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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Investigations into the roles of potassium channels in hair growth. Studies confirming the presence of several ATP-­sensitive potassium (K+ATP) channels in hair follicles and exploring their mechanism of action using molecular biological, cell culture, organ culture and proteomic approaches.

Zemaryalai, Khatera January 2010 (has links)
Hair disorders cause significant distress. The main, but limited, treatment for hair loss is minoxidil, an ATP-­sensitive potassium (KATP) channel opener whose mechanism of stimulation is unclear. The regulatory component of KATP channels has three forms: SUR1, SUR2A and SUR2B which all respond to different molecules. Minoxidil only opens SUR2B channels, though SUR1 and SUR2B are present in human hair follicles. To expand our understanding, the red deer hair follicle model was used initially. Deer follicles expressed the same KATP channel genes as human follicles when growing (anagen), but no channels were detected in resting follicles. This reinforces the importance of KATP channels in active hair growth and the usefulness of the deer model. To assess whether SUR1 KATP channels are actually involved in human hair growth, the effects of a selective SUR1 channel opener, NNC55-­9216, on scalp follicle growth in organ culture was examined. NNC55-­9216 stimulated anagen; its effect was augmented by minoxidil. This creates the potential for more effective pharmaceuticals to treat hair loss via SUR1 channels, either alone or in combination with minoxidil. The dermal papilla plays a crucial regulatory role in hair follicle activity determining the type of hair produced. Minoxidil had no effect on dermal papilla cell proliferation, but altered the profile of proteins produced when assessed by proteomics. Further research into the roles of KATP channels and greater understanding of the significance of these protein changes should enhance our knowledge of hair biology and help the development of new, improved therapies for hair pathologies.
12

Investigations into the roles of potassium channels in hair growth : studies confirming the presence of several ATP-­sensitive potassium (K+ATP) channels in hair follicles and exploring their mechanism of action using molecular biological, cell culture, organ culture and proteomic approaches

Zemaryalai, Khatera January 2010 (has links)
Hair disorders cause significant distress. The main, but limited, treatment for hair loss is minoxidil, an ATP-sensitive potassium (KATP) channel opener whose mechanism of stimulation is unclear. The regulatory component of KATP channels has three forms: SUR1, SUR2A and SUR2B which all respond to different molecules. Minoxidil only opens SUR2B channels, though SUR1 and SUR2B are present in human hair follicles. To expand our understanding, the red deer hair follicle model was used initially. Deer follicles expressed the same KATP channel genes as human follicles when growing (anagen), but no channels were detected in resting follicles. This reinforces the importance of KATP channels in active hair growth and the usefulness of the deer model. To assess whether SUR1 KATP channels are actually involved in human hair growth, the effects of a selective SUR1 channel opener, NNC55-9216, on scalp follicle growth in organ culture was examined. NNC55-9216 stimulated anagen; its effect was augmented by minoxidil. This creates the potential for more effective pharmaceuticals to treat hair loss via SUR1 channels, either alone or in combination with minoxidil. The dermal papilla plays a crucial regulatory role in hair follicle activity determining the type of hair produced. Minoxidil had no effect on dermal papilla cell proliferation, but altered the profile of proteins produced when assessed by proteomics. Further research into the roles of KATP channels and greater understanding of the significance of these protein changes should enhance our knowledge of hair biology and help the development of new, improved therapies for hair pathologies.
13

Συνθέσεις αναλόγων της μινοξιδίλης, της ασιτρετίνης και του ψωραλενίου κατάλληλων για μελέτες σχέσεις δομής-βιολογικής δραστικότητας / Syntheses of analogs of minoxidil, acitretin and psoralens suitable for structure activity relationship studies

Μπαριάμης, Σταύρος 04 December 2012 (has links)
Η ασιτρετίνη, τα ψωραλένια και η μινοξιδίλη αποτελούν φάρμακα επιλογής για την αντιμετώπιση δερματικών ασθενειών (ψωρίαση, καρκίνος δέρματος, λεύκη, ανδρογενής αλωπεκία). Στο πλαίσιο της παρούσας διδακτορικής διατριβής αναπτύχθηκαν συγκλίνουσες συνθετικές μεθοδολογίες για την ολική σύνθεση αναλόγων της ασιτρετίνης με μεταβολές στο λιπόφιλο τμήμα της. Επιπλέον, τροποποιήθηκαν με χημικό τρόπο ψωραλένια, όπως το τριοξαλένιο, το μπερκαπτένιο και το ξανθοτοξένιο και συντέθηκε μια πληθώρα υβριδικών αναλόγων και συζευγμάτων τους με όξινα ρετινοειδή. Τέλος, αναπτύχθηκαν μεθοδολογίες για την ολική σύνθεση αναλόγων και συζευγμάτων της μινοξιδίλης με πολυαμίνες και άλλα βιοδραστικά μόρια. / Acitretin, Psoralens and Minoxidil are the drug of choice for the treatment of several dermatological disorders, such as psoriasis, vitiligo, cancer and adrogenic alopecia. In the context of the present thesis we developed efficient convergent synthetic methodologies for the total syntheses of acitretin analogs, incorporating changes in the lipophilic part. Moreover, psoralens, such as trioxsalen, bergapten and xanthotoxin, were chemically modified, in order to synthesize, hybrid analogs and conjugates with acidic retinoids. Finally, we developed efficient synthetic methodologies for the total synthesis of analogs and conjugates of Minoxidil with polyamines and other molecules with biological interest.
14

Estratégias para a determinação de minoxidil

Sousa, Rogério Adelino de 04 September 2009 (has links)
Made available in DSpace on 2016-06-02T20:34:18Z (GMT). No. of bitstreams: 1 2757.pdf: 3606841 bytes, checksum: 1cbaf9d57ef931332c3b9f278a479c5a (MD5) Previous issue date: 2009-09-04 / Universidade Federal de Sao Carlos / In this work methods for determining minoxidil (MX) in commercial samples and electrolytes of synthetic plasma and urine are presented. The minoxidil is a pharmaceutical whose blood vessel dilation property is used in the treatment of the Arterial Hypertension and in the treatment of the Alopécia Areata. Three commercial samples were analyzed, the Regaine® (Pharmacia, USA) and the magistral formulation (Porto Bianco, Brazil) both are topical use solutions, in a mixture of ethanol and propilenoglicol as vehicle, containing 2 % (20 mg mL-1) and 5 % of minoxidil (50 mg mL-1) respectively, and Loniten® (Rhodia, Brasil) containing 10 mg of MX per tablet. Three proposals for the determination of minoxidil in commercial samples and electrolytes of synthetic plasma and urine were considered. The first procedure was the determination of MX in the samples using flow injection analysis with spectrophotometric detection in two setups. For the setup procedure using single line with a wavelength of 400 nm, which can quantify the MX present in samples, showing recovery values of 99.7 and 104.8 % for Loniten® and the Regaine® respectively, and 102.5 % for the magistral sample. In merging-zones setup, the detection was in 345 nm, the MX was determined in the samples with recovery 101.3 % for Loniten® and 99.8 % to Regaine® and 103.7 % for the magistral. For both configurations, all the results from flow agree with the labeled values and the results from the chromatographic method (comparative method) in 95 % confidence (t-Student test). In the second procedure, an electroanalytical determination of MX is described using two composite electrodes, the graphite-polyurethane (GPUE) and graphite-silicone rubber (GSRE). Cyclic voltammetry was used to study the electroactive area of electrodes (GPUE = 0.093 cm2; GSRE = 0.089 cm2), the diffusion coefficient of MX (in order of 8.0 x10-6 cm2 s-1) and to study the mechanism of electro-oxidation of MX of which involves one electron per proton. With the support of analytical curves were determined the levels of MX in the samples by different voltammetric techniques; cyclic voltammetry (CV), square wave voltammetry (SWV) and differential pulse voltammetry (DPV). The recovery values are in the range between 96.0 and 110 %, depending on the sample and the voltammetric technique. The electrochemical impedance spectroscopy showed that the mass transport is controlled by diffusion and also there is a weak and reversible adsorption that for both the electrodes. The third method describes the determination of MX and furosemide (FR) using high performance liquid chromatography (HPLC) with spectrophotometric detection. The wavelengths of 275 and 285 nm were for the detection of FR and MX respectively. The mobile phase used was methanol/triethylamine (99:1, V/V) in the flow rate of 0.5 mL min-1. The column used was a C18 Supelco®. The recoveries were 97.7 and 102.4 % for Loniten® and Lasix® respectively. Finally is presented the characterization of the product of oxidation of MX. The informations obtained from infrared spectroscopy technique, were compared with results obtained by nuclear proton magnetic resonance. Two structures were proposed as product of redox reaction between the MX and KMnO4, the desoximinoxidil and another new structure. / No presente trabalho, são apresentados métodos para a determinação minoxidil (MX) em amostras comercias e eletrólitos de plasma e urina sintéticos. O MX é um fármaco que, devido à sua propriedade vasodilatadora, é usado no tratamento da Hipertensão Arterial e no tratamento da Alopécia Areata (calvice). Foram analisadas três amostras comerciais, Regaine® (Pharmacia, EUA), formulação de uso tópico manipulada pela Farmácia de Manipulação Porto Bianco (São Carlos, Brasil) e o Loniten® (Rhodia, Brasil), sendo o primeiro e o segundo soluções de uso tópico contendo 2 % (20 mg mL-1 m/v) e 5 % (50 mg mL-1 m/V) de MX, respectivamente; o terceiro medicamento é apresentado em forma de comprimidos contendo 10 mg de minoxidil, o qual é utilizado no tratamento da hipertensão arterial. Também foram analisados os teores de MX contido nos eletrólitos do plasma e da urina artificiais.Nesse trabalho foram propostas três metodologias para a determinação do MX nas amostras. O primeiro procedimento foi a determinação de MX nas amostras usando análise em fluxo com detecção espectrofotométrica em duas configurações diferentes, as quais monitoraram a formação de um produto amarelado formado a partir da reação entre MX e HNO2 formado in situ. A primeira configuração foi de linha única, com detecção no comprimento de onda de 400 nm, na qual foi possível quantificar o MX presente nas amostras, com recuperações de 99,7 e 104,8 % para o Loniten® e o Regaine®, respectivamente, e 102,5 % para a amostra manipulada. Na segunda configuração, de zonas coalescentes e detecção 345 nm, o MX foi determinado nas amostras com recuperação entre 101,3 % para o Loniten®, 99,8 % para o Regaine ® e 103,7 % para o Manipulado. Observou-se, para ambas as configurações, que todos os resultados do método de análise em fluxo concordam com os valores rotulados das amostras analisadas e com os resultados do método cromatográfico (método comparativo), em 95 % de confiança (teste t-Student). No segundo método, é descrita a determinação eletroanalítica de MX usando dois eletrodos compósitos de grafite-poliuretana (GPUE) e grafiteborracha de silicone (GSRE). Foi usada voltametria cíclica para o obtenção da área eletroativa dos eletrodos (GPUE = 0,093 cm2; GSRE = 0,089 cm2), do coeficiente difusão do MX (na ordem de 8,0x10-6 cm2 s-1) e para estudo do mecanismo da eletro-oxidação da MX, que é de um elétron por próton. Com o auxílio das curvas analíticas, foram determinados os teores de MX contidos nas amostras por diferentes técnicas voltamétricas, voltametria cíclica (CV), voltametria de onda quadrada (SWV) e voltametria de pulso diferencial (DPV), usando ambos os eletrodos. Os valores de recuperação estão no intervalo entre 96,0 e 110 %, dependendo da amostra e da técnica voltamétrica. A espectroscopia de impedância eletroquímica descreveu qual o circuito elétrico foi equivalente à eletro-oxidação do minoxidil e, ainda, mostrou que há adsorção fraca e reversível para ambos os eletrodos. O terceiro método descreve a determinação de MX e furosemida (FR), usando cromatografia líquida de alta eficiência (HPLC) com detecção espectrofotométrica. Os comprimentos de onda de detecção foram 275 e 285 nm para a FR e o MX, respectivamente. A fase móvel usada foi metanol/trietilamina (99:1; V/V) na vazão de 0,5 mL min-1. A coluna usada foi uma C18 da Supelco®. As recuperações foram 97,7 e 102,4 % para o Loniten® e o Furosem®, respectivamente. Finalmente, é apresentada a caracterização do produto de oxidação do MX. Para a caracterização, foi usada a espectroscopia de infravermelho e as informações obtidas foram comparadas com os resultados obtidos na ressonância magnética nuclear de prótons. Foram propostas, através da técnicas IR e RMN, duas estruturas resultantes da reação redox entre o MX e o KMnO4, o desoximinoxidil e uma outra estrutura, inédita na literatura o 3,5-dióxido-2,4- dinitro-6-piperidinopirimidina.
15

Minoxidil 1 mg oral versus minoxidil 5% tópico para tratamento da alopecia de padrão feminino ensaio clínico randomizado /

Ramos, Paulo Müller. January 2019 (has links)
Orientador: Helio Amante Miot / Resumo: Introdução: Minoxidil tópico é o único medicamento com aprovação pelo FDA (Food and Drug Administration) para tratamento da alopecia de padrão feminino (APF). Muitas pacientes interrompem o tratamento prematuramente devido a falta de eficácia, intolerância ou por alteração na textura dos fios de cabelo. Minoxidil oral mostrou-se efetivo para tratamento da APF em estudo não controlado. Objetivo: Comparar eficácia, segurança e tolerabilidade do minoxidil 1 mg oral uma vez ao dia versus minoxidil 5% solução tópica uma vez ao dia no tratamento da APF. Métodos: Estudo prospectivo, randomizado, paralelo, comparativo, avaliador cego com duração de 24 semanas conduzido em um único centro de janeiro de 2017 a março de 2018 incluindo 52 mulheres (18-65 anos) com APF. Participantes foram randomizadas para receber minoxidil oral 1 mg ao dia ou minoxidil 5% tópico uma vez ao dia. O desfecho primário foi a variação na densidade de fios na área alvo. Desfechos secundários: variação na densidade de fios terminais na área alvo, escore na avaliação fotográfica panorâmica por avaliadores cegos, variação no escore da escala de queda, variação no escore do Women's Androgenetic Alopecia Quality of Life Questionnaire (WAA-QoL). Resultados: Participantes de ambos os grupos apresentaram melhora na densidade de fios na área alvo (p<0,01), porém, sem diferença entre os grupos (p=0,09): oral 12% (IC95%: 8,0 – 16,1%) e tópico 7,2% (IC95%: 1,5 - 12,9%). Houve melhora na densidade de fios terminais: oral 6... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Introduction: Topical minoxidil is the only FDA (Food and Drug Administration) approved drug for female pattern hair loss (FPHL). Many patients discontinue treatment prematurely due to lack of efficacy, intolerance or altered hair texture. Oral minoxidil was effective for FPHL in uncontrolled studies. Objectives: To compare the efficacy, safety and tolerability of once-daily treatment with 1 mg oral minoxidil versus once-daily 5% minoxidil solution applied topically for FPHL. Methods: A 24-week, prospective, randomized, open-label, parallel, two-arm comparative, evaluator-blinded study conducted in a single center from January 2017 through March 2018 including 52 women (18-65 years old) with FPHL. Participants were randomly assigned to receive once daily minoxidil 1 mg orally or once a day minoxidil 5% solution applied topically. The primary endpoint was change from baseline in hair density from a target area at week 24. Secondary endpoints were change in terminal hair density, global photographic assessment by three group-blinded evaluators, hair shedding score, and the Women's Androgenetic Alopecia Quality of Life Questionnaire (WAA-QoL). Results: Participants of both groups had improvement of hair density in the target area (p<0.01), without difference between the groups (p=0.09): oral 12% (CI95%: 8.0- 16.1%) and topical 7,2% (CI95%: 1.5-12.9%). There was improvement on terminal hair density: oral 6% (IC95%: 2.9 – 8.6%) and topical 2,7% (IC95%: -1.4 – 6.8%), with no differ... (Complete abstract click electronic access below) / Doutor
16

Human hair follicles contain two forms of ATP-sensitive potassium channels, only one of which is sensitive to minoxidil

Shorter, K., Farjo, N.P., Picksley, Stephen M., Randall, Valerie A. January 2008 (has links)
Hair disorders cause psychological distress but are generally poorly controlled; more effective treatments are required. Despite the long-standing use of minoxidil for balding, its mechanism is unclear; suggestions include action on vasculature or follicle cells. Similar drugs also stimulate hair, implicating ATP-sensitive potassium (K(ATP)) channels. To investigate whether K(ATP) channels are present in human follicles, we used organ culture, molecular biological, and immunohistological approaches. Minoxidil and tolbutamide, a K(ATP) channel blocker, opposed each other's effects on the growing phase (anagen) of scalp follicles cultured in media with and without insulin. Reverse transcriptase-polymerase chain reaction identified K(ATP) channel component gene expression including regulatory sulfonylurea receptors (SUR) SUR1 and SUR2B but not SUR2A and pore-forming subunits (Kir) Kir6.1 and Kir6.2. When hair bulb tissues were examined separately, epithelial matrix expressed SUR1 and Kir6.2, whereas both dermal papilla and sheath exhibited SUR2B and Kir6.1. Immunohistochemistry demonstrated similar protein distributions. Thus, human follicles respond biologically to K(ATP) channel regulators in culture and express genes and proteins for two K(ATP) channels, Kir6.2/SUR1 and Kir6.1/SUR2B; minoxidil only stimulates SUR2 channels. These findings indicate that human follicular dermal papillae contain K(ATP) channels that can respond to minoxidil and that tolbutamide may suppress hair growth clinically; novel drugs designed specifically for these channels could treat hair disorders.

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