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1.
COPD ; 21(1): 2361669, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38863257

RESUMO

This study aimed to explore the self-management strategies of Danish patients living with advanced Chronic Obstructive Pulmonary Disease (COPD), with a particular focus on their daily life and their interactions with the respiratory outpatient clinic. Data were collected through semi-structured interviews with 11 patients with COPD affiliated with a Danish respiratory outpatient clinic. The data were thematically analyzed as suggested by Braun & Clarke. The analysis revealed one overarching theme, three main themes, and six subthemes. The overarching theme 'In a strained healthcare system patients with COPD struggle to access needed support to be able to self-manage their disease' revolved around the challenges that patients face in an overburdened healthcare system as they seek support to effectively self-manage their condition. The three main themes were: (1) Only physical symptoms provide legal access to the respiratory outpatient clinic, (2) For patients, the measurements serve as indicators of their health status and overall well-being, (3) Healthcare professionals' skills and not the mode of contact matters to the patients. Healthcare professionals should be aware that the rhetoric surrounding a busy healthcare system with a stressed-out staff also affects patients. Patients with COPD may be particularly sensitive to this message and try to avoid burdening the healthcare system further by setting aside their own needs. However, this approach can lead to neglecting symptoms of deterioration and mental symptoms, which increase the risk of disease progression and subsequent risk of hospital admission.


Assuntos
Doença Pulmonar Obstrutiva Crônica , Pesquisa Qualitativa , Humanos , Doença Pulmonar Obstrutiva Crônica/terapia , Doença Pulmonar Obstrutiva Crônica/psicologia , Masculino , Feminino , Idoso , Pessoa de Meia-Idade , Dinamarca , Acessibilidade aos Serviços de Saúde , Autogestão , Autocuidado , Entrevistas como Assunto , Idoso de 80 Anos ou mais , Instituições de Assistência Ambulatorial
2.
Osteoarthritis Cartilage ; 29(5): 750-761, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33582239

RESUMO

OBJECTIVE: Synovial inflammation is one of the most characteristic events in different types of arthritis, including Osteoarthritis (OA). Emerging evidence also suggests the involvement of lipids in the regulation of inflammatory processes. The aim of this study was to elucidate the heterogeneity and spatial distribution of lipids in the OA synovial membrane and explore their putative involvement in inflammation. METHOD: The abundance and distribution of lipids were examined in human synovial membranes. To this end, histological cuts from this tissue were analysed by matrix-assisted laser desorption ionization - mass spectrometry imaging (MALDI-MSI). The lipidomic profile of OA synovium was characterized and compared with healthy and other forms of inflammatory arthropathies as Rheumatoid Arthritis (RA) and Psoriatic Arthritis (PsA) using principal component analysis and discriminant analysis methods. Lipid identification was undertaken by tandem MS analyses and database queries. RESULTS: Our results reveal differential and characteristic lipidomic profiles between OA and control samples. Specifically, we unveiled that OA synovium presents elevated levels of phosphatidylcholines, fatty acids and lysophosphatidic acids and lower levels of lysophosphatidylcholines compared to control tissues. The spatial distribution of particular glycerophospholipids was also correlated with hypertrophic, inflamed or vascularized synovial areas. Compared with other inflammatory arthritis, the OA tissue showed lower amounts of phosphatidylethanolamine-based plasmalogens. CONCLUSIONS: This study provides a novel insight into the lipid profiles of synovial membrane and differences in abundance between OA and control tissues. The lipidomic alterations improves understanding of the pathogenic mechanisms of OA and may be important for its diagnosis.


Assuntos
Articulação do Joelho/metabolismo , Metabolismo dos Lipídeos , Osteoartrite do Joelho/metabolismo , Membrana Sinovial/metabolismo , Idoso , Estudos de Casos e Controles , Análise Discriminante , Feminino , Humanos , Lipidômica , Masculino , Pessoa de Meia-Idade , Análise de Componente Principal , Espectrometria de Massas em Tandem
3.
Insect Mol Biol ; 25(2): 171-80, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26790026

RESUMO

Honey bees, Apis mellifera, are markedly less sensitive to neonicotinoid insecticides containing a cyanoimino pharmacophore than to those with a nitroimino group. Although previous work has suggested that this results from enhanced metabolism of the former by detoxification enzymes, the specific enzyme(s) involved remain to be characterized. In this work, a pretreatment of honey bees with a sublethal dose of thiacloprid resulted in induced insensitivity to the same compound immediately following thiacloprid feeding. A longer pretreatment time resulted in no, or increased, sensitivity. Transcriptome profiling, using microarrays, identified a number of genes encoding detoxification enzymes that were over-expressed significantly in insecticide-treated bees compared with untreated controls. These included five P450s, CYP6BE1, CYP305D1, CYP6AS5, CYP315A1, CYP301A1, and a carboxyl/cholinesterase (CCE) CCE8. Four of these P450s were functionally expressed in Escherichia coli and their ability to metabolize thiacloprid examined by liquid chromatography-mass spectrometry (LC-MS) analysis.


Assuntos
Abelhas/efeitos dos fármacos , Sistema Enzimático do Citocromo P-450/genética , Inativação Metabólica/genética , Anabasina/farmacologia , Animais , Abelhas/metabolismo , Sistema Enzimático do Citocromo P-450/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Inseticidas/farmacologia , Neonicotinoides , Piridinas/farmacologia , Tiazinas/farmacologia , Ativação Transcricional/efeitos dos fármacos
4.
Cell Tissue Res ; 358(2): 433-42, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25012520

RESUMO

During the formation of dental enamel, maturation-stage ameloblasts express ion-transporting transmembrane proteins. The SLC4 family of ion-transporters regulates intra- and extracellular pH in eukaryotic cells by cotransporting HCO3 (-) with Na(+). Mutation in SLC4A4 (coding for the sodium-bicarbonate cotransporter NBCe1) induces developmental defects in human and murine enamel. We have hypothesized that NBCe1 in dental epithelium is engaged in neutralizing protons released during crystal formation in the enamel space. We immunolocalized NBCe1 protein in wild-type dental epithelium and examined the effect of the NBCe1-null mutation on enamel formation in mice. Ameloblasts expressed gene transcripts for NBCe1 isoforms B/D/C/E. In wild-type mice, weak to moderate immunostaining for NBCe1 with antibodies that recognized isoforms A/B/D/E and isoform C was seen in ameloblasts at the secretory stage, with no or low staining in the early maturation stage but moderate to high staining in the late maturation stage. The papillary layer showed the opposite pattern being immunostained prominently at the early maturation stage but with gradually less staining at the mid- and late maturation stages. In NBCe1 (-/-) mice, the ameloblasts were disorganized, the enamel being thin and severely hypomineralized. Enamel organs of CFTR (-/-) and AE2a,b (-/-) mice (CFTR and AE2 are believed to be pH regulators in ameloblasts) contained higher levels of NBCe1 protein than wild-type mice. Thus, the expression of NBCe1 in ameloblasts and the papillary layer cell depends on the developmental stage and possibly responds to pH changes.


Assuntos
Órgão do Esmalte/citologia , Órgão do Esmalte/embriologia , Simportadores de Sódio-Bicarbonato/metabolismo , Ameloblastos/citologia , Ameloblastos/metabolismo , Amelogênese , Animais , Western Blotting , Calcificação Fisiológica/genética , Antiportadores de Cloreto-Bicarbonato/metabolismo , Cricetinae , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Órgão do Esmalte/diagnóstico por imagem , Órgão do Esmalte/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Incisivo/metabolismo , Mandíbula/metabolismo , Camundongos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Simportadores de Sódio-Bicarbonato/deficiência , Simportadores de Sódio-Bicarbonato/genética , Regulação para Cima/genética , Microtomografia por Raio-X
5.
Acta Neurol Scand ; 127(5): 301-8, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-22970985

RESUMO

BACKGROUND: Patients with multiple sclerosis (MS) are more frequently born in spring when compared to autumn. Fluctuation of UV-light has been hypothesized to drive this phenomenon. AIM: To assess the correlation between fluctuation of sunlight and birth season in persons with MS. METHODS: For this record-linkage study, we collected from the international MSBase and the Italian MS iMed-web databases the dates of birth of 11,415 patients with MS from 36 centres from 15 countries worldwide and compared these to dates of live-births from national registries. From all participating sites, we collected data on UV-light fluctuation and assessed its correlation with seasonal fluctuation in MS births. RESULTS: Compared with the reference cohort, an increased proportion of persons with MS were born in spring and a decreased proportion in autumn (odds ratio (OR) to be born in spring versus autumn = 1.158, χ² = 36.347, P < 0.001). There was no significantly increased fluctuation of MS births with increased quartile of ambient UV-light fluctuation (Ptrend = 0.086). CONCLUSION: Seasonal fluctuation of MS births as found in this worldwide cohort of patients with MS did not correlate with variation in seasonal fluctuation of UV-light. Most likely, it results from a complex interplay between fluctuation of sunlight, behavioural factors, other environmental factors and (epi)genetic factors.


Assuntos
Esclerose Múltipla/epidemiologia , Efeitos Tardios da Exposição Pré-Natal , Estações do Ano , Luz Solar , Raios Ultravioleta , Bases de Dados Factuais , Feminino , Saúde Global , Humanos , Masculino , Gravidez , Sistema de Registros , Fatores de Risco
6.
J Neurol Neurosurg Psychiatry ; 83(3): 311-4, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22193562

RESUMO

BACKGROUND: Axonal loss is a major determinant of disability in multiple sclerosis (MS). While acute inflammatory demyelination is a principal cause of axonal transection and subsequent axonal degeneration in acute disease, the nature of chronic axonal loss is less well understood. In the current study, the relationship between degree of chronic demyelination and axonal degeneration was investigated using optic neuritis (ON) as a model. METHOD: 25 patients with a first episode of unilateral ON, good recovery of visual function and concurrent brain or spinal cord MRI lesions were enrolled. Axonal loss was assessed using change in retinal nerve fibre layer (RNFL) thickness between 1 and 3 years after ON. Optic nerve conduction was evaluated using latency of multifocal visual evoked potentials (mfVEP). The level of mfVEP latency delay at 12 and 36 months was considered indicative of the degree of permanent demyelination. Data from 25 age and gender matched normal controls were used for comparison. RESULTS: RNFL thickness was significantly reduced in ON eyes at 12 months compared with controls but remained unchanged in fellow eyes. Average RNFL thickness demonstrated a small but significant reduction between 12 and 36 months for both ON and fellow eyes. Change in RNFL thickness between 12 and 36 months, however, did not correlate with the degree of mfVEP latency delay. CONCLUSION: The results, therefore, show no association between the degree of permanent optic nerve demyelination (as measured by latency delay) and progressive axonal degeneration, at least in the early stages of the disease. The fact that fellow eyes demonstrated a similar degree of progressive axonal loss supports this suggestion.


Assuntos
Axônios/patologia , Doenças Desmielinizantes/patologia , Esclerose Múltipla/patologia , Nervo Óptico/patologia , Adulto , Estudos de Casos e Controles , Doenças Desmielinizantes/fisiopatologia , Potenciais Evocados Visuais/fisiologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Esclerose Múltipla/fisiopatologia , Nervo Óptico/fisiopatologia , Neurite Óptica/patologia , Neurite Óptica/fisiopatologia
7.
Parasit Vectors ; 14(1): 115, 2021 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-33602297

RESUMO

BACKGROUND: It is important to understand whether the potential impact of pyrethroid resistance on malaria control can be mitigated by switching between different pyrethroids or whether cross-resistance within this insecticide class precludes this approach. METHODS: Here we assess the relationships among pyrethroids in terms of their binding affinity to, and depletion by, key cytochrome P450 enzymes (hereafter P450s) that are known to confer metabolic pyrethroid resistance in Anopheles gambiae (s.l.) and An. funestus, in order to identify which pyrethroids may diverge from the others in their vulnerability to resistance. We then investigate whether these same pyrethroids also diverge from the others in terms of resistance in vector populations. RESULTS: We found that the type I and II pyrethroids permethrin and deltamethrin, respectively, are closely related in terms of binding affinity to key P450s, depletion by P450s and resistance within vector populations. Bifenthrin, which lacks the common structural moiety of most pyrethroids, diverged from the other pyrethroids tested in terms of both binding affinity to key P450s and depletion by P450s, but resistance to bifenthrin has rarely been tested in vector populations and was not analysed here. Etofenprox, which also lacks the common structural moiety of most pyrethroids, diverged from the more commonly deployed pyrethroids in terms of binding affinity to key P450s and resistance in vector populations, but did not diverge from these pyrethroids in terms of depletion by the P450s. The analysis of depletion by the P450s indicated that etofenprox may be more vulnerable to metabolic resistance mechanisms in vector populations. In addition, greater resistance to etofenprox was found across Aedes aegypti populations, but greater resistance to this compound was not found in any of the malaria vector species analysed. The results for pyrethroid depletion by anopheline P450s in the laboratory were largely not repeated in the findings for resistance in malaria vector populations. CONCLUSION: Importantly, the prevalence of resistance to the pyrethroids α-cypermethrin, cyfluthrin, deltamethrin, λ-cyhalothrin and permethrin was correlated across malaria vector populations, and switching between these compounds as a tool to mitigate against pyrethroid resistance is not advised without strong evidence supporting a true difference in resistance.


Assuntos
Aedes/efeitos dos fármacos , Anopheles/efeitos dos fármacos , Sistema Enzimático do Citocromo P-450/metabolismo , Proteínas de Insetos/metabolismo , Resistência a Inseticidas , Inseticidas/farmacologia , Mosquitos Vetores/efeitos dos fármacos , Piretrinas/farmacologia , Aedes/enzimologia , Animais , Anopheles/enzimologia , Vetores de Doenças , Inseticidas/química , Malária/transmissão , Controle de Mosquitos , Mosquitos Vetores/enzimologia , Piretrinas/química
8.
Genet Mol Res ; 9(1): 554-64, 2010 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-20391340

RESUMO

Anopheles funestus, one of the main African malaria vectors, caused a major malaria outbreak in South Africa during 1999/2000, even though South Africa had an effective vector control program in place. The outbreak was due to pyrethroid resistant An. funestus invading KwaZulu/Natal. Increased activity of cytochrome P450 (monooxygenase) was responsible for the pyrethroid resistance in this species. A monooxygenase gene, CYP6P9, was highly overexpressed in the pyrethroid-resistant strain compared with a susceptible strain. Characterization of this gene as well as the redox partners involved in the catalytic cycle of P450s was investigated. The full length of the CYP6P9 sequence was isolated, sequenced and compared between the pyrethroid-resistant and -susceptible strains. Sequence identity between the two strains was 99.3%; the sequence differences were mainly outside of the conserved regions. The functional significance is still unknown, but it is feasible that these variations are associated with differences in insecticide metabolism. A second CYP6 gene (CYP6P13) was also isolated; it shared close similarities with CYP6P9. The putative redox partners, cytochrome b(5) (cyt b(5)) and NADPH-cytochrome P450 reductase (CPR), were isolated from An. funestus (resistant strain) and showed high levels of sequence identity to other insect cyt b(5) and CPRs. Isolation of the coding sequences CYP6P9 and its cognate redox partners enables expression of functional recombinant protein for biochemical and structural analysis.


Assuntos
Anopheles/enzimologia , Anopheles/genética , Sistema Enzimático do Citocromo P-450/genética , Resistência a Inseticidas/genética , Piretrinas/toxicidade , Análise de Sequência de DNA , Sequência de Aminoácidos , Animais , Anopheles/efeitos dos fármacos , Sequência de Bases , Sistema Enzimático do Citocromo P-450/química , Citocromos b5/metabolismo , DNA Complementar/genética , Resistência a Inseticidas/efeitos dos fármacos , Dados de Sequência Molecular , NADPH-Ferri-Hemoproteína Redutase/genética , Filogenia , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico
9.
Sci Rep ; 10(1): 19158, 2020 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-33154449

RESUMO

The safety and efficacy of kratom (Mitragyna speciosa) for treatment of pain is highly controversial. Kratom produces more than 40 structurally related alkaloids, but most studies have focused on just two of these, mitragynine and 7-hydroxymitragynine. Here, we profiled 53 commercial kratom products using untargeted LC-MS metabolomics, revealing two distinct chemotypes that contain different levels of the alkaloid speciofoline. Both chemotypes were confirmed with DNA barcoding to be M. speciosa. To evaluate the biological relevance of variable speciofoline levels in kratom, we compared the opioid receptor binding activity of speciofoline, mitragynine, and 7-hydroxymitragynine. Mitragynine and 7-hydroxymitragynine function as partial agonists of the human µ-opioid receptor, while speciofoline does not exhibit measurable binding affinity at the µ-, δ- or ƙ-opioid receptors. Importantly, mitragynine and 7-hydroxymitragynine demonstrate functional selectivity for G-protein signaling, with no measurable recruitment of ß-arrestin. Overall, the study demonstrates the unique binding and functional profiles of the kratom alkaloids, suggesting potential utility for managing pain, but further studies are needed to follow up on these in vitro findings. All three kratom alkaloids tested inhibited select cytochrome P450 enzymes, suggesting a potential risk for adverse interactions when kratom is co-consumed with drugs metabolized by these enzymes.


Assuntos
Analgésicos/farmacologia , Mitragyna/química , Extratos Vegetais/química , Receptores Opioides mu/metabolismo , Alcaloides de Triptamina e Secologanina/farmacologia , Cromatografia Líquida , Humanos , Metabolômica , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/metabolismo , Espectrometria de Massas em Tandem
10.
Doc Ophthalmol ; 118(2): 129-37, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18779985

RESUMO

PURPOSE: To investigate topographical relationship between amplitude of multifocal visual evoked potentials (mfVEP) and retinal nerve fibre layer (RNFL) thickness following acute optic neuritis (ON). PATIENTS AND METHODS: Fifty patients with a clinical diagnosis of acute unilateral ON between 6 and 36 months prior to the study and 25 age-matched controls underwent mfVEP testing (Accumap V 2.1, ObjectiVision Pty Ltd, Sydney, Australia) and OCT imaging (fast RNFL protocol, Stratus, software version 3.0, Carl Zeiss Meditec, Inc., Dublin, CA). RNFL thickness and mfVEP amplitude were measured for upper, temporal and lower retinal sectors and corresponding areas of the visual field in affected eyes of ON patients and control eyes. Inter-eye asymmetry coefficients for both RNFL thickness and mfVEP amplitude were calculated for each zone, and corresponding coefficients were correlated between each other. RESULTS: There was highly significant reduction of RNFL thickness and mean mfVEP amplitude in all three retinal sectors of the affected eye. Largest reduction of RNFL thickness was noticed in temporal sector and of mfVEP amplitude in corresponding central part of the visual field. RNFL thickness correlated highly with amplitude of the mfVEP derived from corresponding areas of the visual field in all three zones. CONCLUSIONS: We demonstrated strong topographical associations between structural and functional measures of optic nerve integrity in patients with ON.


Assuntos
Potenciais Evocados Visuais , Neurite Óptica , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fibras Nervosas/patologia , Fibras Nervosas/fisiologia , Nervo Óptico/patologia , Nervo Óptico/fisiopatologia , Neurite Óptica/patologia , Neurite Óptica/fisiopatologia , Neurônios Retinianos/patologia , Neurônios Retinianos/fisiologia , Tomografia de Coerência Óptica , Campos Visuais/fisiologia
11.
Orthod Craniofac Res ; 12(3): 243-53, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19627527

RESUMO

Emdogain (enamel matrix derivative, EMD) is well recognized in periodontology, where it is used as a local adjunct to periodontal surgery to stimulate regeneration of periodontal tissues lost to periodontal disease. The biological effect of EMD is through stimulation of local growth factor secretion and cytokine expression in the treated tissues, inducing a regenerative process that mimics odontogenesis. The major (>95%) component of EMD is Amelogenins (Amel). No other active components have so far been isolated from EMD, and several studies have shown that purified amelogenins can induce the same effect as the complete EMD. Amelogenins comprise a family of highly conserved extracellular matrix proteins derived from one gene. Amelogenin structure and function is evolutionary well conserved, suggesting a profound role in biomineralization and hard tissue formation. A special feature of amelogenins is that under physiological conditions the proteins self-assembles into nanospheres that constitute an extracellular matrix. In the body, this matrix is slowly digested by specific extracellular proteolytic enzymes (matrix metalloproteinase) in a controlled process, releasing bioactive peptides to the surrounding tissues for weeks after application. Based on clinical and experimental observations in periodontology indicating that amelogenins can have a significant positive influence on wound healing, bone formation and root resorption, several new applications for amelogenins have been suggested. New experiments now confirm that amelogenins have potential for being used also in the fields of endodontics, bone regeneration, implantology, traumatology, and wound care.


Assuntos
Amelogenina/uso terapêutico , Proteínas do Esmalte Dentário/uso terapêutico , Doenças Periodontais/cirurgia , Amelogenina/fisiologia , Calcificação Fisiológica/fisiologia , Sequência Conservada , Proteínas do Esmalte Dentário/fisiologia , Proteínas da Matriz Extracelular/fisiologia , Humanos , Metaloproteinases da Matriz/fisiologia , Osteogênese/fisiologia , Regeneração/efeitos dos fármacos , Reabsorção da Raiz/fisiopatologia , Cicatrização/fisiologia
12.
J Proteomics ; 193: 184-191, 2019 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-30343012

RESUMO

Mass spectrometry imaging (MSI) has emerged as a powerful tool in biomedical research to reveal the localization of a broad scale of compounds ranging from metabolites to proteins in diseased tissues, such as malignant tumors. MSI is most commonly used for the two-dimensional imaging of tissues from multiple patients or for the three-dimensional (3D) imaging of tissue from a single patient. These applications are potentially introducing a sampling bias on a sample or patient level, respectively. The aim of this study is therefore to investigate the consequences of sampling bias on sample representativeness and on the precision of biomarker discovery for histological grading of human bladder cancers by MSI. We therefore submitted formalin-fixed paraffin-embedded tissues from 14 bladder cancer patients with varying histological grades to 3D analysis by matrix-assisted laser desorption/ionization (MALDI) MSI. We found that, after removing 20% of the data based on novel outlier detection routines for 3D-MSI data based on the evaluation of digestion efficacy and z-directed regression, on average 33% of a sample has to be measured in order to obtain sufficient coverage of the existing biological variance within a tissue sample. SIGNIFICANCE: In this study, 3D MALDI-MSI is applied for the first time on a cohort of bladder cancer patients using formalin-fixed paraffin-embedded (FFPE) tissue of bladder cancer resections. This work portrays the reproducibility that can be achieved when employing an optimized sample preparation and subsequent data evaluation approach. Our data shows the influence of sampling bias on the variability of the results, especially for a small patient cohort. Furthermore, the presented data analysis workflow can be used by others as a 3D FFPE data-analysis pipeline working on multi-patient 3D-MSI studies.


Assuntos
Imageamento Tridimensional , Proteínas de Neoplasias/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Neoplasias da Bexiga Urinária , Estudos de Coortes , Feminino , Humanos , Masculino , Neoplasias da Bexiga Urinária/diagnóstico por imagem , Neoplasias da Bexiga Urinária/metabolismo
13.
Br J Pharmacol ; 153 Suppl 1: S82-9, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18026129

RESUMO

The cytochromes P450 (CYPs) comprise a vast superfamily of enzymes found in virtually all life forms. In mammals, xenobiotic metabolizing CYPs provide crucial protection from the effects of exposure to a wide variety of chemicals, including environmental toxins and therapeutic drugs. Ideally, the information on the possible metabolism by CYPs required during drug development would be obtained from crystal structures of all the CYPs of interest. For some years only crystal structures of distantly related bacterial CYPs were available and homology modelling techniques were used to bridge the gap and produce structural models of human CYPs, and thereby obtain useful functional information. A significant step forward in the reliability of these models came seven years ago with the first crystal structure of a mammalian CYP, rabbit CYP2C5, followed by the structures of six human enzymes, CYP1A2, CYP2A6, CYP2C8, CYP2C9, CYP2D6 and CYP3A4, and a second rabbit enzyme, CYP2B4. In this review we describe as a case study the evolution of a CYP2D6 model, leading to the validation of the model as an in silico tool for predicting binding and metabolism. This work has led directly to the successful design of CYP2D6 mutants with novel activity-including creating a testosterone hydroxylase, converting quinidine from inhibitor to substrate, creating a diclofenac hydroxylase and creating a dextromethorphan O-demethylase. Our modelling-derived hypothesis-driven integrated interdisciplinary studies have given key insight into the molecular determinants of CYP2D6 and other important drug metabolizing enzymes.


Assuntos
Citocromo P-450 CYP2D6/química , Citocromo P-450 CYP2D6/efeitos dos fármacos , Sistema Enzimático do Citocromo P-450/química , Sistema Enzimático do Citocromo P-450/metabolismo , Preparações Farmacêuticas/metabolismo , Animais , Sistema Enzimático do Citocromo P-450/efeitos dos fármacos , Interações Medicamentosas , Humanos , Modelos Moleculares , Especificidade por Substrato
14.
Insect Mol Biol ; 17(2): 125-35, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18353102

RESUMO

Three CYP6Z genes are linked to a major pyrethroid resistance locus in the mosquito Anopheles gambiae. We have expressed CYP6Z2 in Escherichia coli and produced a structural model in order to examine its role in detoxification. E. coli membranes co-expressing CYP6Z2 and An. gambiae P450 reductase (AgCPR) catalysed the dealkylation of benzyloxyresorufin with kinetic parameters K(m) = 0.13 microM; K(cat) = 1.5 min(-1). The IC(50) values of a wide range of compounds were measured. Pyrethroids cypermethrin and permethrin produced low IC(50) values, but were not metabolized. Plant flavanoids were the most potent inhibitors. Several compounds were shown to be substrates, suggesting that CYP6Z2 has broad substrate specificity and plays an important chemo-protective role during the herbivorous phase of the life-cycle.


Assuntos
Anopheles/enzimologia , Inibidores das Enzimas do Citocromo P-450 , Sistema Enzimático do Citocromo P-450/metabolismo , Insetos Vetores/enzimologia , Inseticidas/farmacologia , Piretrinas/farmacologia , Laranja de Acridina , Sequência de Aminoácidos , Animais , Anopheles/genética , Clonagem Molecular , Sistema Enzimático do Citocromo P-450/genética , DNA/química , DNA/genética , Escherichia coli/enzimologia , Escherichia coli/genética , Concentração Inibidora 50 , Insetos Vetores/genética , Resistência a Inseticidas , Inseticidas/farmacocinética , Isoenzimas , Modelos Moleculares , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Piretrinas/farmacocinética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Alinhamento de Sequência
15.
J Dent Res ; 87(4): 391-5, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18362326

RESUMO

The H(+)/base transport processes that control the pH of the microenvironment adjacent to ameloblasts are not currently well-understood. Mice null for the AE2 anion exchanger have abnormal enamel. In addition, persons with mutations in the electrogenic sodium bicarbonate co-transporter NBCe1 and mice lacking NBCe1 have enamel abnormalities. These observations suggest that AE2 and NBCe1 play important roles in amelogenesis. In the present study, we aimed to understand the roles of AE2 and NBCe1 in ameloblasts. Analysis of the data showed that NBCe1 is expressed at the basolateral membrane of secretory ameloblasts, whereas AE2 is expressed at the apical membrane. Transcripts for AE2a and NBCe1-B were detected in RNA isolated from cultured ameloblast-like LS8 cells. Our data are the first evidence that AE2 and NBCe1 are expressed in ameloblasts in vivo in a polarized fashion, thereby providing a mechanism for ameloblast transcellular bicarbonate secretion in the process of enamel formation and maturation.


Assuntos
Ameloblastos/metabolismo , Proteínas de Transporte de Ânions/genética , Antiporters/genética , Proteínas do Tecido Nervoso/genética , Simportadores de Sódio-Bicarbonato/genética , Amelogênese/genética , Animais , Membrana Celular/metabolismo , Células Cultivadas , Incisivo/citologia , Camundongos , Dente Molar/citologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas SLC4A , Transcrição Gênica/genética
16.
Audiol Neurootol ; 13(1): 19-28, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-17715466

RESUMO

A randomised control prospective study was carried out examining patient outcomes after performing a 10-week vestibular home exercise programme. Thirty-two adults with vestibular dysfunction who reported vestibular symptoms negatively affecting daily life were enrolled. Test subjects were provided with an individualised vestibular rehabilitation programme designed by a physiotherapist. Control subjects received a set of strength and endurance exercises only. All subjects performed their exercises 3 times a day for 10 weeks. Subjective and objective patient measures were collected at 0, 6, 10 and 26 weeks. Results showed that both groups improved after beginning exercise, and that test subjects significantly benefited compared to the controls. These benefits were long term and measurable 6 months later. This study provides evidence that individualised vestibular exercises promote better outcomes for patients with vestibular dysfunction.


Assuntos
Tontura/reabilitação , Terapia por Exercício/métodos , Satisfação do Paciente , Modalidades de Fisioterapia , Doenças Vestibulares/reabilitação , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Equilíbrio Postural , Estudos Prospectivos , Inquéritos e Questionários
17.
J Dent Res ; 97(5): 483-491, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29328868

RESUMO

For decades, dental schools in the United States have endured a significant faculty shortage. Studies have determined that the top 2 sources of dental faculty are advanced education programs and private practice. Those who have completed both DDS and PhD training are considered prime candidates for dental faculty positions. However, there is no national database to track those trainees and no evidence to indicate that they entered academia upon graduation. The objective of this study was to assess outcomes of dental school-affiliated oral sciences PhD program enrollment, graduates, and placement between 1994 and 2016. Using the American Dental Association annual survey of advanced dental education programs not accredited by the Commission on Dental Accreditation and data obtained from 22 oral sciences PhD programs, we assessed student demographics, enrollment, graduation, and placement. Based on the data provided by program directors, the average new enrollment was 33, and graduation was 26 per year. A total of 605 graduated; 39 did not complete; and 168 were still in training. Among those 605 graduates, 211 were faculty in U.S. academic institutions, and 77 were faculty in foreign institutions. Given that vacant budgeted full-time faculty positions averaged 257 per year during this period, graduates from those oral sciences PhD programs who entered academia in the United States would have filled 9 (3.6%) vacant faculty positions per year. Therefore, PhD programs have consistently generated only a small pipeline of dental school faculty. Better mentoring to retain talent in academia is necessary. Stronger support and creative funding plans are essential to sustain the PhD program. Furthermore, the oral sciences PhD program database should be established and maintained by dental professional organizations to allow assessments of training models, trends of enrollment, graduation, and placement outcomes.


Assuntos
Educação de Pós-Graduação em Odontologia/estatística & dados numéricos , Humanos , Faculdades de Odontologia/estatística & dados numéricos , Inquéritos e Questionários , Estados Unidos
18.
J Clin Invest ; 90(4): 1414-24, 1992 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1401075

RESUMO

IL-5 and granulocyte macrophage-colony-stimulating factor (GM-CSF) are important regulators of eosinophil survival, proliferation, and effector function. To determine whether IL-5 and/or GM-CSF are generated by eosinophils at sites of allergic inflammation, we have used in situ hybridization with 35S-labeled RNA probes to study the expression of IL-5 and GM-CSF mRNA in bronchoalveolar lavage (BAL) eosinophils derived from asthmatics (n = 5) before and after endobronchial allergen challenge. Endobronchial allergen challenge induced a significant airway eosinophilia (pre-allergen challenge 0.6 +/- 0.5% eosinophilia vs post-allergen challenge 48.2 +/- 25.6% eosinophilia). Post-allergen challenge eosinophils expressed IL-5 and GM-CSF mRNA, but did not express IL-1 beta or IL-2 mRNA. To determine whether the IL-5 mRNA-positive cells coexpressed GM-CSF mRNA, double mRNA labeling experiments with a digoxigenin-11-UTP nonradioactive labeled IL-5 RNA probe and a GM-CSF 35S-labeled RNA probe were performed. These studies demonstrated that individual eosinophils expressed one of four cytokine mRNA profiles (IL-5+, GM-CSF+, 34 +/- 13%; IL-5+, GM-CSF-, 34 +/- 5%; IL-5-, GM-CSF+, 11 +/- 9%; IL-5-, GM-CSF-, 21 +/- 25%). The expression of IL-5 and GM-CSF by eosinophils at sites of allergic inflammation in asthmatics may provide an important autocrine pathway, maintaining the viability and effector function of the recruited eosinophils.


Assuntos
Asma/metabolismo , Eosinófilos/metabolismo , Fator Estimulador de Colônias de Granulócitos e Macrófagos/genética , Inflamação/metabolismo , Interleucina-5/genética , RNA Mensageiro/análise , Adolescente , Adulto , Feminino , Humanos , Imuno-Histoquímica , Interleucina-1/genética , Interleucina-2/genética , Masculino
19.
Clin Pharmacol Ther ; 101(4): 430-434, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28318023

RESUMO

New drugs were not required to undergo premarket safety testing in the United States until 1938, when a therapeutic disaster-the Elixir Sulfanilamide tragedy-prompted Congress to pass a bill mandating this now-routine process. History repeated itself nearly 25 years later, when another therapeutic disaster-the thalidomide tragedy-led to passage of new amendments in 1962 to ensure drug efficacy and greater drug safety. As is typical with historical events, critical information was gained that led to novel approaches for understanding, predicting, diagnosing, and managing drug-induced toxicities. Continued refinement of current, along with development of new, approaches will mitigate future drug-related catastrophes, with the goal of avoiding them entirely.


Assuntos
Aprovação de Drogas/história , Aprovação de Drogas/legislação & jurisprudência , Legislação de Medicamentos/história , United States Food and Drug Administration/história , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/história , História do Século XX , Humanos , Segurança , Sulfanilamida , Sulfanilamidas/efeitos adversos , Sulfanilamidas/história , Estados Unidos
20.
Chem Commun (Camb) ; 53(53): 7246-7249, 2017 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-28573274

RESUMO

Coupling laser post-ionisation with a high resolving power MALDI Orbitrap mass spectrometer has realised an up to ∼100-fold increase in the sensitivity and enhanced the chemical coverage for MALDI-MS imaging of lipids relative to conventional MALDI. This could constitute a major breakthrough for biomedical research.


Assuntos
Lasers , Lipídeos/análise , Pesquisa Biomédica , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
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