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Objective: To investigate the feasibility, safety and efficacy of transoral robotic surgery (TORS) in the treatment of lingual thyroglossal duct cyst (LTGDC). Methods: The clinical data of 10 patients with LTGDC treated with TORS in Tongji Hospital affiliated to Tongji Medical College of Huazhong University of Science and Technology from May 2017 to November 2020 were analyzed retrospectively,including 6 males and 4 females, aged 5-44 years. The cysts were fully exposed, and resection usually started from the cephalic side of lesions. The range of resection was 3 to 5 mm away from the lesions, and partial hyoid bone was removed if necessary. Intra-operative robotic set-up time,operation time and estimated blood loss,and post-operative local bleeding, dyspnea and recovery time for oral intake were analyzed. SPSS 12.0 software was used for statistical analysis. Results: The cysts in all 10 patients were successfully resected by TORS with da Vinci Si surgical system. The mean robotic set-up and exposure time, operation time, estimated intraoperative blood loss and recovery time for oral intake were (15.5±7.1) min, (17.6±7.4) min, (8.9±6.4)ml and (2.3±2.2)days, respectively. No patient required tracheostomy intra-or post-operatively, and no symptoms of airway obstruction, postoperative bleeding, pharyngeal fistula, hoarseness and neurological impairment occurred after operation. The patients were followed up for 5 to 47 months, with median follow-up time of 17 months, and no recurrence was observed. Conclusion: TORS is safe and feasible for resection of LTGDC, with rapid recovery and low recurrence rate.
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Femenino , Humanos , Masculino , Estudios Retrospectivos , Procedimientos Quirúrgicos Robotizados , Robótica , Quiste Tirogloso/cirugía , Lengua/cirugía , Resultado del TratamientoRESUMEN
To evaluate the indication, safety and effectiveness of transoral robotic surgery (TORS) for oropharyngeal cancer based on our preliminary experience. Twelve patients, including six with tonsil cancer, five with tongue base cancer and one with posterior pharyngeal wall cancer, who underwent TORS with Da Vinci Si surgical system from March 2017 to October 2018 at Tongji Hospital of Huazhong University of Science Technology were respectively analyzed. And the surgical time, intraoperative blood loss, postoperative local bleeding, dyspnea, nerve function injury, oral intake time, whether or not to receive chemoradiotherapy were analyzed. All tumors in the 12 patients were en bloc removed by TORS. Surgical time ranged from 25 to 80 min with an average of 34.2 min. The blood loss ranged from 10 ml to 50 ml with an average of 20.8 ml. The recovery time for oral intake ranged from 1 day to 30 days with an average of 8.4 days. No patient underwent tracheostomy after TORS. Also, no patient manifested with airway obstruction, bleeding or nerve injury symptoms after operation. All 12 patients reached pathologically negative surgical margins. The patients were followed up for 4 to 22 months, with a median of 12 months. All patients who combined with more advanced than T3 stage, or more advanced than N2 stage were recommended to oncologist, then, followed with radiotherapy or chemoradiotherapy if no relevant contradictions occurred. No local recurrence or distant metastasis case was found. With proper indications, the application of TORS in oropharyngeal cancer is a relatively safe, effective and minimal invasive therapy, which merits more clinical applications.
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Age-related hearing loss (AHL) is one of the most common sensory disorders among elderly persons. The inwardly rectifying potassium channel 5.1 (Kir5.1) plays a vital role in regulating cochlear K(+) circulation which is necessary for normal hearing. The distribution of Kir5.1 in C57BL/6J mice cochleae, and the relationship between the expression of Kir5.1 and the etiology of AHL were investigated. Forty C57BL/6J mice were randomly divided into four groups at 4, 12, 24 and 52 weeks of age respectively. The location of Kir5.1 was detected by immunofluorescence technique. The mRNA and protein expression of Kir5.1 was evaluated in mice cochleae using real-time polymerase-chain reactions (RT-PCR) and Western blotting respectively. Kir5.1 was detected in the type II and IV fibrocytes of the spiral ligament in the cochlear lateral wall of C57BL/6J mice. The expression levels of Kir5.1 mRNA and protein in the cochleae of aging C57BL/6J mice were down-regulated. It was suggested that the age-related decreased expression of Kir5.1 in the lateral wall of C57BL/6J mice was associated with hearing loss. Our results indicated that Kir5.1 may play an important role in the pathogenesis of AHL.
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Animales , Ratones , Envejecimiento , Genética , Metabolismo , Cationes Monovalentes , Técnica del Anticuerpo Fluorescente , Regulación de la Expresión Génica , Transporte Iónico , Ratones Endogámicos C57BL , Microtomía , Potasio , Metabolismo , Canales de Potasio de Rectificación Interna , Genética , Metabolismo , Presbiacusia , Genética , Metabolismo , ARN Mensajero , Genética , Metabolismo , Ligamento Espiral de la Cóclea , MetabolismoRESUMEN
<p><b>OBJECTIVE</b>To investigate the age related changes of the expression of programmed cell death 5 (PDCD5) and caspase 3 in the cochlea of the different age of C57BL/6J mice. The relationship of PDCD5 and caspase 3 and the possible roles in the pathogenesis of presbycusis were also discussed.</p><p><b>METHODS</b>C57 mice of 3, 6, 9 and 12 months old were selected and divided into 4 groups, with 15 mice in each group. Auditory function of C57BL/6J mice was measured by auditory brainstem response (ABR) respectively. The changes of PDCD5 and Caspase 3 protein in the cochlea were detected by immunohistochemistry and Western blotting, the changes of PDCD5 mRNA and caspase 3 mRNA were detected using RT-PCR.</p><p><b>RESULTS</b>With the increase of age, the mean value for ABR thresholds in response to click, 4 kHz and 8 kHz sound stimulus of C57 mice gradually increased, the expression of PDCD5 and caspase 3 were increased also. At 3 months and 6 months of age in the cochlea of C57, all sorts of expression of PDCD5 and caspase 3 and the expression were enhanced with age. There was an evident expression at 9 months age, but the highest expression was detected at 12 months age. The PDCD5 and Caspase 3 expression were statistically different in each group (P < 0.05). The changes of PDCD5 and caspase 3 mRNA expression were in accordance with that of PDCD5 and Caspase 3 protein expression by the real-time PCR.</p><p><b>CONCLUSIONS</b>The expression levels of PDCD5 and caspase 3 in the cochlea of C57 mice increase with age, the results suggested that the expression of PDCD5 and caspase 3 might play an important role in the pathogenic mechanism of presbycusis.</p>
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Animales , Ratones , Envejecimiento , Proteínas Reguladoras de la Apoptosis , Metabolismo , Umbral Auditivo , Caspasa 3 , Metabolismo , Cóclea , Metabolismo , Ratones Endogámicos C57BL , Proteínas de Neoplasias , Metabolismo , Presbiacusia , Metabolismo , PatologíaRESUMEN
<p><b>OBJECTIVE</b>To investigate the age-related expression of KCNQ1 and NKCC1 ion transporters in the stria vascularis in the cochlea of C57BL/6J mice, and to analyze the relationship between the two ion transporters and age-related hearing loss.</p><p><b>METHODS</b>Auditory function of C57BL/6J mice was measured by auditory brainstem response (ABR) at the ages of 4, 8, 14, 24, 40 weeks old respectively. The location of KCNQ1 and NKCC1 ion transporters in the cochlea of C57BL/6J mice was detected by immunohistochemistry staining. Reverse transcription polymerase chain reaction (RT-PCR) was used to detect the levels of KCNQ1 and NKCC1 mRNA in the cochlea of C57BL/6J mice at different ages.</p><p><b>RESULTS</b>The mean values for ABR thresholds in response to click, 4 kHz and 8 kHz sound stimulus of C57BL/6J mice gradually increased with age. The ABR thresholds of the mice of over 14 weeks age were significantly elevated in comparison with lower ages (P < 0.05). In the lateral wall of C57BL/6J mice cochlea, the KCNQ1 protein was mainly expressed at the apical membrane of the strial marginal cells. The localization of NKCC1 protein was mainly present at the basolateral membrane of the stria marginal cells, spiral ligament and the fibrocytes in the inferior portion of spiral limbus. Expression of KCNQ1 and NKCC1 protein in cochlea of C57BL/6J mice showed age-related decreasing. The level of KCNQ1 and NKCC1 mRNA in cochlea of C57BL/6J also showed a age-related decreasing trend. There was a significant reducing of KCNQ1 mRNA level between C57BL/6J mice of 40 and 4 weeks old (P < 0.05). In comparison with the C57BL/6J mice of 4 weeks old, the NKCC1 mRNA levels of 24 and 40 weeks old also showed significant reducing (P < 0.05).</p><p><b>CONCLUSIONS</b>The mean value for ABR thresholds of C57BL/6J mice gradually increased with age. Expression of KCNQ1 and NKCC1 protein in the stria vascularis of C57BL/6J mice decreases with age. The levels of KCNQ1 and NKCC1 mRNA in cochlea of C57BL/6J showed a age-related reducing trend. Regulating after post-translation may also participate in the adjusting of the age-related decreasing of KCNQ1 and NKCC1 protein in the cochlea of C57BL/6J mice. KCNQ1 and NKCC1 ion transporters may play a critical role in maintaining normal hearing function of inner ear.</p>
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Animales , Ratones , Factores de Edad , Cóclea , Metabolismo , Fisiología , Potenciales Evocados Auditivos del Tronco Encefálico , Canal de Potasio KCNQ1 , Metabolismo , Ratones Endogámicos C57BL , Simportadores de Cloruro de Sodio-Potasio , Metabolismo , Miembro 2 de la Familia de Transportadores de Soluto 12RESUMEN
<p><b>OBJECTIVE</b>To establish a preliminary foundation for developing a serum proteomics diagnostic model of nasopharyngeal carcinoma (NPC) by comparing the differences in serum protein fingerprints between patients with NPC and healthy subjects and between different types of NPC.</p><p><b>METHODS</b>The serum samples of 41 patients with different types of NPC and 20 healthy subjects were collected. Surface-enhanced laser desorption ionization time-of-flight mass spectrometry (SELDI-TOF-MS) were used to detect the blood samples to obtain serum protein mass spectrum, i.e. serum protein fingerprinting. Biomarker Wizard and Biomarker Patterns system software were used to compare the differences in serum protein mass spectrum between NPC patients and healthy subjects and between different types of NPC, and to screen out the NPC-related serum proteins.</p><p><b>RESULTS</b>Compared with the healthy control, NPC patients emerged 9 very prominent protein peaks (P < 0.001), with the combined differential peaks. No significant difference was found in relative amount of serum proteins with different molecular mass between different types of NPC (P > 0.05).</p><p><b>CONCLUSIONS</b>The serum marker proteins and specific protein fingerprints of NPC can be screened out by SELDI-TOF-MS, which could be used to develop a serum proteomics model for clinical screening and early diagnosis of NPC.</p>
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Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Biomarcadores de Tumor , Sangre , Proteínas Sanguíneas , Carcinoma , Carcinoma de Células Escamosas , Sangre , Patología , Estudios de Casos y Controles , Espectrometría de Masas , Neoplasias Nasofaríngeas , Sangre , Patología , Estadificación de Neoplasias , Mapeo Peptídico , Proyectos Piloto , Proteómica , Espectrometría de Masa por Láser de Matriz Asistida de Ionización DesorciónRESUMEN
<p><b>OBJECTIVE</b>To study the expression of plasma membrane Ca(2+)-ATPase isoform 2 (PMCA2) in spiral ganglion cell (SGC) from inner ear of newborn rats and further check PMCA2 splice variants at site A and C.</p><p><b>METHODS</b>Spiral ganglion tissues isolated from cochlea of newborn rats (P3-P4) were cultured and identified in vitro. The cochlea of newborn rats (P3-P4) were isolated and cut into frozen sections. The expression of PMCA2 was detected by immunofluorescence analyses. The SGC cultured in 4 wells of the 6-well culture plate were collected and the total RNA was extracted by Trizol and reverse transcribed to cDNA. The site A and C splice variants of PMCA2 were respectively checked by nested PCR and common PCR.</p><p><b>RESULTS</b>The SGC grew well with good refraction and showed positive immunoreactivity for neuronal marker NF-200. Strong green fluorescence could be seen in cytomembrane, cytoplasm and neuritis, as well showing SGC immunoreactivity for PMCA2 antibody. In the cochlear sections, the spiral ganglion tissues were strongly stained by PMCA2. PMCA2z was present at splice site A, but PMCA2b and PMCA2c were present at splice site C.</p><p><b>CONCLUSION</b>SGC from newborn rats strongly expresses PMCA2 and different splice variants are present at PMCA2 splice site A and C.</p>
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Animales , Femenino , Masculino , Ratas , ATPasas Transportadoras de Calcio de la Membrana Plasmática , Metabolismo , Isoformas de Proteínas , Metabolismo , Sitios de Empalme de ARN , Ratas Sprague-Dawley , Ganglio Espiral de la Cóclea , Biología Celular , MetabolismoRESUMEN
<p><b>OBJECTIVE</b>To introduce a novel retractor with magnetic fixator for mouse microsurgery.</p><p><b>METHODS</b>The retractor was consisted of a magnet, a screw, two screw nuts and a hook made of dental stainless wire. The screw was connected to the magnet with magnetic force, and then was assembled to be a so-called magnetic fixator. The hook was clamped by two screw nuts on the screw, and these makes up of the retractor finally. Comparison has been done between the novel retractor and traditional retractor in the clinical application of the otocyst exposure.</p><p><b>RESULTS</b>The retractor can quickly claw and retract massive tissue like muscles and vessels to the target position, thus, this properties would tend to offer a clear and expanded operative field. In addition, the height, orientation and strength of traction was all adjustable. By Comparison with tradition retractor, the operative incision can be shorten via the application of the retractor, also, it would reduce the trauma of muscles and vessels as well as the accidental rate of bleeding in the process of operation.</p><p><b>CONCLUSIONS</b>The retractor can offer a expanded operative field of the mouse otocyst conveniently. It could be a simple, powerful and minimal invasive tool for mouse microsurgery.</p>
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Animales , Ratones , Diseño de Equipo , Microcirugia , Instrumentos QuirúrgicosRESUMEN
<p><b>OBJECTIVE</b>To investigate the ototoxicity of co-administration of kanamycin and furosemide in mouse and establish a reliable model to induce a sensorineural hearing loss.</p><p><b>METHODS</b>CBA/J mice strain was selected, with the age around 3-4 weeks old, to be received a single subcutaneous injection of kanamycin at dose of 1 g/kg and another single intraperitoneal injection of furosemide at dose of 0.4 g/kg 30 - 45 min afterward. The auditory brainstem response (ABR) threshold shift was tested. The series of experimental methods including propidium iodide, phalloidin staining, semithin section toluidine blue staining, TUNEL, scanning electron microscopy and transmission electron microscopy were applied to observe the characteristics of the lesion of cochlea and hair cells. The time course was set as following: before injection, 12, 24, 48 hours and 1, 2, 4, 12 weeks after injections, respectively.</p><p><b>RESULTS</b>The ABR threshold shift was firstly presented a significant increase at 12 h after injection at 2, 4, 8 kHz, then the ABR threshold kept going up during next 36 h until it was presented a stable level around 90 dB. Pathological examination showed an absence of outer hair cells at basal turn rapidly since 12 h after treatment, and then by 48 h the most commonly observed lesion, where all outer hair cells throughout the length of the cochlea were killed, in the contrast, however, the inner hair cells loss were delayed and mild. TUNEL-positive nuclei demonstrated that most hair cells died via an apoptotic pathway. In scanning electron microscopy abundance of necrotic outer hair cells were detected by 24 h after treatment, in which reticular lamina were collapsed. Then all outer hair cells were replaced by expansion of heads of supporting cells. At 48 h after treatment, marginal cells presented a swollen and some of them were observed to be fused. In addition, spherical cell extrusion appeared to leak out from some marginal cells. By 2 weeks, nearly all microvillus were lost and marginal cells presented a shape of stone-like change. A significant and progressive decrease in strial vascularis thickness was found, of which the reason probably related with a reduction in volume of marginal cells.</p><p><b>CONCLUSION</b>This systemic protocol eliminates hair cells extensively in vivo, and it could be a reliable model to examine different aspects of cochlear pathology in transgenic or mutant mice strains.</p>
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Animales , Ratones , Muerte Celular , Cóclea , Patología , Modelos Animales de Enfermedad , Sinergismo Farmacológico , Potenciales Evocados Auditivos del Tronco Encefálico , Furosemida , Células Ciliadas Auditivas , Biología Celular , Patología , Kanamicina , Ratones Endogámicos CBARESUMEN
<p><b>OBJECTIVE</b>To establish a mice model of aminoglycoside antibiotics (AmAn) induced ototoxicity. Then to investigate the sensitivity of AmAn induced ototoxicity in three mouse strains and effect of kanamycin on the expression of Na-K-2Cl co-transporter-1 (NKCC1) in stria vascularis.</p><p><b>METHODS</b>C57BL/ 6J, CBA/CaJ, NKCC1 +/- mice (each of twenty-four) were randomly divided into four experimental groups A, B, C and D (A kanamycin alone, B kanamycin plus 2, 3-dihydroxybenzoate, C 2, 3-dihydroxybenzoate alone, D control group). Mice were injected with kanamycin or/and 2, 3-dihydroxybenzoate for 14 days. Auditory function was measured by auditory brainstem response (ABR) and morphology of cochlea was observed by succinate dehydrogenase staining. Expression of NKCC1 was detected by immunohistochemistry.</p><p><b>RESULTS</b>Mice in group A developed significant ABR threshold shifts (P < 0.01), which were accompanied by out hair cells loss. Mice in group B significantly attenuated ABR threshold shifts with out hair cells loss (P <0.01). The immunostaining of NKCC1 in stria vascularis was attenuated significantly in group A compared with group D (P < 0.01) while the immunostaining in group B was enhanced than which in group A (P < 0.01). CBA/CaJ mice has the highest sensitivity to AmAn in three mouse strains.</p><p><b>CONCLUSIONS</b>An mouse model of AmAn induced ototoxicity could be established by administration of kanamycin. Kanamycin could inhibit the expression of NKCC1 in stria vascularis. 2, 3-dihydroxybenzoate could attenuate AmAn induced ototoxicity maybe by enhancing the expression of NKCC1. Mice that had the characteristic of presbycusis didn't show additional sensitivity of AmAn induced ototoxicity.</p>
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Animales , Ratones , Antibacterianos , Toxicidad , Vasos Sanguíneos , Metabolismo , Cóclea , Metabolismo , Kanamicina , Toxicidad , Ratones Endogámicos C57BL , Ratones Endogámicos CBA , Parabenos , Toxicidad , Simportadores de Cloruro de Sodio-Potasio , Metabolismo , Miembro 2 de la Familia de Transportadores de Soluto 12RESUMEN
<p><b>OBJECTIVE</b>To generate transgenic mice of NKCC1 +/- (heterozygous) and NKCC1 +/+ (wild-type) that have a targeted disruption in the NKCC1 gene in order to investigate the relationship of one copy of NKCC1 gene (NKCC1 +/-) and age-related hearing loss (AHL) and to study the possible pathogenesis of AHL METHODS: Auditory function of NKCC1 +/- mice was detected regularly by auditory brain response (ABR) and endocochlear potential (EP). Morphology of cochlea was observed by scanning electron microscope and content of NKCC1 protein was detected by Western blot.</p><p><b>RESULTS</b>The mean value for ABR thresholds was elevated in NKCC1 +/- mice more than that of NKCC1 +/+ mice (P < 0.01). A progression of age-related hearing loss was found in NKCC1 +/- mice. Compared with younger NKCC1 +/- mice, the mean value for ABR thresholds in aged NKCC1 +/- mice was significantly increased (P < 0.05). The EP of NKCC1 +/- aged mice was also significantly decreased more than that of the younger NKCC1 +/+ mice (P < 0.05). And content of NKCC1 protein were reduced with the growth of the age. The scanning electron microscope showed a kind of scattered punctiform absence of outer hair cells in elder NKCC1 +/- mice cochlea.</p><p><b>CONCLUSIONS</b>NKCC1 gene maybe takes part in the pathogenesis of AHL. Mice that expressed only one copy of NKCC1 could lead to AHL. AHL may be correlative with the amounts of NKCC1 protein and its function and also with the loss of outer hair cells perhaps.</p>
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Animales , Ratones , Factores de Edad , Envejecimiento , Genética , Fisiología , Trastornos de la Audición , Genética , Heterocigoto , Ratones Noqueados , Ratones Transgénicos , Simportadores de Cloruro de Sodio-Potasio , Genética , Miembro 2 de la Familia de Transportadores de Soluto 12RESUMEN
<p><b>OBJECTIVE</b>To investigate the auditory function and the role of NKCC1 and alpha2 Na, K-ATPase in the potassium recycling of cochlea.</p><p><b>METHODS</b>NKCC1(+/-) / alpha2 Na, K-ATPase(+/-) mice model was established from NKCC1(+/-) and alpha2 Na, K-ATPase(+/-) mice. The auditory function of all strain mice were detected by auditory brainstem response (ABR) and endocochlear potential (EP) to investigate the role of NKCC1 and alpha2 Na, K-ATPase in the potassium recycling of cochlea. Furosemide and ouabain were applied to block the two channels in Castel mice line which can long-time maintain normal auditory function and then their auditory function was detected by ABR to authenticate the mode of potassium recycling in vivo and the relationship between cochlear potassium recycling and NKCC1(+/-) and alpha2 Na, K-ATPase.</p><p><b>RESULTS</b>The mean value for ABR thresholds in response to stimulus was elevated in NKCC1(+/-) and alpha2 Na, K-ATPase (+/-) mice [(38.49 +/- 12.29) dB and (53.32 +/- 7.62) dB) ] respectively, which was significantly increased compared with that observed in wild type mice [(23.13 +/- 3.78) dB, P < 0.05) ]; The EP value of NKCC1(+/-) [(78 +/- 7) mV] and alpha2 Na, K-ATPase(+/-) mice [(71 +/- 14) mV] was decreased compared with that of NKCC1(+/-) / alpha2 Na, K-ATPase(+/-) mice [( 86 +/- 11) mV]. The auditory function of NKCC1(+/-) / alpha2 Na, K-ATPase(+/-) mice could simulate the model of cochlear potassium recycling well. NKCC1 and Na, K-ATPase were great of importance in the potassium recycling, while the two ion channels were in restrict dynamic equilibrium. Castel mice line after administration with furosemide developed significant ABR threshold shifts (P < 0.05) compared with control group. Castel mice line after administration with ouabain also developed greatly significant ABR threshold shifts (P < 0.05) compared with control group. ABR threshold shifts in mice after administration both furosemide and ouabain was attenuated compared with only administration with furosemide (P < 0.01).</p><p><b>CONCLUSIONS</b>Ion channel NKCC1 and alpha2 Na, K-ATPase played important roles in the inner ear potassium recycling. Dysfunction of either of them could influence potassium concentration in the endolymph and lead to hearing loss subsequently. The role of NKCC1 and alpha2 Na, K-ATPase in cochlear potassium recycling was authenticated in vivo. The two ion channels contribute the key role for dynamic equilibrium in cochlear potassium recycling and are of great importance for the metabolism of potassium in the inner ear to maintain the normal auditory function.</p>
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Animales , Ratones , Umbral Auditivo , Cóclea , Metabolismo , Fisiología , Potenciales Evocados Auditivos del Tronco Encefálico , Genotipo , Ratones Noqueados , Potasio , Metabolismo , Simportadores de Cloruro de Sodio-Potasio , Metabolismo , ATPasa Intercambiadora de Sodio-Potasio , Metabolismo , Miembro 2 de la Familia de Transportadores de Soluto 12RESUMEN
<p><b>BACKGROUND</b>After establishing a murine model of aminoglycoside antibiotic (AmAn) induced ototoxicity, the sensitivity of AmAn induced ototoxicity in three murine strains and the effect of kanamycin on the expression of Na-K-2Cl cotransporter-1 (NKCC1) in stria vascularis were investigated.</p><p><b>METHODS</b>C57BL/6J, CBA/CaJ, NKCC1(+/-) mice (24 of each strain) were randomly divided into four experimental groups: A: kanamycin alone; B: kanamycin plus 2, 3-dihydroxybenzoate; C: 2, 3-dihydroxybenzoate alone; and D: control group. Mice were injected with kanamycin or/and 2, 3-dihydroxybenzoate twice daily for 14 days. Auditory brainstem response (ABR) was measured and morphology of cochlea delineated with succinate dehydrogenase staining. Expression of NKCC1 in stria vascularis was detected immunohistochemically.</p><p><b>RESULTS</b>All three strains in groups A and B developed significant ABR threshold shifts (P < 0.01), which were accompanied by outer hair cell loss. NKCC1 expression in stria vascularis was the weakest in group A (A cf D, P < 0.01) and the strongest in groups C and D (P < 0.05). CBA/CaJ mice had the highest sensitivity to AmAn.</p><p><b>CONCLUSIONS</b>Administration of kanamycin established AmAn induced ototoxicity. Kanamycin inhibited the expression of NKCC1 in stria vascularis. 2, 3-dihydroxybenzoate attenuated AmAn induced ototoxicity-possibly by enhancing the expression of NKCC1. Age related hearing loss did not show additional sensitivity to AmAn induced ototoxicity in murine model.</p>