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1.
PLoS Comput Biol ; 18(5): e1010150, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35617364

RESUMO

Kaposi's sarcoma-associated herpes virus (KSHV) is a human oncovirus. KSHV relies on manipulating the host cell N6-methyl adenosine (m6A) RNA modification pathway to enhance virus replication. Methylation within a RNA stem loop of the open reading frame 50 (ORF50) increases transcript stability via the recruitment of the m6A reader, SND1. In this contribution we explore the energy landscapes of the unmethylated and methylated RNA stem loops of ORF50 to investigate the effect of methylation on the structure of the stem loop. We observe a significant shift upon methylation between an open and closed configuration of the top of the stem loop. In the unmethylated stem loop the closed configuration is much lower in energy, and, as a result, exhibits higher occupancy.


Assuntos
Herpesvirus Humano 8 , Sarcoma de Kaposi , Adenosina/metabolismo , Linhagem Celular , Endonucleases/genética , Endonucleases/metabolismo , Regulação Viral da Expressão Gênica , Herpesvirus Humano 8/genética , Herpesvirus Humano 8/metabolismo , Humanos , Metilação , Fases de Leitura Aberta/genética , RNA/metabolismo , Sarcoma de Kaposi/genética
2.
PLoS Biol ; 17(12): e3000554, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31790392

RESUMO

Junctional complexes between endothelial cells form a dynamic barrier that hinders passive diffusion of blood constituents into interstitial tissues. Remodelling of junctions is an essential process during leukocyte trafficking, vascular permeability, and angiogenesis. However, for many junctional proteins, the mechanisms of junctional remodelling have yet to be determined. Here, we used receptor mutagenesis, horseradish peroxidase (HRP), and ascorbate peroxidase 2 (APEX-2) proximity labelling, alongside light and electron microscopy (EM), to map the intracellular trafficking routes of junctional adhesion molecule-C (JAM-C). We found that JAM-C cotraffics with receptors associated with changes in permeability such as vascular endothelial cadherin (VE-Cadherin) and neuropilin (NRP)-1 and 2, but not with junctional proteins associated with the transmigration of leukocytes. Dynamic JAM-C trafficking and degradation are necessary for junctional remodelling during cell migration and angiogenesis. By identifying new potential trafficking machinery, we show that a key point of regulation is the ubiquitylation of JAM-C by the E3 ligase Casitas B-lineage lymphoma (CBL), which controls the rate of trafficking versus lysosomal degradation.


Assuntos
Moléculas de Adesão Celular/metabolismo , Movimento Celular/fisiologia , Células Endoteliais/fisiologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Antígenos CD/metabolismo , Caderinas/metabolismo , Permeabilidade Capilar , Adesão Celular , Moléculas de Adesão Celular/fisiologia , Endotélio Vascular/metabolismo , Células HEK293 , Células Endoteliais da Veia Umbilical Humana , Humanos , Junções Intercelulares/fisiologia , Molécula C de Adesão Juncional , Leucócitos/fisiologia , Neuropilinas/metabolismo , Transporte Proteico/fisiologia , Proteínas Proto-Oncogênicas c-cbl/metabolismo
3.
Proc Natl Acad Sci U S A ; 115(31): E7341-E7350, 2018 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-30030284

RESUMO

The 9 + 2 axoneme structure of the motile flagellum/cilium is an iconic, apparently symmetrical cellular structure. Recently, asymmetries along the length of motile flagella have been identified in a number of organisms, typically in the inner and outer dynein arms. Flagellum-beat waveforms are adapted for different functions. They may start either near the flagellar tip or near its base and may be symmetrical or asymmetrical. We hypothesized that proximal/distal asymmetry in the molecular composition of the axoneme may control the site of waveform initiation and the direction of waveform propagation. The unicellular eukaryotic pathogens Trypanosoma brucei and Leishmania mexicana often switch between tip-to-base and base-to-tip waveforms, making them ideal for analysis of this phenomenon. We show here that the proximal and distal portions of the flagellum contain distinct outer dynein arm docking-complex heterodimers. This proximal/distal asymmetry is produced and maintained through growth by a concentration gradient of the proximal docking complex, generated by intraflagellar transport. Furthermore, this asymmetry is involved in regulating whether a tip-to-base or base-to-tip beat occurs, which is linked to a calcium-dependent switch. Our data show that the mechanism for generating proximal/distal flagellar asymmetry can control waveform initiation and propagation direction.


Assuntos
Dineínas/química , Flagelos/fisiologia , Axonema/química , Flagelos/química , Multimerização Proteica
4.
J Cell Sci ; 129(20): 3732-3743, 2016 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-27577095

RESUMO

Cilia are conserved organelles that have important motility, sensory and signalling roles. The transition zone (TZ) at the base of the cilium is crucial for cilia function, and defects in several TZ proteins are associated with human congenital ciliopathies such as nephronophthisis (NPHP) and Meckel-Gruber syndrome (MKS). In several species, MKS and NPHP proteins form separate complexes that cooperate with Cep290 to assemble the TZ, but flies seem to lack core components of the NPHP module. We show that MKS proteins in flies are spatially separated from Cep290 at the TZ, and that flies mutant for individual MKS genes fail to recruit other MKS proteins to the TZ, whereas Cep290 seems to be recruited normally. Although there are abnormalities in microtubule and membrane organisation in developing MKS mutant cilia, these defects are less apparent in adults, where sensory cilia and sperm flagella seem to function quite normally. Thus, localising MKS proteins to the cilium or flagellum is not essential for viability or fertility in flies.


Assuntos
Envelhecimento/metabolismo , Cílios/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/crescimento & desenvolvimento , Drosophila melanogaster/metabolismo , Órgãos dos Sentidos/metabolismo , Animais , Axonema/metabolismo , Comportamento Animal , Flagelos/metabolismo , Masculino , Mecanorreceptores/metabolismo , Proteínas de Membrana/metabolismo , Mutação/genética , Transporte Proteico , Espermatócitos/metabolismo , Testículo/metabolismo , Testículo/patologia
5.
J Biol Chem ; 289(39): 26859-26871, 2014 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-25100729

RESUMO

Although amyloid fibrils assembled in vitro commonly involve a single protein, fibrils formed in vivo can contain multiple protein sequences. The amyloidogenic protein human ß2-microglobulin (hß2m) can co-polymerize with its N-terminally truncated variant (ΔN6) in vitro to form hetero-polymeric fibrils that differ from their homo-polymeric counterparts. Discrimination between the different assembly precursors, for example by binding of a biomolecule to one species in a mixture of conformers, offers an opportunity to alter the course of co-assembly and the properties of the fibrils formed. Here, using hß2m and its amyloidogenic counterpart, ΔΝ6, we describe selection of a 2'F-modified RNA aptamer able to distinguish between these very similar proteins. SELEX with a N30 RNA pool yielded an aptamer (B6) that binds hß2m with an EC50 of ∼200 nM. NMR spectroscopy was used to assign the (1)H-(15)N HSQC spectrum of the B6-hß2m complex, revealing that the aptamer binds to the face of hß2m containing the A, B, E, and D ß-strands. In contrast, binding of B6 to ΔN6 is weak and less specific. Kinetic analysis of the effect of B6 on co-polymerization of hß2m and ΔN6 revealed that the aptamer alters the kinetics of co-polymerization of the two proteins. The results reveal the potential of RNA aptamers as tools for elucidating the mechanisms of co-assembly in amyloid formation and as reagents able to discriminate between very similar protein conformers with different amyloid propensity.


Assuntos
Amiloide/química , Aptâmeros de Nucleotídeos/química , Multimerização Proteica , Microglobulina beta-2/química , Humanos , Ressonância Magnética Nuclear Biomolecular
6.
Hepatology ; 59(2): 408-22, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24022996

RESUMO

UNLABELLED: Current interferon-based therapy for hepatitis C virus (HCV) infection is inadequate, prompting a shift toward combinations of direct-acting antivirals (DAA) with the first protease-targeted drugs licensed in 2012. Many compounds are in the pipeline yet primarily target only three viral proteins, namely, NS3/4A protease, NS5B polymerase, and NS5A. With concerns growing over resistance, broadening the repertoire for DAA targets is a major priority. Here we describe the complete structure of the HCV p7 protein as a monomeric hairpin, solved using a novel combination of chemical shift and nuclear Overhauser effect (NOE)-based methods. This represents atomic resolution information for a full-length virus-coded ion channel, or "viroporin," whose essential functions represent a clinically proven class of antiviral target exploited previously for influenza A virus therapy. Specific drug-protein interactions validate an allosteric site on the channel periphery and its relevance is demonstrated by the selection of novel, structurally diverse inhibitory small molecules with nanomolar potency in culture. Hit compounds represent a 10,000-fold improvement over prototypes, suppress rimantadine resistance polymorphisms at submicromolar concentrations, and show activity against other HCV genotypes. CONCLUSION: This proof-of-principle that structure-guided design can lead to drug-like molecules affirms p7 as a much-needed new target in the burgeoning era of HCV DAA.


Assuntos
Antivirais/farmacologia , Modelos Moleculares , Modelos Estruturais , Proteínas Virais/antagonistas & inibidores , Proteínas Virais/química , Vírion/efeitos dos fármacos , Sítio Alostérico/efeitos dos fármacos , Antivirais/uso terapêutico , Genótipo , Hepacivirus/efeitos dos fármacos , Hepacivirus/fisiologia , Hepatite C/tratamento farmacológico , Humanos , Espectroscopia de Ressonância Magnética , Conformação Proteica , Proteínas Virais/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos
7.
Org Biomol Chem ; 13(1): 258-64, 2015 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-25408290

RESUMO

The exploitation of multivalent ligands for the inhibition of protein-protein interactions has not yet been explored as a supramolecular design strategy. This is despite the fact that protein-protein interactions typically occur within the context of multi-protein complexes and frequently exploit avidity effects or co-operative binding interactions to achieve high affinity interactions. In this paper we describe preliminary studies on the use of a multivalent N-alkylated aromatic oligoamide helix mimetic for inhibition of p53/hDM2 and establish that protein dimerisation is promoted, rather than enhanced binding resulting from a higher effective concentration of the ligand.


Assuntos
Amidas/química , Amidas/farmacologia , Materiais Biomiméticos/química , Materiais Biomiméticos/farmacologia , Proteínas de Ligação a RNA/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Alquilação , Amidas/síntese química , Materiais Biomiméticos/síntese química , Modelos Moleculares , Ligação Proteica/efeitos dos fármacos , Conformação Proteica , Proteínas de Ligação a RNA/química , Proteína Supressora de Tumor p53/química
8.
BMC Genomics ; 15: 531, 2014 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-24969356

RESUMO

BACKGROUND: Cilia are critical for diverse functions, from motility to signal transduction, and ciliary dysfunction causes inherited diseases termed ciliopathies. Several ciliopathy proteins influence developmental signalling and aberrant signalling explains many ciliopathy phenotypes. Ciliary compartmentalisation is essential for function, and the transition zone (TZ), found at the proximal end of the cilium, has recently emerged as a key player in regulating this process. Ciliary compartmentalisation is linked to two protein complexes, the MKS and NPHP complexes, at the TZ that consist largely of ciliopathy proteins, leading to the hypothesis that ciliopathy proteins affect signalling by regulating ciliary content. However, there is no consensus on complex composition, formation, or the contribution of each component. RESULTS: Using bioinformatics, we examined the evolutionary patterns of TZ complex proteins across the extant eukaryotic supergroups, in both ciliated and non-ciliated organisms. We show that TZ complex proteins are restricted to the proteomes of ciliated organisms and identify a core conserved group (TMEM67, CC2D2A, B9D1, B9D2, AHI1 and a single TCTN, plus perhaps MKS1) which are present in >50% of all ciliate/flagellate organisms analysed in each supergroup. The smaller NPHP complex apparently evolved later than the larger MKS complex; this result may explain why RPGRIP1L, which forms the linker between the two complexes, is not one of the core conserved proteins. We also uncovered a striking correlation between lack of TZ proteins in non-seed land plants and loss of TZ-specific ciliary Y-links that link microtubule doublets to the membrane, consistent with the interpretation that these proteins are structural components of Y-links, or regulators of their formation. CONCLUSIONS: This bioinformatic analysis represents the first systematic analysis of the cohort of TZ complex proteins across eukaryotic evolution. Given the near-ubiquity of only 6 proteins across ciliated eukaryotes, we propose that the MKS complex represents a dynamic complex built around these 6 proteins and implicated in Y-link formation and ciliary permeability.


Assuntos
Cílios/genética , Biologia Computacional , Evolução Molecular , Animais , Cílios/metabolismo , Cílios/ultraestrutura , Biologia Computacional/métodos , Humanos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Complexos Multiproteicos/metabolismo , Ratos , Transdução de Sinais
9.
Pharm Res ; 31(7): 1867-76, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24643933

RESUMO

Biorelevant in vitro performance testing of orally administered dosage forms has become an important tool for the assessment of drug product in vivo behavior. An in vitro performance test which mimics the intraluminal performance of an oral dosage form is termed biorelevant. Biorelevant tests have been utilized to decrease the number of in vivo studies required during the drug development process and to mitigate the risk related to in vivo bioequivalence studies. This report reviews the ability of current in vitro performance tests to predict in vivo performance and generate successful in vitro and in vivo correlations for oral dosage forms. It also summarizes efforts to improve the predictability of biorelevant tests. The report is based on the presentations at the 2013 workshop, Biorelevant In Vitro Performance Testing of Orally Administered Dosage Forms, in Washington, DC, sponsored by the FIP Dissolution/Drug Release Focus Group in partnership with the American Association of Pharmaceutical Scientists (AAPS) and a symposium at the AAPS 2012 Annual meeting on the same topic.


Assuntos
Química Farmacêutica/educação , Química Farmacêutica/métodos , Avaliação Pré-Clínica de Medicamentos/métodos , Preparações Farmacêuticas/administração & dosagem , Administração Oral , Química Farmacêutica/normas , Preparações de Ação Retardada/química , Preparações de Ação Retardada/metabolismo , Formas de Dosagem , Avaliação Pré-Clínica de Medicamentos/normas , Humanos , Farmacocinética , Controle de Qualidade , Solubilidade
10.
Health Technol Assess ; 28(59): 1-123, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39364555

RESUMO

Background: Hand eczema is common and a cause of morbidity and occupational disability. When education, irritant/contact allergen avoidance, moisturisation and topical corticosteroids are insufficient to control chronic hand eczema, ultraviolet therapy or systemic immune-modifying drugs are used. There is no treatment pathway generally accepted by UK dermatologists. Primary objective: Compare alitretinoin and ultraviolet therapy as first-line therapy in terms of disease activity at 12 weeks post planned start of treatment. Design: Prospective, multicentre, open-label, two-arm parallel group, adaptive randomised controlled trial with one planned interim analysis, and an economic evaluation. Setting: UK secondary care dermatology outpatient clinics. Participants: Patients with severe chronic hand eczema unresponsive to at least 4 weeks of treatment with potent topical corticosteroids. Primary end point: Natural logarithm of the Hand Eczema Severity Index + 1, 12 weeks post planned start of treatment. Randomisation: Participants randomised 1 : 1 by minimisation to alitretinoin or ultraviolet therapy for 12 to 24 weeks. Blinding: Blinded primary end-point assessor. Results: Intention-to-treat population: 441 (100.0%) participants; 220 (49.9%) alitretinoin and 221 (50.1%) ultraviolet therapy. At least one dose was received by 212 (96.4%) alitretinoin and 196 (88.7%) ultraviolet therapy participants. Primary outcome: The unadjusted median (interquartile range) relative change in hand eczema severity index at 12 weeks was 30% (10-70%) of that at baseline for alitretinoin compared with 50% (20-100%) for ultraviolet therapy. There was a statistically significant benefit of alitretinoin compared with ultraviolet therapy at 12 weeks, with an estimated fold change or relative difference (95% confidence interval) = 0.66 (0.52 to 0.82), p = 0.0003 at 12 weeks. There was no evidence of a difference at 24 or 52 weeks, with the estimated fold change (95% confidence interval) equal to 0.92 (0.798 to 1.08) and 1.27 (0.97 to 1.67), respectively. Primary analysis results were consistent for secondary end points: Fifty-nine per cent allocated to alitretinoin and 61% allocated to ultraviolet therapy achieved a clear/almost clear assessment during the trial period. Differential treatment compliance observed: 145 (65.9%) alitretinoin and 53 (24.0%) ultraviolet therapy participants confirmed compliance (≥ 80% received, no treatment breaks > 7 days during first 12 weeks). High levels of missing data were observed. Safety: One hundred and thirty-five reportable adverse events across 79 participants, 55 (25.0%) alitretinoin and 24 (10.9%) ultraviolet therapy. Four serious adverse events (two alitretinoin, two ultraviolet therapy). Four pregnancies reported (three alitretinoin, one ultraviolet therapy). No new safety signals were detected. Conclusion: As a first-line therapy, alitretinoin showed more rapid improvement and superiority to ultraviolet therapy at week 12. This difference was not observed at later time points. Alitretinoin is cost-effective at weeks 12 and 52. Ultraviolet therapy is cost-effective after 10 years, with a high degree of uncertainty. Hand eczema severity index may be a useful primary outcome measure for hand eczema trials; ALPHA results will inform future trials. Limitations: Treatment compliance was poor for ultraviolet therapy. Regular twice weekly treatment was not received by most patients. Assessment of long-term effects of randomised treatments was complicated by use of second-line treatments post treatment phase. Further work: Further analysis of substudies and pilot data will provide valuable information for future studies. A clear need for better therapeutic approaches for severe chronic hand eczema remains. Future studies will need to further address long-term benefits of treatments given. Trial registration: This trial is registered as ISRCTN80206075. Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 12/186/01) and is published in full in Health Technology Assessment; Vol. 28, No. 59. See the NIHR Funding and Awards website for further award information.


The main question was which treatment was better at easing symptoms of severe hand eczema after 12 weeks. The two treatments compared were ones used most often by UK dermatologists. The first is a tablet called alitretinoin, which is taken once a day. The second is called ultraviolet therapy, where hands are soaked in a special liquid and placed under ultraviolet light twice a week at a hospital. We treated 220 patients with alitretinoin and 221 patients with ultraviolet therapy. Patients received treatment for 12 to 24 weeks depending on how well their hand eczema responded. Patients could have different treatments afterwards, and we collected information on their hand eczema symptoms for up to 1 year. After 12 weeks, severe hand eczema symptoms improved for both groups of patients but improved most for patients who took alitretinoin. However, 1 year after joining the trial, there was no evidence of a difference between alitretinoin and ultraviolet therapy as a first-line treatment. More patients stopped ultraviolet therapy early compared with patients who received alitretinoin. Different treatments may have been prescribed after the first treatment. Alitretinoin provides a convenient, instant relief or a 'quick fix' for patients with severe hand eczema. Alitretinoin is more convenient for lots of people, but it is important to have other options available for people who would prefer not to, or are unable to, take alitretinoin. For example, people who take alitretinoin can experience unwanted side effects, and people who are able to become pregnant must also use contraception. Long-term control of severe hand eczema is important. Individual discussions on the pros and cons of each treatment for hand eczema symptoms is needed. Providing flexible options to attend ultraviolet therapy appointments could be helpful (e.g. weekend/evenings).


Assuntos
Alitretinoína , Eczema , Dermatoses da Mão , Tretinoína , Humanos , Alitretinoína/uso terapêutico , Feminino , Masculino , Tretinoína/uso terapêutico , Eczema/tratamento farmacológico , Pessoa de Meia-Idade , Adulto , Dermatoses da Mão/tratamento farmacológico , Estudos Prospectivos , Doença Crônica , Reino Unido , Índice de Gravidade de Doença , Terapia Ultravioleta , Idoso , Resultado do Tratamento , Análise Custo-Benefício
11.
Nat Microbiol ; 8(3): 533-547, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36804636

RESUMO

Trypanosoma brucei is a model trypanosomatid, an important group of human, animal and plant unicellular parasites. Understanding their complex cell architecture and life cycle is challenging because, as with most eukaryotic microbes, ~50% of genome-encoded proteins have completely unknown functions. Here, using fluorescence microscopy and cell lines expressing endogenously tagged proteins, we mapped the subcellular localization of 89% of the T. brucei proteome, a resource we call TrypTag. We provide clues to function and define lineage-specific organelle adaptations for parasitism, mapping the ultraconserved cellular architecture of eukaryotes, including the first comprehensive 'cartographic' analysis of the eukaryotic flagellum, which is vital for morphogenesis and pathology. To demonstrate the power of this resource, we identify novel organelle subdomains and changes in molecular composition through the cell cycle. TrypTag is a transformative resource, important for hypothesis generation for both eukaryotic evolutionary molecular cell biology and fundamental parasite cell biology.


Assuntos
Parasitos , Trypanosoma brucei brucei , Animais , Humanos , Trypanosoma brucei brucei/fisiologia , Parasitos/metabolismo , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Proteoma/análise , Genoma
12.
J Mol Biol ; 434(20): 167797, 2022 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-35998704

RESUMO

Many single-stranded, positive-sense RNA viruses regulate assembly of their infectious virions by forming multiple, cognate coat protein (CP)-genome contacts at sites termed Packaging Signals (PSs). We have determined the secondary structures of the bacteriophage MS2 ssRNA genome (gRNA) frozen in defined states using constraints from X-ray synchrotron footprinting (XRF). Comparison of the footprints from phage and transcript confirms the presence of multiple PSs in contact with CP dimers in the former. This is also true for a virus-like particle (VLP) assembled around the gRNA in vitro in the absence of the single-copy Maturation Protein (MP) found in phage. Since PS folds are present at many sites across gRNA transcripts, it appears that this genome has evolved to facilitate this mechanism of assembly regulation. There are striking differences between the gRNA-CP contacts seen in phage and the VLP, suggesting that the latter are inappropriate surrogates for aspects of phage structure/function. Roughly 50% of potential PS sites in the gRNA are not in contact with the protein shell of phage. However, many of these sit adjacent to, albeit not in contact with, PS-binding sites on CP dimers. We hypothesize that these act as PSs transiently during assembly but subsequently dissociate. Combining the XRF data with PS locations from an asymmetric cryo-EM reconstruction suggests that the genome positions of such dissociations are non-random and may facilitate infection. The loss of many PS-CP interactions towards the 3' end of the gRNA would allow this part of the genome to transit more easily through the narrow basal body of the pilus extruding machinery. This is the known first step in phage infection. In addition, each PS-CP dissociation event leaves the protein partner trapped in a non-lowest free-energy conformation. This destabilizes the protein shell which must disassemble during infection, further facilitating this stage of the life-cycle.


Assuntos
Proteínas do Capsídeo , Levivirus , Montagem de Vírus , Proteínas do Capsídeo/química , Genoma Viral/genética , Levivirus/química , Levivirus/patogenicidade , Levivirus/fisiologia , RNA Viral/genética , Montagem de Vírus/genética
13.
AAPS J ; 24(3): 50, 2022 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-35352186

RESUMO

This report summarizes podium presentations and breakout sessions from the second day of the 2019 M-CERSI workshop on In Vitro Dissolution Similarity Assessment in Support of Drug Product Quality: What, How, and When? Presenters from the U.S. Food and Drug Administration (FDA), Health Canada (HC), European Medicines Agency (EMA), Brazilian Health Surveillance Agency (ANVISA), and the pharmaceutical industry shared experiences/concerns with dissolution profile similarity assessment supporting minor/moderate Chemistry, Manufacturing and Control (CMC) changes. Members from regulatory agencies explained that dissolution profile similarity testing is only part of the overall assessment of the acceptability of the proposed changes; decisions are usually made based on aggregate weight of evidence. Scientific shortcomings of f2 were highlighted but no proposal on how to replace it was made. Controlling dissolution timepoint variability and application of pairwise batch-to-batch comparisons (PBC) of dissolution profiles caused considerable debate. Several industry participants suggested increased sample sizes to raise confidence in decision-making and to avoid PBC. They proposed identification of a single mathematical method with predefined acceptance criteria and suggested that dissolution timepoint selection should follow EMA and HC guidance. A majority of meeting attendees favored applying clinically relevant dissolution specifications (CRDS) and dissolution safe space to determine the impact of minor/moderate CMC changes as opposed to dissolution profile similarity assessment via statistical methods. Day 2 of the workshop highlighted the need and opportunities for global harmonization including variability, timepoint selection, role of CRDS, and statistical methods to address the ambiguity globally operating pharmaceutical companies are currently facing.


Assuntos
Indústria Farmacêutica , Motivação , Humanos , Preparações Farmacêuticas , Solubilidade , Estados Unidos , United States Food and Drug Administration
14.
BMJ Open ; 12(2): e060029, 2022 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-35197358

RESUMO

INTRODUCTION: Hand eczema (HE) is one of the most common skin disorders and an important cause for morbidity and occupational disability. The 1-year prevalence of HE is estimated to be up to 10% and it is estimated that 5%-7% of those develop severe chronic HE. However, current clinical evidence is not compelling enough to guide clinical practice. In a survey among 194 UK dermatologists the most frequent first choice approaches were psoralen combined with ultraviolet A (UVA) treatment (PUVA), oral steroids and alitretinoin (AL). When asked which strategy was most efficient for long-term outcome 20% of clinicians indicated they did not know; 43% of clinicians reported AL and 30% reported PUVA. METHODS AND ANALYSIS: ALPHA is a multicentre, open, prospective, two-arm parallel group, randomised controlled trial comparing PUVA and AL with a planned sample size re-estimation. Between 500 and 780 participants will be randomised on a 1:1 basis. The physician's global assessment (PGA) will direct treatment after randomisation, non-responders will be treated according to usual clinical practice; providing valuable pilot data on second line therapeutic approaches to inform future trials.Assessments will be conducted up to 52 weeks post randomisation. The primary outcome measure is the Hand Eczema Severity Index at 12 weeks. Secondary outcome measures include modified Total Lesion Symptom Score, PGA, time to relapse, patient reported outcome measures and DNA extraction and assessment of genetic variants. A substudy on molecular inflammatory mediators will provide information on subgroup specific treatment responses. Photographs will be taken and HE severity assessed by a central review panel. ETHICS AND DISSEMINATION: Ethics approval was obtained from Leeds West Research Ethics Committee (14/YH/1259).Trial results will be disseminated at relevant clinical conferences and societies, published in peer-reviewed journals and through relevant patient groups. TRIAL REGISTRATION NUMBER: ISRCTN80206075.


Assuntos
Eczema , Humanos , Alitretinoína/uso terapêutico , Eczema/tratamento farmacológico , Estudos Multicêntricos como Assunto , Medidas de Resultados Relatados pelo Paciente , Estudos Prospectivos , Ensaios Clínicos Controlados Aleatórios como Assunto
15.
Biochem Soc Trans ; 39(4): 966-70, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21787331

RESUMO

Trypanosomatids are protozoan parasites that cause human and animal disease. Trypanosoma brucei telomeric ESs (expression sites) contain genes that are critical for parasite survival in the bloodstream, including the VSG (variant surface glycoprotein) genes, used for antigenic variation, and the SRA (serum-resistance-associated) gene, which confers resistance to lysis by human serum. In addition, ESs contain ESAGs (expression-site-associated genes), whose functions, with few exceptions, have remained elusive. A bioinformatic analysis of the ESAG5 gene of T. brucei showed that it encodes a protein with two BPI (bactericidal/permeability-increasing protein)/LBP (lipopolysaccharide-binding protein)/PLUNC (palate, lung and nasal epithelium clone)-like domains and that it belongs to a multigene family termed (GR)ESAG5 (gene related to ESAG5). Members of this family are found with various copy number in different members of the Trypanosomatidae family. T. brucei has an expanded repertoire, with multiple ESAG5 copies and at least five GRESAG5 genes. In contrast, the parasites of the genus Leishmania, which are intracellular parasites, have only a single GRESAG5 gene. Although the amino acid sequence identity between the (GR)ESAG5 gene products between species is as low as 15-25%, the BPI/LBP/PLUNC-like domain organization and the length of the proteins are highly conserved, and the proteins are predicted to be membrane-anchored or secreted. Current work focuses on the elucidation of possible roles for this gene family in infection. This is likely to provide novel insights into the evolution of the BPI/LBP/PLUNC-like domains.


Assuntos
Proteínas de Protozoários/genética , Trypanosoma/genética , Glicoproteínas Variantes de Superfície de Trypanosoma/genética , Genoma de Protozoário , Interações Hospedeiro-Parasita , Humanos , Estrutura Terciária de Proteína , Proteínas de Protozoários/química , Proteínas de Protozoários/metabolismo , Trypanosoma/metabolismo , Trypanosoma/patogenicidade , Tripanossomíase/parasitologia , Glicoproteínas Variantes de Superfície de Trypanosoma/química , Glicoproteínas Variantes de Superfície de Trypanosoma/metabolismo
16.
AAPS J ; 23(6): 112, 2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34654974

RESUMO

Recent changes in the pharmaceutical industry have led to significant paradigm shifts in the pharmaceutical quality environment. Globalization of the pharmaceutical industry, increasingly rapid development of novel therapies, and adoption of new manufacturing techniques have presented numerous challenges for the established regulatory framework and quality environment and are impacting the approaches utilized to ensure the quality of pharmaceutical products. Regulators, industry, and standards-setting organizations have begun to recognize the need to rely more on integrated risk-based approaches and to create more nimble and flexible standards to complement these efforts. They also increasingly have recognized that quality needs to be built into systems and processes throughout the lifecycle of the product. Moreover, the recent COVID-19 crisis has emphasized the need to adopt practices that better promote global supply chain resilience. In this paper, the USP Quality Advisory Group explores the various paradigm shifts currently impacting pharmaceutical quality and the approaches that are being taken to adapt to this new environment. Broad adoption of the Analytical Procedure Lifecycle approach, improved data management, and utilization of digital technologies are identified as potential solutions that can help meet the challenges of these quality paradigm shifts. Further discussion and collaboration among stakeholders are needed to pursue these and other solutions that can ensure a continued focus on quality while facilitating pharmaceutical innovation and development.


Assuntos
COVID-19/epidemiologia , Indústria Farmacêutica/normas , Preparações Farmacêuticas/provisão & distribuição , Preparações Farmacêuticas/normas , Farmacopeias como Assunto/normas , Controle de Qualidade , COVID-19/prevenção & controle , Indústria Farmacêutica/métodos , Humanos , Tecnologia Farmacêutica/métodos , Tecnologia Farmacêutica/normas , Estados Unidos/epidemiologia
17.
J Cell Biol ; 166(1): 97-109, 2004 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-15240572

RESUMO

Endorepellin, the COOH-terminal domain of the heparan sulfate proteoglycan perlecan, inhibits several aspects of angiogenesis. We provide evidence for a novel biological axis that links a soluble fragment of perlecan protein core to the major cell surface receptor for collagen I, alpha2beta1 integrin, and provide an initial investigation of the intracellular signaling events that lead to endorepellin antiangiogenic activity. The interaction between endorepellin and alpha2beta1 integrin triggers a unique signaling pathway that causes an increase in the second messenger cAMP; activation of two proximal kinases, protein kinase A and focal adhesion kinase; transient activation of p38 mitogen-activated protein kinase and heat shock protein 27, followed by a rapid down-regulation of the latter two proteins; and ultimately disassembly of actin stress fibers and focal adhesions. The end result is a profound block of endothelial cell migration and angiogenesis. Because perlecan is present in both endothelial and smooth muscle cell basement membranes, proteolytic activity during the initial stages of angiogenesis could liberate antiangiogenic fragments from blood vessels' walls, including endorepellin.


Assuntos
Actinas/metabolismo , Citoesqueleto/metabolismo , Células Endoteliais/metabolismo , Adesões Focais/metabolismo , Proteoglicanas de Heparan Sulfato/fisiologia , Integrina alfa2beta1/metabolismo , Fragmentos de Peptídeos/fisiologia , Adenoviridae/genética , Adesão Celular , Linhagem Celular , Células Cultivadas , Colágeno/química , Colágeno/metabolismo , AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Relação Dose-Resposta a Droga , Regulação para Baixo , Combinação de Medicamentos , Retículo Endoplasmático/metabolismo , Endotélio Vascular/citologia , Endotélio Vascular/metabolismo , Ativação Enzimática , Quinase 1 de Adesão Focal , Proteína-Tirosina Quinases de Adesão Focal , Proteoglicanas de Heparan Sulfato/metabolismo , Heparitina Sulfato/química , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Laminina/química , Microscopia de Fluorescência , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Modelos Biológicos , Miócitos de Músculo Liso/metabolismo , Neovascularização Fisiológica , Fragmentos de Peptídeos/metabolismo , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Estrutura Terciária de Proteína , Proteínas Tirosina Quinases/metabolismo , Proteoglicanas/química , Proteínas Recombinantes/química , Transdução de Sinais , Fatores de Tempo , Proteínas Quinases p38 Ativadas por Mitógeno , Proteína rhoA de Ligação ao GTP/metabolismo
18.
Strategies Trauma Limb Reconstr ; 14(1): 34-44, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32559266

RESUMO

INTRODUCTION: Clinical studies in orthopedics are using patient-reported outcome measures (PROMs) increasingly. PROMs are often being designed for a specific disease or an area of the body with the aim of being patient centered. As yet, none exists specifically for treatment with circular ring external fixation devices. AIM: The purpose of this study is to provide a comprehensive systematic review of the published literature related to the use of PROMs in patients that underwent treatment with circular frames (Ilizarov or Hexapod Type Fixators). METHODS: An online literature search was conducted for English language articles using the Scopus. RESULTS: There were 534 published articles identified. After initial filtering for relevance and duplication, this figure reduced to 17, with no further articles identified through searching the bibliographies. Exclusion criteria removed two articles resulting in 15 articles included in the final review. Out of the 15 studies identified, a total of 10 different scoring measures where used. The majority of studies used a combination of joint/limb-specific and generic health PROMs with an average of 2.5 per study. No paper specifically discussed all eight PROMs criteria when justifying which PROMs they used. CONCLUSION: Our findings indicate that none of the PROMs analyzed in this systematic review are truly representative of the health outcomes specific to this patient group and, therefore, propose that a PROM specific to this patient group needs to be developed. HOW TO CITE THIS ARTICLE: Antonios T, Barker A, Ibrahim I, et al. A Systematic Review of Patient-reported Outcome Measures Used in Circular Frame Fixation. Strategies Trauma Limb Reconstr 2019;14(1):34-44.

19.
Mol Biochem Parasitol ; 162(2): 112-22, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18773926

RESUMO

Trypanosoma brucei, the causative agent of African sleeping sickness, evades the immune response by expressing a coat of variant surface glycoprotein (VSG). VSG is expressed from a single telomeric expression site (ES), along with a number of expression site associated genes (ESAGs). Thus far, the function of most ESAGs is unknown. One ES contains the serum resistance associated gene (SRA), which confers resistance to trypanosome lytic factor in T. b. rhodesiense. Only three other ESAGs -5, 6 and 7 - are present in this ES. ESAGs 6 and 7 encode a heterodimeric transferrin receptor, but the function of ESAG5 has not been identified. We present here a bioinformatic analysis of ESAG5 and distinguish between T. brucei-specific ESAGs and Genes Related to ESAG5 (GRESAGs), which occur outside of ESs in chromosomal-internal contexts. Further, a genome-wide survey of these genes across kinetoplastids identifies a family of GRESAG5s in a number of species. Analysis of phylogenetic relationships indicates that this family may have evolved from a single ancestral copy. Predicted properties of (GR)ESAG5 proteins indicate a glycosylated protein containing either a signal peptide or transmembrane domain. Further analysis indicates a possible relationship to the lipid transfer/lipopolysaccharide-binding family which includes the bactericidal/permeability increasing (BPI) protein. Together, these results provide insights into the structure and evolution of an important extended gene family, and present a number of testable hypotheses which will aid in elucidating the function of ESAG5.


Assuntos
Genes de Protozoários , Proteínas de Protozoários/genética , Trypanosoma brucei brucei/genética , Animais , Biologia Computacional , Expressão Gênica , Genoma de Protozoário , Modelos Moleculares , Conformação Proteica , Trypanosoma brucei brucei/metabolismo
20.
J Pharm Sci ; 107(12): 2995-3002, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30148985

RESUMO

Dissolution testing is an important physiochemical test for the development of solid oral dosage forms, tablets, and capsules. As a quality control test, the dissolution test is used for assessment of drug product quality and is specified for batch release and regulatory stability studies. In vitro dissolution test results can often be correlated with the biopharmaceutical behavior of a product.This article provides a summary of views from major global agencies (Europe, Japan, United States), pharmacopoeias, academia, and industry. Based on available guidance and literature, this article summarizes highlights for development and validation of a suitable dissolution method, setting appropriate specifications, in vitro-in vivo comparison, and how to obtain a biowaiver.


Assuntos
Química Farmacêutica/métodos , Composição de Medicamentos/métodos , Excipientes/química , Preparações Farmacêuticas/química , Cápsulas/química , Química Farmacêutica/instrumentação , Preparações de Ação Retardada/química , Composição de Medicamentos/instrumentação , Humanos , Controle de Qualidade , Solubilidade , Comprimidos/química
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