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<p>Ultrastructural studies of airway epithelium in airway disease are important for diagnosis and understanding the underlying pathology which helps clinicians to improve the patients' treatment.</p><p>Airway biopsies from a 5-month old boy with respiratory problems and gastro-oesophageal reflux were studied by transmission electron microscopy (TEM). The tracheal columnar cells showed accumulation of lamellar bodies, indicative of lysosomal storage disease. The patient was diagnosed with Gaucher disease type 2.</p><p>Shedding of airway epithelial cells is commonly found in asthma. The attachment of these cells to the basal lamina was investigated by TEM of biopsies from patients with asthma and healthy controls. The contact area between columnar cells and basal lamina in asthmatics was significantly less than in controls. Attachment of columnar cells to the basal lamina occurs mainly indirectly, via desmosomal attachment to basal cells. </p><p>Primary ciliary dyskinesia (PCD) is a congenital disease. It is important to differentiate PCD from acquired (secondary) ciliary dyskinesia (SCD). The number of dynein arms determined by TEM was 1.5 and 1.4 for outer and inner dynein arms, respectively in PCD, versus 7.9 and 5.2 for controls and 8.1 and 5.9 in SCD. Compared to PCD patients, SCD patients have more structurally abnormal cilia. A significant difference was found in orientation of the central microtubule pair between PCD and SCD, but also overlap. </p><p>Leukotriene receptor antagonists are a new treatment for asthma. Both corticosteroids and montelukast caused apoptosis and necrosis of airway epithelial cells, and reduced the expression of intercellular adhesion molecule-1. Treatment of cells with tumor necrosis factor-α or interferon-γ reduced the fraction of the lateral cell membrane occupied by desmosomes and this effect was counteracted by corticosteroids. </p>

Ultrastructural studies of airway epithelium in airway disease are important for diagnosis and understanding the underlying pathology which helps clinicians to improve the patients' treatment. Airway biopsies from a 5-month old boy with respiratory problems and gastro-oesophageal reflux were studied by transmission electron microscopy (TEM). The tracheal columnar cells showed accumulation of lamellar bodies, indicative of lysosomal storage disease. The patient was diagnosed with Gaucher disease type 2. Shedding of airway epithelial cells is commonly found in asthma. The attachment of these cells to the basal lamina was investigated by TEM of biopsies from patients with asthma and healthy controls. The contact area between columnar cells and basal lamina in asthmatics was significantly less than in controls. Attachment of columnar cells to the basal lamina occurs mainly indirectly, via desmosomal attachment to basal cells. Primary ciliary dyskinesia (PCD) is a congenital disease. It is important to differentiate PCD from acquired (secondary) ciliary dyskinesia (SCD). The number of dynein arms determined by TEM was 1.5 and 1.4 for outer and inner dynein arms, respectively in PCD, versus 7.9 and 5.2 for controls and 8.1 and 5.9 in SCD. Compared to PCD patients, SCD patients have more structurally abnormal cilia. A significant difference was found in orientation of the central microtubule pair between PCD and SCD, but also overlap. Leukotriene receptor antagonists are a new treatment for asthma. Both corticosteroids and montelukast caused apoptosis and necrosis of airway epithelial cells, and reduced the expression of intercellular adhesion molecule-1. Treatment of cells with tumor necrosis factor-α or interferon-γ reduced the fraction of the lateral cell membrane occupied by desmosomes and this effect was counteracted by corticosteroids.

Characterization of new pharmacological targets is a promising approach in research of neurorepair mechanisms. The G protein-coupled receptor 17 (GPR17) has recently been proposed as an interesting pharmacological target, e.g., in neuroregenerative processes. Using the well-established ex vivo model of organotypic slice co-cultures of the mesocortical dopaminergic system (prefrontal cortex (PFC) and substantia nigra/ventral tegmental area (SN/VTA) complex), the influence of GPR17 ligands on neurite outgrowth from SN/VTA to the PFC was investigated. The growthpromoting effects of Montelukast (MTK; GPR17- and cysteinyl-leukotriene receptor antagonist), the glial cell line-derived neurotrophic factor (GDNF) and of two potent, selective GPR17 agonists (PSB-16484 and PSB-16282) were characterized. Treatment with MTK resulted in a significant increase in mean neurite density, comparable with the effects of GDNF. The combination of MTK and GPR17 agonist PSB-16484 significantly inhibited neuronal growth. qPCR studies revealed an MTK-induced elevated mRNA-expression of genes relevant for neuronal growth. Immunofluorescence labelling showed a marked expression of GPR17 on NG2-positive glia. Western blot and RT-qPCR analysis of untreated cultures suggest a time-dependent, injury-induced stimulation of GPR17. In conclusion, MTK was identified as a stimulator of neurite fibre outgrowth, mediating its effects through GPR17, highlighting GPR17 as an interesting therapeutic target in neuronal regeneration.

Made available in DSpace on 2014-07-29T15:25:22Z (GMT). No. of bitstreams: 1 Tese Carina-pos defesa.pdf: 485460 bytes, checksum: 2ca505db4ca73a05349dd92fbfc7df1d (MD5) Previous issue date: 2011-03-18 / Montelukast is a potent reversible selective inhibitor of cysteinilleukotrien- 1 receptor, avoiding that these mediators promote the asthmatic response. Its commercialization in Brazil, as a terminated product, is protected by patent up to 2010. Once the active ingredient Montelukast is recent in the pharmaceutical market and there is no methodology description in official compendiums capable to assure the quality of new formulations, the objective of this paper was the pharmaceutics of montelukast film coated tablets, the development and the validation of analytical and bioanalytical methodologies foreseeing the pharmaceutical equivalence and bioequivalence with the reference medication of the market. With this purpose, some physicalchemical parameters were characterized, assay and dissolution methodologies were developed and validated per high performance liquid chromatography with ultraviolet detection (HPLC-UV) for the quantification of montelukast present in 10.0mg film coated tablets. The quantification of montelukast sodium in human plasma was performed using Loratadine as internal standard and high performance liquid chromatography attached to mass detector (HPLC - MS / MS). The active ingredient was extracted from the human plasma using precipitation extraction. The results found for the parameters of specificity, linearity, accuracy, precision, quantification and detection limits and stability in the methodologies validation confirm they were adequate for the objective proposed. The analytical methodologies developed and validated were applied in the pharmaceutics of the tablets for the determination of the formulation similar to the market reference medication Singulair®. This formulation was submitted to stability assays to assure its quality and to allow the performance of pharmaceutical equivalence and bioequivalence with the purpose of registering as a generic medication. / O Montelucaste é um potente inibidor seletivo reversível do receptor cisteinil-leucotrieno-1, evitando que os mediadores provoquem a resposta asmática. Sua comercialização no Brasil, na forma de produto acabado, é protegida por patente até 2010. Uma vez que o fármaco Montelucaste é recente no mercado farmacêutico e não há descrição de metodologia em compêndios oficiais capaz de assegurar a qualidade das novas formulações, o objetivo deste trabalho foi o desenvolvimento farmacotécnico de comprimidos revestidos de montelucaste, desenvolvimento e validação de métodos analítico e bioanalítico visando obtenção de equivalência farmacêutica e bioequivalência com o medicamento referência de mercado. Com esta finalidade, foram caracterizados alguns parâmetros físico-químicos, desenvolvidos e validados métodos de doseamento e dissolução por cromatografia líquida de alta eficiência com detecção ultravioleta (HPLC-UV) para quantificação de montelucaste presente em comprimidos revestidos de 10,0 mg. A determinação de montelucaste sódico em plasma humano foi realizada utilizando-se loratadina como padrão interno e cromatografia líquida de alta eficiência acoplada a detector de massas (HPLC MS/MS). O fármaco foi extraído do plasma humano utilizando extração por precipitação. Os resultados encontrados dos parâmetros de especificidade, linearidade, exatidão, precisão, limites de quantificação e detecção e estabilidade nas validações dos métodos confirmam que os mesmos foram adequados para a finalidade proposta. Os métodos analíticos desenvolvidos e validados foram aplicados no desenvolvimento farmacotécnico dos comprimidos para determinação de uma formulação próxima ao medicamento referência de mercado Singulair®. Esta formulação foi submetida a ensaios de estabilidade para assegurar sua qualidade e permitir a realização de equivalência e bioequivalência farmacêutica com o intuito de registro como medicamento genérico.

The kinetics of drugs photodegradation have traditionally been treated using thermal kinetic analysis methods consisting most commonly in zero and first order kinetics. These treatment strategies were shown to lack specificity and present a number of limitations when applied to photoreactions kinetics. Nevertheless, these methods have widely been used due to a lack of integrated rate-laws for the majority of photoreactions types, in turn, due to the presence of a variable time-dependent factor in most photoreactions rate-laws that prevents their mathematical integration. To address these limitations, a new methodology for the development and validation of semi-empirical integrated rate-laws that faithfully describe photoreactions kinetics and photoreactions simulated cases generated by numerical integration methods (NIMs), is hereby presented. Using this methodology, a new kinetic order was ascribed to photoreactions namely the Φ-order kinetics. Semi-empirical integrated rate-laws were, thus, developed for three photoreaction types namely, unimolecular, AB(1Φ), photoreversible ,AB(2Φ), and consecutive, AB4(4Φ), photoreactions. The proposed models were further tested experimentally on drugs following these photodegradation mechanisms using; nifedipine and nisoldipine for unimolecular photoreactions; montelukast and fluvoxamine for photoreversible reactions; and riboflavin for consecutive photoreactions. The developed models not only accurately described the photoreaction kinetics of these drugs but also allowed the determination of all the kinetic parameters that characterise them. Furthermore, the above studied drugs were shown to act as precise and simple actinometers when analytically treated with the Φ-order kinetic methods, hereby presented. A universal standard method for the precise and worldwide reproducible study of drugs stability and compounds photoreactions, based on monochromatic irradiation and Φ-kinetics data analysis, is also detailed and adopted throughout the thesis. Finally, two new kinetic parameters namely, the pseudo-rate-constant and pseudo-initial velocity have been identified and shown to be more reliable and accurate in the description and universal comparison of photoreactions kinetics.