Immunohistochemical study on distribution of mast cell phenotypes in human laryngeal mucosa: evidence for laryngeal type I allergy.

It is controversial whether or not type I allergic reactions can occur in the human laryngeal mucosa. To clarify this issue, we studied the distribution of mast cell phenotypes in the human laryngeal mucosa using the immunohistochemical staining method with antihuman tryptase and chymase antibodies. A large number of mast cells are present in the superficial layer of subepithelial connective tissue (SECT) of the epiglottis, arytenoid, and subglottis. Although mast cells containing both tryptase and chymase are predominant in the deep layer of the SECT, the majority of mast cells containing tryptase alone are located in both the epithelial layer and the superficial layer of the SECT. We conclude that the human laryngeal mucosa has the potential to induce type I allergic reaction.

Laryngeal manifestation of gout: a case report of a subglottic gout tophus.

A subglottic tophaceous deposition of urate crystals is a rare finding. We report on a case of a male Caucasian who had a moderate dysphonia without any further laryngeal symptoms. The laryngoscopy revealed a hemispheric lesion on the left subglottic region. An excision biopsy was performed, and the histopathological examination of the dissected specimen showed a tophus. Diagnostic and therapeutic strategies are discussed.

Osteoarthritis in cricoarytenoid joint.

OBJECTIVE: Occurrence of osteoarthritis is a frequent event of limb joints in people over 40 years of age. The human cricoarytenoid joint is comparable with the joints of the limbs despite its structure and extracellular matrix composition. To date, little is known about the occurrence of osteoarthritis in the human cricoarytenoid joint. METHODS: Sixty-eight cricoarytenoid joints (42 male and 26 female, age 25-98 years) were analysed by means of histology, lectin histochemistry, immunohistochemistry as well as scanning and transmission electron microscopy. RESULTS: About 50% of the investigated cricoarytenoid joints aged over 40 years show degenerative changes in their joint surface structure at varying levels of intensity. The articular cartilage surface is fibrillated in some places and sometimes shows fissures. A demascing of collagen fibrils next to the joint surface and a loss of proteoglycans in the upper cartilage layers can be observed. Chondrocytes near the joint surface appear as voluminous chondrocyte clusters. The clusters and the superficial cartilage layer show a positive reaction to type VI collagen antibodies. The distribution patterns of lectins are completely changed in fibrillated cartilage areas. CONCLUSION: Degenerative alterations in diarthrodial joints resembling osteoarthritis can occur in the joints of the larynx. These structural changes of the articular cartilage are comparable to osteoarthritis of the limb joints. Osteoarthritis in the cricoarytenoid joint may lead to impaired movements of the arytenoid cartilages. Functionally the structural changes may lead to negative consequences during vocal production, such as impaired vocal quality and reduced vocal intensity.

Composition of the extracellular matrix in human cricoarytenoid joint articular cartilage.

The extracellular matrix of the human cricoarytenoid joint articular cartilage is involved in different pathological changes. Interestingly, in contrast to the limb joints, the extracellular matrix composition of the healthy cricoarytenoid joint articular cartilage has not yet been elucidated except by some light microscopical investigations. The present study investigates the extracellular matrix components of the cricoarytenoid joint articular cartilage by means of light microscopy, immunohistochemistry, transmission electron microscopy and scanning electron microscopy and compares them with the limb joints for a better understanding of their involvement in joint disease. Chondrocytes near the joint surface of the cricoid and arytenoid cartilage differ from chondrocytes of deeper cartilage layers. The extracellular matrix of the articular cartilage contains chondroitin-4-sulfate, chondroitin-6-sulfate and keratansulfate as well as collagen types II, III, VI, IX and XI. Type-III-collagen shows a special distribution throughout the joint cartilage. In deeper cartilage layers, type-III-collagen occurs only pericellularly; in higher cartilage layers type-III-collagen is also located territorially and interterritorialy in small amounts. Scanning and transmission electron microscopy have revealed the articular surface of the cricoid and arytenoid cartilage to consist of a network of irregularly organized collagen fibrils, which are lined by a layer of electron dense material. The network coats subjacent collagen bundles which descend obliquely downward and intermingle at right angles in the middle part of the articular cartilage with collagen bundles of the deeper cartilage zones. The articular cartilage surface shows structural characteristics which differ from the underlying cartilage. The superficial electron dense layer possibly plays a role in the lubrication of the articular cartilage surface. The alignment of the fibrillar structures in the articular cartilage of the cricoarytenoid joint varies from those of the limb joints based on the different strain occurring during arytenoid movement. Nevertheless, the human cricoarytenoid joint articular cartilage can be compared with the joints of the limbs despite its extracellular matrix composition and its involvement in joint pathology. Evidence of type III collagen in the outermost layer of the articular cartilage of the cricoarytenoid joint presents a peculiarity, which has yet not be demonstrated in the articular cartilage of limb joints.

[Motor innervation of the canine arytenoid muscle].

Dual motor innervation by the bilateral recurrent laryngeal nerves (RLNs) has been demonstrated in the human arytenoid muscle (AR). Whether AR of the dog receives dual motor innervation remains to be cleared yet, although the canine larynx is frequently used in experimental studies. To answer this question, the author observed the muscular structure in detail and anastomotic nerve branch between the bilateral RLNs, and then carried out glycogen depletion experiments on AR of dog compared with typical unpaired ARs of monkey and of guinea pig. 1) Muscular structure AR of the dog consisted of three parts of muscle bundles: the transverse arytenoid muscle (TVA), ventricular muscle (VT) and anonymous small bundle provisionally named the smaller interarytenoid muscle (IAm). While TVA and VT were paired type, IAm was unpaired type and lay horizontally on the dorsal aspect of the sesamoid cartilage around the midline. So the canine AR displayed a trigastric muscle as a whole. 2) Anastomotic nerve branch By the vital staining with methylene blue, the arytenoid branch of canine RLN ramified in three directions: anteriorly to the bellies of TVA and VT, medially to the anastomotic branch and superomedially to IAm. By the silver impregnation method of Barker and Ip, the bilateral IAm ramuli were found to form collateral anastomoses and terminate disorderly on the individual fibers. 3) Glycogen depletion experiments When an electrical stimulation was applied to the unilateral RLN in the monkey and the guinea pig, about one half of AR fibers were unstained with PAS staining and, in turn, these unstained fibers were known to be innervated by the ipsilateral RLN. While these unpaired ARs receive dual motor innervation as a whole muscle, every individual fiber is innervated by the unilateral RLN. In the canine VT and TVA, almost 90% of fibers were depleted of glycogen on the belly of the stimulated side, while the reverse was on the nonstimulated side. This finding suggests that most fibers of canine VT and TVA are ipsilaterally and the remaining fibers are contralaterally innervated. About one half of fibers of IAm were unstained and the others were stained. This pattern was similar to that observed in the monkey and the guinea pig. Therefore, IAm receives dual motor innervation from both RLNs as a whole muscle.