Tadashi Nakashima

Vitamin A-storing stellate cells in the human newborn vocal fold.

Objectives: Vocal fold stellate cells (VFSCs) in the newborn vocal fold were examined and compared with VFSCs in the adult vocal fold. Methods: Light and electron microscopic investigation of VFSCs was carried out on 5 human newborn larynges. Results: The VFSCs were distributed in human newborn maculae flavae. They were stellate or oval in shape, and possessed cytoplasmic processes. The VFSCs in some cells formed a gap junction with each other. A few lipid droplets were present in the cytoplasm, but they were much fewer than those of an adult. The nucleus-cytoplasm ratio was high, and the intracellular organelles were not very well developed. Free ribosomes were well developed in the cytoplasm. The VFSCs in some cells showed strong cytoplasm staining with periodic acid-Schiff stain and type III collagen. There were vesicles along the periphery of the cytoplasm of the VFSCs, and newly released amorphous materials were seen, but fewer were observed on the cell surface. The newborn VFSCs had started to synthesize extracellular matrices such as collagenous fibers, reticular fibers, elastic fibers, and glycosaminoglycan. Conclusions: The VFSCs in the newborn maculae flavae were immature, but had already started the synthesis of extracellular matrices essential for the viscoelastic properties of the vocal fold mucosa.

Unilateral associated laryngeal paralysis due to varicella-zoster virus: virus antibody testing and videofluoroscopic findings

The relationship between varicella-zoster virus and idiopathic associated laryngeal paralysis was examined in five patients, using complement fixation or enzyme immunoassay testing. In all cases, significant changes in serum levels of varicella-zoster virus antibody were observed. Videofluoroscopy was useful in assessing the severity of the dysphagia and in making an accurate diagnosis; both laryngeal elevation and weakness of pharyngeal wall contraction were also observed. In two cases in which antiviral therapy was delayed, the outcome was poor, with increased levels of varicella-zoster virus immunoglobulin M found on enzyme immunoassay. The outcome of the condition may thus depend both on the speed of antiviral therapy commencement following onset of symptoms, and on the levels of varicella-zoster virus immunoglobulin M antibody (measured by enzyme immunoassay). Our study suggests that varicella-zoster virus should be considered in the differential diagnosis of patients with idiopathic associated laryngeal paralysis, and rapid antiviral therapy should be initiated when necessary.

Expression and Distribution of CD44 and Hyaluronic Acid in Human Vocal Fold Mucosa

Objectives: Expression of CD44 (a cell surface receptor for hyaluronic acid) and the distribution of hyaluronic acid were examined in the human vocal fold mucosa. Methods: Light microscopic investigation was carried out on 10 normal larynges of newborn, infant, younger adult, and older adults with Alcian blue staining, a hyaluronidase digestion study, and immunohistochemistry for CD44. Results: Before the appearance of hyaluronic acid in the newborn vocal fold mucosa, CD44 was expressed on the stellate cells in the macula flava and on the fibroblasts in Reinkes space. During infancy, hyaluronic acid appeared and was distributed in the vocal fold mucosa. Many more stellate cells in the macula flava showed CD44 expression, and a large amount of hyaluronic acid was present around the infant stellate cells; however, the fibroblasts in Reinkes space expressed little CD44. During adulthood, hyaluronic acid was distributed in the vocal fold mucosa. Almost all of the stellate cells in the macula flava showed CD44 expression, and much hyaluronic acid existed around the stellate cells in the adult macula flava. However, fibroblasts in the adult Reinkes space expressed little CD44, and hyaluronic acid density in that space was lower than that in the macula flava. Conclusions: Stellate cells in the macula flava and CD44 cooperatively play important roles in maintaining hyaluronic acid in the human vocal fold mucosa as a vibrating tissue.

Comparative study of framework surgery and fat injection laryngoplasty

OBJECTIVEnTo evaluate differences between the functional results of framework surgery and autologous fat injection laryngoplasty, for patients with unilateral vocal fold paralysis.nnnSTUDY DESIGNnSixty-two patients underwent framework surgery, while 64 received autologous fat injection laryngoplasty. Voice function before and after both procedures was assessed using aerodynamic and acoustic analysis, with differences evaluated using paired t-test in both groups.nnnRESULTSnIn both groups, all parameters improved significantly after surgery, compared with before surgery. Post-operative improvement in all parameters was significantly greater after fat injection laryngoplasty, compared with framework surgery.nnnCONCLUSIONnAutologous fat injection laryngoplasty was thus found to be a more effective and reliable therapy for improving voice function in patients with vocal fold paralysis, compared with framework surgery.

Radiotherapy of the neck influences the distribution of laryngeal secretory glands.

To elucidate the influence of radiation therapy on the larynx in patients who receive radiotherapy to the neck, we observed the changes in the distribution of the laryngeal glands. Human adult larynges from patients with either laryngeal or hypopharyngeal cancer were histopathologically examined, and the changes in the glandular distribution as well as in the ratio of serous or mucous type cells were surveyed using an image analysis system. The mean ratio of the area occupied by glandular acini in the subglottic larynx was 0.182 in the non-radiation group and 0.098 in the radiation group (p < 0.001). Although no statistical difference was observed, the average density of the glands decreased and the average ratio of serous-type/mucous-type glandular cells decreased in the irradiated larynx. The glandular acini are often replaced with fibrous connective tissue and the ratio of serous-type glandular cells decreases. These results indicate that not only the voice function but also the local defence function of the larynx might be impaired after radiotherapy.

The immunohistochemical expression of p21WAF1/Cip1 and Proliferating cell nuclear antigen in laryngeal squamous cell carcinomas.

The purpose of this study was to assess the significance of the expression of p21WAF1/Cip1 and proliferating cell nuclear antigen (PCNA) in human laryngeal squamous cell carcinomas. Forty-eight patients (25 supraglottic, 23 glottic) who had undergone operations between 1998 and 2003 were included in this study. The Envision immunohistochemistry method was utilized to stain these tissue specimens. The results showed that the immunostaining of p21WAF1/Cip1 do not show any correlation with differentiation, N stage, metastasis, survival, recurrence or the laryngeal site of involvement. A significant inverse correlation was detected between p21WAF1/Cip1 and the T stage. In contrast, the percentage of PCNA labelled cells showed a significant correlation with the T stage, but not with other clinicopathological parameters. There were differences in the expression of p21WAF1/Cip1 and PCNA between the supraglottic and the glottic carcinomas. In conclusion, our findings suggest that p21WAF1/Cip1 and PCNA may play an important role in the progression of carcinoma of the supraglottic larynx.