Sulfated glycosaminoglycans in human vocal fold lamina propria / Glicosaminoglicanos sulfatados na lâmina própria de prega vocal humana

Abstract Introduction: The distribution, concentration and function of glycosaminoglycans in the various vocal fold tissues are still unclear. Objective: To evaluate the distribution and concentration of sulfated glycosaminoglycans in different layers of the human vocal fold according to gender and age. Methods: We used 11 vocal folds obtained from cadavers (7 men and 4 women) with no laryngeal lesion, less than 12 h after death, and aged between 35 and 98 years. The folds underwent glycosaminoglycans extraction from the cover and ligament, and post-electrophoresis analysis. Data were compared according to the layer, age and gender. Results: The concentration of dermatan sulfate was significantly higher in all layers. No differences were observed in the total concentrations of glycosaminoglycans in layers studied according to gender. It is significantly lower in the cover of individuals aged below 60 years. Conclusion: Dermatan sulfate, chondroitin sulfate, and heparan sulfate were observed in the human vocal folds cover and ligament of both genders, with the concentration of dermatan sulfate being significantly higher in all layers. Glycosaminoglycans concentration on the cover is significantly lower in individuals below 60 years compared with elderly.

Resumo Introdução: A distribuição, concentração e função dos glicosaminoglicanos nos diversos tecidos da prega vocal ainda não está esclarecida. Objetivo: Avaliar a distribuição e concentração dos glicosaminoglicanos sulfatados nas diferentes camadas da prega vocal humana de acordo com o sexo e a idade. Método: Foram usadas 11 pregas vocais obtidas de cadáveres (sete homens e quatro mulheres) sem lesão de laringe, com menos de 12 horas de óbito e entre 35 e 98 anos. As pregas foram submetidas à extração de glicosaminoglicanos da cobertura e ligamento e leitura pós-eletroforese. Os dados foram comparados segundo camada, idade e sexo. Resultados: A concentração de dermatan sulfato foi significativamente maior em todas as camadas. Não foram observadas diferenças nas concentrações totais de glicosaminoglicanos nas camadas estudadas quanto ao gênero. É significantemente menor em indivíduos abaixo de 60 anos na cobertura. Conclusão: Dermatam sulfato, condroitim sulfato e heparam sulfato foram observados na cobertura e no ligamento de pregas vocais humanas, de ambos os sexos, sendo a concentração de dermatam sulfato foi significativamente maior em todas as camadas. A concentração de glicosaminoglicanos na cobertura é significativamente menor em indivíduos abaixo de 60 anos em comparação com idosos.

Sulfated glycosaminoglycans in human vocal fold lamina propria.

INTRODUCTION: The distribution, concentration and function of glycosaminoglycans in the various vocal fold tissues are still unclear. OBJECTIVE: To evaluate the distribution and concentration of sulfated glycosaminoglycans in different layers of the human vocal fold according to gender and age. METHODS: We used 11 vocal folds obtained from cadavers (7 men and 4 women) with no laryngeal lesion, less than 12h after death, and aged between 35 and 98 years. The folds underwent glycosaminoglycans extraction from the cover and ligament, and post-electrophoresis analysis. Data were compared according to the layer, age and gender. RESULTS: The concentration of dermatan sulfate was significantly higher in all layers. No differences were observed in the total concentrations of glycosaminoglycans in layers studied according to gender. It is significantly lower in the cover of individuals aged below 60 years. CONCLUSION: Dermatan sulfate, chondroitin sulfate, and heparan sulfate were observed in the human vocal folds cover and ligament of both genders, with the concentration of dermatan sulfate being significantly higher in all layers. Glycosaminoglycans concentration on the cover is significantly lower in individuals below 60 years compared with elderly.

Influence of aging on hyaluronic acid concentration in the vocal folds of female rats.

UNLABELLED: The vibration of the vocal fold lamina propria is an important factor involved in vocal production and aging may change the amount of hyaluronic acid in the vocal fold leading to dysphonia. AIMS: This study compares the concentration of hyaluronic acid in vocal folds of aged and young female rats. STUDY DESIGN: experimental. MATERIALS AND METHODS: We used the vocal cords of 13 female rats divided into two groups: five aged rats and eight young ones. The tissue concentration of hyaluronic acid was determined using the fluorimetric method with the hyaluronic acid binding-protein coated on plates of enzyme-linked immunosorbent assay (ELISA), conjugated with biotin. Europium-labeled streptavidin was added and, after europium release with the use of enhancement solution, the final fluorescence was measured in a fluorometer. RESULTS: We found the following concentrations of hyaluronic acid in vocal fold according to the group: 581.7 ng/mg in old female rats and 1275.6 ng/mg in young female rats. Statistical analysis showed differences between groups. CONCLUSIONS: The vocal folds of old female rats have a lower concentration of hyaluronic acid when compared to such concentration on the vocal folds of young female rats.

Influência do envelhecimento na concentração de ácido hialurônico nas pregas vocais de ratas fêmeas / Influence of aging on hyaluronic acid concentration in the vocal folds of female rats

A vibração das pregas vocais é um importante fator envolvido na produção vocal e o envelhecimento pode alterar a quantidade de ácido hialurônico da prega vocal levando a disfonia. OBJETIVO: Este estudo compara a concentração de ácido hialurônico nas pregas vocais de ratas fêmeas idosas e jovens. Desenho do estudo: estudo experimental. MATERIAL E MÉTODO: Foram utilizadas pregas vocais de 13 ratas fêmeas divididas em dois grupos: cinco ratas idosas e oito ratas jovens. A concentração tecidual do ácido hialurônico foi determinada por meio de método fluorimétrico utilizando a proteína de ligação ao ácido hialurônico imobilizada em placas de enzyme-linked immunosorbent assay (ELISA) e também conjugada à biotina. Estreptavidina marcada com európio foi adicionada e, depois de európio ter sido liberado com o uso de solução de enhancement; a fluorescência final foi medida em um fluorímetro. RESULTADOS: Foram encontradas as seguintes concentrações de ácido hialurônico nas pregas vocais de acordo com os grupos: 581,7 ng/mg em ratas idosas e 1275,6 ng/mg em ratas jovens. A análise estatística mostrou diferença entre os grupos. CONCLUSÃO: A prega vocal de ratas idosas tem uma menor concentração de ácido hialurônico do que a concentração da prega vocal de ratas jovens.

The vibration of the vocal fold lamina propria is an important factor involved in vocal production and aging may change the amount of hyaluronic acid in the vocal fold leading to dysphonia. AIMS: This study compares the concentration of hyaluronic acid in vocal folds of aged and young female rats. Study design: experimental. MATERIALS AND METHODS: We used the vocal cords of 13 female rats divided into two groups: five aged rats and eight young ones. The tissue concentration of hyaluronic acid was determined using the fluorimetric method with the hyaluronic acid binding-protein coated on plates of enzyme-linked immunosorbent assay (ELISA), conjugated with biotin. Europium-labeled streptavidin was added and, after europium release with the use of enhancement solution, the final fluorescence was measured in a fluorometer. RESULTS: We found the following concentrations of hyaluronic acid in vocal fold according to the group: 581.7 ng/mg in old female rats and 1275.6 ng/mg in young female rats. Statistical analysis showed differences between groups. CONCLUSIONS: The vocal folds of old female rats have a lower concentration of hyaluronic acid when compared to such concentration on the vocal folds of young female rats.

Vocal polyps: clinical, morphological, and immunohistochemical aspects.

OBJECTIVES: To study the clinical, morphological, and immunohistochemical characteristics of vocal polyps. STUDY DESIGN: Prospective and retrospective. METHODS: Clinical study: 76 medical charts from patients with polyps were reviewed. Histology study: in 42 slides from surgical specimens, the following were analyzed: epithelium, basal membrane, and lamina propria. In the transmission and scanning electron microscopy (TEM and SEM) studies, eight new cases of polyps were included. An immunohistochemical study was carried out in the 42 specimens, using antibody antifibronectin, antilaminin, and anticollagen IV. RESULTS: Genders--43% males and 57% females; age range--between 21 and 40 years (36.85%); and between 41 and 60 years of age (51.31%); smoking and drinking-reported by 39 and 15 patients, respectively; associated symptoms-vocal abuse (61%), gastroesophageal (47%), and nasosinusal symptoms (32%); occupation--teachers (24.0%) and maids (18.0%). Histology--epithelial hyperplasia (31.71%), hyperkeratosis, (14.28%), edema (100%), vessel proliferation (92.86%), and congestion (83.33%). SEM--reduction in mucous lacing and increase in desquamating cells. TEM--hyperplastic epithelium, enlargement of the intercellular junctions, dense subepithelial network of collagen and basal membrane with adhesion loss. Immunohistochemistry--greater immunoexpression of fibronectin, laminin, and collagen IV around the vessels. CONCLUSIONS: In vocal polyps, the morphological analyses show lamina propria with edema, vessel proliferation and inflammation, basement membrane with adhesion loss in some areas and dense network of subepithelial collagen. Immunohistochemistry techniques identify pigmentation of the antibodies anti-fibronectin, anti-laminin, and anti-collagen IV in the endothelium of blood vessels.

Vocal fold nodules: morphological and immunohistochemical investigations.

The objective of this study was to investigate the morphological and immunohistochemical characteristics of vocal fold nodules. The study design was prospective and retrospective. For the histological study, we reviewed 15 slides from the surgical cases of vocal fold nodules, in which we analyzed epithelium, basal membrane (bm), and lamina propria. For the transmission and scanning electron microscopy (TEM, SEM) studies, five new cases on vocal fold nodules were included. Immunohistochemistry study was carried out in the 15 specimens, using antifibronectin, antilaminin, and anticollagen IV antibodies. The main histological alterations were epithelial hyperplasia (73.33%), basement membrane thickening (86.66%), edema, and fibrosis (93.33%). SEM--reduction in mucous lacing and increase in the desquamating cells, without epithelial erosion. TEM--hyperplasia of the epithelium, enlargement of the intercellular junctions, which was filled by fluid, subepithelial thickening of the lamina reticularis, and break points in the basal membrane. Immunohistochemistry--we identified greater immunoexpression of fibronectin on the basal membrane, on the lamina propria, and around the vessels. Antilaminin and anticollagen IV antibodies showed higher pigmentation on the endothelium of the vessels than that on the basal membrane. In vocal fold nodules, combined assessment using light microscopy, electron microscopy, and immunohistochemistry can reveal important morphological details useful in characterizing these lesions.

The presence of a vocal ligament in fetuses: a histochemical and ultrastructural study.

Although it is currently believed that the vocal ligament of humans undergoes considerable development postnatally, there is no consensus as to the age at which it first emerges. In the newborn infant, the lamina propria has been described as containing a sparse collection of relatively unorganized fibres. In this study we obtained larynges from autopsy of human fetuses aged 7-9 months and used light and electron microscopy to study the collagenous and elastic system fibres in the lamina propria of the vocal fold. Collagen fibres were viewed using the Picrosirius polarization method and elastic system fibres were stained using Weigert's resorcin-fuchsin after oxidation with oxone. The histochemical and electron microscopic observations were consistent, showing collagen populations with an asymmetric distribution across different compartments of the lamina propria. In the central region, the collagen appeared as thin, weakly birefringent, greenish fibres when viewed using the Picrosirius polarization method, whereas the superficial and deep regions contained thick collagen fibres that displayed a strong red or yellow birefringence. These findings suggest that the thin fibres in the central region consist mainly of type III collagen, whereas type I collagen predominates in the superficial and deep regions, as has been reported in studies of adult vocal folds. Similarly, elastic system fibres showed a differential distribution throughout the lamina propria. Their distribution pattern was complementary to that of collagen fibres, with a much greater density of elastic fibres apparent in the central region than in the superficial and deep regions. This distribution of collagen and elastic fibres in the fetal vocal fold mirrors that classically described for the adult vocal ligament, suggesting that a vocal ligament has already begun to develop by the time of birth. The apparently high level of organization of connective tissue components in the newborn is in contrast to current hypotheses that argue that the mechanical stimuli of phonation are essential to the determination of the layered structure of the lamina propria and suggests that genetic factors may play a more significant role in the development of the vocal ligament than previously believed.

Analysis of hyaluronic acid concentration in rat vocal folds during estral and gravidic puerperal cycles.

UNLABELLED: Hormone plays an important role in the larynx. Among other substances, vocal folds contain hyaluronic acid, which tissue concentration may vary according to hormone action. AIM: the objective of this study is to analyze hyaluronic acid concentration in the vocal folds during estral and gravidic-puerperal cycles. MATERIALS AND METHODS: Experimental study. 40 adult rats were divided into two groups. In the first group we used 20 rats to establish the concentration of hyaluronic acid during the estral cycle and in the second group, 20 animals were submitted to the same procedure but during the gravidic-puerperal cycle. RESULTS: Variations in hyaluronic acid concentration was not observed during the estral cycle. In the gravidic puerperal cycle group, an increase in hyaluronic acid concentration was observed in the puerperal subgroup. Comparing the two groups of estral and gravidic-puerperal cycles, no difference was observed. CONCLUSIONS: In comparing all subgroups of estral and gravidic-puerperal cycles, an increase in hyaluronic acid concentration was noticed only in the puerperal phase.

Analysis of hyaluronic acid concentration in rat vocal folds during estral and gravidic puerperal cycles / Análise da concentração do ácido hialurônico nas pregas vocais de ratas durante o ciclo estral e ciclo gravídico-puerperal

Hormone plays an important role in the larynx. Among other substances, vocal folds contain hyaluronic acid, which tissue concentration may vary according to hormone action. AIM: the objective of this study is to analyze hyaluronic acid concentration in the vocal folds during estral and gravidic-puerperal cycles. MATERIALS AND METHODS: Experimental study. 40 adult rats were divided into two groups. In the first group we used 20 rats to establish the concentration of hyaluronic acid during the estral cycle and in the second group, 20 animals were submitted to the same procedure but during the gravidic-puerperal cycle. RESULTS: Variations in hyaluronic acid concentration was not observed during the estral cycle. In the gravidic puerperal cycle group, an increase in hyaluronic acid concentration was observed in the puerperal subgroup. Comparing the two groups of estral and gravidic-puerperal cycles, no difference was observed. CONCLUSIONS: In comparing all subgroups of estral and gravidic-puerperal cycles, an increase in hyaluronic acid concentration was noticed only in the puerperal phase.

Os hormônios exercem importante influência sobre a laringe. A prega vocal contém, entre outras substâncias, o ácido hialurônico, cuja concentração nos tecidos pode variar com a ação dos hormônios. OBJETIVO: O objetivo deste trabalho é analisar comparativamente a concentração do ácido hialurônico nas pregas vocais de ratas durante o ciclo estral e ciclo gravídico-puerperal. FORMA DE ESTUDO: Experimental. MATERIAL E MÉTODO: Foram utilizadas 40 ratas adultas, divididas em dois grupos, no primeiro grupo utilizamos 20 ratas para determinação da concentração do ácido hialurônico no ciclo estral, no segundo grupo, também de 20 animais, foi realizado o mesmo experimento no ciclo gravídico-puerperal. RESULTADOS: No grupo do ciclo estral não observou-se variação da concentração do ácido hialurônico. No grupo do ciclo gravídico-puerperal houve aumento da concentração do ácido hialurônico no subgrupo do puerpério. Na comparação entre os dois grupos do ciclo estral e gravídico-puerperal não houve diferença. Quando comparamos todos os subgrupos há diferença no grupo do puerpério. CONCLUSÕES: Comparando-se todos os subgrupos do ciclo estral e ciclo gravídico-puerperal, só no puerpério houve aumento da concentração do ácido hialurônico.

Comparative study in swines' vocal cords healing after excision of fragment with CO2 laser with mitomycin and 5-fluorouracil postoperative topical application / Estudo comparado da cicatrização da prega vocal de suínos após exérese de fragmento com laser de CO2 e aplicação tópica pós-operatória de mitomicina e 5-fluorouracil

PURPOSE: To evaluate the deposition of collagen fibers at pig's vocal folds after topical use of mitomycin or 5-fluorouracil, when partial exeresis of mucosa layer had been promoted by CO2 laser. METHODS: There were used 18 Larger white pigs which were anesthetized and submitted to mucosa fragment's exeresis, bilaterally, at its free border. The animals were divided into 3 groups, each one with 6 animals: control group, without topical drug application; mitomycin group; and 5-fluorouracil group. After 30 days, the animals were subjected to euthanasia, and samples of the vocal folds were collected and stained by picrosirius red technique with polarization for quantification of total collagen deposition. RESULTS: In control group, the mean rate of right vocal fold's collagen deposition at submucosa consisted in a 3428.66 micrometers area. There was found an area whose size had, in average, 2196.36 micrometers, in mitomycin group, and 2269.19 micrometers, in 5-fluorouracil group. CONCLUSION: Mitomycin and 5-fluorouracil had promoted beneficial change in vocal fold's cicatrization with less collagen deposition, but there was no significant statistically difference when they were compared between themselves.

OBJETIVO: Avaliar a deposição das fibras de colágeno total em pregas vocais suínas após o uso tópico de mitomicina ou 5-fluorouracil nas exéreses parciais de mucosa com laser de CO2. MÉTODOS: Foram utilizados 18 porcos da raça Larger white anestesiados e submetidos à exérese de fragmento de mucosa de borda livre da prega vocal direita e prega vocal esquerda. Os animais foram divididos em 3 grupos com 6 animais cada: grupo controle, sem aplicação de medicação tópica; grupo mitomicina, com uso tópico dessa substância; grupo 5-fluorouracil, uso tópico. Após 30 dias do experimento os animais foram submetidos à eutanásia, coletadas amostras das pregas vocais e coradas pela técnica do picrosirius red com polarização para a quantificação computadorizada da deposição do colágeno total. RESULTADOS: No grupo controle, a média da área do colágeno depositado na submucosa da prega vocal direita foi de 3428,66 micrômetros. No grupo mitomicina a média foi de 2196,36 micrômetros. No grupo 5-fluorouracil, a média foi de 2269,19 micrômetros. CONCLUSÃO: A mitomicina e o 5-fluorouracil promoveram mudança benéfica na cicatrização da prega vocal, com menor deposição de colágeno, porém, quando comparados entre si, eles não apresentaram diferença estatisticamente significante.

Comparative study in swines' vocal cords healing after excision of fragment with CO2 laser with mitomycin and 5-fluorouracil postoperative topical application.

PURPOSE: To evaluate the deposition of collagen fibers at pig's vocal folds after topical use of mitomycin or 5-fluorouracil, when partial exeresis of mucosa layer had been promoted by CO2 laser. METHODS: There were used 18 Larger white pigs which were anesthetized and submitted to mucosa fragment's exeresis, bilaterally, at its free border. The animals were divided into 3 groups, each one with 6 animals: control group, without topical drug application; mitomycin group; and 5-fluorouracil group. After 30 days, the animals were subjected to euthanasia, and samples of the vocal folds were collected and stained by picrosirius red technique with polarization for quantification of total collagen deposition. RESULTS: In control group, the mean rate of right vocal fold's collagen deposition at submucosa consisted in a 3428.66 micrometers area. There was found an area whose size had, in average, 2196.36 micrometers, in mitomycin group, and 2269.19 micrometers, in 5-fluorouracil group. CONCLUSION: Mitomycin and 5-fluorouracil had promoted beneficial change in vocal fold's cicatrization with less collagen deposition, but there was no significant statistically difference when they were compared between themselves.

Immunohistochemical searching for estrogen and progesterone receptors in women vocal fold epithelia.

UNLABELLED: Larynx is extremely sensitive to endocrinologic changes. Most vocal fold mucosa alterations are caused by changes in vocal fold liquid content and its epithelial changes. Estrogen and progesterone interfere and change this liquid content in the vocal folds. Our goal with the present paper is to study the presence of estrogen and progesterone receptors on vocal fold epithelium in 19 vocal fold epithelium specimens that did not present any indication of disease, especially inflammatory disease. We discarded those cases of patients above 40 years of age and those below 15. RESULTS: We found progesterone receptors in 18 of the 19 patients. The progesterone receptors are located both in the nucleus and the cytoplasm of cells, and mainly in the basal layer. There was no report of estrogen receptors present in the vocal folds. CONCLUSION: Vocal fold epithelium bears progesterone receptors, in the cytoplasm and in the nucleus. We did not find estrogen receptors in the epithelia of the vocal folds investigated.

Pesquisa de estrógeno e progesterona no epitélio das pregas vocais de mulheres por imunohistoquímica / Immunohistochemical searching for estrogen and progesterone receptors in women vocal fold epithelia

A laringe é extremamente sensível a mudanças endocrinológicas. A maioria das alterações da mucosa das pregas vocais é causada por modificações do conteúdo líquido das pregas vocais e das suas modificações epiteliais. O estrógeno e a progesterona interferem e modificam esse conteúdo líquido das pregas vocais. O objetivo deste trabalho é verificar a presença de receptores de estrógeno e progesterona no epitélio das pregas vocais de mulheres. MATERIAL E MÉTODO: Estudo de casos prospectivos. Foram realizados exames de imunohistoquímica para receptores de estrógeno e progesterona em 19 espécimes de epitélio de pregas vocais que não apresentavam quaisquer indícios de afecção, inclusive inflamatória. Foram descartados casos de pacientes com idade superior a 40 anos e inferior a 15 anos. RESULTADOS: Foram encontrados receptores para progesterona em 18 de 19 pacientes. Os receptores de progesterona estão localizados tanto no núcleo quanto no citoplasma e principalmente na camada basal. Não houve nenhum caso de receptores de estrógeno nas pregas vocais. CONCLUSÃO: O epitélio das pregas vocais apresenta receptores para progesterona, tanto no citoplasma quanto no núcleo. Não foram encontrados receptores para estrógeno no epitélio das pregas vocais estudadas.

Larynx is extremely sensitive to endocrinologic changes. Most vocal fold mucosa alterations are caused by changes in vocal fold liquid content and its epithelial changes. Estrogen and progesterone interfere and change this liquid content in the vocal folds. Our goal with the present paper is to study the presence of estrogen and progesterone receptors on vocal fold epithelium in 19 vocal fold epithelium specimens that did not present any indication of disease, especially inflammatory disease. We discarded those cases of patients above 40 years of age and those below 15. RESULTS: we found progesterone receptors in 18 of the 19 patients. The progesterone receptors are located both in the nucleus and the cytoplasm of cells, and mainly in the basal layer. There was no report of estrogen receptors present in the vocal folds. CONCLUSION: Vocal fold epithelium bears progesterone receptors, in the cytoplasm and in the nucleus. We did not find estrogen receptors in the epithelia of the vocal folds investigated.

Detection of hyaluronic acid receptor in human vocal folds by immunohistochemistry.

UNLABELLED: Hyaluronic acid receptor is a glycoprotein of the plasmatic membrane, and the CD44 is its representative, expressed in many cell types where it has the task of cell adhesion. AIM: the goal of the present experimental study is to investigate the possibility of using immunohistochemistry to identify the distribution of hyaluronic acid along the vocal fold. MATERIALS AND METHODS: We resected the normal vocal folds from a normal 23 year-old male black individual. The slides were analyzed by means of a histomorphometric study, comparing the color intensity in the superficial, middle and deep layers of the lamina propria. In the silanized slides we used immunohistochemistry, and evaluated the slides under light microscopy with 40x magnification, and the color changed to brown when there was a reaction with the receptor for hyaluronic acid. RESULTS: Immunohistochemical findings showed the presence of hyaluronic acid receptors in the epithelium covering the vocal fold, being more concentrated in the central region of the vocal fold. CONCLUSION: immunohistochemistry, used to assess the distribution of hyaluronic acid receptors in the central portion of the vocal fold, proved it to be present in the vocal fold epithelium and it prevailed in its middle third.

Disarrangement of collagen fibers in Reinke's edema.

OBJECTIVE/HYPOTHESIS: To describe the arrangement of collagen fibers in the superficial layer of the lamina propria of the vocal folds with Reinke' edema. STUDY DESIGN: Cross sectional analysis of the lamina propria of the vocal folds with Reinke's edema (RE). METHOD: The picrosirius polarization method was used to study the arrangement of collagen fiber. Findings of collagen disarrangement were categorized semiquantitatively and correlated with RE severity, age, cigarette smoking and duration of dysphonia. RESULTS: Analysis of 20 specimens of vocal folds with RE showed that the intertwined network of collagen fibers resembling a wicker-basket normally observed in vocal folds was disarranged in RE. The collagen fibers were loosely arranged, fragmented and intermixed with varying amounts of myxoid stroma. Moderate and large areas of disarrangement (90% of cases) predominated. Collagen fiber arrangement in the region underneath the epithelium was better preserved when compared with fibers in the deeper region of the superficial layer of the lamina propria. There was a statistical difference in collagen disarrangement between grade II and grade III severity (P = .007) that appeared to be due to the large areas of disarrangement observed in 73% of patients with grade III severity and in 44% of grade II severity. Age was the only variable correlated with collagen fiber disarrangement (r = 0.47, P = .037). CONCLUSION: Our findings suggest that the flexible framework which maintains the uniformity of the lamina propria was lost in RE caused by the disarrangement of the collagen fibers.

Detecção de receptor de ácido hialurônico em prega vocal humana por método imunohistoquímico / Detection of hyaluronic acid receptor in human vocal folds by immunohistochemistry

O receptor do ácido Hialurônico é uma glicoproteína da membrana plasmática, sendo o principal o CD44, e está expresso em vários tipos de células onde possui a função de adesão celular. OBJETIVO: Estudar a possibilidade de empregar o método imunohistoquímico para identificar a distribuição dos receptores de ácido hialurônico ao longo da prega vocal humana. MATERIAL E MÉTODOS: Foram ressecadas as pregas vocais normais de um indivíduo de 23 anos, sexo masculino, cor negra. As lâminas foram analisadas por meio de estudo histomorfométrico, comparando-se a intensidade das cores nas camadas superficial, média e profunda da lâmina própria. Nas lâminas silanizadas foi utilizado método imunohistoquímico, sendo avaliadas através de microscopia óptica com aumento 40 vezes, obtendo coloração marrom onde houve a reação com receptor para ácido hialurônico. RESULTADOS: Os achados imunohistoquímicos mostraram presença de receptores para ácido hialurônico no epitélio de cobertura da prega vocal tendo maior concentração na região central da prega vocal. CONCLUSÃO: A técnica de imunohistoquímica, utilizada para avaliar a distribuição dos receptores para ácido hialurônico na pregas vocais humanas, mostrou sua disposição em epitélio da prega vocal e predomínio no terço médio, em relação às demais regiões na prega vocal estudada.

Hyaluronic acid receptor is a glycoprotein of the plasmatic membrane, and the CD44 is its representative, expressed in many cell types where it has the task of cell adhesion. AIM: the goal of the present experimental study is to investigate the possibility of using immunohistochemistry to identify the distribution of hyaluronic acid along the vocal fold. MATERIALS AND METHODS: We resected the normal vocal folds from a normal 23 year-old male black individual. The slides were analyzed by means of a histomorphometric study, comparing the color intensity in the superficial, middle and deep layers of the lamina propria. In the silanized slides we used immunohistochemistry, and evaluated the slides under light microscopy with 40x magnification, and the color changed to brown when there was a reaction with the receptor for hyaluronic acid. RESULTS: Immunohistochemical findings showed the presence of hyaluronic acid receptors in the epithelium covering the vocal fold, being more concentrated in the central region of the vocal fold. CONCLUSION: immunohistochemistry, used to assess the distribution of hyaluronic acid receptors in the central portion of the vocal fold, proved it to be present in the vocal fold epithelium and it prevailed in its middle third.

Concentration and distribution of hyaluronic acid in human vocal folds.

OBJECTIVE/HYPOTHESIS: To evaluate the concentration and distribution of hyaluronic acid (HA) in human adult vocal folds. STUDY DESIGN: Experimental study. METHODS: Histologic samples of the anterior, middle, and posterior regions of the vocal folds were studied to determine the tissue distribution of HA. The HA was traced with hyaluronan-binding proteins (HAPB) from bovine cartilage. Chemical bonds were detected through the avidin-biotin immunoperoxidase method. A control with the specific Streptomyces hyalurolyticus hyaluronidase was conducted to avoid false-positive results. The concentration levels of HA were determined through a fluorescence-based assay method with the same HAPB and europium-labeled streptavidin. RESULTS: Women presented higher HA concentrations than men in every studied region of the vocal folds and overall HA concentration levels twice as higher. In regard to the distribution of HA, the macula flavae and the vocal fold intermediate and deep layers presented marked staining, with moderate staining around the vessels, on the gland capsules, and the connective tissue surrounding the vocal fold muscular fibers. CONCLUSIONS: HA is diffusely distributed along the vocal folds; the profuse amounts of HA observed in the female vocal folds may be related to impact absorption, acting as a protective factor against the characteristic high vibration frequency.

Distribution of collagen in the lamina propria of the human vocal fold.

OBJECTIVES: To describe the arrangement of collagen fibers in the lamina propria of the human vocal fold. STUDY DESIGN: Analysis of the lamina propria of the vocal fold obtained from human cadavers. METHODS: The Picrosirius-polarization method was used to visualize collagen fibers. RESULTS: Analysis of 20 human vocal folds by the Picrosirius-polarization method permitted the visualization of two fiber populations arranged in three layers in the lamina propria: two layers of thick, strongly birefringent collagen fibers (collagen type I), one immediately below the epithelium and another more dense layer in the deep region superficially to the vocal muscle, penetrating between muscle fibers. The third layer consisted of fine, weakly birefringent fibers (collagen type III) located between the two layers of thick fibers. In addition, the collagen fibers in the lamina propria showed an intertwined network arrangement in the form of a "wicker basket." CONCLUSIONS: This basket-like configuration better explains how the vocal fold is able to stretch even though it contains nonstretchable fibers and to modulate the frequency of the voice under the action of the intrinsic musculature of the larynx. Segmental areas of disarray of the basket-like structure of the collagen layers were systematically observed in older patients. Thus, it is possible that vocal alterations occurring in the elderly might be the result of a loss of histoarchitectural arrangement of the collagen system and its relationship with the lamina propria and underlying musculature.