Elderly patients with maxillofacial trauma: study of mandibular condyle fractures.

BACKGROUND/AIM: The aim of this study was to investigate the trends and characteristic features of mandibular condyle fractures in elderly patients in terms of etiology, patterns, and treatment modalities. PATIENTS AND METHODS: Records of 201 patients aged 65 years and older, who were treated for maxillofacial fractures at the Department of Oral and Maxillofacial Surgery, Kyushu Dental University, and Tohoku University from January 2002 to December 2013, were retrospectively analyzed. Patient records and radiographs were examined, with the following information: relevant medical history, cause of fracture, the presence and state of premolars and molars in the maxilla and mandible, number and location of mandible fracture, and method of treatment. As for the state of premolars and molars, premolars or molars in the mandible in contact with the maxilla were regarded as contacted. RESULTS: A fall was responsible for the majority of the fractures (173/201). With condyle fractures, there was a significant difference between the contacted and non-contacted group in regard to incidence. Furthermore, there was a significantly greater number of cases with symphysis and condyle combination fractures in the non-contacted group (70.9%) than in the contacted group (51.9%). As for the method of treatment, arthrocentesis was the most commonly employed. CONCLUSIONS: The present findings suggest that contacted molars in the maxilla and mandible have an influence on condyle fractures in elderly individuals.

[A case report: multiple air embolism after the laryngopharyngoesophagectomy occurred by the cervical infection from postoperative fistula].

Systemic air embolism, a very rare clinical condition, has many causes. We report a case of multiple air embolisms following laryngopharyngoesophagectomy salvage surgery for hypopharyngeal residual cancer after concurrent chemoradiotherapy. Cervical infection arose from a fistula caused by postoperative suture failure in which the 56-year-old man suddenly lost consciousness and went into shock. A few days post operation, an air embolism happened and caused in the brain, pulmonary, myocardiac and cerebral infarction. The man died two months after initial occurrence. We suspect that air entered through the ruptured left internal jugular vein via infection due to aspiration at the injury site. Air embolisms are associated with different medical maneuvers, and it is necessary to recognize that they may become a serious perioperative complication.

Gene transfer into guinea pig cochlea using adeno-associated virus vectors.

BACKGROUND: Several genes are candidates for treating inner ear diseases. For clinical applications, minimally invasive approaches to the inner ear are desirable along with minimal side-effects. METHODS: Adeno-associated virus (AAV) was used as a vector into the guinea pig inner ear. Six AAV-cytomegalovirus hybrids (AAV-2/1, -2/2, -2/5, -2/7, -2/8 and -2/9) were infused into perilymph of the cochlea basal turn, an approach that could be used in cochlear implant surgery. At 7 days after injection, distribution of gene expression, hearing and morphology were evaluated. Adenoviral vector was also used to compare distributions of gene expression. Moreover, distribution of cell surface receptors of AAV in the cochlea was examined using immunohistochemistry. RESULTS: Using the perilymphatic approach, adenovirus could be transferred to mesothelial cells lining the perilymph, but not sensory cells. Conversely, all AAV serotypes displayed tissue tropism to inner hair cells, with AAV-2/2 showing particularly efficient transfer to sensory cells. This tissue tropism of AAV could not be explained by the distribution of AAV receptors. Hearing and morphology were largely unaffected. CONCLUSIONS: Our results indicate that AAV vector can be safely applied to the inner ear and AAV-2/2 offers a good tool for transferring transgenes into sensory cells of the inner ear efficiently without toxicity.

Long-term maintenance of donor-derived hematopoiesis by intra-bone marrow-bone marrow transplantation.

The long-term maintenance of hematopoietic stem cells (HSCs) is assessed by serial bone marrow transplantation (BMT), in which HSCs are injected intravenously. Recently, we have found that intra-bone marrow (IBM)-BMT can efficiently reconstitute the hematopoietic system with cells of donor origin, in contrast to conventional intravenous (i.v.) BMT. In the present study, we have compared the long-term maintenance of HSCs using multiple rounds of serial i.v.-BMT and IBM-BMT. The frequencies of donor-derived progenitor cells (Lin(-)/c-kit(+) cells) and more primitive progenitors (Lin(-)/c-kit(+)/CD34(+)/Sca-1(+) cells) were higher in the tertiary recipients by serial IBM-BMT than in those that had received bone marrow cells by serial i.v.-BMT. Furthermore, neither donor-derived progenitor cells nor mature hematolymphoid cells were detected in approximately 25% of the tertiary recipients after serial i.v.-BMT, indicating that progenitor cells can be efficiently maintained by IBM-BMT but not by i.v.-BMT. Finally, we confirmed that the recipients treated with the primary IBM-BMT (without carrying out serial BMT) showed a significantly higher survival rate than those treated with i.v.-BMT. These findings clearly show that IBM-BMT efficiently promotes the longterm maintenance of donor-derived hematopoiesis.

Maintenance of systemic immune functions prevents accelerated presbycusis.

There is no effective therapy for progressive hearing loss such as presbycusis, the causes of which remain poorly understood because of the difficulty of separating genetic and environmental contributions. In the present study, we show that the age-related dysfunctions of the systemic immune system in an animal model of accelerated presbycusis (SAMP1, senescence-accelerated mouse P1) can be corrected by allogeneic bone marrow transplantation (BMT). We also demonstrate that this presbycusis can be prevented; BMT protects the recipients from age-related hearing impairment and the degeneration of spiral ganglion cells (SGCs) as well as the dysfunctions of T lymphocytes, which have a close relation to immune senescence. No donor cells are infiltrated to the spiral ganglia, confirming that this experimental system using BMT is connected to the systemic immune system and does not contribute to transdifferentiation or fusion by donor hematopoietic stem cells (HSCs), or to the direct maintenance of ganglion cells by locally infiltrated donor immunocompetent cells. Therefore, another procedure which attempts to prevent the age-related dysfunctions of the recipient immune system is the inoculation of syngeneic splenocytes from young donors. These mice show no development of hearing loss, compared with the recipient mice with inoculation of saline or splenocytes from old donors. Our studies on the relationship between age-related systemic immune dysfunctions and neurodegeneration mechanisms open up new avenues of treatment for presbycusis, for which there is no effective therapy.

Induction of inducible nitric oxide synthase and apoptosis by LPS and TNF-alpha in nasal microvascular endothelial cells.

CONCLUSION: This study demonstrates that the co-administration of lipopolysaccharide (LPS) and tumor necrosis factor-alpha (TNF-alpha) (LPS/TNF-alpha) can induce the expression of inducible nitric oxide synthase (iNOS), which results in the generation of apoptosis in cultured human nasal microvascular endothelial cells (HNMECs). Since LPS and TNF-alpha have been suggested to play an important role in the pathophysiology of nasal disease, we conclude that microvascular leakage may therefore contribute to the inflammatory process in nasal disease, such as allergic rhinitis and asthma. MATERIALS AND METHODS: The HNMECs were obtained from the inferior turbinate and subsequently cultured. The expression of iNOS induced by both the LPS and TNF-alpha was investigated by fluorescent immunohistochemistry, using confocal laser microscopy. The DNA-binding dye, Hoechist 33342, was also used to analyze the apoptosis in the HNMECs. RESULTS: The fluorescent immunohistochemistory study demonstrated that LPS and TNF-alpha induced the expression of iNOS in HNMECs. LPS/TNF-alpha remarkably augmented the expression of iNOS in HNMECs in comparison to stimulation by either LPS or TNF-alpha alone. LPS/TNF-alpha also induced apoptosis in HNMECs. 1400W, a highly selective inhibitor of iNOS, inhibited both the expression of iNOS and the apoptosis induced by LPS/TNF-alpha.

Platelet-activating factor (PAF) induced cytokine production and otitis media with effusion (OME) in the rat middle ear.

OBJECTIVES: We examined the effect of platelet-activating factor (PAF) on IL-8 production in cultured rat middle ear epithelial cells (RMECs), and the concentrations of cytokine, PAF, and PAF-acetylhydrolase (PAF-AH) were also examined in the PAF-induced experimental OME (otitis media with effusion) of rats. METHODS: Using an enzyme-linked immunospecific assay, we measured the levels of cytokines in the cultured RMECs and the PAF-induced OME of rats. The PAF was quantitated by the platelet-aggregating activity and the PAF-AH was measured by radioimmunoassay. RESULTS: Both PAF and C-PAF, which is a stable analogue of PAF, significantly induced production of IL-8 in the RMECs in a dose-dependent manner. The PAF-induced IL-8 production was abolished by co-incubation with WEB2170, a specific PAF receptor antagonist. The concentrations of the cytokines and PAF in the PAF-induced OME of rats were higher on day 1 and the PAF and cytokine levels seemed to correspond well with the persistence of OME. CONCLUSION: PAF may stimulate the local production of cytokines and may induce OME in the middle ear.

Preoperative concurrent chemoradiotherapy versus pre- and postoperative radiotherapy for advanced hypopharyngeal carcinoma: a single-center study.

OBJECTIVE: The purpose of this study was to improve the survival and phonatory rates in patients with advanced hypopharyngeal carcinoma. METHODS: Seventy-two consecutive patients with advanced hypopharyngeal carcinoma were treated with pre- and postoperative radiotherapy (RTS), or preoperative concomitant chemoradiotherapy (CCRTS). Surgical procedures, including total laryngectomy plus partial pharyngectomy (TLPP) to preserve the posterior pharyngeal wall offering a functional neoglottis for esophageal or tracheoesophageal shunt phonation postoperatively, were conducted for patients who did not achieve CR. RESULTS: A significantly higher survival rate at 5 years (93.3%) was observed for N0-2b stage patients in the CCRTS group (n=16) than the RTS group (n=34; 41.5%) (p<.005). The distant metastasis-free rate was 92.9% (CCRTS group) versus 55.4% (RTS group) (p<.05) in these patients. In the CCRTS group, the 5-year survival rate with laryngeal or esophageal and/or tracheoesophageal shunt phonation was 22.2%. CONCLUSION: It is suggested that the CCRTS protocol and TLPP procedure may improve the survival rates without deterioration of phonatory rates in patients with N0-2b advanced hypopharyngeal carcinoma.

Administration of amitriptyline attenuates noise-induced hearing loss via glial cell line-derived neurotrophic factor (GDNF) induction.

Antidepressant treatments have been described to induce neurotrophic factors (NTFs) and reverse the cell loss observed in rodent stress models. Amitriptyline (AT), a tricyclic antidepressant agent, has been reported in recent studies to induce glial cell line-derived neurotrophic factor (GDNF) synthesis and release in rat C6 glioblastoma cells. GDNF has shown protection against acoustic trauma in previous studies. Therefore, we investigated whether AT could induce GDNF synthesis in the cochlea and attenuate cochlea damage against acoustic trauma. We used Hartley guinea pigs and injected AT (30 mg/kg) or saline into the peritoneum. Subjects were exposed to 117 dB SPL octave band noise centered at 4 kHz for 24 h. Noise-induced hearing loss (NIHL) was assessed with auditory brain stem response (ABR) at 4, 8 and 16 kHz measured prior to the injection, 3 days and 7 days after noise exposure. For histological assessment, we observed the sensory epithelium using a surface preparation technique and assessed the quantitative hair cell (HC) damage. We evaluated GDNF synthesis with or without intense noise exposure at 3, 12 and 24 h after the administration of AT in the cochlea using Western blot analysis. GDNF expression was shown 3 h and 12 h after the injection without noise, whereas with noise the GDNF expression lasted for 24 h. The AT-administrated group showed significantly reduced ABR threshold shift and less HC damage than the saline-administrated group. These findings suggest that the administration of AT-induced GDNF levels in the cochlea and attenuated cochlea damage from NIHL.

Hyposmotic stimulation-induced nitric oxide production in outer hair cells of the guinea pig cochlea.

Nitric oxide (NO) production during hyposmotic stimulation in outer hair cells (OHCs) of the guinea pig cochlea was investigated using the NO sensitive dye DAF-2. Simultaneous measurement of the cell length and NO production showed rapid hyposmotic-induced cell swelling to precede NO production in OHCs. Hyposmotic stimulation failed to induce NO production in the Ca2+-free solution. L-NG-nitroarginine methyl ester (L-NAME), a non-specific NO synthase inhibitor and gadolinium, a stretch-activated channel blocker inhibited the hyposmotic stimulation-induced NO production whereas suramin, a P2 receptor antagonist did not. S-nitroso-N-acetylpenicillamine (SNAP), a NO donor inhibited the hyposmotic stimulation-induced increase in the intracellular Ca2+ concentrations ([Ca2+]i) while L-NAME enhanced it. 1H-[1,2,4]oxadiazole[4,3a]quinoxalin-1-one, an inhibitor of guanylate cyclase and KT5823, an inhibitor of cGMP-dependent protein kinase (PKG) mimicked effects of L-NAME on the Ca2+ response. Transient receptor potential vanilloid 4 (TRPV4), an osmo- and mechanosensitive channel was expressed in the OHCs by means of immunohistochemistry. 4alpha-phorbol 12,13-didecanoate, a TRPV4 synthetic activator, induced NO production in OHCs. These results suggest that hyposmotic stimulation can induce NO production by the [Ca2+]i increase, which is presumably mediated by the activation of TRPV4 in OHCs. NO conversely inhibits the Ca2+ response via the NO-cGMP-PKG pathway by a feedback mechanism.

Hyposmotic stimulation-induced nitric oxide production in outer hair cells of the guinea pig cochlea.

Nitric oxide (NO) production during hyposmotic stimulation in outer hair cells (OHCs) of the guinea pig cochlea was investigated using the NO sensitive dye DAF-2. Simultaneous measurement of the cell length and NO production showed rapid hyposmotic-induced cell swelling to precede NO production in OHCs. Hyposmotic stimulation failed to induce NO production in the Ca(2+)-free solution. L-N(G)-nitroarginine methyl ester (L-NAME), a non-specific NO synthase inhibitor and gadolinium, a stretch-activated channel blocker inhibited the hyposmotic stimulation-induced NO production whereas suramin, a P2 receptor antagonist did not. S-nitroso-N-acetylpenicillamine (SNAP), a NO donor inhibited the hyposmotic stimulation-induced increase in the intracellular Ca(2+) concentrations ([Ca(2+)](i)) while L-NAME enhanced it. 1H-[1,2,4]oxadiazole[4,3a]quinoxalin-1-one, an inhibitor of guanylate cyclase and KT5823, an inhibitor of cGMP-dependent protein kinase (PKG) mimicked effects of L-NAME on the Ca(2+) response. Transient receptor potential vanilloid 4 (TRPV4), an osmo- and mechanosensitive channel was expressed in the OHCs by means of immunohistochemistry. 4alpha-phorbol 12,13-didecanoate, a TRPV4 synthetic activator, induced NO production in OHCs. These results suggest that hyposmotic stimulation can induce NO production by the [Ca(2+)](i) increase, which is presumably mediated by the activation of TRPV4 in OHCs. NO conversely inhibits the Ca(2+) response via the NO-cGMP-PKG pathway by a feedback mechanism.

Kimura disease: diagnosis and prognostic factors.

OBJECTIVES: To establish a preoperative diagnostic system and examine prognostic factors for Kimura disease. STUDY DESIGN: Retrospective study. SETTING: Hospital records were reviewed for nine cases of Kimura disease treated in our department. Preoperative eosinophil counts for 74 cases with untreated malignancy in the parotid gland were also examined. RESULTS: Parotid swelling with inhomogeneities and subcutaneous invasion on magnetic resonance imaging and eosinophils > 10.5 percent in Asian patients clearly indicates Kimura disease. Eosinophils > 50 percent, serum IgE levels > 10,000 IU/mL, and multifocal lesions outside salivary glands are prognostic factors suggesting disease recurrence. CONCLUSIONS: A preoperative decision based on our diagnostic criteria and prognostic factors should lead to better therapeutic outcomes for Kimura disease, for which a definitive treatment policy has never been determined.

Hearing results for ossicular reconstruction using a cartilage-connecting hydroxyapatite prosthesis with a spearhead.

OBJECTIVE: Assessment of the efficacy of ossicular reconstruction using a cartilage-connecting hydroxyapatite prosthesis designed with a spearhead to reduce extrusion and dislocation of the implant. PATIENTS: All patients undergoing ossicular reconstruction after chronic ear surgery, connecting the cartilage to the prosthesis, with a minimum of 1 year of postoperative follow-up. MAIN OUTCOME MEASURES: Postoperative change in pure-tone averages. Air-bone gap closures, and implant extrusion rates. RESULTS: Overall mean pure-tone averages improved by 12.2 dB (ranged between -40 and 60 dB). In total, 68.4% of the patients achieved an air-bone gap less than 20 dB. Gains in the mean air conduction thresholds were 9.5 dB in cases of partial ossicular reconstruction and 14.9 dB in cases with total ossicular reconstruction (p < 0.05). The overall extrusion rate was 4.21%. CONCLUSION: The cartilage-connecting hydroxyapatite prosthesis with a spearhead was found to restore hearing to a satisfactory level. The extrusion rate was relatively low. The cartilage-connecting hydroxyapatite prosthesis with a spearhead is an effective ossicular implant and offers an attractive alternative for ossicular reconstruction, particularly for total ossicular reconstructions.

[Clinical study of adenoid cystic carcinoma of the parotid gland].

We report results of a retrospective study of 12 cases of adenoid cystic carcinoma (ACC) in the parotid gland. Local pain was often observed in ACC among other malignant parotid tumors. Although fine-needle aspiration cytology (FNA) was not effective for preoperative diagnosis, frozen section diagnosis (FS) during surgery showed excellent results. Cases with T3 or T4 underwent total or enlarged parotidectomy, but, often showed positive surgical margins. Postoperative radiation therapy seemed useful in these cases and the 5-and 10-year disease-specific survivals in these 12 cases were 90.0% and 80.8%. These compare favorably with other reports in the literature. All 12 cases showed NO and no cervical relapse with or without neck dissection, indicating little effectiveness in prophylactic neck dissection. Tumor size, positive surgical margins, and perineural invasion are risk factors for this tumor as mention previously. Patients with perineural invasion, especially preoperative facial nerve palsy (T4a), are more likely to fail than those with two other factors, so, it seems conceivable for cases of T4a to undergo more positive treatment with surgery and postoperative radiation.

Salivary duct carcinoma treated with cetuximab-based targeted therapy: A case report.

Salivary duct carcinoma is a highly aggressive disease with a poor prognosis. Surgical resection is currently the only curative treatment, as there is no effective systemic therapy for this malignancy. Recently, trastuzumab has been shown to exhibit therapeutic efficacy in the treatment of salivary duct carcinoma; similarly, molecularly targeted agents, such as cetuximab, are expected to be useful for salivary duct carcinoma treatment. We herein describe the case of a 56-year-old man diagnosed with salivary duct carcinoma in the left submandibular region, with ipsilateral multiple metastases to the neck lymph nodes. Radical resection of the tumor and submandibular gland with neck dissection were performed. One month after radical surgery, computed tomography (CT) scans indicated metastasis in the lower lobe of the left lung. CT-guided transthoracic fine-needle aspiration biopsy revealed a single metastasis and lung metastasectomy was immediately performed. The tumor cells of the primary lesion and those of the lung metastasis were immunohistochemically positive for epidermal growth factor receptor. One month later, multiple right lung metastases appeared, and the patient was treated with cisplatin/5-fluorouracil (5-FU) chemotherapy plus cetuximab, achieving a complete radiographic response. However, multiple lung metastases developed during adjuvant weekly cetuximab monotherapy. Subsequently, treatment with S-1 and weekly cetuximab was initiated, and the multiple lung metastases have been maintained as stable disease for 5 months. To the best of our knowledge, this is the first report of cetuximab use for the treatment of salivary duct carcinoma. Although cisplatin/5-FU chemotherapy plus cetuximab was efficacious in treating the lung metastasis, cetuximab monotherapy was insufficient for controlling tumor growth.

A phase I study of concurrent chemoradiotherapy with S-1 for T2N0 glottic carcinoma.

OBJECTIVE: Chemoradiation based on S-1, a novel oral antitumor agent of fluorinated pyrimidines, is the treatment for T2N0 glottic carcinoma; however, the optimal scheduling and dosing have still not been established. A phase I study was conducted to determine the maximum tolerated dose of S-1 with radiotherapy of 2 Gy/day for 5 days a week to a total dose of 60 Gy. Endpoints of this study were to examine the toxicity profile of this regimen and to determine the recommended dose of S-1. METHODS: Concomitant administration with the above-mentioned radiotherapy of S-1 once a day for 2 weeks, beginning on the day therapy was started, followed by 2 weeks off the drug and 2 weeks on the drug with the dose escalating from S-1 60 mg/body (level 1) to 80 mg/body/day (level 2), and then to 100 mg/body/day (level 3). RESULTS: Twenty-one patients were valid for safety. Eighteen patients were enrolled in the dose-escalation phase. In all patients, S-1 was administered. The maximum tolerated dose was determined to be 100 mg/body/day and the dose-limiting toxicity was indicated by the onset of grade 3 chemoradiation dermatitis. Therefore, the determined recommended dose of S-1 was 80 mg/body/day. Objective response according to Response Evaluation Criteria in Solid Tumors were observed in 20 of 21 patients who had measurable disease (95.2%). CONCLUSION: Concurrent S-1 and radiotherapy was feasible and well tolerated, and was suggested to produce a worthwhile response in T2N0 glottic carcinoma. These results warrant further investigation, and a phase II has already been started.

Functional expression of transient receptor potential vanilloid 4 in the mouse cochlea.

Transient receptor potential vanilloid 4, the Ca2+-permeable cation channel has been proposed as an osmosensitive and a mechanosensitive channel. We investigated functional expression of transient receptor potential vanilloid 4 in inner hair cells, outer hair cells, and spiral ganglion neurons of the mouse cochlea. Transient receptor potential vanilloid 4 mRNA and protein were expressed in inner hair cells, outer hair cells, and spiral ganglion neurons on the basis of the findings of reverse transcriptase-polymerase chain reaction, single-cell reverse transcriptase-polymerase chain reaction, and immunohistochemistry, whereas they were negative in transient receptor potential vanilloid 4-/- mice cochleae. Hypotonic stimulation and 4-alpha-phorbol 12,13-didecanoate, a transient receptor potential vanilloid 4 synthetic activator, increased the intracellular Ca2+ concentrations in wild-type outer hair cells, whereas in transient receptor potential vanilloid 4-/- mice, outer hair cells failed to exhibit a Ca2+ response to both stimulations. In conclusion, transient receptor potential vanilloid 4 may function as an osmosensory and a mechanosensory receptor in the cochlea.

Role of nitric oxide on ATP-induced Ca2+ signaling in outer hair cells of the guinea pig cochlea.

Recently, a negative feedback effect of nitric oxide (NO) on the adenosine 5'-triphosphate (ATP)-induced Ca2+ response has been described in cochlear inner hair cells. We here investigated the role of NO on the ATP-induced Ca2+ response in outer hair cells (OHCs) of the guinea pig cochlea using the NO-sensitive dye DAF-2 and Ca2+ -sensitive dye fura-2. Extracellular ATP induced NO production in OHCs, which was inhibited by L-NG-nitroarginine methyl ester (L-NAME), a non-specific NO synthase (NOS) inhibitor, and suramin, a P2 receptor antagonist. ATP failed to induce NO production in the Ca2+ -free solution. S-nitroso-N-acetylpenicillamine (SNAP), a NO donor, enhanced the ATP-induced increase of the intracellular Ca2+ concentrations ([Ca2+]i), while L-NAME inhibited it. SNAP accelerated ATP-induced Mn2+ quenching in fura-2 fluorescence, while L-NAME suppressed it. 8-Bromoguanosine-cGMP, a membrane permeable analog of cGMP, mimicked the effects of SNAP. 1H-[1,2,4]oxadiazole[4,3-a] quinoxalin-1-one, an inhibitor of guanylate cyclase and KT5823, an inhibitor of cGMP-dependent protein kinase inhibited the ATP-induced [Ca2+]i increase. Selective neuronal NOS inhibitors, namely either 7-nitro-indazole or 1-(2-trifluoromethylphenyl) imidazole, mimicked the effects of L-NAME regarding both ATP-induced Ca2+ response and NO production. Immunofluorescent staining of neuronal nitric oxide synthase (nNOS) in isolated OHCs showed the localization of nNOS in the apical region of OHCs. These results suggest that the ATP-induced Ca2+ influx via a direct action of P2X receptors may be the principal source for nNOS activity in the apical region of OHCs. Thereafter, NO can be produced while conversely enhancing the Ca2+ influx via the NO-cGMP-PKG pathway by a feedback mechanism.

Transfer of accelerated presbycusis by transplantation of bone marrow cells from senescence-accelerated mice.

Until now, there has been no effective therapy for chronic sensorineural hearing impairment. This study investigated the role of bone marrow cells (BMCs) in cochlear dysfunction. BALB/c mice (2 months of age), a non-presbycusis-prone mouse strain, were lethally irradiated and then transplanted with BMCs from SAMP1 mice (2 months of age), a presbycusis-prone mouse strain. Acceleration of age-related hearing loss, early degeneration of spiral ganglion cells (SGCs) and impairment of immune function were observed in the recipient mice as well as in the SAMP1 mice. However, no spiral ganglion cells of donor (SAMP1) origin were detected in the recipient mice. These results indicated that accelerated presbycusis, cochlear pathology, and immune dysfunction of SAMP1 mice can be transferred to BALB/c recipient mice using allogeneic bone marrow transplantation (BMT). However, although the BMCs themselves cannot differentiate into the spiral ganglion cells (SGCs), they indirectly cause the degeneration of the SGCs. Further studies into the relationship between the inner ear cells and BMCs are required.

Early acquisition of esophageal phonation following tracheoesophageal phonation.

CONCLUSIONS: Tracheoesophageal phonation appears to participate in early acquisition of esophageal phonation, which remains the preferred method of voice restoration among patients. Further studies into factors predicting and mechanisms underlying acquisition of esophageal phonation among alaryngeal patients may provide information facilitating superior quality of life. OBJECTIVE: The aim of this study was to examine early acquisition of esophageal phonation following tracheoesophageal phonation, and underlying mechanisms and preferred phonatory methods for alaryngeal patients who master both tracheoesophageal and esophageal phonation. PATIENTS AND METHODS: Subjects comprised 44 alaryngeal patients and were divided into three groups: group A (n=13), esophageal phonation alone; group B (n=21), tracheoesophageal phonation alone; and group C (n=10), patients who acquired esophageal phonation after learning tracheoesophageal phonation. RESULTS: The results indicated that acquisition of tracheoesophageal phonation significantly accelerated acquisition of esophageal phonation to 59.3 days from 184.6 days. Patients in group C stopped tracheoesophageal phonation and predominantly used esophageal phonation. No factors predicting acquisition of esophageal phonation were identified among patients who had mastered tracheoesophageal phonation, including age at time of surgery, irradiation, neck dissection, acquisition time of tracheoesophageal phonation, and maximum phonation time of tracheoesophageal phonation. No evidence of air leakage through the shunt during esophageal phonation was noted in group C.