Akihiro Shiotani

Myosin Heavy Chain Composition in Human Laryngeal Muscles

Objectives: Myosin heavy chain (MHC) composition of human thyroarytenoid (TA), lateral cricoarytenoid (LCA), interarytenoid (IA), vocalis, posterior cricoarytenoid (PCA), and cricothyroid muscles were examined using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE) and Western bolt techniques. The presence of superfast MHC was also assessed using antibodies directed against the extraocular MHC.

Lubrication Mechanism of the Larynx during Phonation: An Experiment in Excised Canine Larynges

To evaluate how the viscosity of the laryngeal mucus influences vocal fold vibration, two fluids of differing viscosity were applied separately to excised canine larynges and experimental phonation was induced. Vibration of the vocal folds was measured by use of a laryngostroboscope and an X-ray stroboscope. With the high viscosity fluid, the amplitude of vibration of the free edge and the peak glottal area was decreased while the open quotient was increased. Because the viscosity of this fluid affected the wave motion of the vocal fold mucosa, changes in viscosity of the mucus may be involved in causing such disorders as hoarseness, in the absence of apparent changes in the vocal folds themselves.

Adenoviral GDNF gene transfer prevents motoneuron loss in the nucleus ambiguus.

We examined neuroprotective effects of an adenoviral vector encoding glial cell line-derived neurotrophic factor (AxCAhGDNF) on the lesioned adult rat motoneurons in the nucleus ambiguus. After vagal nerve avulsion, AxCAhGDNF, AxCALacZ (adenovirus encoding beta-galactosidase gene) or PBS was inoculated into the jugular foramen. Four days after the avulsion and treatment with AxCALacZ, the animals expressed beta-galactosidase activity in the lesioned motoneurons in the nucleus ambiguus. The animals avulsed and inoculated with AxCAhGDNF showed immunolabeling for GDNF in the nucleus ambiguus on the treated side and expression of virus-induced human GDNF mRNA transcripts in the brainstem tissue that contained the nucleus ambiguus of the treated side. The treatment with AxCAhGDNF after avulsion prevented the loss of lesioned motoneurons in the nucleus ambiguus, ameliorated the choline acetyltransferase immunoreactivity, and also suppressed the activity of nitric oxide synthase in these neurons. These results indicate that adenovirus-mediated GDNF gene transfer may prevent the degeneration of motoneurons in humans after either vagal nerve injury or recurrent laryngeal nerve injury.

Adenoviral gene transfer of BDNF and GDNF synergistically prevent motoneuron loss in the nucleus ambiguus

We have previously shown that neuroprotective effects of an adenoviral glial cell line-derived neurotrophic factor (GDNF) gene transfer on the lesioned adult rat motoneurons in the nucleus ambiguus. In the present study, we examined neuroprotective effects of adenoviral gene transfer of brain-derived neurotrophic factor (BDNF) or/and GDNF to motoneurons in nucleus ambiguus using an adult rat vagal nerve avulsion model. The animals avulsed and inoculated with adenoviral vectors encoding BDNF (AxCAmBDNFME) or/and GDNF (AxCAhGDNF) showed immunolabeling for BDNF or/and GDNF in the nucleus ambiguus on the treated side, respectively, and expression of virus-induced BDNF or/and GDNF mRNA transcripts in the brainstem tissue that contained the nucleus ambiguus of the treated side. The treatment with AxCAhGDNF or AxCAmBDNFME significantly prevented the loss of vagal motoneurons in comparison to the control; the protective effect of AxCAmBDNFME was greater than that of AxCAhGDNF. The combined treatment with AxCAmBDNFME and AxCAhGDNF acted synergistically and significantly larger number of vagal motoneurons was preserved as compared to either AxCAmBDNFME treatment or AxCAhGDNF treatment. The treatment with AxCAmBDNFME or/and AxCAhGDNF after avulsion also suppressed the activity of nitric oxide synthase in lesioned motoneurons in the nucleus ambiguus. These results indicate that adenovirus-mediated BDNF and GDNF gene transfer may prevent the degeneration of motoneurons in humans after either vagal nerve injury or recurrent laryngeal nerve injury.

Effects of Insulin-Like Growth Factor-1 Gene Transfer on Myosin Heavy Chains in Denervated Rat Laryngeal Muscle

Objectives/Hypothesis: To determine whether the myotrophic activity of human insulin‐like growth factor (hIGF)‐1 promotes restoration of normal myosin heavy chain (MHC) composition after nerve injury, MHC composition was analyzed after hIGF‐1 gene transfer in denervated rat laryngeal muscle.

Papillary Adenocarcinoma Possibly Arising from an Intraductal Papilloma of the Parotid Gland

We report a case of a 70-year-old female with a papillary adenocarcinoma which we believe to have originated from an intraductal papilloma of the parotid gland. A few cases of intraductal papilloma of a minor salivary gland have been reported; however, to our knowledge, intraductal papilloma and, hence, adenocarcinoma originating from an intraductal papilloma of the parotid gland, have never been described.

Study of movements of individual structures of the larynx during swallowing.

OBJECTIVEnThe purpose of this study was to reveal movements of individual structures of the larynx during swallowing.nnnMETHODSnSubjects were 7 healthy adults, aged 24 to 32 years (average 27 years), who had no organic or functional disease of the pharynx and larynx and 2 adults with unilateral recurrent nerve palsy, aged 49 and 60 years, respectively. We used the Toshiba IIDR system, which is composed of an X-ray TV system and a digital image managing circuit. One-fifth diluted Omnipark 300 was used as contrast medium (lohexol), with 15 cc for each swallow. The mask image for subtraction was designated as the frame before laryngeal elevation during swallowing for subtraction. We obtained the images for observation and analysis after subtracting the mask image from continuously obtained images. These images were captured into a personal computer at 30 frames per s and thereafter frame-by-frame observation and analysis were performed by means of NIH image 1.56.nnnRESULTSnWe observed that the vocal folds underwent a series of movements during swallowing. (1) They adduct slowly and do not ascend; (2) then begin to ascend and continue adducting; whereby (3) they abduct for a moment while ascending. (4) Again, they adduct and achieve closure. (5) While maintaining closure, vocal folds elevate further to reach their maximal elevation; and (6) begin to abduct rapidly while maintaining maximal elevation. Finally, (7) they begin to descend and undergo repeated irregular abduction and adduction while descending. In examining the relationship between closure and opening at levels of the vocal fold and false vocal fold, we found that closure at the false vocal fold level precedes that at the vocal fold level and that opening at the vocal fold level precedes that at the level of the false vocal fold.nnnCONCLUSIONnClosure of the false vocal fold level appears important in the protection of the lower respiratory tract during swallowing.

Isolated Non-Hodgkin’s Malignant Lymphoma of the Larynx Presenting as a Large Pedunculated Tumor

This paper presents a case of non-Hodgkins lymphoma (NHL) of the larynx. The patient was an 86-year-old man who complained of foreign-body sensation and dysphagia. Laryngoendoscopic examination revealed a large pedunculated mass arising from the left aryepiglottic fold. A diffuse, large, B-cell-type NHL was diagnosed histopathologically. The patient was treated with combination chemotherapy, resulting in complete clinical remission. The clinicopathological features of this case have been described and compared with previously reported cases.

Primary Small Cell Carcinoma of the Larynx

Small cell carcinoma is a rare tumor of the larynx. We present such a case in a 78-year-old female. The histopathological diagnosis at the time of laryngomicroscopic biopsy was squamous cell carcinoma, upon which basis we initially chose surgical treatment. The surgical specimen, however, revealed small cell carcinoma. Despite the administration of radiotherapy and chemotherapy, the patient died 9 months after initial presentation. We believe that this case illustrates the need for a sufficiently large biopsy specimen in order to arrive at the correct histopathological diagnosis when small cell carcinoma of the larynx is present, and that immunohistochemistry and electron microscopy should be performed to aid the diagnosis.

Vocal fold vibration in simulated head voice phonation in excised canine larynges

In order to establish precise vibratory patterns and their clinical implication for phonation, the mode of vibration of the vocal folds around the time of register transition in excised canine larynges was analyzed multi-directionally according to various acoustic parameters. Phonation was simulated by artificially tensing the cricothyroid muscles. Vibration of the vocal folds around the time of register transition was filmed from above using ultra-high-speed cinematography and in a frontal plane using X-ray stroboscopy. Acoustic parameters included sub-glottic pressure, pitch, intensity and tension and were recorded simultaneously during register transition. The fundamental vibration patterns observed during vocal phonation were the same as that involved in chest voice phonation in excised canine larynges, with respect to the traveling wave of the vocal fold vibration. Changes in the physical properties of the vocal folds were considered to occur at register transition. These changes were probably strongly dependent upon changes in the structure of the lamina propria. Head voice phonation requires adaptability of the lamina propria and is less efficient than chest voice phonation. Hence, head voice phonation would be one method for assessing the condition of the vocal folds.