RESUMO
Misoprostol (MSP) is commonly prescribed in obstetrics and gynecology clinical practice for labor induction, cervical ripening, first-trimester pregnancy termination, and the treatment of postpartum hemorrhage. Furthermore, there is a lack of comprehensive discussion evaluating how different commercially available formulations influence the overall efficacy of MSP, even though reports indicate issues with the quality of these formulations, particularly regarding stability and vaginal absorption processes. This study investigates the stability of MSP under acidic conditions and its in vitro permeation using swine vaginal mucosa. A forced degradation study was conducted using 0.2 M HCl, and a high-efficiency LC method was developed. Three degradation products were identified and characterized using electrospray ionization-high-resolution quadrupole-time-of-flight-MS, with respective m/z values of 391.2508, 405.2705, and 387.2259, respectively. These results suggest that the degradation mechanism involves dehydration of the ß-hydroxy ketone moiety, followed by isomerization to its most resonance-stable form and de-esterification. Finally, the in vitro permeation study revealed that the esterified form of MSP was unable to permeate the mucosa and required prior degradation for any component to be detected in the receptor fluid.
Assuntos
Estabilidade de Medicamentos , Misoprostol , Vagina , Animais , Feminino , Suínos , Vagina/química , Vagina/metabolismo , Misoprostol/química , Misoprostol/farmacocinética , Misoprostol/análise , Reprodutibilidade dos Testes , Cromatografia Líquida/métodos , Espectrometria de Massas/métodos , Mucosa/química , Mucosa/metabolismo , Permeabilidade , Espectrometria de Massa com Cromatografia LíquidaRESUMO
Curcumin is a natural phenol found in the rhizome of Curcuma longa. It has been studied to treat several human carcinomas, such as melanomas and breast, head and neck, prostate, and ovary cancers. Here, we develop and validate a method for recovering curcumin from the skin layers and mucosa and selectively quantifying it, aiming to support permeation studies in developing topical formulations containing the natural compound. Recovery of curcumin from the stratum corneum, remaining skin, and mucosa was performed using ethanol, DMSO/ethanol, and DMSO, respectively, under mild stirring for specific periods. The separation of curcumin from the other curcuminoids, skin, and mucosa interferents was obtained using a C18 column as a stationary phase. The mobile phase was composed of pH 3.0 phosphoric acid at 1.0 mmol/L and acetonitrile (47:53, v/v), which flowed at 1 mL min-1. UV-Vis detection of curcumin was at 424 nm. The chromatographic method was selective, linear (r > 0.999), with a regression curve in the concentration range from 1.0 to 30.0 µg mL-1, robust, precise, and accurate, with curcumin recovery rates higher than 95 ± 7 % from the mucosa, 82 ± 2 % from the stratum corneum, and 65 ± 10 % from the remaining skin. Finally, the method was successfully used in a skin permeation test performed with porcine skin and mucosa. The validated method is, therefore, suitable for the recovery and quantification of curcumin from the skin layers and mucosa, favoring the development of new topical formulations destined for these sites of administration.
Assuntos
Curcumina , Animais , Suínos , Humanos , Curcumina/análise , Cromatografia Líquida de Alta Pressão/métodos , Dimetil Sulfóxido , Mucosa/química , EtanolRESUMO
Tumors located in the oral mucosa are challenging to treat since surgery can lead to aesthetic, speech, and salivation problems, radiotherapy alone is often ineffective, and systemic chemotherapy brings meaningful side effects to the patient. Here, we proposed to develop mucoadhesive chitosan nanoparticles entrapping the chemotherapeutic oxaliplatin (OXPt) and to evaluate ex vivo its penetration in porcine mucosa under both passive and iontophoretic topical treatments. OXPt-loaded chitosan nanoparticles presented a small hydrodynamic size (188 ± 20 nm), narrow distribution (PDI of 0.28 ± 0.02) and positive zeta potential (+44.8 ± 2.8 mV). These nanoparticles provided a "burst effect" on drug release followed by a longer-term controlled release. When applied to the oral mucosa, the chitosan nanoparticles increased 3-fold drug penetration, and this rate was maintained even when the mucosa was "washed" with a buffer to mimic salivation. Iontophoresis doubled the amount of OXPt transported to the mucosa. These amounts exceeded the dose required to cause cell death of an oral tumor cell line. Besides, chitosan nanoparticles increased the rate of cells that entered into apoptosis. In summary, this study points to the feasibility of topical therapy with chitosan nanoparticles, potentialized by the application of iontophoresis, to treat oral tumors.
Assuntos
Quitosana/química , Portadores de Fármacos/química , Neoplasias Bucais/tratamento farmacológico , Mucosa/química , Nanopartículas/química , Oxaliplatina/administração & dosagem , Oxaliplatina/química , Adesividade , Administração Tópica , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Liberação Controlada de Fármacos , Humanos , Hidrodinâmica , Iontoforese , Oxaliplatina/uso terapêutico , SuínosRESUMO
Recently, chitosan-based nanoparticles with mucoadhesive properties emerged as a strategy for mucosal drug release. This study aimed to characterize the interaction of mucoadhesive system chitosancoated PLGA nanoparticles (NPMA) with fish external mucus. NP suspensions with fluorescent probe were prepared and characterized by size, polydispersity, zeta potential and pH measures. In post-exposure fish were observed an increase in fluorescence imaging over time and it was significantly influenced by NPMA concentration. We also observed the main predominance the fluorescence in the spleen, followed by liver, gill and other tissues. The use of mucoadhesive nanocarriers becomes an alternative for administration of drugs and immunomodulators in immersion systems since the nanosystem can adhere to the mucosal surface of the fish with little residual effect in the water.
Assuntos
Quitosana/administração & dosagem , Portadores de Fármacos/administração & dosagem , Nanopartículas/administração & dosagem , Ácido Poliglicólico/administração & dosagem , Adesividade , Animais , Quitosana/química , Portadores de Fármacos/química , Corantes Fluorescentes/administração & dosagem , Brânquias/metabolismo , Imunomodulação , Fígado/metabolismo , Mucosa/química , Nanopartículas/química , Ácido Poliglicólico/química , Baço/metabolismo , Peixe-ZebraRESUMO
BACKGROUND: Bladder cancer is the second type of malignant carcinoma of the urinary tract. The treatment is time-consuming and requires maintenance doses of the drug for long period of time with important side effects. Curcumin has shown evident clinical advances in the treatment of cancer. The technology of microencapsulation and the use of mucoadhesive materials can contribute to modify the delivery and improve the bioavailability of curcumin. OBJECTIVE: The aim of this study was to design and characterize mucoadhesive microparticles containing curcumin using multivariate analysis and the spray-drying technique. METHODS: A factorial design 32+1 was employed to investigate the influence of gelatin, ethylcellulose, and curcumin on size, polydispersity index, drug content and entrapment efficiency. Microparticles were also evaluated by ATR-FTIR, X-ray diffraction, antioxidant activity, in-vitro release profile, exvivo mucoadhesion performance, and in-vitro cytotoxicity. RESULTS: Microparticles showed non-uniform surface, mean diameter from 2.73 µm to 4.62 µm and polydispersity index from 0.72 to 1.09, according to the different combinations of the independent factors. These independent variables also had a significant effect on the drug content. The highest values of drug trapping efficiency were obtained with the highest concentration of curcumin and polymers. Formulations displayed slow drug release and important antioxidant activity. The good mucoadhesive performance of microparticles was assessed by the falling film technique. Moreover, the formulations did not display in vitro toxicity against Artemia salina and Fibroblasts LM(TK). CONCLUSION: The design results were useful for developing of curcumin dosage form with good physicochemical characteristics and mucoadhesive properties for the bladder administration.
Assuntos
Antioxidantes/administração & dosagem , Celulose/análogos & derivados , Curcumina/administração & dosagem , Portadores de Fármacos/administração & dosagem , Gelatina/administração & dosagem , Microesferas , Nanopartículas/administração & dosagem , Adesividade , Animais , Antioxidantes/química , Artemia/efeitos dos fármacos , Benzotiazóis/química , Sobrevivência Celular/efeitos dos fármacos , Celulose/administração & dosagem , Celulose/química , Curcumina/química , Portadores de Fármacos/química , Desenho de Fármacos , Liberação Controlada de Fármacos , Fibroblastos/efeitos dos fármacos , Gelatina/química , Mucosa/química , Nanopartículas/química , Ácidos Sulfônicos/química , Suínos , Bexiga Urinária/metabolismoRESUMO
trans-Aconitic acid (TAA) is the main constituent of the leaves from the medicinal plant Echinodorus grandiflorus, used to treat different inflammatory diseases. TAA induces a potent but short-lasting biological response, credited to its high polarity and unfavorable pharmacokinetics. Here we developed, characterized and evaluated the anti-inflammatory activity of mucoadhesive microspheres loaded with TAA. Seven batches of mucoadhesive microspheres were prepared by the emulsification/solvent evaporation method, employing different proportions of TAA and Carbopol 934 or/and hydroxypropylmethylcellulose. All batches were characterized for their particle medium size, polydispersity index and entrapment percentage. The batch coded F3c showed highest entrapment percentage and was characterized by infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analyses (TGA) and zeta potential. The anti-inflammatory activity of F3c was assessed in a model of acute arthritis induced by injection of LPS in the knee joint of Swiss mice. The granulometric analyses indicated heterogeneous size distribution for F3c. SEM characterization indicated microspheres with slightly irregular shape and rough surface. Results from ATR-FTIR and thermal analyses (DSC and TGA) pointed out absence of incompatibility between the components of the formulation; thermal events related to the constituents were isolated and randomly located, suggesting amorphous distribution of TAA in the formulation matrix. The zeta potential of the formulations varied from -30 to -34â¯mV, which may contribute to good stability. When given orally to mice, F3c induced a prolonged anti-inflammatory response by reducing total cell count and neutrophilic accumulation in the joint cavity even when given 48 and 36â¯h before the stimulus, respectively, in comparison to free TAA (up to 24 and 6â¯h, respectively). Therefore, the encapsulation of TAA in mucoadhesive microspheres provided its sustained release, indicating that this drug delivery system is a potential agent to treat inflammatory diseases by regulating cell influx.
Assuntos
Ácido Aconítico/administração & dosagem , Anti-Inflamatórios não Esteroides/administração & dosagem , Artrite Experimental/tratamento farmacológico , Ácido Aconítico/uso terapêutico , Doença Aguda , Adesividade , Animais , Anti-Inflamatórios não Esteroides/uso terapêutico , Artrite Experimental/induzido quimicamente , Artrite Experimental/imunologia , Articulação do Joelho/efeitos dos fármacos , Articulação do Joelho/imunologia , Contagem de Leucócitos , Lipopolissacarídeos , Masculino , Camundongos , Microesferas , Mucosa/química , Neutrófilos/efeitos dos fármacos , Neutrófilos/imunologiaRESUMO
Mucoadhesion is a useful strategy for drug delivery systems, such as tablets, patches, gels, liposomes, micro/nanoparticles, nanosuspensions, microemulsions and colloidal dispersions. Moreover, it has contributed to many benefits like increased residence time at application sites, drug protection, increased drug permeation and improved drug availability. In this context, investigation into the mucoadhesive properties of pharmaceutical dosage forms is fundamental, in order to characterize, understand and simulate the in vivo interaction between the formulation and the biological substrate, contributing to the development of new mucoadhesive systems with effectiveness, safety and quality. There are a lot of in vivo, in vitro and ex vivo methods for the evaluation of the mucoadhesive properties of drug delivery systems. However, there also is a lack of standardization of these techniques, which makes comparison between the results difficult. Therefore, this work aims to show an overview of the most commonly employed methods for mucoadhesion evaluation, relating them to different proposed systems and using artificial or natural mucosa from humans and animals.
Assuntos
Sistemas de Liberação de Medicamentos/métodos , Lipossomos/química , Mucosa/química , Nanopartículas/química , Comprimidos/administração & dosagem , Adesividade , Animais , Química Farmacêutica , Humanos , Comprimidos/químicaRESUMO
The development of binary polymeric mixtures (polymer blends) containing bioadhesive and thermoresponsive polymers can provide new materials for biomedical applications, with higher contact, increased adhesion, prolonged residence time, protection, and in determined cases, secured absorption of an active agent from the site of application. Mixtures were prepared using a wide range of poloxamer 407 and Carbopol 971P(®) amounts. The rheological (flow and oscillatory), sol-gel transition temperature, mechanical (hardness, compressibility, adhesiveness, cohesiveness and elasticity), softness, and mucoadhesive properties of formulations were investigated. Moreover, the interaction between the different proportions of polymers was also analyzed. Continuous shear and oscillatory rheometry identified the plastic flow with various degrees of thixotropy, besides the viscoelastic behavior of formulations. The determination of gelation temperature displayed values ranged from 27.17 to 41.09°C. It was also found that low carbomer concentrations were enough to provide positive interaction parameter. However, the highest values were obtained for the polymeric blends with higher concentration of poloxamer 407. The mucoadhesion and softness index were greater in preparations containing 20% (w/w) poloxamer 407. The rheological, mechanical and mucoadhesive properties of the polymeric blends can be manipulated by changing the concentrations of the polymers and they suggest the blends are worthy of biomedical applications.
Assuntos
Materiais Biocompatíveis/química , Fenômenos Mecânicos , Poloxâmero/química , Reologia , Temperatura , Adesividade , Animais , Força Compressiva , Mucinas/química , Mucosa/química , Resistência ao Cisalhamento , Suínos , Temperatura de TransiçãoRESUMO
This study centers on relationships among national and international actors in preparation of the first health policy document for East Timor, under the United Nations transitional administration, between 1999 and 2002. International cooperation support for the health system rehabilitation process during the post-conflict period is analyzed as part of reconstruction of the State in parallel with construction of the country's political and institutional framework. Knowledge, ideas, "ways of doing," and induced and accepted practices permeate an interplay of power relationships that condition both national political alliance-building and the architecture of international aid, pointing to input to a discussion of how these mechanisms interact at different conjunctures and times in different negotiating frameworks. .
Dedica-se, aqui, às relações entre diferentes atores na elaboração do primeiro documento de política de saúde para o Timor-Leste, sob a administração transitória das Nações Unidas, de 1999 a 2002. O apoio da cooperação internacional no processo de reabilitação do sistema de saúde no período pós-conflito é analisado como parte da reconstrução do Estado e concomitante à construção do arcabouço político e institucional no país. Conhecimentos, ideias, "modos de fazer" e práticas induzidas e aceitas entremeiam um jogo de relações de poder que condiciona tanto a articulação política nacional quanto a arquitetura da ajuda externa, apontando elementos para a discussão de como esses mecanismos se organizam em conjunturas diferentes de negociação.
Assuntos
Humanos , Antígenos de Neoplasias/análise , Carcinoma de Células Escamosas/química , DNA Topoisomerases Tipo II/análise , Proteínas de Ligação a DNA/análise , Neoplasias de Cabeça e Pescoço/química , Imuno-Histoquímica , /análise , Mucosa/química , Lesões Pré-Cancerosas/química , Biomarcadores Tumorais/análise , Biópsia , Estudos de Casos e Controles , Carcinoma de Células Escamosas/patologia , Diagnóstico Diferencial , Progressão da Doença , Neoplasias de Cabeça e Pescoço/patologia , Mucosa/patologia , Valor Preditivo dos Testes , Lesões Pré-Cancerosas/patologia , Fatores de TempoRESUMO
The probiotic Lactobacillus casei catabolizes galacto-N-biose (GNB) and lacto-N-biose (LNB) by using a transport system and metabolic routes different from those of Bifidobacterium. L. casei contains a gene cluster, gnbREFGBCDA, involved in the metabolism of GNB, LNB and also N-acetylgalactosamine. Inactivation of gnbC (EIIC) or ptsI (Enzyme I) of the phosphoenolpyruvate : sugar phosphotransferase system (PTS) prevented the growth on those three carbohydrates, indicating that they are transported and phosphorylated by the same PTS(Gnb) . Enzyme activities and growth analysis with knockout mutants showed that GnbG (phospho-ß-galactosidase) hydrolyses both disaccharides. However, GnbF (N-acetylgalactosamine-6P deacetylase) and GnbE (galactosamine-6P isomerase/deaminase) are involved in GNB but not in LNB fermentation. The utilization of LNB depends on nagA (N-acetylglucosamine-6P deacetylase), showing that the N-acetylhexosamine moieties of GNB and LNB follow different catabolic routes. A lacAB mutant (galactose-6P isomerase) was impaired in GNB and LNB utilization, indicating that their galactose moiety is channelled through the tagatose-6P pathway. Transcriptional analysis showed that the gnb operon is regulated by substrate-specific induction mediated by the transcriptional repressor GnbR, which binds to a 26 bp DNA region containing inverted repeats exhibiting a 2T/2A conserved core. The data represent the first characterization of novel metabolic pathways for human milk oligosaccharides and glycoconjugate structures in Firmicutes.
Assuntos
Acetilglucosamina/análogos & derivados , Dissacarídeos/metabolismo , Lacticaseibacillus casei/genética , Lacticaseibacillus casei/metabolismo , Leite Humano/química , Mucosa/química , Família Multigênica , Fosfoenolpiruvato/metabolismo , Acetilglucosamina/metabolismo , Proteínas de Bactérias/metabolismo , Galactose/metabolismo , Perfilação da Expressão Gênica , Técnicas de Inativação de Genes , Genes Bacterianos , Humanos , Mutação , Óperon , Polissacarídeos , Reação em Cadeia da Polimerase em Tempo Real , beta-Galactosidase/genéticaRESUMO
In amphibians, the components of the jelly coats that surround the oocytes at the time of fertilization and coordinate gamete interaction are secreted by the oviduct. We analysed the histological variations in the mucosa of the oviductal pars convoluta (PC) of Rhinella arenarum during the reproductive cycle and its relationship with secretion. During the preovulatory period, the mucosa reaches a high degree of morphological and functional development, with a large number of epithelial (ESC) and glandular secretory cells (GSC) loaded with contents that are secreted into the oviductal lumen. During the ovulatory period, the secretory cells (SC) of both layers present maximum secretory activity through apocrinia and merocrinia. While the ESC located at the tips of the folds release their content directly in contact with the oocytes, the GSC secrete material from the bottom of the epithelial folds that, by interaction with the secretion of the ESC in the lateral faces, form a product with a certain degree of organization. Secretion is a continuous process with formation of coats of increasing complexity from the intermediate proximal zone (IPZ) to the pars convoluta (pc) itself, and the passage of the oocyte is a requisite for the organization of the jelly coats around the gamete. During the early postovulatory period, although there is a marked decrease in the number and volume of the SC, the ESC still release material into the oviductal lumen. In the late postovulatory period the morphological characteristics of the PC begin to recovery although there is no evidence of secretion.
Assuntos
Bufo arenarum/fisiologia , Fertilização/fisiologia , Mucosa/química , Oócitos/fisiologia , Oviductos/metabolismo , Reprodução/fisiologia , Animais , Células Cultivadas , Células Epiteliais/citologia , Células Epiteliais/fisiologia , Feminino , Mucosa/metabolismo , Oócitos/citologia , Ovulação/metabolismo , Interações Espermatozoide-ÓvuloRESUMO
Lipoid proteinosis or Urbach-Wiethe disease is a rare autosomal recessive mucocutaneous disorder caused by mutation in the EMC1 gene. Hoarseness is observed in early childhood associated with infiltration and thickening of skin. Multiple systemic manifestations develop involving mucosal deposition of hyalin material. We describe a 12-year-old boy with typical manifestations: a hoarse voice, thick skin with yellowish papules, including the typical disposition on the margin of the eyelids, infiltration of the tongue and lips, and varicella-like scars. Histopathological examination revealed deposition of hyaline substance with PAS-positive diastase-resistance at the dermoepidermal junction and around vessels. Ultrastructural study showed considerable thickening of the basal lamina of vessels besides the intense deposition of amorphous material in the dermis. Genetic analysis was not available.
Assuntos
Proteinose Lipoide de Urbach e Wiethe/patologia , Criança , Proteínas da Matriz Extracelular/genética , Humanos , Hialina/química , Hialina/ultraestrutura , Proteinose Lipoide de Urbach e Wiethe/diagnóstico , Proteinose Lipoide de Urbach e Wiethe/genética , Masculino , Mucosa/química , Mucosa/ultraestrutura , Pele/química , Pele/ultraestruturaRESUMO
Sperm binding to oviductal epithelium would be involved in sperm reservoir formation in the utero tubal junction (UTJ). Although in other mammals sperm-oviduct interaction has been proved to be mediated by carbohydrate-recognition mechanisms, the factors implicated in the sperm adhesion to oviductal epithelium of llama are still unknown. In order to assess the role of carbohydrates present in the mucosa surface, we examined the distribution of glycoconjugates in the llama oviduct by confocal lectin-histochemistry. Mannosyl, glucosyl, N-acetylglucosaminyl, galactosyl, N-acetylgalactosaminyl and sialic acid residues were detected in the oviductal mucose glycocalyx. By incubation of UTJ oviductal explants with LCA, DBA, UEA-1 or PNA lectin previous to co-culture with sperm, we observed a significant decrease in sperm binding only with LCA lectin. In the mucosa surface there were numerous d-glucosyl and D-manosyl residues, which were spotted by this lectin. Probably, this fact promotes the whole covering of the oviduct luminal surface by the sugar-lectin complex, preventing sperm access and adhesion of further residues. However, sperm incubation with mannose or glucose does not significantly prevent binding, which means that glucose and mannose would not be involved in a specific sperm-oviduct interaction. On the other hand, we observed a high reduction in sperm binding to UTJ explants with N-acetylgalactosamine and galactose (p<0.001). Coincidentally, binding sites for N-acetylgalactosamine-PAA-FITC conjugate were observed on the whole surface of the sperm, supporting the concept that llama sperm have lectin-like molecules in their surface, as is the case in other mammals. Probably, these lectin-like molecules, by means of N-acetylgalactosamine and galactose recognition, could link the sperm to the oviductal mucosa with the purpose of forming storing sites in the UTJ. Our results support the idea that more than one carbohydrate could participate in sperm reservoir formation in the llama UTJ oviductal segment.
Assuntos
Camelídeos Americanos/fisiologia , Carboidratos/fisiologia , Tubas Uterinas/metabolismo , Lectinas/metabolismo , Espermatozoides/metabolismo , Acetilgalactosamina/farmacologia , Animais , Carboidratos/análise , Adesão Celular/efeitos dos fármacos , Células Epiteliais/metabolismo , Tubas Uterinas/química , Tubas Uterinas/citologia , Feminino , Galactose/farmacologia , Glucose/farmacologia , Glicoconjugados/análise , Histocitoquímica , Lectinas/análise , Lectinas/farmacologia , Masculino , Manose/farmacologia , Microscopia de Fluorescência , Mucosa/química , Espermatozoides/química , Técnicas de Cultura de Tecidos/veterináriaRESUMO
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.
Assuntos
Imuno-Histoquímica , Prega Vocal/química , Prega Vocal/patologia , Distúrbios da Voz/diagnóstico , Membrana Basal/química , Membrana Basal/patologia , Brasil , Colágeno Tipo IV/análise , Células Epiteliais/química , Células Epiteliais/patologia , Fibronectinas/análise , Fibrose , Humanos , Hiperplasia , Laminina/análise , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Mucosa/química , Mucosa/patologia , Estudos Prospectivos , Estudos Retrospectivos , Prega Vocal/ultraestrutura , Distúrbios da Voz/metabolismo , Distúrbios da Voz/patologiaRESUMO
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.
Assuntos
Prega Vocal/embriologia , Colágeno/ultraestrutura , Tecido Elástico/embriologia , Tecido Elástico/ultraestrutura , Feminino , Idade Gestacional , Humanos , Masculino , Mucosa/química , Mucosa/embriologia , Mucosa/ultraestrutura , Prega Vocal/química , Prega Vocal/ultraestruturaRESUMO
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.
Assuntos
Colágeno/ultraestrutura , Prega Vocal/química , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Cadáver , Colágeno Tipo I/ultraestrutura , Colágeno Tipo III/ultraestrutura , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mucosa/química , Distribuição TecidualRESUMO
Conventional carbohydrate histochemistry and the binding patterns of 21 lectins were analysed to characterise the glycoconjugate content in the components of the vomeronasal organ of the armadillo Chaetophractus villosus. The mucomicrovillous complex of the sensory epithelium bound most of the lectins studied. No reaction was observed with Con A, PSA, S-Con A and SBA, and the sustentacular cells were-stained with UEA-I, DSL, LEL, STL and Con A. The vomeronasal receptor neurons were labelled with S-WGA, WGA, PNA, UEA-I, STL, Con A, S-Con A, ECL and RCA120. The basal cell layer reacted with S-WGA, WGA, LCA, UEA-I, DSL, LEL, STL, Con A, JAC and VVA. The nonsensory epithelium exhibited a differential staining in relation to the different components. The mucociliary complex stained with ECL, DBA, JAC, RCA120, STL, LCA, PHA-E, PHA-L, LEL, BSL-I and VVA. However, SJA and UEA-I stained the mucus complex lining a subpopulation of columnar cells. The cytoplasm and cell membranes of columnar cells was labelled with DBA, DSL and LCA. The apical region of these cells exhibited moderate reactivity with LEL and SJA. None of the lectins bound specifically to secretory granules of the nonsecretory cells. Basal cells of the nonsensory epithelium were labelled with DSL, LEL, LCA, BSL-I and STL. The vomeronasal glands showed a positive reaction with WGA, DSL, LEL, LCA, DBA, PNA, RCA120 and SBA. Subpopulations of acinar cells were observed with ECL, S-WGA, Con A, S-Con A and DBA. PNA and RCA120 stained the cells lining the glandular ducts. In comparison with previous results obtained in the olfactory mucosa of the same group of armadillos, the carbohydrate composition of the vomeronasal organ sensory epithelium differed from the olfactory sensory epithelium. This is probably related to the different nature of molecules involved in the perireceptor processes.
Assuntos
Tatus/metabolismo , Glicoconjugados/análise , Órgão Vomeronasal/química , Animais , Sítios de Ligação , Feminino , Histocitoquímica/métodos , Lectinas/metabolismo , Masculino , Mucosa/química , Mucosa Olfatória/químicaRESUMO
Puffer fish (Tetraodontidae and Diodontidae) possess paralysing toxins (tetrodotoxin and analogues) that are secreted upon stimulation. In a previous work it was demonstrated that mucous secretion from the puffer fish Sphoeroides spengleri, when mixed in sea water passing through the orobranchial cavity of groupers, induced cardiorespiratory alterations. In the present study, skin secretions from Ciclichthys spinosus, S. spengleri and Diodon hystrix were tested on crustacean nerves, sea urchin eggs and mouse erythrocyte suspensions to verify neurotoxic and cytotoxic activities. Ciclichthys spinosus and D. hystrix secretions induced transient depolarizations with 0.16 mg and blocked crustacean nerve conduction after prolonged exposure. Both secretions had cytotoxic effects; when applied to sea urchin eggs they caused cleavage inhibition and anomalies in a dose-dependent manner (ED50 +/- S. E. M. = 2.59 +/- 0.08 mg/ml for C. spinosus and 1.23 +/- 0.07 mg/ml for D. hystrix); moreover, hemolysis occurred with an ED50 = 0.76 mg/ml of 0.5% mouse erythrocyte suspensions to C. spinosus and 0.59 mg/ml to D. hystrix. These secretions were not lethal in acute toxicity tests, even at 335 mg/ml. The neurotoxic components were thermolabile while the hemolytic activity was resistant to boiling. Tests with the secretion from S. spengleri did not show cytotoxic effects but promptly blocked action potentials of crustacean nerves and were lethal for mice in acute toxicity rests. When applied to groupers, the C. spinosus secretion caused cardiorespiratory alterations. These results suggest the presence of neurotoxins (other than tetrodotoxin) and cytotoxins in skin of diodontid puffer fish.
Assuntos
Venenos de Peixe/metabolismo , Pele/química , Animais , Antineoplásicos/toxicidade , Citotoxinas/metabolismo , Citotoxinas/toxicidade , Potenciais Evocados/efeitos dos fármacos , Venenos de Peixe/toxicidade , Peixes Venenosos , Frequência Cardíaca/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Camundongos , Mucosa/química , Mucosa/metabolismo , Neurotoxinas/metabolismo , Neurotoxinas/toxicidade , Respiração/efeitos dos fármacos , Pele/metabolismoRESUMO
The present study deals with the interaction of mucosal anions with apical Ca(2+)-blockable cation channels of the skin of Rana ridibunda. The intracellular potential was depolarized by exposing the basolateral membranes to K2SO4 Ringer solution. The apical bathing medium consisted of nominal Ca(2+)-free K+ or Na+ solutions with SO4(2-), Cl-, Br-, or I- as the major anion. The effects of mucosal anion substitutions were studied by analyzing 1) the fluctuation in K+ current across the apical membrane driven by imposed transepithelial clamping potentials and 2) alterations of the transepithelial current (It) and conductance (Gt) as well as the Lorentzian parameters in response to anion substitution in the mucosal bathing solution. It and current noise spectra were recorded at different transepithelial potentials (Vt). A Lorentzian component was present in the power density spectrum when Vt was clamped at mucosa-positive voltages. Such noise components were never observed with mucosa-negative potentials. These findings suggest a rectifying behavior of the transepithelial cation currents. The Lorentzian noise component and the inward-oriented cation currents were depressed by the addition of micromolar concentrations of Ca2+ to the apical solutions as well as by replacing mucosal K+ or Na+ by N-methyl-D-glucamine. The Ca(2+)-blockable current and Lorentzian noise plateau (So) were gradually increased by raising Vt. Both parameters, as well as the corner frequency (fc), depended strongly on the major anion species in the apical solution; replacing mucosal SO4(2-) by one of the halides tested reduced fc and elevated So, It, and Gt considerably.