the retina was determined by immunohistochemistry. Expression of RDH10 in rMC-1, a cell line derived from rat Muller cells, was determined by RT-PCR and Western blot analysis. All-trans retinol dehydrogenase activity assays were performed using lysates from rMC-1 cells. The generation of all-trans retinal from tritiated all-trans retinol was analyzed by HPLC. RESULTS: RDH10, retinal G protein-coupled receptor (RGR), and RPE65 all had higher expression levels in the eyecups of BALB/c than in C57Bl/6 mice. In addition to the RPE, RDH10 was also detected at lower levels in the retina and liver. Immunohistochemistry showed that RDH10 was localized in Muller cells in retinal sections. RDH10 was detected in rMC-1 cells, at both the RNA and protein levels. The rat RDH10 cDNA containing the full-length coding region was cloned from rMC-1 cells. The rat RDH10 cDNA encodes a protein of 341 amino acids and shares 99% sequence identity with human, bovine, and mouse RDH10 at the amino acid level. In rMC-1 cells, all-trans retinol dehydrogenase activity was detected in the microsomal fraction. NADP was shown to be the preferred cofactor, which is identical with the cofactor preference of the recombinant RDH10. CONCLUSIONS: RDH10 was expressed in retinal Muller cells, in addition to the RPE. RDH10 generates all-trans retinal, which is the substrate for the photoisomerase RGR in Muller cells.

Alcohol Oxidoreductases↗

Comparing study of the effect of nanosized silicon dioxide and microsized silicon dioxide on fibrogenesis in rats.

This study compares the effect of nanosized silicon dioxide (nanosized SiO2) and microsized silicon dioxide (microsized SiO2) particles on fibrogenesis in rats. Wistar rats were instilled intratracheally with saline, 20 mg of nanosized SiO2 or 20 mg of microsized SiO2, and were sacrificed at 1 and 2 months after instillation. The lungs of rats were analysed for the changes of lung/body coefficient and hydroxyproline content. Changes in pathology and fibrotic grade were observed by use of hematoxylin and eosin and Van Gieson dyeing. The expression of interleukin-4 (IL-4) and transforming growth factor-beta1 (TGF-beta1) was observed by use of immunohistochemical technique, and protein expression quantitatively analysed by image analysis. The lung/body coefficient and hydroxyproline content of nanosized SiO2 groups were significantly lower than those of microsized SiO2 groups at both 1 and 2 months after instillation (P<0.05 or P<0.01), but without significant differences from those of saline control groups. At 1 month after instillation, there were mainly cellular nodules (Stage I) in nanosized SiO2 group, while in microsized SiO2 group Stage II, II+ of silicotic nodules were observed. At 2 months after instillation, there were still Stage I of silicotic nodules in nanosized SiO2 group. In microsized SiO2 group mainly Stage II+, III of silicotic nodules were found. Quantity image analysis showed that the expressions of IL-4 and TGF-beta1 in nanosized SiO2 groups were significantly lower than those in microsized SiO2 groups (P<0.01), but without significant difference from those of saline control groups. Our experiment revealed that the effect of fibrogenesis of nanosized SiO2 might be milder than that of microsized SiO2 in rats, potentially resulting from nanoparticals tending to be diffused and easily translocated due to their ultrafine particle size compared to microsized particles.

Animals↗

Study on shift schedule saving energy of automatic transmission of ground vehicles.

To improve ground vehicle efficiency, shift schedule energy saving was proposed for the ground vehicle automatic transmission by studying the function of the torque converter and transmission in the vehicular drivetrain. The shift schedule can keep the torque converter working in the high efficiency range under all the working conditions except in the low efficiency range on the left when the transmission worked at the lowest shift, and in the low efficiency range on the right when the transmission worked at the highest shift. The shift quality key factors were analysed. The automatic trans-mission's bench-test adopting this shift schedule was made on the automatic transmission's test-bed. The experimental results showed that the shift schedule was correct and that the shift quality was controllable.

Algorithms↗

HBV cccDNA in patients' sera as an indicator for HBV reactivation and an early signal of liver damage.

AIM: To evaluate the covalently closed circle DNA (cccDNA) level of hepatitis B virus (HBV) in patients' liver and sera. METHODS: HBV DNA was isolated from patients' liver biopsies and sera. A sensitive real-time PCR method, which is capable of differentiation of HBV viral genomic DNA and cccDNA, was used to quantify the total HBV cccDNA. The total HBV viral DNA was quantitated by real-time PCR using a HBV diagnostic kit (PG Biotech, LTD, Shenzhen, China) described previously. RESULTS: For the first time, we measured the level of HBV DNA and cccDNA isolated from ten HBV patients' liver biopsies and sera. In the liver biopsies, cccDNA was detected from all the biopsy samples. The copy number of cccDNA ranged from from 0.03 to 173.1 per cell, the copy number of total HBV DNA ranged from 0.08 to 3 717 per cell. The ratio of total HBV DNA to cccDNA ranged from 1 to 3 406. In the sera, cccDNA was only detected from six samples whereas HBV viral DNA was detected from all ten samples. The ratio of cccDNA to total HBV DNA ranged from 0 to 1.77%. To further investigate the reason why cccDNA could only be detected in some patients' sera, we performed longitudinal studies. The cccDNA was detected from the patients' sera with HBV reactivation but not from the patients' sera without HBV reactivation. The level of cccDNA in the sera was correlated with ALT and viral load in the HBV reactivation patients. CONCLUSION: HBV cccDNA is actively transcribed and replicated in some patients' hepatocytes, which is reflected by a high ratio of HBV total DNA vs cccDNA. Detection of cccDNA in the liver biopsy will provide an end-point for the anti-HBV therapy. The occurrence of cccDNA in the sera is an early signal of liver damage, which may be another important clinical parameter.

Alanine Transaminase↗

Effects of mutation and expression of PTEN gene mRNA on tumorigenesis and progression of epithelial ovarian cancer.

OBJECTIVE: To investigate the mutation and expression of tumor suppressor gene-PTEN mRNA and explore their roles in tumorigenesis and progression of ovarian cancer. METHODS: Mutated exon 5 of PTEN gene was examined in normal ovary (n=5), ovarian cyst (n=5), ovarian borderline tumor (n=9), epithelial ovarian cancer (n=60), and ovarian cancer cell line (n=1) by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP). mRNA expression of PTEN gene was evaluated in corresponding tissues and cell line by reverse transcription polymerase chain reaction (RT-PCR). The mutation and mRNA expression of PTEN gene were compared with clinicopathological features of ovarian cancer. RESULTS: Mutated exon 5 of PTEN gene was detected only in 5 (7.1%) cases of epithelial ovarian cancer. mRNA expression level of PTEN gene in ovarian borderline tumor or ovarian cancer was lower than that in normal ovary or ovarian cyst (P < 0.05). The level of PTEN gene mRNA expression was negatively correlated with clinicopathological staging of ovarian cancer, whereas positively correlated with histological differentiation (P < 0.05). mRNA expression level of PTEN gene in ovarian endometrioid cancer was significantly lower than that in ovarian serous or mucinous cancer (P < 0.05). CONCLUSIONS: Mutation of PTEN gene occurs in ovarian cancer. Down-regulated expression of PTEN is probably an important molecular event in tumorigenesis of ovarian cancer. Abnormal expression of PTEN gene is involved in progression of ovarian cancer. Reduced expression of PTEN gene is closely associated with tumorigenesis and pathobiological behaviors of ovarian endometrioid cancer.

Adolescent↗

[Immunoblot and immunohistochemical analysis of CYP2A expression in human olfactory mucosa].

OBJECTIVE: To investigate the nasal expression of CYP2A proteins in human. METHODS: Immunoblot analysis was used to detect fetal tissues at 96-185 days of gestational age and in surgical biopsy tissues from different regions of nasal cavity of 36 adult patients, and immunohistochemical methods were used to localize CYP2A proteins' cellular distribution. RESULTS: In adults, CYP2A protein was detected in olfactory microsomes from 8 of 10 individual, but not in the respiratory nasal microsomes from 37 individual. Quantitative immunoblot analysis confirmed that CYP2A proteins were selectively expressed in the olfactory region in both adult and fetal tissues. Interestingly, the levels of CYP2A proteins in nasal microsomes were generally higher in fetuses than in adults. The CYP2A protein content in olfactory microsomes ranged from 0.1 to 1.1 pmol/mg among adult nasal microsomes, while among five fetuses ranged from 0.8 to 5.3 pmol/mg microsomal protein, with a trend of developmental increase in expression level. Immunohistochemical studies confirmed that the CYP2A proteins were expressed in the supporting cells in the olfactory epithelium and in the Bowman's glands in the lamina propria. CONCLUSIONS: CYP2A proteins expression in human olfactory mucosa indicates that olfactory mucosa is metabolic target site of the xenobiotics. Also CYP2A has a relationship with olfaction. The prenatal expression of the CYP2A proteins in the OM suggests potential risks of developmental toxicity from maternally derived xenobiotics.

Adolescent↗

Polyamine catabolism in platinum drug action: Interactions between oxaliplatin and the polyamine analogue N1,N11-diethylnorspermine at the level of spermidine/spermine N1-acetyltransferase.

A great deal of experimental evidence connects induction of polyamine catabolism via spermidine/spermine N1-acetyltransferase (SSAT) to antiproliferative activity and apoptosis. Following our initial observation from gene expression profiling that platinum drugs induce SSAT, we undertook this present study to characterize platinum drug induction of SSAT and other polyamine catabolic enzymes and to examine how these responses might be enhanced with the well-known inducer of SSAT and clinically relevant polyamine analogue, N1,N11-diethylnorspermine (DENSPM). The results obtained in A2780 ovarian cancer cells by real-time quantitative RT-PCR and Northern blot analysis show that a 2-hour exposure of A2780 cells to platinum drugs induces expression of SSAT, a second SSAT (SSAT-2), spermine oxidase, and polyamine oxidase in a dose-dependent manner. At equitoxic doses, oxaliplatin is more effective than cisplatin in SSAT induction. The most affected enzyme, SSAT, increased 15-fold in mRNA expression and 2-fold in enzyme activity. When combined with DENSPM to further induce SSAT and to enhance conversion of mRNA to activity, oxaliplatin increased SSAT mRNA 50-fold and activity, 210-fold. Polyamine pools declined in rough proportion to levels of SSAT induction. At pharmacologically relevant oxaliplatin exposure times (20 hours) and drug concentrations (5 to 15 micromol/L), these responses were increased even further. Combining low-dose DENSPM with oxaliplatin produced a greater than additive inhibition of cell growth based on the sulforhodamine-B assay. Taken together, the findings confirm potent induction of polyamine catabolic enzymes, such as SSAT by platinum drugs, and demonstrate that these biochemical responses as well as growth inhibition can be potentiated by co-treatment with the polyamine analogue DENSPM. With appropriate in vitro and in vivo optimization, these findings could lead to clinically relevant therapeutic strategies.

Acetyltransferases↗

[Protective and therapeutic effect of pulmonary surfactant on the experimental chronic obstructive pulmonary disease in hamsters].

OBJECTIVE: To investigate the protective and therapeutic effects of pulmonary surfactant in the pathogenesis of chronic obstructive pulmonary disease (COPD) in hamsters. METHODS: COPD animal model was established by smoke inhalations and intratracheal instillations of pancreatic elastase in hamsters. Ninty hamsters were divided into 9 groups as follows: normal group (N), two groups received smoke inhalations for 1 and 3 months (S1 and S3), one group received intratracheal instillation of surfactant (10 mg/100 g BW) for once after 1 month smoking (SP1), one group was treated with surfactant after 1.5, 2 and 2.5 months of smoking (SP3), and two groups received intratracheal administration of elastase (40 U/100 g BW) and were killed after 1 month and 3 months, respectively (E1 and E3). The surfactant was injected intratracheally after 1 week, 0.5, 1.0, 1.5, 2.0, and 2.5 months, followed by administration with elastase (EP1 and EP3). EP1 group were killed at the first month, and EP3 at the third month. Light microscopy and electromicroscopy observations were performed in each group. Pulmonary mean linear intercept (MLI), mean alveolar numbers (MAN), and pulmonary alveolar area (PAA) was measured by image analysis. The expression of surfactant protein A (SP-A) were observed by immunohistochemistry. RESULTS: Smoking for 3 months and instillations of elastase resulted in chronic bronchitis and emphysema. MLI and PAA increased and MAN decreased in all the experimental groups compared with in the normal group (P < 0.05 or P < 0.01). Administration of surfactant for 3 months resulted in statistically significant inhibition of pulmonary injury. MLI and PAA decreased and MAN increased in SP3 compared with in S3. Only MLI decreased in EP3 compared with E3. The expressions of SP-A in the type II alveolar epithelia decreased in S3 and E3 (compared with the normal group P < 0.01). After pulmonary surfactant intervention, the expression of SP-A increased significantly. CONCLUSION: Pulmonary surfactant may have a long-term protective effect on chronic smoking and elastase-induced COPD.

Animals↗

Conversion regular patterns of acetic acid, propionic acid and butyric acid in UASB reactor.

On the basis of continuous tests and batch tests, conversion regular patterns of acetate, propionate and butyrate in activated sludge at different heights of the UASB reactor were conducted. Results indicated that the conversion capacity of the microbe is decided by the substrate characteristic when sole VFA is used as the only substrate. But when mixed substrates are used, the conversion regulations would have changed accordingly. Relationships of different substrates vary according to their locations. In the whole reactor, propionate's conversion is restrained by acetate and butyrate of high concentration. On the top and at the bottom of the reactor, conversion of acetate, but butyrate, is restrained by propionate. And in the midst, acetate's conversion is accelerated by propionate while that of butyrate is restrained. It is proved, based on the analysis of specific conversion rate, that the space distribution of the microbe is the main factor that affects substrates' conversion. The ethanol-type fermentation of the acidogenic-phase is the optimal acid-type fermentation for the two-phase anaerobic process.

Acetic Acid↗

[The developmental expression of embryonic-neural cell adhesive molecule in human olfactory mucosa].

OBJECTIVE: To discuss the expressional features and physical function of E-NCAM (embryonic- neural cell adhesive molecule) in human fetal olfactory mucosa. METHOD: The immune expressions of E-NCAM in human olfactory mucosa at different gestational stages was detected with the technique of immunohistochemistry. RESULT: The positive expression of E-NCAM began at gestational week 14 (14W), and was localized in the cell bodied, dendrites, axis of olfactory neurons and olfactory nerve fiber bundles in lamina propria. The positive cells increased and the densities of staining of fiber bundles rose with the development of the fetus and reached the peak at 28W and decreased gradually then on. And at each stage the E-NCAM positive cells were localized at middle-lower parts of olfactory mucosa while the sustentacular cells and neurons at the top part were always E-NCAM negative. CONCLUSION: The expression features of E-NCAM are coincident with the plastict transformation of olfactory neurons. The high expression of E-NCAM at early half parts of gestation is helpful to the growth of neurons in differentiation and the down-regulation at late-half parts of gestation is helpful to the stabilization of structure of mature neurons.

Embryo, Mammalian↗

[The relationships between changes of serum osteoprotegerin, nuclear factor-kappa B ligand receptor activator, and age, menopause, bone biochemical markers and bone mineral densities in women aged 20 - 75].

OBJECTIVE: To investigate the relationships between the serum levels of osteoprotegerin (OPG), receptor activator of nuclear factor-kappa B ligand (RANKL) with age, menopause, bone biochemical markers and bone mineral densities (BMDs) in pre- and postmenopausal women and to determine the contributing factors for serum OPG and RANKL. METHODS: 504 pre- and postmenopausal women aged between 20 and 75 years were enrolled in this study. BMDs at lumbar spine and proximal femur were measured with dual-energy X-ray absorption meter. The serum osteocalcin (BGP), OPG, RANKL and urinary type I collagen (NTx) were also tested. RESULTS: Age was positively related with serum OPG (r = 0.442, P < 0.001) and was negatively in association with serum RANKL (r = -0.263, P < 0.001). Postmenopausal women showed higher levels of serum OPG [(107.6 +/- 3.0) ng/L], while their serum concentrations of RANKL [(4.7 +/- 0.4) ng/L] and RANKL/OPG ratios (0.045 +/- 0.004) were significantly lower than those of premenopausal women [(72.0 +/- 1.8) ng/L, (5.8 +/- 0.3) ng/L and 0.099 +/- 0.008]. Neither serum OPG nor RANKL or RANKL/OPG was in association with BMDs at lumbar spine or proximal femur after adjustment of age, years-since-menopause (YSM) and body mass index. Serum OPG was positively related with urinary NTx/creatinine. Serum RANKL was negatively related with serum BGP. Serum OPG, RANKL and RANKL/OPG showed no differences among normal, osteopenic and osteoporotic postmenopausal women. In multiple regression analysis, YSM, age and bone markers were the independent contributors to OPG-RANKL system. CONCLUSIONS: The elevation of serum OPG along with age might be a compensatary mechanism against the accelerated bone resorption, while the decreased level of serum RANKL might be helpful for restoring the reduced bone formation in postmenopausal women. YSM, age, together with bone tune-over markers were the main factors affecting serum concentrations of OPG and RANKL.

Adult↗

[Clinical application of the combined presigmoid supra-infratentorial approach].

OBJECTIVE: To explore the surgical approach to the lesions of the cerebellopontine angle and the petroclival region. METHOD: Nine cases of the cerebellopontine angle or petroclival large tumors and one case of the posterior cerebral thrombotic aneurysm were treated by the combined presigmoid supra-infratentorial approach. The tumors including 3 cases of schwannomas and 6 cases of meningiomas spaned supra-infratentorium in our study. RESULT: Complete tumor removal were achieved in 6 cases, and subtotal tumor removal in 4 cases. After the operation, Cerebrospinal fluid leakage followed intracranial infection occurred in 1 case which losing follow-up. Headache and dizziness relieved in the other 9 cases. One case improved and 3 cases with no improvement after surgery among the 4 preoperative facial paralysis patients. Three cases with cerebellar symptoms were much relieved, but most deficits involving other cranial nerves preoperation did not recover. According to Samii's prognosis standard, 7 cases with good results and 1 case with common and 1 case with bad had been achieved. The hearing level had no influence in 5 cases, declined 20 dB HL in 2 cases, 30 dB HL in 1 case and 60 dB HL, in I case. CONCLUSION: The combined presigmoid supra-infratentorial approach is a direct route to the petroclival region and the cerebellopontine angle, provides a wide surgical field with less cerebellar or brain retraction, facilitates the removal of lesions and preserves the cranial nerves functions.

Adolescent↗

[Effect of inhaled cyclosporin A on antigen-induced airway inflammation in asthmatic rats].

AIM: To investigate the effect of inhalation of cyclosporin (CsA) on antigen-induced airway inflammation in Sprague-Dawley rats. METHODS: Rats were sensitized with antigen (ovalbumin, OA). After two weeks, the sensitized rats were pretreated with aerosol CsA (5, 10, 20 g x L(-1)), once per day for 7 days. Then, the sensitized rats were challenged with OA (10 g x L(-1), once per day) for 2 days at day 20 after sensitization. The number of eosinophils in bronchoalveolar lavage fluid (BALF) and peripheral blood, histological changes of lung tissue, and TNF-alpha content in BALF were investigated. RESULTS: Inhalation of CsA significantly reduced the number of eosinophils in BALF and peripheral blood, inflammatory infiltration and tissue edema of lung tissue, decreased the content of TNF-alpha in BALF. CONCLUSION: Inhalation of CsA inhibited airway inflammation in rats, and the mechanism is related to inhibition of TNF-alpha release.

Administration, Inhalation↗

[The role of high-resolution CT in the preoperative assessment of chronic otitis media].

OBJECTIVE: To assess the high-resolution CT scan in depicting the middle ear structures. METHOD: The surgical findings of 51 ears operated on were retrospectively compared with the CT findings. The followings were analysed: diagnostic features of chronic otitis media (COM) on CT status of the middle ear structures (ossicles, facial nerve canal, semicircular canals and tegmen tympani), and anatomical variations. RESULT: The radio-surgical agreement was excellent for the malleus (kappa statistics, k = 0.840) and tegmen (0.788), good for the incus (0.700) and semicircular canals (0.56), but poor for the stapes (0.366) and facial nerve dehiscence (0.310). Potential surgical hazards detected by the scans included: Low lying dura, high jugular bulb, anterior lying sigmoid sinus, facial nerve dehiscence and other situations brought about by the destructive nature of the lesion. CONCLUSION: There is a good radio-surgical correlation in COM for most middle ear structures except for the integrity of the facial canal and stapes. The scan alerts the surgeon the potential surgical dangers and complications of disease. High-resolution CT scan should be a routine examination prior to middle ear and mastoid surgery.

Adolescent↗