Expression of artemin and GFRα3 in an animal model of migraine: possible role in the pathogenesis of this disorder.

BACKGROUND: Neurotrophic factors have been implicated in hyperalgesia and peripheral levels of these molecules are altered in migraine pathophysiology. Artemin, a vasculature-derived neurotrophic factor, contributes to pain modulation and trigeminal primary afferent sensitization through binding its selective receptor GFRα3. The distribution of artemin and GFRα3 in the dura mater raises an anatomy supports that they may be involved in migraine. In this study we evaluated the expression of artemin and GFRα3 in an animal migraine model that may be relevant for migraine. METHODS: In this study, using a rat migraine model by administration of nitroglycerin (NTG), we investigated the expression of artemin in the dura mater and GFRα3 in the trigeminal ganglia (TG) by means of quantitative reverse transcription-polymerase chain reaction, western blot and immunofluorescence labeling. RESULTS: Artemin immunoreactivity was found in the smooth muscle cells of dural vasculature and GFRα3 was present in cytoplasm of TG neurons. The mRNA levels of artemin and GFRα3 were significantly elevated after NTG treatment at 2 and 4 h respectively (P < 0.05). The expression of artemin protein was increased at 4 h and continually up to 8 h in the dura mater following NTG administration (P < 0.05). The expression of GFRα3 protein was elevated at 4 h and continually up to 10 h in the TG following NTG administration (P < 0.05). CONCLUSION: The findings suggest that artemin and GFRα3 play an important role in the pathogenesis of migraine and may represent potential therapeutic targets for the treatment of migraine.

[Visualization of endolymphatic hydrops in 3D-FLAIR MRI after intratympanic Gd-DTPA administration in Meniere's disease patients].

OBJECTIVE: To study the feasibility of endolymphatic visualization and the diagnosis of Meniere's disease by applying intratympanic gadolinium administration through the tympanic membrance and three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging (3D-FLAIR MRI). To study the relationship between the endolymphatic hydrops visualized by MRI and audio-vestibular functional tests, such as pure tone audiometry (PTA), electrocochleography (EcoG), caloric test and vestibular evoked myogenic potential (VEMP). METHODS: With a three Tesla magnetic resonance imaging (MRI) unit, 3D-FLAIR imaging was performed 24 hours after intratympanic gadolinium through the tympanic membrance in 32 patients with clinically diagnosed unilateral Meniere's Disease. We visualized the enhanced imaging of perilymphatic space in bilateral cochlea, vestibular and (or) canal, scoring scala tympani and scala vestibule of bilateral cochlear basal turn respectively and measuring the developing area of bilateral vestibule and the signal intensity ratio (SIR) between the vestibule and the brain stem subjectively. PTA, EcoG, caloric test and VEMP were performed. The relationship between the endolymphatic hydrops visualized by MRI and audio-vestibular functional tests were studied. RESULTS: The gadolinium appeared in almost all parts of the perilymph in cochlea, vestibular and (or) canals in all 32 patients' inner ears, so the endolymphatic space was clearly shown on 3D-FLAIR imaging. The scala vestibuli score value between the affected side and the healthy side were statistically significant (Z = 4.309, P < 0.05) . The developing vestibular area between the affected side and the healthy side [(6.04 ± 2.89) mm(2), (8.28 ± 3.04)mm(2)] were statistically significant (t = 3.322, P < 0.05) . Abnormal vestibular evoked myogenic potentials were significantly correlated with the developing vestibular area of the affected side (F = 11.96, P < 0.05) . Abnormal electrocochleography were significantly correlated with scala vestibuli score value of cochlear basal turn in the affected side (Z = 3.17, P < 0.05) . No significant correlation was found between the scala vestibuli score value or the developing vestibular area and caloric test or PTA findings. CONCLUSIONS: 3D-FLAIR MRI with intratympanic gadolinium injection through the tympanic membrance can discriminate the border between the perilymph and the endolymph and show endolymphatic hydrops. This method may provide radiographic reference for the diagnosis of Meniere's disease. The results of VEMP and electrocochleography might have appropriate correlation with degree of vestibular and cochlear hydrops.

[Short-term efficacy of semicircular canal occlusion in the treatment of intractable Meniere's disease].

OBJECTIVE: To investigate the short-term efficacy and safety of triple semicircular canal occlusion (TSCO) in the treatment of intractable Meniere's disease (MD), so as to provide an alternative surgical procedure for treating MD. METHODS: Seventeen patients, who had received standardized conservative treatment for at least one year with poor effect, underwent TSCO were retrospectively analyzed. Vertigo control and auditory function were evaluated. Pure tone audiometry, caloric test, and vestibular evoked myogenic potential (VEMP) were performed for evaluation of audiological and vestibular function. Postoperative follow-up period was 6 - 13 months, with an average of ten months. RESULTS: According to the preoperative staging of hearing, among the 17 patients, there were 2 cases in stage II (with an average hearing threshold of 25 - 40 dBHL) and 15 in stage III (41 - 70 dBHL). No vertigo was found during the follow-up period, with 100% control rate of vertigo. During the same period, we had performed endolymphatic sac decompression operation in 25 MD patients. The control rate of vertigo was 72.0%. The vertigo control rate of TSCO was significantly higher than that of endolymphatic sac decompression operation (χ(2) = 3.87, P < 0.05). Three months after surgery, 12 patients showed no significant change in comparison to primary status, 5 patients presented with an mild increase in the average hearing threshold of less than 20 dBHL, with 29.4% of hearing loss rate. Post-operatively, all patients suffered from temporary vertigo and balance disorders. Vertigo was disappeared in all patients within 3 days, while, balance disorders were disappeared in 10 patients within 1 - 2 weeks after surgery, and in another 7 patients within 2 months, with an average recovery time of 12.6 days. Three months after treatment, loss of semicircular canal function by caloric test was found in the operation side of all patients and no change in VEMP test was noted. All patients had no facial paralysis, cerebrospinal fluid leakage, and other complications. CONCLUSIONS: TSCO, which can reduce vertiginous symptoms in patients with intractable MD, represents an effective and safe therapy for this disorder. TSCO is expected to be used as an alternative procedure for the treatment of MD in selected patients suffering from moderate to severe hearing loss.

[Clinical value of dynamic posturography in the evaluation and rehabilitation of vestibular function of patients with benign paroxysmal positional vertigo].

OBJECTIVE: To explore the clinical value of dynamic posturography in the evaluation and rehabilitation of vestibular function of patients with benign paroxysmal positional vertigo (BPPV). METHODS: A total of 48 patients with BPPV of posterior semicircular canal in vertigo clinic of our hospital from May 2007 to December 2008 were retrospectively analyzed in this study. All patients underwent the inspection of caloric test, static posturography, and dynamic posturography. The vestibular tests were performed at two different time points: at onset when patients had typical nystagmus provoked by the Dix-Hallpike maneuver before treatment with the Epley maneuver (canalith repositioning maneuver, CRM), and at one week after treatment with CRM as their nystagmus disappeared. And results at theses two time points were compared. Eight patients whose dynamic balances were still abnormal after CRM accepted vestibular rehabilitation exercise using dynamic posturography, and re-examined 3 weeks later with dynamic posturography. RESULTS: Among 48 cases of BPPV, the abnormal rates of caloric test, static posturography, and dynamic posturography before CRM were 25.0%, 33.3% and 70.8%, respectively. The abnormal rate of dynamic posturography was much higher than that of caloric test or static posturography, and the differences were statistically significant (χ² = 4.84, 7.88; P < 0.05). After CRM, the abnormal rates of caloric test, static posturography, and dynamic posturography were 14.6%, 8.3% and 16.7%, respectively. After CRM, the abnormal rate of static and dynamic posturography showed significant reduction (χ² = 24.04, 10.08; P < 0.05), however, the results of caloric test showed no significant change (χ² = 3.20, P > 0.05). Eight patients whose dynamic balances were still abnormal after CRM, accepted vestibular rehabilitation exercise lasting 3 weeks using dynamic posturography. The dynamic balances were all improved to normal after vestibular rehabilitation. CONCLUSIONS: Dynamic posturography can quantitatively analyze postural balance, and is helpful in comprehensive evaluation of the vestibular function of BPPV patients. Impaired balance often presents in patients with BPPV. Treatment of BPPV using the canalith repositioning maneuver results in improved postural stability in static and dynamic posturography. However, not all patients have normal dynamic stability after successful CRM. The vestibular rehabilitation exercise using dynamic posturography is a helpful adjunct to the treatment for these patients.

[Revision surgery of the posterior fossa cranial nerves disease].

OBJECTIVE: To report the clinical manifestations and the revision surgery principles of recurrent diseases of the posterior fossa nerves after primary surgery. METHODS: Between 2000 to 2007, fourteen patients with recurrent diseases of the posterior fossa nerves in Shandong provincial hospital were recruited in this study, all of whom were subjected to revision surgery. The clinical manifestations and surgical findings were retrospectively reviewed. RESULTS: Of the five patients with recurrent trigeminal neuralgia primarily, two underwent microvascular decompression (MVD); the remaining three firstly received the II and III branches partial sensory rhizotomy and, subsequently, the pain reoccurred in the I branch distribution area. The remnant sensor fibre was resected in the reoperation by which the sufferings were controlled completely in four of these patients during 2 to 11 years of follow-up. In five patients with hemifacial spasm underwent re-exploration, there appeared obvious fibrosis, conglutination, and the formation of new vessels around the facial nerve, with which the result of reoperation for this disorder was unsatisfied. In four glossopharyngeal neuralgia patients, reanastomosis of the glossopharyngeal nerve were found in two patients, adhesion between the glossopharyngeal nerve and the vagus nerve was found in one patient, but occurred in none of the another one. In the revision surgery, the regeneration of nerve fibre and two adjacent branches of vagus nerve fibre were resected, with no occurrence during 2 to 5 years of follow-up. The pathological changes found in revision were severe adhesion between cerebellum, meninges, terylene slim and structures around. Also, the formation of new vessels, cerebellum malacia, and bleeding could be found in the procedures. CONCLUSIONS: The cause of recurrent of trigeminal neuralgia and hemifacial spasm are unclear. Recurrent glossopharyngeal neuralgia may attribute to the nerve fibers reanastomosis, adhesion or the communicating branches with vagus nerve. With respect to the treatment of the recurrence of trigeminal neuralgia, glossopharyngeal neuralgia after primary surgery, the effectiveness of nerve fibre resection is definite, whereas, the result of revision surgery for hemifacial spasm is poor.

[Surgical management of jugular foramen tumors].

OBJECTIVE: To report the clinical manifestations, imaging characteristics, surgical approaches, managements, and outcome of jugular foramen tumors. The detailed clinical information of this extremely rare tumor was presented, with special emphasis on certain key issues, e. g, the preoperative estimation, perioperative management, surgical skill and experience, which exerted an influence on the significance of total tumor resection and preventing complications. METHODS: From 1985 to 2007, 42 patients with jugular foramen tumor (30 cases of jugular paragangliomas and 11 cases of tumor with particular pathological types) were enrolled in this study. Prior to surgical procedures, all patients were subjected to systematic imaging examinations on temporal bone, such as CT, HRCT, CTA, and MRI, and some patients were further examined by angiography or embolization according to the individual situations. The infratemporal type A and combined translabrinthin and/or transchecholea approaches were selected for the treatment of 30 cases of jugular paragangliomas; while, the modalities of infratemporal type A, enlarged mastoidectomy, or mastoid-neck approach were employed for the remaining 11 specific cases. RESULTS: Forty-two patients in this report were categorized into beyond C types based on FISCH classification in which all had invaded to posterior fossa. In the 31 cases, the major initial clinical symptoms were tinnitus, hearing loss, and facial palsy; while, in the 11 specific cases, the main symptoms did not possess any unique trait for the diagnosis and 5 of which were found via CT or MRI examination by chance. Facial nerve management included permanent anterior transposition (19 cases), facial nerve bridge technology (16 cases), interposition graft (4 cases), VII-XI jump graft (2 cases), and VII-XII anastomosis (1 case). CONCLUSIONS: The preoperative estimation of tumor in nature was of great importance in the determination of proper surgical approaches and the infratemporal type A could fully meet the requirement for resection of tumors in jugular foramen. Facial nerve anterior rerouting could provide a clear visual field during the procedure, especially for the lesions in anterior tympanic cavity. In most cases, the facial nerve bridge technology could also fulfill the needs for complete tumor resection as well as the better preservation of facial function. In case of considering the sacrifice of internal carotid artery, balloon test occlusion was indispensable for preoperative estimation. The CT or MRI characteristics of tumors with particular pathological types were different from those of jugular paragangliomas. The preoperative management, surgical skills, and experience played a pivotal role in complete tumor resection.

[Sensitivity to the ototoxicity of kanamycin of the rat model for mimetic aging in the inner ear].

OBJECTIVE: To research the animal model with mimetic aging effect in the inner ear predispose to the ototoxicity of kanamycin. METHODS: Fifty wistar rats were randomly divided into four groups: group A (D-galactose group, n = 14) were treated with hypodermic 5% D-galactose (150 mg x kg(-1) x d(-1)) for 8 weeks and then with intraperitoneal saline for 10 days; group B (D-galactose and kanamycin group, n = 14) were given the same dose of D-galactose but kanamycin (500 mg x kg(-1) x d(-1)) instead of saline; group C (kanamycin group, n = 12) were treated with saline for 8 weeks and then with intraperitoneal kanamycin for 10 days;group D (control group, n = 10) were given saline only. Auditory brainstem response (ABR) was used to detect the hearing threshold of rats and colorimetry was used to analyze the activity of the GSH-PX. The inner ear tissue was harvested and the mitochondrial DNA was amplified to identify the 4834 bp deletion mutation by nested primer polymerase chain reaction (nested PCR) technique. RESULTS: The incidence of mitochondrial DNA 4834 bp deletion mutation was 100% (28/28) in group A, 92.86% (26/28) in group B and 0% in group C or group D. The activity of GSHPX in group A was (59.07 +/- 8.70)U, (63.29 +/- 12. 40)U in group B, (136.67 +/- 9.53)U in group C and (142.10 +/- 7.02)U in group D. The difference between group A and D was significant (P = 0.000) while the difference between group A and B was not significant (P = 0.307), which was similarly as between group C and group D (P = 0.151). ABR threshold was (5.36 +/- 3.08) dB peSPL in group A, (61.79 +/- 11.20) dB peSPL in group B, (34.17 +/- 4.69) dB peSPL in group C and (6.50 +/- 3.37) dB peSPL in group D. No difference was found between group A and D (P = 0.398) while the difference in shift of ABR threshold between group B and group C (or group D) was significant (P = 0.000). CONCLUSIONS: The mimetic aging effect in the inner ear of the rat can be induced by D-galactose, and these rats present high incidence of mtDNA4834 deletion which can greatly enhance the sensitivity of the inner ear to the kanamycin.

[Prevention of facial nerve paralysis induced by herpes simplex virus type 1 (HSV-1) in mouse and establishment of a relapse model induced by reactivation of latent HSV-1].

OBJECTIVE: To establish an animal model of Bell's palsy induced by the reactivation of latent herpes simplex virus type 1 (HSV-1), and observe the effect of interferon and IgG on the facial nerve paralysis induced by HSV-1 infection. METHODS Totally 64 four-week-old female Balb/c mice weighted 16-18 gram were selected. Using scratching the surface of bilateral auricles by a 26-gauge needle, 25 microl HSV-1 with a titer of 6.7 x 10(8) PFU/ml was inoculated into the left auricle and the same volume of PBS was placed in the right in order to develop a mouse model of latent HSV-1. In this study, interferon and IgG administration were performed before and after facial nerve paralysis and continued for 3 days. Controls were given normal sodium instead of interferon and IgG, and the incidence and duration of facial nerve paralysis were compared in the groups interferon and IgG and control. Ciclosporin was given to the mice eight weeks after recovery from facial nerve paralysis caused by inoculation with HSV-1. The HSV-1 DNA in bilateral facial nerve and bilateral trigeminal ganglion after the treatment were examined with polymerase chain reaction (PCR) analysis. RESULTS There were 10 mice of facial nerve paralysis in the first group. The incidence of facial nerve paralysis was 50% and the duration of facial nerve paralysis was (7.2 +/- 2.2) days. There were 6 mice of facial nerve paralysis in the second group. The incidence of facial nerve paralysis was 30% and the duration of facial nerve paralysis was (4.5 +/- 1.8) days. There were 16 mice of facial nerve paralysis in the control group. The incidence of facial nerve paralysis was 67% and the duration of facial nerve paralysis was (8.9 +/-2.6) days. IgG didn't reduce the incidence and duration of facial nerve paralysis by statistics analysis (P > 0.05), but interferon reduced the incidence and duration of facial nerve paralysis (P < 0.05). After administration of ciclosporin, 3/28 of mice developed facial nerve paralysis. The HSV-1 DNA was detected from facial nerve of all the mice of facial palsy. No facial palsy was observed in mice in which no HSV-1 DNA was detected from facial nerve. CONCLUSIONS: Facial nerve paralysis might be caused by reactivation of latent HSV-1, and the reactivation might be related with immunosuppression. Administration of interferon reduces the incidence and duration of facial nerve paralysis. Administration of IgG can't reduced the incidence and duration of facial nerve paralysis.

Comparison of three methods for isolation of nucleic acids from membranate inner ear tissue of rats.

BACKGROUND: Mitochondrial DNA mutations have been found in sensorineural deafness. The aim of this study was to compare three methods for extraction of nucleic acid from membranate inner ear tissue of rats. METHODS: Alkaline denaturation, a conventional phenol-chloroform method and Trizol reagent were respectively used to extract the slight nucleic acid from membranate inner ear tissue of rats. We assessed the amount and quality of nucleic acid using a UV-spectrometer and polymerase chain reaction (PCR). RESULTS: The yield and purity (OD260/OD280) of DNA from inner ear tissue using the phenol-chloroform method was the highest of the three methods. Mitochondrial DNA (mtDNA) fragment can be amplified by PCR from nucleic acid prepared by all methods, while no nuclear DNA (nDNA) fragment can be amplified by method of alkaline denaturation. Both nuclear and mitochondrial genes could be amplified by reverse transcriptional PCR from the RNA prepared by Trizol reagent. CONCLUSION: Adequate amount and high-quality of mtDNA, nDNA and RNA were obtained from unilateral membranate inner ear tissue of rats. Method of alkaline denaturation could be chosen when mtDNA without nDNA was needed, while phenol-chloroform method was suitable for extracting total DNA (including nDNA and mtDNA); method with Trizol reagent was suitable for extracting total RNA and total DNA.

The relation between D-galactose injection and mitochondrial DNA 4834 bp deletion mutation.

Since,D-galactose (D-gal) overload model has been used as a premature aging model, we hypothesized that it may also lead to accelerated aging in the inner ear. Furthermore, though the mitochondrial DNA (mtDNA) 4834 bp deletion mutation has been considered as the marker of aging, there is no information available in the literature concerning the mtDNA 4834 bp deletion mutation condition of the D-gal induced premature aging model. We investigate the changes in inner ear enzymatic activity, the occurring of mtDNA 4834 bp deletion in inner ear and other tissues and the relating hearing thresholds after the administration of high dosage (150 mg/kg per day) and low dosage (50 mg/kg per day) of D-gal to rats. Furthermore, the incidence of the mtDNA 4834 bp deletion in different tissues as well as in blood sample was compared. The results showed that daily subcutaneous injections of D-gal into rats for 8 weeks could lead to the biochemical defects and mtDNA 4834 bp deletion in the inner ear tissue and other tissues, which represent the typical aging animals, but the relating hearing threshold shifts (TS) were nearly identical in the three groups. This study also indicates that using of blood samples to detect mtDNA 4834 bp deletion in clinical research might lead to a 'false negative' result. A higher sensitive result could be gained using tissue biopsy to examine mtDNA 4834 bp deletion.

The effect of the mtDNA4834 deletion on hearing.

Mutations in mitochondrial DNA (mtDNA) are associated with diverse pathological states in humans, notably sensorineural deafness. In humans, mtDNA4977 deletion, known as common deletion, is thought to play a critical role in presbyacusis. A similar mtDNA deletion occurs in the naturally aging rats is mtDNA4834 deletion. Today, it is still obscure about the effect of common mtDNA deletion on the presbyacusis and hearing loss. We establish a model of rat associated with mtDNA4834 deletion in inner ear by d-galactose. It was found that the malondialdehyde (MDA) increased with superoxide dismutase (SOD) decreasing in the inner ear of the rat treated with d-galactose than of the control. However, there was no significant difference in elevation of ABR threshold between the rat with mtDNA4834 deletion induced by d-galactose and control. After aminoglycoside antibiotic injected, the hearing threshold of the rats carrying mtDNA4834 deletion increased significantly compared with the rats without mtDNA4834 deletion. The results show that resembled accelerated aging in the inner ear of the rat could be induced by injecting d-galactose. Moreover, those suggest that mtDNA4834 deletion can not directly induce the hearing loss, but acting as a predisposing factor which can greatly enhance the sensitivity of the inner ear to the aminoglycoside antibiotic.

[Inhibitory effect of 5-Aza-2'-deoxycytidine on human nasopharyngeal carcinoma xenograft in nude mice].

BACKGROUND & OBJECTIVE: 5-Aza-2'-deoxycytidine (5-Aza-CdR) is an inhibitor of DNA methyltransferase; it may reactivate methylated antioncogene, therefore, inhibit the growth of cancer cells. This study was to observe the inhibitory effect of 5-Aza-CdR on the growth of human nasopharyngeal carcinoma (NPC) cells and xenografts in nude mice, explore the possible mechanisms, and search for new treatment target of NPC. METHODS: NPC cell line CNE cells were treated with 5-Aza-CdR; the methylation status of death-associated protein kinase (DAPK) gene was evaluated by methylation-specific polymerase chain reaction (PCR). The model of human NPC xenograft in nude mice was constructed and treated with 5-Aza-CdR; the xenograft growth in nude mice was observed, and the mRNA and protein expression of DAPK was detected by reverse transcription-PCR (RT-PCR) and immunohistochemistry. RESULTS: No expression of DAPK mRNA was found in CNE cells and the xenografts in nude mice without treatment of 5-Aza-CdR. After treatment, the expression of DAPK mRNA in CNE cells and the xenografts was increased along with the increasing concentration of 5-Aza-CdR; the growth of CNE cells and the xenografts in nude mice were obviously inhibited, and the methylated DAPK gene was reactivated. Four weeks after treatment, no significant difference was found in body weight of nude mice between 5-Aza-CdR group and control group [(22.35+/-2.02) g vs. (21.68+/-2.14) g, t=0.011, P>0.05]; the volume of xenografts was significantly smaller in 5-Aza-CdR group than in control group [(195.32+/-27.57) mm(3) vs. (343.67+/-23.08) mm(3), t=10.11, P<0.01]. CONCLUSION: 5-Aza-CdR may reactivate antioncogene silenced by de novo methylation, therefore, inhibit the growth of CNE cells in vivo and in vitro.

[SiRNA expression cassettes targeting VEGF effectively inhibit the growth of laryngeal squamous cell carcinoma cell lines].

OBJECTIVE: To study the effects of siRNA expression cassettes (SECs) targeting VEGF in vitro on cultured Hep-2 cells, the observation of the expression of VEGF, the screening of the best interference sequences, and the exploration of the application of RNA interference on tumor gene therapy in the future. METHODS: On the basis of the principle of target sequence of siRNA, four interference sequences of VEGF were designed, and the downstream gene-specific primers of the SECs were synthesized. The RNAi transcription kit used U6 RNA-based polymerase III promoter and modified terminator for high level, precise siRNA expression inside target cells. The Hep-2 cells was transfected in growth period of index with the PCR products of the four sites separately, and began to observe and measure the results of RNA interference in 48 hours. RESULTS: The transfected 1366-site cells created, turned into the round shape and began to shed off, whereas morphology of the cells of other groups had not obviously changed. Performing the agarose gels electrophoresis with RT-PCR products, compared with the contrast groups, some cells VEGF mRNA of 1366-site were suppressed obviously, the ratio of OD was 0. 05 while the expression of VEGF of the cell of other groups had not obviously changed. Western blot revealed that VEGF expression was decreased obviously post transfection using 1366-site SECs. Flow cytometry showed that apoptosis rate of 1366-site transfected cells is 43%, and apoptosis rate of the rest three site transfected cells scarcely changed. Similar results were obtained in three independent experiments. CONCLUSIONS: The study suggested that siRNA expression cassettes (SECs) targeting VEGF 1366-site can effectively inhibit the growth laryngeal squamous cell carcinoma cell lines (Hep-2).

[Mutation of mitochondrial DNA 4977 bp deletion in laryngeal squamous cell cancer].

BACKGROUND & OBJECTIVE: The 4977 bp deletion of mitochondrial DNA is a molecular marker of cell ageing, and some solid tumors. This study was to detect deletion of mitochondrial DNA 4977 bp in laryngeal squamous cell cancer, and explore its correlation with differentiation of laryngeal cancer tissues. METHODS: Thirty-five specimens were collected from patients with pathologically diagnosed laryngeal squamous cell cancer. The total DNA was amplified to identify the 4977 bp deletion of mitochondrial DNA by polymerase chain reaction (PCR), and PCR products were verified by direct sequencing. RESULTS: The 4977 bp deletion detected in 20 of 35 cancer tissues (57.14%), including 5 of 7 with well differentiation, 15 of 24 with moderate differentiation, and 0 of 4 with poor differentiation. Mutation incidence of cancer tissues with well or moderate differentiation were significantly higher than that of cancer tissues with poor differentiation, but there was no significant difference between cancer tissues with well and moderate differentiation. CONCLUSION: The 4977 bp deletion of mitochondrial DNA was detected in laryngeal squamous cell cancer tissues, it might be relates to differentiation of cancer tissues.

[Protective roles of vitamin E and coenzyme Q10 in the inner ear mitochondrial DNA 4834 bp deletion mutation of rats].

OBJECTIVE: To explore the protective roles of vitamin E and coenzyme Q10 in the inner ear mitochondrial DNA 4834 bp deletion mutation of rats. METHODS: Forty-six Wistar rats were randomly divided into three groups. The rats of group A (18 rats) had admitted adriamycin 1 mg/kg by intraperitoneal injection twice a week and had taken vitamin E 50 mg/kg, coenzyme Q10 10 mg/kg orally everyday for three months. Group B (18 rats) was given the same dose of adriamycin as group A and saline instead of vitamin E and coenzyme Q10. Group C (10 rats) was given Saline only. The inner ear tissue was harvested and mitochondrial DNA was amplified to identify t he 4834 bp deletion mutation by nested-primer polymerase chain reaction (nested-PCR) technique. And the serum glutathione peroxidase (GSH-PX) activity was measured. RESULTS: The incidence of mitochondrial DNA 4834 bp deletion mutation of group A was 23.08% (3/13), group B was 68.75% (11/16), and group C was 0 (0/8). The mutation incidence of group A was significantly lower than group B (Fisher's exact test, 1-sided, P = 0.018) and there was no significant difference between group A and group C (Fisher's exact test, 1-sided, P = 0.215). The activity of serum glutathione peroxidase of group A was marked higher than that of group B (adjusted t' test, 1-sided, t' = 6.474, P < 0.01). And the difference of activity of serum glutathione peroxidase between group A and group C was not significantly (adjusted t' test, 2-sided, t' = 1.920, P > 0.05). CONCLUSION: The results suggested that vitamin E and coenzyme Q10 could improve the ability of free radicals cleaning and protect the mitochondrial DNA from 4834 bp deletion mutation.