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1.
Rev Med Liege ; 79(5-6): 291-296, 2024 Jun.
Artigo em Francês | MEDLINE | ID: mdl-38869114

RESUMO

Belgian community pharmacists play a pivotal role in both primary and tertiary preventive health activities. Their involvement extends beyond the pharmaceutical care associated with dispensing to include innovative services such as medication review. Additionally, they offer therapeutic education sessions to patients as part of the «Good Use of Medicines¼ programme. The recent pandemic has precipitated significant changes in pharmacists' responsibilities: they have been temporarily granted authority to prescribe and administer vaccines for COVID-19 and influenza, as well as to perform nasopharyngeal screenings for SARS-CoV-2. As frontline healthcare providers, pharmacists have the potential to expand their role in secondary prevention, particularly in screening and providing diagnostic guidance using in vitro diagnostic medical assays. The skills developed in the vaccination domain could be leveraged to enhance vaccination coverage for other diseases, emulating models used in other countries. Furthermore, the challenges posed by climate change present opportunities for pharmacists to contribute meaningfully to public health.


Le pharmacien d'officine belge participe activement aux activités de prévention primaire et tertiaire, non seulement par le biais des soins pharmaceutiques accompagnant la délivrance de médicaments ou dispositifs médicaux, mais aussi via les nouveaux services, comme la revue de la médication. Il réalise aussi des séances d'éducation thérapeutique des patients dans le cadre des entretiens d'accompagnement de Bon Usage des Médicaments (BUM). La récente pandémie a mené à une évolution rapide des missions confiées au pharmacien : il est maintenant (temporairement) autorisé à prescrire et à administrer les vaccins contre la COVID-19 et la grippe et à effectuer le dépistage nasopharyngé du SARS-CoV-2. Professionnel de santé de première ligne, le pharmacien pourrait remplir davantage de missions de prévention secondaire, notamment en matière de dépistage et d'orientation diagnostique au moyen de dispositifs médicaux de diagnostic in vitro. Les nouvelles compétences acquises en matière de vaccination pourraient être mises à profit pour contribuer à étendre la couverture vaccinale vis-à-vis d'autres pathologies, à l'instar des missions exercées par les pharmaciens d'officine à l'étranger. Enfin, les enjeux climatiques offrent de nouvelles perspectives.


Assuntos
COVID-19 , Serviços Comunitários de Farmácia , Promoção da Saúde , Farmacêuticos , Papel Profissional , Humanos , COVID-19/prevenção & controle , Serviços Comunitários de Farmácia/organização & administração , Bélgica
2.
Front Neurosci ; 18: 1322105, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38586192

RESUMO

Introduction: Spinal cord stimulation is a common treatment option for neuropathic pain conditions. Despite its extensive use and multiple technological evolutions, long term efficacy of spinal cord stimulation is debated. Most studies on spinal cord stimulation include a rather limited number of patients and/or follow-ups over a limited period. Therefore, there is an urgent need for real-world, long-term data. Methods: In 2018, the Belgian government initiated a nationwide secure platform for the follow-up of all new and existing spinal cord stimulation therapies. This is a unique approach used worldwide. Four years after the start of centralized recording, the first global extraction of data was performed. Results: Herein, we present the findings, detailing the different steps in the centralized procedure, as well as the observed patient and treatment characteristics. Furthermore, we identified dropouts during the screening process, the reasons behind discontinuation, and the evolution of key indicators during the trial period. In addition, we obtained the first insights into the evolution of the clinical impact of permanent implants on the overall functioning and quality of life of patients in the long-term. Discussion: Although these findings are the results of the first data extraction, some interesting conclusions can be drawn. The long-term outcomes of neuromodulation are complex and subject to many variables. Future data extraction will allow us to identify these confounding factors and the early predictors of success. In addition, we will propose further optimization of the current process.

3.
J Pharm Biomed Anal ; 209: 114492, 2022 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-34864591

RESUMO

Vitamin D3 is a key micronutrient whose intakes are inadequate for most populations worldwide. Supplementation with medicines or food supplements is commonly prescribed to correct this imbalance and the quality of these products must be ensured. In this context, a generic methodology for the assay of vitamin D3 in oily formulations is proposed using supercritical fluid chromatography coupled to mass spectrometry (SFC-MS). It is in line with green analytical chemistry principles and combines the use of i) a fast and robust analytical method (4.0 min analysis time) ii) an easy sample preparation compatible with high throughput analysis ("dilute-and-shoot" approach) and iii) a relevant control strategy. Seventeen products from multiple manufacturers and encompassing a large content range were evaluated in this study. They were classified in four groups to streamline their processing considering the use of a matrix-matched calibration procedure. Matrix effect was thoroughly studied and was found to be low (99-106%), stable intra/inter-series and comparable between the different groups and types of matrices. The implemented control strategy was based on a three-level system suitability tests (SST). Level 1 SST: resolution of the critical pair that was above 1.5 for all analysis series. Level 2 SST: evaluation of the adequacy of the calibration for a QC sample in terms of recovery that was between 97% and 104% with a variability between 1% and 2%. Level 3 SST: method trueness that was between 95% and 102%. Sample analysis highlighted differences in types of products and dosage forms. This is the first study to propose a complete strategy for the quality control of vitamin D3 oily formulations and should prove useful in QC laboratories.


Assuntos
Colecalciferol , Cromatografia com Fluido Supercrítico , Espectrometria de Massas , Óleos , Controle de Qualidade
4.
J Neuroendocrinol ; 33(3): e12955, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33769643

RESUMO

Part of the life cycle of several fish species includes important salinity changes, as is the case for the sea bass (Dicentrarchus labrax) or the Atlantic salmon (Salmo salar). Salmo salar juveniles migrate downstream from their spawning sites to reach seawater, where they grow and become sexually mature. The process of preparation enabling juveniles to migrate downstream and physiologically adapt to seawater is called smoltification. Daily and seasonal variations of photoperiod and temperature play a role in defining the timing of smoltification, which may take weeks to months, depending on the river length and latitude. Smoltification is characterised by a series of biochemical, physiological and behavioural changes within the neuroendocrine axis. This review discusses the current knowledge and gaps related to the neuroendocrine mechanisms that mediate the effects of light and temperature on smoltification. Studies performed in S. salar and other salmonids, as well as in other species undergoing important salinity changes, are reviewed, and a particular emphasis is given to the pineal hormone melatonin and its possible role in osmoregulation. The daily and annual variations of plasma melatonin levels reflect corresponding changes in external photoperiod and temperature, which suggests that the hormonal time-keeper melatonin might contribute to controlling smoltification. Here, we review studies on (i) the impact of pinealectomy and/or melatonin administration on smoltification; (ii) melatonin interactions with hormones involved in osmoregulation (e.g., prolactin, growth hormone and cortisol); (iii) the presence of melatonin receptors in tissues involved in osmoregulation; and (iv) the impacts of salinity changes on melatonin receptors and circulating melatonin levels. Altogether, these studies show evidence indicating that melatonin interacts with the neuroendocrine pathways controlling smoltification, although more information is needed to clearly decipher its mechanisms of action.


Assuntos
Peixes/fisiologia , Melatonina/fisiologia , Osmorregulação/fisiologia , Salmo salar/fisiologia , Animais , Água Doce , Estações do Ano , Água do Mar
5.
J Hand Surg Eur Vol ; 45(5): 477-482, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31964213

RESUMO

In this retrospective study we reviewed the outcomes of 46 trapeziometacarpal joint replacements with the Moovis® prosthesis in 46 patients with painful osteoarthritis. The dual mobility design of this prosthesis aims to reduce prosthetic dislocation and subsidence. At follow-up 2 to 6 years (mean 5 years) after operation, pain was reduced from 6 to 0 on a visual analogue scale from 0 to 10. The scores of the Quick Disabilities of the Arm, Shoulder and Hand questionnaire improved significantly. Thumb motion and grip and pinch strength did not differ significantly from the contralateral hand. There were no radiographical signs of implant subsidence or loosening. No implant required revision. Forty-five patients rated the result as excellent or good. We conclude the Moovis® is a reliable and effective implant at short- to mid-term follow-up. Level of evidence: IV.


Assuntos
Articulações Carpometacarpais , Prótese Articular , Osteoartrite , Trapézio , Articulações Carpometacarpais/diagnóstico por imagem , Articulações Carpometacarpais/cirurgia , Seguimentos , Força da Mão , Humanos , Osteoartrite/diagnóstico por imagem , Osteoartrite/cirurgia , Amplitude de Movimento Articular , Estudos Retrospectivos , Polegar/diagnóstico por imagem , Polegar/cirurgia , Trapézio/diagnóstico por imagem , Trapézio/cirurgia
6.
Medicine (Baltimore) ; 95(11): e3027, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26986117

RESUMO

The aim of this study was to describe the clinical and biological features of Mevalonate kinase deficiency (MKD) in patients diagnosed in adulthood. This is a French and Belgian observational retrospective study from 2000 to 2014. To constitute the cohort, we cross-check the genetic and biochemical databases. The clinical, enzymatic, and genetic data were gathered from medical records. Twenty-three patients were analyzed. The mean age at diagnosis was 40 years, with a mean age at onset of symptoms of 3 years. All symptomatic patients had fever. Febrile attacks were mostly associated with arthralgia (90.9%); lymphadenopathy, abdominal pain, and skin lesions (86.4%); pharyngitis (63.6%); cough (59.1%); diarrhea, and hepatosplenomegaly (50.0%). Seven patients had psychiatric symptoms (31.8%). One patient developed recurrent seizures. Three patients experienced renal involvement (13.6%). Two patients had angiomyolipoma (9.1%). All but one tested patients had elevated serum immunoglobulin (Ig) D level. Twenty-one patients had genetic diagnosis; most of them were compound heterozygote (76.2%). p.Val377Ile was the most prevalent mutation. Structural articular damages and systemic AA amyloidosis were the 2 most serious complications. More than 65% of patients displayed decrease in severity and frequency of attacks with increasing age, but only 35% achieved remission. MKD diagnosed in adulthood shared clinical and genetic features with classical pediatric disease. An elevated IgD concentration is a good marker for MKD in adults. Despite a decrease of severity and frequency of attacks with age, only one-third of patients achieved spontaneous remission.


Assuntos
Deficiência de Mevalonato Quinase/epidemiologia , Adolescente , Adulto , Idoso , Bélgica/epidemiologia , Feminino , França/epidemiologia , Humanos , Masculino , Deficiência de Mevalonato Quinase/complicações , Deficiência de Mevalonato Quinase/tratamento farmacológico , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
7.
PLoS One ; 10(4): e0123172, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25856193

RESUMO

The North-east American Rainbow smelt (Osmerus mordax) is composed of two glacial races first identified through the spatial distribution of two distinct mtDNA lineages. Contemporary breeding populations of smelt in the St. Lawrence estuary comprise contrasting mixtures of both lineages, suggesting that the two races came into secondary contact in this estuary. The overall objective of this study was to assess the role of intraspecific genetic admixture in the morphological diversification of the estuarine rainbow smelt population complex. The morphology of mixed-ancestry populations varied as a function of the relative contribution of the two races to estuarine populations, supporting the hypothesis of genetic admixture. Populations comprising both ancestral mtDNA races did not exhibit intermediate morphologies relative to pure populations but rather exhibited many traits that exceeded the parental trait values, consistent with the hypothesis of transgressive segregation. Evidence for genetic admixture at the level of the nuclear gene pool, however, provided only partial support for this hypothesis. Variation at nuclear AFLP markers revealed clear evidence of the two corresponding mtDNA glacial races. The admixture of the two races at the nuclear level is only pronounced in mixed-ancestry populations dominated by one of the mtDNA lineages, the same populations showing the greatest degree of morphological diversification and population structure. In contrast, mixed-ancestry populations dominated by the alternate mtDNA lineage showed little evidence of introgression of the nuclear genome, little morphological diversification and little contemporary population genetic structure. These results only partially support the hypothesis of transgressive segregation and may be the result of the differential effects of natural selection acting on admixed genomes from different sources.


Assuntos
DNA Mitocondrial/genética , Genética Populacional , Osmeriformes/genética , Seleção Genética , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Animais , Evolução Molecular , Variação Genética , Filogenia , Especificidade da Espécie
8.
Blood ; 125(14): 2200-5, 2015 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-25636341

RESUMO

It is common practice in many centers to offer antithrombotic medications to women with unexplained recurrent miscarriage, in the presence or absence of inherited thrombophilia. Although no benefit of aspirin vs placebo has been clearly demonstrated, a double-blind placebo-controlled trial on the effect of low-molecular-weight heparin is lacking. We enrolled 258 pregnant women with a history of unexplained recurrent miscarriage (≥2 consecutive miscarriages before 15 weeks' gestation) and a negative thrombophilia workup. They were randomly assigned to receive one daily subcutaneous injection of enoxaparin 40 mg or placebo until 35 weeks' gestation. We included 256 women (mean age 32 years, ≥3 miscarriages: 72%; mean gestational age 39 days of amenorrhea) in the intention-to-treat analysis; 66.6% of 138 who received enoxaparin had a live birth vs 72.9% of 118 who received placebo. The absolute difference was -6% (95% CI, -17.1 to 5.1), excluding a 10% increase in the rate of live-birth on enoxaparin (P = .34). In this first randomized, double-blind, placebo-controlled trial, enoxaparin (40 mg once daily) did not improve the chance of a live birth in nonthrombophilic women with unexplained recurrent miscarriage. This trial is registered at www.ClinicalTrials.gov as #NCT00740545 and the French National Health and Drug Safety Agency (EudraCT #2006-003350-18).


Assuntos
Aborto Habitual/prevenção & controle , Enoxaparina/uso terapêutico , Complicações na Gravidez/prevenção & controle , Adulto , Anticoagulantes , Método Duplo-Cego , Feminino , Seguimentos , Idade Gestacional , Heparina de Baixo Peso Molecular , Humanos , Nascido Vivo , Gravidez , Prognóstico
9.
Eur J Med Chem ; 74: 12-22, 2014 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-24440378

RESUMO

Nimesulide, a COX-2 preferential inhibitor with a favorable gastric and cardiovascular safety profile, was responsible for some cases of acute liver failure attributed to the nitrobenzene ring. A series of analogs of nimesulide resulting from isosteric replacement of the nitrobenzene ring by the pyridine nucleus, was synthesized and their ability to inhibit both cyclooxygenases (COXs) isoforms was evaluated in vitro using a human whole blood model. Compounds 19c, 23b and 23c displayed an important inhibitory activity associated to a COX-2/COX-1 selectivity ratio similar to or higher than that of celecoxib. The anti-inflammatory activity and the ability of several compounds to decrease leukocyte infiltration were further evaluated in vivo in a model of a λ carrageenan-induced pleurisy. Plasma assays were performed on blood samples collected from rats and allowed us to identify the 4-position of the phenyl ring as a major metabolism site explaining the occasionally observed lack of correlation between in vitro and in vivo results.


Assuntos
Anti-Inflamatórios/farmacologia , Inibidores de Ciclo-Oxigenase/farmacologia , Piridinas/química , Sulfonamidas/farmacologia , Animais , Anti-Inflamatórios/sangue , Anti-Inflamatórios/química , Inibidores de Ciclo-Oxigenase/sangue , Inibidores de Ciclo-Oxigenase/química , Espectroscopia de Ressonância Magnética , Ratos , Sulfonamidas/sangue , Sulfonamidas/química
10.
Ecol Evol ; 4(19): 3723-35, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25614787

RESUMO

A growing number of studies have been investigating the influence of contemporary environmental factors on population genetic structure, but few have addressed the issue of spatial patterns in the variable intensity of factors influencing the extent of population structure, and particularly so in aquatic ecosystems. In this study, we document the landscape genetics of northern pike (Esox lucius), based on the analysis of nearly 3000 individuals from 40 sampling sites using 22 microsatellites along the Lake Ontario - St. Lawrence River system (750 km) that locally presents diverse degrees of interannual water level variation. Genetic structure was globally very weak (F ST = 0.0208) but spatially variable with mean level of differentiation in the upstream section of the studied area being threefold higher (F ST = 0.0297) than observed in the downstream sector (F ST = 0.0100). Beside interannual water level fluctuation, 19 additional variables were considered and a multiple regression on distance matrices model (R (2)  = 0.6397, P < 0.001) revealed that water masses (b = 0.3617, P < 0.001) and man-made dams (b = 0.4852, P < 0.005) reduced genetic connectivity. Local level of interannual water level stability was positively associated to the extent of genetic differentiation (b = 0.3499, P < 0.05). As water level variation impacts on yearly quality and localization of spawning habitats, our study illustrates how temporal variation in local habitat availability, caused by interannual water level fluctuations, may locally decrease population genetic structure by forcing fish to move over longer distances to find suitable habitat. This study thus represents one of the rare examples of how environmental fluctuations may influence spatial variation in the extent of population genetic structure within a given species.

11.
PLoS One ; 8(10): e77483, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24130890

RESUMO

The bonga shad, Ethmalosa fimbriata, is a West African pelagic species still abundant in most habitats of its distribution range and thought to be only recently affected by anthropogenic pressure (habitat destruction or fishing pressure). Its presence in a wide range of coastal habitats characterised by different hydrodynamic processes, represents a case study useful for evaluating the importance of physical structure of the west African shoreline on the genetic structure of a small pelagic species. To investigate this question, the genetic diversity of E. fimbriata was assessed at both regional and species range scales, using mitochondrial (mt) and nuclear DNA markers. Whereas only three panmictic units were identified with mtDNA at the large spatial scale, nuclear genetic markers (EPIC: exon-primed intron-crossing) indicated a more complex genetic pattern at the regional scale. In the northern-most section of shad's distribution range, up to 4 distinct units were identified. Bayesian inference as well as spatial autocorrelation methods provided evidence that gene flow is impeded by the presence of deep-water areas near the coastline (restricting the width of the coastal shelf), such as the Cap Timiris and the Kayar canyons in Mauritania and Senegal, respectively. The added discriminatory power provided by the use of EPIC markers proved to be essential to detect the influence of more subtle, contemporary processes (e.g. gene flow, barriers, etc.) acting within the glacial refuges identified previously by mtDNA.


Assuntos
Peixes/genética , África Ocidental , Migração Animal , Animais , Teorema de Bayes , DNA/genética , DNA/isolamento & purificação , Ecossistema , Fluxo Gênico , Variação Genética , Genética Populacional
12.
J Am Soc Mass Spectrom ; 24(12): 1937-49, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24043520

RESUMO

The gas-phase structures of doubly and triply protonated Amyloid-ß12-28 peptides have been investigated through the combination of ion mobility (IM), electron capture dissociation (ECD) mass spectrometry, and infrared multi-photon dissociation (IRMPD) spectroscopy together with theoretical modeling. Replica-exchange molecular dynamics simulations were conducted to explore the conformational space of these protonated peptides, from which several classes of structures were found. Among the low-lying conformers, those with predicted diffusion cross-sections consistent with the ion mobility experiment were further selected and their IR spectra simulated using a hybrid quantum mechanical/semiempirical method at the ONIOM DFT/B3LYP/6-31 g(d)/AM1 level. In ECD mass spectrometry, the c/z product ion abundance (PIA) has been analyzed for the two charge states and revealed drastic differences. For the doubly protonated species, N - Cα bond cleavage occurs only on the N and C terminal parts, while a periodic distribution of PIA is clearly observed for the triply charged peptides. These PIA distributions have been rationalized by comparison with the inverse of the distances from the protonated sites to the carbonyl oxygens for the conformations suggested from IR and IM experiments. Structural assignment for the amyloid peptide is then made possible by the combination of these three experimental techniques that provide complementary information on the possible secondary structure adopted by peptides. Although globular conformations are favored for the doubly protonated peptide, incrementing the charge state leads to a conformational transition towards extended structures with 310- and α-helix motifs.


Assuntos
Peptídeos beta-Amiloides/química , Fragmentos de Peptídeos/química , Humanos , Íons/química , Espectrometria de Massas/métodos , Modelos Moleculares , Estrutura Secundária de Proteína , Prótons , Espectrofotometria Infravermelho/métodos
13.
PLoS One ; 8(8): e71052, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23990925

RESUMO

Metapopulation dynamics over the course of an invasion are usually difficult to grasp because they require large and reliable data collection, often unavailable. The invasion of the fish-free freshwater ecosystems of the remote sub-Antarctic Kerguelen Islands following man-made introductions of brown trout (Salmo trutta) in the 1950's is an exception to this rule. Benefiting from a full long term environmental research monitoring of the invasion, we built a Bayesian dynamic metapopulation model to analyze the invasion dynamics of 85 river systems over 51 years. The model accounted for patch size (river length and connections to lakes), alternative dispersal pathways between rivers, temporal trends in dynamics, and uncertainty in colonization date. The results show that the model correctly represents the observed pattern of invasion, especially if we assume a coastal dispersal pathway between patches. Landscape attributes such as patch size influenced the colonization function, but had no effect on propagule pressure. Independently from patch size and distance between patches, propagule pressure and colonization function were not constant through time. Propagule pressure increased over the course of colonization, whereas the colonization function decreased, conditional on propagule pressure. The resulting pattern of this antagonistic interplay is an initial rapid invasion phase followed by a strong decrease in the invasion rate. These temporal trends may be due to either adaptive processes or environmental gradients encountered along the colonization front. It was not possible to distinguish these two hypotheses. Because invasibility of Kerguelen Is. freshwater ecosystems is very high due to the lack of a pre-existing fish fauna and minimal human interference, our estimates of invasion dynamics represent a blueprint for the potential of brown trout invasiveness in pristine environments. Our conclusions shed light on the future of polar regions where, because of climate change, fish-free ecosystems become increasingly accessible to invasion by fish species.


Assuntos
Espécies Introduzidas , Truta/fisiologia , Animais , Regiões Antárticas , Teorema de Bayes , Ecologia , Ecossistema , Monitoramento Ambiental/métodos , Peixes , Água Doce , Modelos Teóricos , Dinâmica Populacional , Probabilidade , Rios , Processos Estocásticos , Fatores de Tempo
14.
Surg Radiol Anat ; 35(3): 217-24, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23053118

RESUMO

PURPOSE: Our goals were to carry out an anatomical description of the internal architecture of the supinator muscle in order to describe potentially compressive structures for the deep branch of the radial nerve (DBRN) and to establish reference landmarks for the surgical treatment of radial tunnel syndrome. METHODS: Thirty upper limbs were dissected. The pennation angle of proximal and distal arcades of the supinator to the radial shaft axis was measured. Possible compressive structures of both superficial and deep heads of supinator were recorded. Proximal and distal arcades of the superficial layer of the supinator were classified according to their fiber content as tendinous, musculo-tendinous, muscular or membranous. The distances of superficial layer of the supinator muscle to the humeroradial joint line and lateral epicondyle were measured. RESULTS: Pennation angle was 33.6° (±4.2°) for the superficial layer and 50.2° (±6.6°) for the deep layer. The difference was statistically significant (p < 0.0001). The proximal arcade was purely tendinous in 20 cases (66.7 %). The distal arcade was mainly tendinous or musculo-tendinous (70 %). The average distance between the lateral epicondyle and the proximal arcade was 41.6 mm. We did not find any other potentially compressive structure within DBRN course between both layers. CONCLUSION: Our anatomical results about pennation angle could be used as a basis for a thorough functional study about the supinator. Both proximal and distal arcades appeared as the two zones ables to compress the DBRN. Their localization should help the surgeon for the DBRN neurolysis.


Assuntos
Músculo Esquelético/anatomia & histologia , Síndromes de Compressão Nervosa/etiologia , Nervo Radial/anatomia & histologia , Neuropatia Radial/etiologia , Extremidade Superior/inervação , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Síndromes de Compressão Nervosa/cirurgia , Neuropatia Radial/cirurgia
15.
J Pharm Biomed Anal ; 74: 273-83, 2013 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-23245261

RESUMO

This paper focuses on implementing a design space approach and on the critical process parameters (CPPs) to consider when applying the Quality by Design (QbD) concepts outlined in ICH Q8(R2), Q9 and Q10 to analytical method development and optimization for three chiral compounds developed as modulators of small conductance calcium-activated potassium (SK) channels. In this sense, an HPLC method using a polysaccharide-based stationary phase containing a cellulose tris (4-chloro-3-methylphenylcarbamate) chiral selector in polar organic solvent chromatography mode was considered. The effects of trifluoroacetic acid (TFA) and n-hexane concentration in an acetonitrile (MeCN) mobile phase were investigated under a wide range of column temperatures. Good correlations were found between the observed data obtained after using a central composite design and the expected chromatographic behaviours predicted by applying the design of experiments-design space (DoE-DS) methodology. The critical quality attribute represented here by the separation criterion (S(crit)) allowed assessing the quality of the enantioseparation. Baseline separation for the compounds of interest in an analysis time of less than 20 min was possible due to the original and powerful tools applied which facilitated an enhanced method comprehension. Finally, the advantage of the DoE-DS approach resides in granting the possibility to concurrently assess robustness and identify the optimal conditions which are compound dependent.


Assuntos
Desenho de Equipamento/métodos , Solventes/análise , Solventes/química , Acetonitrilas/análise , Acetonitrilas/química , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida de Alta Pressão/normas , Dietilaminas/análise , Dietilaminas/química , Desenho de Equipamento/normas , Estereoisomerismo , Ácido Trifluoracético/análise , Ácido Trifluoracético/química
16.
Chemphyschem ; 12(10): 1822-32, 2011 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-21618379

RESUMO

We studied the single-photon ionization of gas-phase δ-valerolactam (piperidin-2-one) and of its dimer using vacuum-ultraviolet (VUV) synchrotron radiation coupled to a velocity map imaging electron/ion coincidence spectrometer. The slow photoelectron spectrum (SPES) of the monomer is dominated by the vibrational transitions to the ͠X state. Moreover, several weaker and complex bands are observed, corresponding to the population of the vibrational bands (pure or combination) of the electronically excited states of the cation arising from their mutual vibronic interactions. For the dimer, we measure a unique large band. These spectra are assigned with the help of theoretical calculations dealing with the equilibrium geometries, electronic-state patterns and evolutions, harmonic and anharmonic wavenumbers of the monomer and dimer, either neutral or positively charged. The state energies of the [δ-valerolactam](+) cation in the ͠X ground, ͠A, ͠B, ͠C, excited electronic states, and of the [δ-valerolactam](2) (+) cation's lowest states are determined. After its formation, [δ-valerolactam](2) (+) is subject to intramolecular isomerization, H transfer and then unimolecular fragmentation processes. Close to the ionization thresholds, the photoionization of these molecules is found to be mainly dominated by a direct process whereas the indirect route (autoionization) contributes at higher energies.


Assuntos
Piperidonas/química , Cátions/química , Dimerização , Modelos Teóricos , Espectroscopia Fotoeletrônica , Teoria Quântica , Vibração
17.
AAPS PharmSciTech ; 11(2): 966-75, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20512433

RESUMO

To investigate the encapsulation of Print 3G, a peptidic agent that could reduce the angiogenic development of breast tumors, pegylated liposomes used as intravenous vectors were studied and characterized. Recently, the path of liposomes has been explored with success to improve the pharmacological properties of peptidic drugs and to stabilize them. In this study, loaded unilamellar vesicles composed of SPC:CHOL:mPEG2000-DSPE (47:47:6) were prepared by the hydration of lipid film technique. An HPLC method was developed and validated for the determination of Print 3G to calculate its encapsulation efficiency. Observed Print 3G adsorption on different materials employed during liposome preparation (such as glass beads, tubing, and connections for extrusion) led to the modification of the manufacturing method. The freeze-thawing technique was used to enhance the amount of Print 3G encapsulated into blank liposomes prepared using the hydration of lipid film procedure. Many factors may influence peptide entrapment, namely the number of freeze-thawing cycles, the lipid concentration, the peptide concentration, and the mixing time. Consequently, a design of experiments was performed to obtain the best encapsulation efficiency while minimizing the number of experiments. The lipid concentration and the number of freeze-thawing cycles were identified as the positive factors influencing the encapsulation. As a result of the optimization, an optimum was found and encapsulation efficiencies were improved from around 30% to 63%. Liposome integrity was evaluated by photon correlation spectroscopy and freeze-fracture electron microscopy to ensure that the selected formulation possesses the required properties to be a potential candidate for further in vitro and in vivo experiments.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Portadores de Fármacos/química , Composição de Medicamentos/métodos , Lipossomos/química , Peptídeos/química
18.
Phys Chem Chem Phys ; 12(14): 3606-15, 2010 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-20336259

RESUMO

Biomolecular recognition of vancomycin antibiotics with its cell-wall precursor analogue Ac(2)(L)K(D)A(D)A has been investigated in the gas phase through a combined laser spectroscopy/mass spectrometry approach. The mid-IR spectra (1100-1800 cm(-1)) of these mass-selected anionic species have been recorded by means of resonant infrared multiphoton dissociation (IRMPD) spectroscopy performed with the free-electron laser CLIO. Structural assignment has been achieved through comparisons with the low-energy conformers obtained from replica-exchange molecular dynamics simulations, for which IR spectra were calculated using a hybrid quantum mechanics/semi-empirical (QM/SE) method at the DFT/B3LYP/6-31+G*/AM1 level. Comparison between deprotonated vancomycin and its non-covalently bound V + Ac(2)(L)K(D)A(D)A complex shows significant spectral shifts of the carboxylate stretches and the Amide I and Amide II modes that are satisfactorily reproduced in the structures known from the condensed phase. Both theoretical and experimental findings provide strong evidence that the native structure of the deprotonated V + Ac(2)(L)K(D)A(D)A complex is preserved in the gas phase.


Assuntos
Antibacterianos/química , Gases , Análise Espectral/métodos , Vancomicina/química , Cristalografia por Raios X , Sondas Moleculares , Ressonância Magnética Nuclear Biomolecular , Espectrofotometria Infravermelho
19.
Chemphyschem ; 10(17): 3097-100, 2009 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-19806629

RESUMO

Gas-phase intrinsic structures of intact neutral and anionic glutathione (GSH) have been determined by means of a combination of negative ion photo-electron spectroscopy and quantum chemistry calculations. The inferred structures of the neutral parents of those peptide anions are canonical (non-zwitterionic). These intrinsic structures are compared to those already known in aqueous solution or determined by crystallography in binding sites of enzymes.


Assuntos
Glutationa/química , Ânions/química , Gases , Estrutura Molecular , Teoria Quântica , Análise Espectral
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