Anatomical and Surface Electron Microscopic Investigation of the Tongue and Laryngeal Prominence in the Red-Eyed Turtle Dove (Streptopelia semitorquata, Rüppel 1837).

This study investigated the morphology of tongue and laryngeal structures in red-eyed dove and related it to feeding habits. Samples were examined using gross anatomy, scanning electron microscopy (SEM), and histological techniques. The tongue conformed to the shape of the lower beak, and the apex with a pointed tip, body, and root were distinguished. A median grove was apparent, and a papillary crest with pointed triangular papillae separated the body from the root. The length of the tongue, its width (body), and the percentage of the length of the lower jaw occupied by the tongue were, on average, 12.5 mm, 2.3 mm, and 57.3%, respectively. SEM showed highly desquamated dorsal epithelium with pointed papillae-like projections. The papillary crest presented pointed papillae of about 20-22. Salivary openings were apparent in the root, surrounded by mucosal folds and blunt papillae. Laryngeal prominence was irregularly triangular shaped and elevated. The rim of the glottis showed glandular pinpointed marks. Typical cornified multilayered mucosal epithelium was present in the apex and decreased caudally. Hyaline entoglossal cartilage and adjoining connective tissue were present in the body and apex. Numerous tubuloalveolar glands were seen in the body and root. The rim of the glottis showed mucous intraepithelial glands. The rostral and caudal lingual glands indicated positive reaction to neutral and acidic mucins. This study demonstrated a morphofunctional relationship of the tongue of a red-eyed dove to its diet.

Chrysotile fibers in tissue adjacent to laryngeal squamous cell carcinoma in cases with a history of occupational asbestos exposure.

Asbestos describes a group of naturally occurring fibrous silicate mineral compounds that have been associated with a number of respiratory maladies, including mesothelioma and lung cancer. In addition, based primarily on epidemiologic studies, asbestos has been implicated as a risk factor for laryngeal and pharyngeal squamous cell carcinoma (SCC). The main objective of this work was to strengthen existing evidence via empirical demonstration of persistent asbestos fibers embedded in the tissue surrounding laryngeal and pharyngeal SCC, thus providing a more definitive biological link between exposure and disease. Six human papillomavirus (HPV)-negative laryngeal (n = 4) and pharyngeal (n = 2) SCC cases with a history working in an asbestos-exposed occupation were selected from a large population-based case-control study of head and neck cancer. A laryngeal SCC case with no history of occupational asbestos exposure was included as a control. Tissue cores were obtained from adjacent nonneoplastic tissue in tumor blocks from the initial primary tumor resection, and mineral fiber analysis was performed using a scanning electron microscope equipped with an energy dispersive X-ray analyzer (EDXA). Chrysotile asbestos fiber bundles were identified in 3/6 of evaluated cases with a history of occupational asbestos exposure. All three cases had tumors originating in the larynx. In addition, a wollastonite fiber of unclear significance was identified one of the HPV-negative pharyngeal SCC cases. No mineral fibers were identified in adjacent tissue of the case without occupational exposure. The presence of asbestos fibers in the epithelial tissue surrounding laryngeal SCC in cases with a history of occupational asbestos exposure adds a key line of physical evidence implicating asbestos as an etiologic factor.

Anatomical investigations of the tongue and laryngeal entrance of the Egyptian laughing dove Spilopelia senegalensis aegyptiaca in Egypt.

In the present work, the first full anatomical description of the tongue and laryngeal entrance of the Egyptian laughing dove Spilopelia senegalensis aegyptiaca, which was obtained with the aid of scanning electron microscopy (SEM) and histological techniques, is provided. The lingual apex was rounded and the cranially convex papillary crest exhibited a transverse papillary row, in addition to another row consisting of two giant papillae. Papillae were not observed on the elevated, triangular laryngeal mound except for the glottic opening, which was bounded by two lateral elevated borders that presented a row of small papillae. Two fissures occurred on the laryngeal mound: a rostral fissure at the rostral border of the laryngeal mound, and a caudal fissure that occurred caudally to the glottic opening and continued caudally as the laryngeal fissure. SEM analysis showed filiform papillae on the dorsal surface of the apex and body, and indicated that each giant papilla was long with a pointed apex and exhibited one or two secondary papillae on its surface. The dorsal surface of the lingual root exhibited numerous openings of the lingual salivary glands. The caudal part of the laryngeal mound presented numerous openings of the laryngeal salivary glands. Histologically, the dorsal surface of the anterior and middle lingual part was covered with a thick and stratified squamous epithelium. The anterior and middle lingual part presented entoglossum cartilaginous ossification of the entoglossal bone, which had numerous chondrocytes lodged within the lacunae of the entoglossum. The lingual glands appeared in the middle and caudal lingual part.

Transmission Electron Microscopy of the Presbylarynx in the Process of Voice Aging.

INTRODUCTION: Microscopy studies of presbylarynx have identified epithelial atrophy, as well as vocal muscle atrophy, increased collagen, and decreased nonfibrous proteins of the extracellular matrix. Studies on the ultrastructure of presbylarynx are rare and can help us understand the pathophysiology of presbyphonia. OBJECTIVE: To describe details on the ultrastructure of presbylarynx by transmission electron microscopy (TEM). SUBJECTS AND METHODS: Sixteen human larynges were removed and distributed in two groups: control (n = 8; 30-50 years; six females, two males) and seniors (n = 8; 75-92 years; six females, two males). After preparation for TEM, the specimens, including epithelium and lamina propria, were examined and photographed at increasing magnification. RESULTS: Control: the epithelium was intact, with overlapped cells, and with desmosomes between the intercellular junctions. The basement membrane was continuous and uniform, and the lamina propria contained collagen and elastic fibers in a regularly distributed loose arrangement, as well as some fibroblasts of different shapes. Senior: the epithelial cells were separated by enlarged intercellular junctions. The basement membrane was delicate and continuous. In the lamina propria there was predominance of elongated fibroblasts. Under the basement membrane a dense network of collagen fibers could be identified. CONCLUSIONS: In this study with TEM some structural changes were identified, particularly in the larynx of the elderly, both in the epithelium and lamina propria, some of them with likely participation of fibroblasts, which reinforces the importance of additional ultrastructure as well as molecular studies targeting those cells, as they are the main precursors of the components of the extracellular matrix.

A Method to Administer Agents to the Larynx in an Awake Large Animal.

Purpose: This research note describes an adapted experimental methodology to administer an exogenous agent to the larynx and upper airway of awake animals. The exogenous agent could be a perturbation. In the current study, the agent was isotonic saline. Isotonic saline was selected because it is safe, of similar composition to extracellular fluid, and used in voice studies. The described approach allowed large animals such as pigs to be comfortably restrained without chemical sedation or anesthesia for extended periods while receiving the agent. Method: Six Sinclair pigs were successfully trained with positive reinforcement to voluntarily enter and then be restrained in a Panepinto Sling. Once restrained, the pigs accepted a nose cone that delivered nebulized isotonic saline. This procedure was repeated 3 times per day for 20 days. At the end of the study, the larynx and airway tissues were excised and examined using histology and transmission electron microscopy. Results: Pathology related to the procedure (i.e., nebulized inhaled isotonic saline or stress) was not identified in any examined tissues. Conclusions: This methodology allowed for repeated application of exogenous agents to awake, unstressed animals. This method can be used repeatedly in the laboratory to test various therapeutics for safety, toxicity, and dosage. Future studies will specifically manipulate the type of agent to further our understanding of laryngeal pathobiology.

Morphological Characteristics of the Oropharyngeal Cavity (Tongue, Palate and Laryngeal Entrance) in the Eurasian Coot (Fulica atra, Linnaeus, 1758).

The present study represents the first definitive anatomical description of the oropharyngeal cavity of the coot Fulica atra. For this purpose, the organs of six birds were prepared to examine grossly and by SEM and stereomicroscope. The oval lingual apex had multiple overlapping branched acicular processes on its anterior and lateral border. The lingual apex and body had multiple caudally directed filiform-like papillae. By stereomicroscopy, the lingual root had a characteristic appearance and consisted of four parts. The openings of the anterior glands were present on the dorsal lingual surface of the body, while the projected papillae with wide openings of the posterior glands were present on the dorsal surface of lingual root. There was a row of caudally directed pharyngeal papillae at the caudal border of the laryngeal mound. Grossly, the pharyngeal papillae arrangement took a W-shape, while by stereomicroscopy was observed to be heart shape. The palate was divided into two regions: a small rostral non-papillary and a large caudal papillary region, but the rostral region was characterized by the presence of three longitudinal ridges. The papillary crest had two paramedian longitudinal papillary rows, which continued caudally until the beginning of the third median row. The freely distributed papillae took a caudolateral direction, while the papillae encircling the rostral part of choanal cleft took a caudomedial direction. There was a transverse papillary row between the two parts of choanal cleft. There was a transverse papillary row between the caudal border of the infundibular cleft and oesophagus.

Morphological features of the tongue and laryngeal entrance in two predatory birds with similar feeding preferences: common kestrel (Falco tinnunculus) and Hume's tawny owl (Strix butleri).

The aim of this investigation was to describe the morphological characters of the tongue of two predatory birds with similar feeding preferences, i.e. the common kestrel and Hume's tawny owl. Descriptive information on the lingual morphology of these two birds, particularly Hume's tawny owl, is incomplete. We found that the lingual apex of the owl has an oval, concave, shovel-like form with a bifid lingual tip, while that of the kestrel has the shape of a horny tip-like spoon with a central process in addition to there being several filiform-like papillae on the dorsal surface of the apex and body. In the owl, the dorsal surface of the apex and body is subdivided into four U-shaped regions: lingual tip, two lateral regions and a median region. The two lateral regions are characterized by the presence of papillae and several openings of lingual glands, while the median region carries filiform-like papillae. In both birds, the papillary crest is located between the body and root. In the kestrel, there is an additional row of papillae rostral to crest, while in the owl there is a rostral lateral extension of papillae on the lateral lingual surface so the distribution pattern has a W-shape. In the kestrel, the posterior part of lingual body has several openings of glands, while the root lacks glands completely, although it has many taste buds. In the owl, the lingual root is folded and has a large number of gland openings. In the kestrel caudally to the glottis, there are two paramedian transverse rows of pharyngeal papillae with a pair of median huge papillae, while in the owl, there is only one transverse row of papillae. The dorsal and ventral lingual surfaces of both birds are lined with non-keratinized stratified squamous epithelium.

The influence of low-dose cadmium on the laryngeal microstructure and ultrastructure of Pelophylax nigromaculata.

Cadmium (Cd) is one of the common heavy metals dispersed throughout the modern environment that disrupts the development of aquatic organisms. Amphibians appear to be particularly vulnerable to this heavy metal contaminant since their eggs and aquatic larvae live in aquatic habitats and have permeable skin. During this critical sensitive period, amphibians live primarily in the water and are thus susceptible to the effects of environmental pollutants in water. Pelophylax nigromaculata completes their laryngeal development from Gosner stage 19 (GS 19, embryonic stage) to GS 46 (metamorphosis stage). To study whether long-term (from GS 19 to GS 46) exposure to low Cd concentrations (0, 4, 8, 16, 32, 64, and 128 µg/L) affects the development of the larynx in P. nigromaculata, a comparative study of microstructures and ultrastructures of female and male P. nigromaculata larynges was carried out. In histological structure, the larynx was composed of epithelial tissue, skeletal muscle, and hyaline cartilage, and there were no differences between male and female frogs except that males had a larger cross-section area than females. In contrast to controls, 64 and 128 µg/L Cd treatments caused a significant decrease in cross-sectional area, while other treatments showed no significant differences. Under the scanning electron microscope, the surface of the larynx could be seen to be attached to developed and evenly distributed cilia, with no significant differences between young male and female frogs, even among the Cd treatments. Under transmission electron microscopy, developed laryngeal epithelial cells could be observed, with obvious cross striations of skeletal muscle cells and mitochondria distributed around the muscle and skeletal muscle satellite cells. Compared with the control group, mitochondria around the skeletal muscle grew in size and decreased in number in the high-concentration treatment.

Scanning electron microscopy of the tongue, pharynx, and larynx of rats exposed to cigarette smoke.

OBJECTIVE: To examine, by using scanning electron microscopy, the surface of the tongue, pharynx, and larynx of animals exposed to tobacco. STUDY DESIGN: Experimental study. METHODS: Twenty rats were allocated to two groups: group I, control group: 10 rats not exposed to any inhaling pollutant and group II, tobacco group: 10 rats exposed to smoke from 10 cigarettes twice a day for 260 days. Animals of both groups had no restriction of food or water. After those 260 days, their aerodigestive segment was removed, and fragments of their tongue, hypopharynx, and right vocal fold were immersed in 2.5% glutaraldehyde and prepared for scanning electron microscopy. RESULTS: The filiform tongue papillae of the tobacco group were irregularly displayed, flattened, and adhered to each other. The hypopharynx mucosa was highly irregular, thickened, rough and had increased superficial peeling. The mucosa of the vocal folds had deep furrows surrounding the cells. These alterations were not identified for the control group. CONCLUSION: Several changes were recorded for the tongue, pharynx, and larynx of tobacco group animals, confirming the harmful effects of smoking to the respiratory and digestive epithelium.

Dilated intercellular space in the larynx and esophagus of a rabbit reflux model.

OBJECTIVE: In this study, we investigated histological and electron microscopic changes of the laryngeal and esophageal epithelium in an animal model of reflux to demonstrate: (1) the association between laryngopharyngeal reflux (LPR) and gastroesophageal reflux disease (GERD) and (2) the value of dilated intercellular space (DIS) as a marker of LPR. METHODS: Eight New Zealand albino rabbits were utilized. Four rabbits underwent total cardiomyectomy to induce reflux. The remains underwent a sham operation as controls. The animals were sacrificed 12 weeks after surgery to obtain histological and electron microscopic results. RESULTS: There were significant differences in the histological results between the study group and the control group in both the esophagus and the larynx (P=0.041 and 0.014). Significant changes in the intercellular space (IS) were observed between the study group and the control group in the esophageal and laryngeal samples (P<0.001). CONCLUSION: The results of this study suggest that LPR and GERD have a common mechanism and DIS is a morphologic marker of LPR in rabbits.

Anatomical and scanning electron microscopic investigations of the tongue and laryngeal entrance in the long-legged buzzard (Buteo rufinus, Cretzschmar, 1829).

This research aimed to examine the morphological features of the tongue and laryngeal entrance of long-legged buzzard by macroscopic and scanning electron microscopic methods. Two adult buzzards were used as material. The tongue was fairly elongated and terminated in oval shovel-like apex. Scale-like projections were localized on the apex and body of tongue. Both lateral sides of lingual body were contained considerably long thread-like projections. Many orifices of lingual posterior salivary glands were discerned among scale-like projections in median sulcus of the lingual body. Papillary crest of sharp conical papilla were observed on the between the body and root of the tongue. No conical papillae or other projections were existent on the root of the tongue, but numerous orifices of posterior salivary gland ducts were detected. In addition, orifices of anterior salivary gland ducts were present on the dorsal and lateral surfaces of the lingual body. Numerous conical papillae were observed on the caudal region of glottis and no conical papillae or any similar projection which were bordered the glottic fissure was noted. Anatomy of these organs in the long-legged buzzard and white tailed eagle which are the member of the same family, Accipitridae, revealed very high similarity.

Optical microscopy of the pediatric vocal fold.

OBJECTIVES: To compare and contrast 4 optical imaging techniques for evaluating the developing microstructure of the pediatric vocal fold and to identify the optimal strategy for in vivo imaging. DESIGN: Prospective study. SETTING: Academic medical center. PATIENTS: A total of 6 laryngeal specimens: 5 pediatric (ages 10 months to 16 years) (4 from cadavers and 1 from a living patient immediately after laryngectomy) and 1 cadaveric young adult specimen (age, 23 years). INTERVENTION: Sequential noninvasive optical imaging of pediatric vocal fold specimens using optical frequency domain imaging (OFDI), angle-resolved OFDI (AR-OFDI), spectrally encoded confocal microscopy (SECM), and full-field optical coherence microscopy (FF-OCM), followed by fixation, sectioning, and histologic analysis of the same specimen for comparison. MAIN OUTCOME MEASURE: Correlation between the microstructure observed using the 4 noninvasive optical imaging techniques and with the results of histopathologic analysis for the same specimen. RESULTS: A successful in vivo imaging technique for developmental assessment of the pediatric vocal fold would include visualization of distinct layers (epithelium, lamina propria, and muscularis mucosa) and allow for identification of the individual cells composing the layers. The OFDI and AR-OFDI techniques provide a global assessment of the microstructure of the pediatric vocal fold to a depth of 1200 mum but lack the ability to distinguish cellular and subcellular structures. The FF-OCM technique allows for visualization with improved cellular detail (1-mum resolution), but the image acquisition speed is too slow for clinical use. The SECM technique has a faster acquisition rate and shows good cellular and subcellular detail to a depth of 250 mum. CONCLUSIONS: The OFDI and SECM techniques were identified as promising and complementary candidates for in vivo cellular and subcellular imaging of the epithelium, basement membrane, and lamina propria of the pediatric vocal fold. To further validate the clinical potential of these techniques, a handheld SECM probe has been developed and demonstrated for in vivo evaluation of the pediatric vocal fold.

Effect of irradiation on the human laryngeal glands.

OBJECTIVES: The present study was conducted to determine the effects of irradiation on the human laryngeal glands. METHODS: Light and transmission electron microscopic observations were made. RESULTS: Granular endoplasmic reticula and Golgi apparatuses were sparse in the cytoplasm of serous and mucous cells in cases with a short duration after radiotherapy. The secretory granules in serous cells had decreased in number. The secretory granules were less electron-dense compared to those in non-irradiated specimens, but were electron-lucent. The mucigen droplets in mucous cells were not as numerous as those in non-irradiated specimens. The discharge of secretory granules and mucigen droplets had decreased. In cases with a long duration after radiotherapy, there were some granular endoplasmic reticula and Golgi apparatuses in the cytoplasm. However, the transmission electron microscopy findings of secretory granules and mucigen droplets were the same as those in the irradiated glands with a short duration after radiotherapy. CONCLUSIONS: Morphological changes in the irradiated laryngeal glands influenced not only the amount but also the quality of secretions. The above changes lessened the lubrication of the vocal folds, thus causing a voice disorder to some extent. Local immunity and mucociliary transport were also affected. The effects of irradiation on the laryngeal glands partially altered the laryngeal functions.

Mutational falsetto: intervention outcomes in 45 patients.

OBJECTIVE: The aim of this study was to evaluate the outcomes of therapeutic intervention in patients with mutational falsetto, by applying perceptual and acoustic analysis before and after voice therapy. MATERIALS AND METHODS: Forty-five consecutive patients with mutational falsetto were studied retrospectively. Acoustic analysis (i.e. fundamental frequency, jitter, shimmer, and formants one, two and three) was performed using the Multi-Dimensional Voice Program. Perceptual voice analyses were performed, including graded severity-roughness-breathiness-aesthenicity-strain assessment. RESULTS: Subjects' fundamental frequency, voice formants one, two and three, jitter, and shimmer were greater before than after treatment. There were statistically significant differences between pre- and post-treatment average values for fundamental frequency, jitter and shimmer. There were also statistically significant differences between pre- and post-treatment average values for formants one and two. These results were maintained after six months of follow up, and there was no significant difference between results at three- and six-month follow up. According to perceptual evaluation, each subject's voice had altered from mutational falsetto to chest voice by completion of the intervention. Thus, all of the patients successfully lowered their modal speaking voice to an appropriate level. CONCLUSION: In the light of objective evaluations, and by applying the study treatment protocol, these results suggest that normal voice can be maintained after intervention, at six months' follow up.

[Laryngectomy as a salvage procedure of the patients with massive postradiation injury of the larynx]. / Laryngektomia jako postepowanie ratujace u chorych z nasilonym odczynem popromiennym po radioterapii raka krtani.

INTRODUCTION: Author discusses problems and treatment principles of patients with massive postradiation injury, who had laryngectomy procedure as a result of insufficience of the farmacological treatment. MATERIAL AND METHODS: There were 12 patients who were performed laryngectomy as a treatment of massive postradiation injury of the larynx in the period 1975-2005. We suspected presence of persistent neoplasm with postradiation changes. Seven laryngectomies were performed after confirmation of the neoplasm in 1-3 biopsies. Three patients were treated operatively without this confirmation in spite of two biopsies which were negatively, and two patients were treated in this way without biopsies. RESULTS: Two patients had tomour free postlaryngectomy specimens in the histopathological examinations, and among 10 others the reccurence of the tumour after radiotherapy was present during the post-laryngectomy histopathological examinations. In 7 cases this reccurence was proved with massive postradiation injury in endoscopic biopsies before laryngectomy. DISCUSSION: Author presents his own problems and presents methods of treatment of the patients with massive postradiation injury of the larynx described in literature.

Morphological and Histochemical Analysis of the Human Vestibular Fold / Análisis Morfológico e Histoquímico del Pliegue Vestibular Humano

A morphological and histochemical study of the human vestibular fold was carried out using routine histological techniques. Seven µm-thick histo logical sections stained with hematoxylin-eosin (HE) and Callej a showed the presence of elastic collagen fibers and seromucous glands in the vestibular fold. Muscle fibers forming the ventricular muscle were also identified. Ultrastructural analyses of the epithelial layer by scanning electron microscopy (SEM) revealed ciliated cells and gland ducts opening on the epithelial surface. Histochemical analyses were performed on ventricular muscles submitted to nicotinamide-adenine-dinucleotide tetrazolium reductase (NADH-TR), succinate dehydrogenase (SDH), and myofibrillar adenosine triphosphatase (mATPase) reactions. Based on these reactions, it was observed that the muscle is formed by three types of muscle fibers: slow-twitch oxidative (SO), fast-twitch oxydative glycolytic (FOG) and fast-twitch glycolytic (FG) fibers distributed in a mosaic pattern. The fiber frequency was 22.7%, 69.9% and 7.4%, respectively. The higher frequency of SO and FOG fibers characterized the muscle as having aerobic metabolism and resistance to fatigue. The ventricular muscle was considered fast. The study of the neuromuscular junctions performed after nonspecific esterase reaction showed that they are of the en-plaque type and have multiple occurrences in the ventricular muscle.

Fue realizado un estudio morfológico e histoquímico del pliegue vestibular humano a través de técnicas histológicas de rutina. Cortes histológicos de 7µm de grosor fueron teñidos con HE y Calleja, los cuales revelaron la presencia de fibras colágenas, elásticas y glándulas seromucosas en el pliegue vestibular. También fueron identificadas fibras musculares que constituyen el músculo ventricular. Los análisis ultraestruturales de la capa epitelial realizados a través de microscopía electrónica de barrido, mostraron la presencia de células ciliadas, caliciformes y abertura de conductos glandulares en la superficie epitelial. Los análisis histoquímicos fueron realizados con músculos ventriculares sometidos a las reacciones NADH-TR, SDH y mATPasa. En base en estas reacciones se observó que el músculo está constituido por tres tipos de fibras musculares SO, FOG y FG, distribuidas en la forma de mosaico. La frecuencia de las fibras fue de 22,7%, 69,9% e 7,4%, respectivamente. La mayor frecuencia de fibras oxidativas SO+FOG caracterizó al músculo, con metabolismo aeróbico, resistente a la fatiga. El músculo ventricular fue considerado como rápido. El estudio de las uniones neuromusculares, después de la reacción de la esterasa inespecífica, evidenció que estas uniones son del tipo placa y de ocurrencia múltiple en el músculo ventricular.

Annexin 1: differential expression in tumor and mast cells in human larynx cancer.

Annexin 1 protein (ANXA1) expression was evaluated in tumor and mast cells in human larynx cancer and control epithelium. The effect of the exogenous ANXA1 (peptide Ac 2-26) was also examined during the cellular growth of the Hep-2 human larynx epidermoid carcinoma cell line. This peptide inhibited the proliferation of the Hep-2 cells within 144 hr. In surgical tissue specimens from 20 patients with larynx cancer, ultrastructural immunocytochemistry analysis showed in vivo down-regulation of ANXA1 expression in the tumor and increased in mast cells and Hep-2 cells treated with peptide Ac2-26. Combined in vivo and in vitro analysis demonstrated that ANXA1 plays a regulatory role in laryngeal cancer cell growth. We believe that a better understanding of the regulatory mechanisms of ANXA1 in tumor and mast cells may lead to future biological targets for the therapeutic intervention of human larynx cancer.

Receptor-mediated uptake of pepsin by laryngeal epithelial cells.

OBJECTIVES: Previous data suggest a mechanistic link between exposure to pepsin and cellular changes that lead to laryngopharyngeal disorders. Initial confocal microscopy analysis of pepsin uptake by cultured hypopharyngeal epithelial cells revealed that pepsin may be taken up by a specific process. The objective of this study was to use electron microscopy to confirm the initial confocal findings and to determine whether uptake of pepsin by laryngeal epithelial cells is receptor-mediated. METHODS: Cultured human hypopharyngeal FaDu cells and human laryngeal biopsy specimens, taken from the posterior larynx of "control" patients without symptoms or findings of laryngopharyngeal reflux, were exposed to purified human pepsin 3b with or without transferrin (a marker for receptor-mediated endocytosis) in vitro. Uptake of pepsin was documented by electron microscopy. RESULTS: Pepsin co-localized with transferrin in intracellular vesicles; this finding confirms that pepsin is taken up by laryngeal epithelial cells by receptor-mediated endocytosis. CONCLUSIONS: This is a novel finding that further defines the role and mechanism of pepsin-mediated injury in laryngopharyngeal reflux. The objective of ongoing research is to identify the receptor and investigate potential antagonists as a new therapeutic option for patients with reflux-attributed disease--in particular, those patients who have persistent symptoms despite acid suppression therapy.

In vivo optical coherence tomography of the human larynx: normative and benign pathology in 82 patients.

OBJECTIVES: Optical coherence tomography (OCT) is an emerging imaging modality that combines low-coherence light with interferometry to produce cross-sectional images of tissue with resolution about 10 mum. Patients undergoing surgical head and neck endoscopy were examined using a fiberoptic OCT imaging probe to study and characterize microstructural anatomy and features of the larynx and benign laryngeal pathology in vivo. STUDY DESIGN: Prospective clinical trial. MATERIALS AND METHODS: OCT imaging of the larynx was performed in 82 of 115 patients who underwent surgical endoscopy for various head and neck pathologies. The OCT device employs a 1.3 microm broadband light source (FWHM, 80 nm). The frame rate is 1 Hz. Imaging was performed using a handheld probe placed in near contact with the target site. The maximum axial and lateral dimensions for the region of interest imaged were 2.5 mm x 6 mm, with resolutions of 10 microm. Simultaneously, conventional endoscopic images were obtained to provide anatomic correlation with OCT images and histology. Optical micrometry was performed to measure the epithelium thickness. RESULTS: Systematic OCT imaging of laryngeal structures and subsites provided information on the thickness of the epithelium, integrity of the basement membrane, and structure of the lamina propria. Microstructural features identified included glands, ducts, blood vessels, fluid collection/edema, and the transitions between pseudostratified columnar and stratified squamous epithelium. The mean epithelial thickness of laryngeal subsites was calculated: true vocal cord (129 microm), false vocal cords (124 microm), aryepiglottic fold (177 microm), subglottis (98 microm), and epiglottis (185 microm). True vocal cord pathology imaged included Reinke's edema, papillomatosis, polyps, mucous cysts, and granulation tissue. Subglottic imaging identified boundaries between epithelium, lamina propria, and cartilage. The OCT images compared favorably with conventional histopathology. CONCLUSION: OCT has the unique ability to image laryngeal tissue microstructure and can detail microanatomic changes in benign, premalignant, and malignant laryngeal pathologies. OCT holds the potential to guide surgical biopsies, direct therapy, and monitor disease, particularly when office-based systems are developed. This is a promising imaging modality to study the larynx.

Characterisation of adherens and tight junctional molecules in normal animal larynx; determining a suitable model for studying molecular abnormalities in human laryngopharyngeal reflux.

BACKGROUND: The disruption of intercellular junctions in the larynx is a pathological feature of laryngopharyngeal reflux (LPR). Good experimental models are necessary to gain greater insight into the molecular mechanisms and alterations that result from abnormal exposure of the laryngeal epithelium to acid refluxate. AIMS: To characterise laryngeal tissues from different species to determine the most suitable for use in experimental studies of LPR. METHODS: Human and non-human laryngeal tissues (mouse, rat, guinea pig, porcine, and rabbit) were studied. Histological characterisation was performed by light microscopy. The expression and subcellular localisation of adherens junctional molecules (E-cadherin and beta catenin) was evaluated by immunohistochemistry, and tight junction molecules (occludin and zonula occludens 1 (ZO-1)) by western blotting. The ultrastructural features of porcine and human tissue were assessed by electron microscopy. RESULTS: Porcine tissue revealed both respiratory-type and stratified squamous epithelium, as seen in the human larynx. The expression and subcellular localisation of the E-cadherin-catenin complex was detected in all species except mouse and rat. The pattern of ZO-1 and occludin expression was preserved in all species. CONCLUSION: The expression of intercellular junctional complexes in porcine epithelium is similar to that seen in humans. These results confirm the suitability of these species to study molecular mechanisms of LPR in an experimental system.