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2.
Br J Community Nurs ; 22(9): 448-457, 2017 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-28862905

RESUMO

The overall aim of the investigation was to redress a knowledge gap by exploring community nursing middle managers' (CNMMs') experiences of role enactment through change within Community Health Partnerships (CHPs) in Scotland-now further evolved into Health and Social Care Partnerships (HSCPs). HSCPs play a key role in shifting care from the acute to the primary care/community setting. However, a literature review demonstrated there has been very little research into the role of CNMMs within the changing primary care context. This concept was considered important in understanding how CNMMs enacted their roles to implement service change. A qualitative longitudinal interpretative phenomenological analysis (IPA) ( Smith, 1996 ) study was conducted in four distinct phases, comprising the reflexive, foundational, recursive and expansive, from 2008-2011. Some 35 semi-structured interviews were conducted with 26 participants. CNMMs perceived that their responsibilities had increased, become more complex and wider ranging. Maintaining an implicit connection with service users was a primary motivation for CNMMs. They were proud to be members of the nursing profession aligning their identity with their career history. A small but significant proportion resigned during the study and some were considering leaving the NHS. The study addresses a gap in literature, contributes to the understanding of NHS community nursing, middle management, role, change and gives a voice to CNMMs in Scotland. They are the lynchpins in taking change forward and maintaining quality services. Much more attention needs to be paid to the needs, constitution and sustenance of middle managers in Scottish community nursing-which has policy, practice, education, and research and retention implications.


Assuntos
Enfermeiros Administradores , Papel do Profissional de Enfermagem , Enfermagem em Saúde Comunitária , Humanos , Entrevistas como Assunto , Escócia , Medicina Estatal
3.
Anaerobe ; 37: 96-102, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26708704

RESUMO

Clostridium difficile infection is one of the leading causes of healthcare associated diarrhoea in the developed world. Although the contribution of C. difficile toxins to disease pathogenesis is now well understood, many facets of host-pathogen interactions between the human intestinal epithelia and the C. difficile bacterium that may contribute to asymptomatic carriage and/or clinical disease remain less clear. Herein, we tested the hypothesis that C. difficile strains mediate intestinal epithelial cell (IEC) antimicrobial immunity via toxin dependent and independent means and that the 'anaerobic' environment has a significant impact on bacterial-IEC interactions. Crosstalk between three C. difficile PCR ribotypes (RT) [RT027 (strain R20291), RT012 (strain 630) and RT017 (strains M68 and CF5)] and IEC cell-lines were investigated. All RTs showed significant engagement with human Toll-like receptors (TLR)-5, TLR2-CD14 and TLR2/6 as measured by IL-8 release from TLR-transfected HEK cells. Co-culture studies indicated minimal impact of R20291 and 630 TcdA and TcdB on bacterial adherence to Caco-2 cells. An apical anaerobic environment had a major effect on C. difficile-T84 crosstalk as significantly greater cytokine immunity and trans-epithelial electrical resistance (TEER) dysfunction was recorded when co-cultures were performed in an Ussing chamber system compared to standard 5% CO2 conditions. Overall, this study suggests that anaerobic C. difficile engagement with human IECs is a complex interplay that involves bacterial and toxin-mediated cellular events.


Assuntos
Clostridioides difficile/fisiologia , Mucosa Intestinal/microbiologia , Aderência Bacteriana , Toxinas Bacterianas , Células CACO-2 , Clostridioides difficile/imunologia , Citocinas/biossíntese , Cultura em Câmaras de Difusão , Enterotoxinas , Células HEK293 , Humanos , Imunidade Inata , Mucosa Intestinal/imunologia , Modelos Biológicos
4.
Infect Immun ; 83(12): 4884-95, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26438798

RESUMO

Campylobacter jejuni is a commensal bacterium in the intestines of animals and birds and a major cause of food-borne gastroenteritis in humans worldwide. Here we show that exposure to pancreatic amylase leads to secretion of an α-dextran by C. jejuni and that a secreted protease, Cj0511, is required. Exposure of C. jejuni to pancreatic amylase promotes biofilm formation in vitro, increases interaction with human epithelial cell lines, increases virulence in the Galleria mellonella infection model, and promotes colonization of the chicken ileum. We also show that exposure to pancreatic amylase protects C. jejuni from stress conditions in vitro, suggesting that the induced α-dextran may be important during transmission between hosts. This is the first evidence that pancreatic amylase functions as an interkingdom signal in an enteric microorganism.


Assuntos
Proteínas de Bactérias/genética , Biofilmes/efeitos dos fármacos , Infecções por Campylobacter/veterinária , Campylobacter jejuni/efeitos dos fármacos , alfa-Amilases Pancreáticas/farmacologia , Peptídeo Hidrolases/genética , Doenças das Aves Domésticas/microbiologia , Animais , Proteínas de Bactérias/metabolismo , Biofilmes/crescimento & desenvolvimento , Células CACO-2 , Infecções por Campylobacter/enzimologia , Infecções por Campylobacter/microbiologia , Infecções por Campylobacter/patologia , Campylobacter jejuni/patogenicidade , Campylobacter jejuni/fisiologia , Linhagem Celular Tumoral , Galinhas , Dextranos/biossíntese , Dextranos/metabolismo , Células Epiteliais , Regulação da Expressão Gênica , Interações Hospedeiro-Patógeno , Humanos , Intestinos/microbiologia , Intestinos/patologia , Mariposas/microbiologia , alfa-Amilases Pancreáticas/isolamento & purificação , Peptídeo Hidrolases/metabolismo , Doenças das Aves Domésticas/enzimologia , Doenças das Aves Domésticas/patologia , Transdução de Sinais , Suínos
5.
Blood ; 122(19): 3335-9, 2013 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-24041577

RESUMO

Chronic myeloid leukemia (CML) stem cells are not dependent on BCR-ABL kinase for their survival, suggesting that kinase-independent mechanisms must contribute to their persistence. We observed that CML stem/progenitor cells (SPCs) produce tumor necrosis factor-α (TNF-α) in a kinase-independent fashion and at higher levels relative to their normal counterparts. We therefore investigated the role of TNF-α and found that it supports survival of CML SPCs by promoting nuclear factor κB/p65 pathway activity and expression of the interleukin 3 and granulocyte/macrophage-colony stimulating factor common ß-chain receptor. Furthermore, we demonstrate that in CML SPCs, inhibition of autocrine TNF-α signaling via a small-molecule TNF-α inhibitor induces apoptosis. Moreover TNF-α inhibition combined with nilotinib induces significantly more apoptosis relative to either treatment alone and a reduction in the absolute number of primitive quiescent CML stem cells. These results highlight a novel survival mechanism of CML SPCs and suggest a new putative therapeutic target for their eradication.


Assuntos
Cromonas/farmacologia , Indóis/farmacologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Regulação Leucêmica da Expressão Gênica , Humanos , Interleucina-3/antagonistas & inibidores , Interleucina-3/genética , Interleucina-3/imunologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , NF-kappa B/antagonistas & inibidores , NF-kappa B/genética , NF-kappa B/imunologia , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Cultura Primária de Células , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/farmacologia , Receptores de Interleucina-3/antagonistas & inibidores , Receptores de Interleucina-3/genética , Receptores de Interleucina-3/imunologia , Transdução de Sinais , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia
6.
Stem Cells ; 32(9): 2324-37, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24806995

RESUMO

Chronic myeloid leukemia (CML) is initiated and maintained by the tyrosine kinase BCR-ABL which activates a number of signal transduction pathways, including PI3K/AKT signaling and consequently inactivates FOXO transcription factors. ABL-specific tyrosine kinase inhibitors (TKIs) induce minimal apoptosis in CML progenitor cells, yet exert potent antiproliferative effects, through as yet poorly understood mechanisms. Here, we demonstrate that in CD34+ CML cells, FOXO1 and 3a are inactivated and relocalized to the cytoplasm by BCR-ABL activity. TKIs caused a decrease in phosphorylation of FOXOs, leading to their relocalization from cytoplasm (inactive) to nucleus (active), where they modulated the expression of key FOXO target genes, such as Cyclin D1, ATM, CDKN1C, and BCL6 and induced G1 arrest. Activation of FOXO1 and 3a and a decreased expression of their target gene Cyclin D1 were also observed after 6 days of in vivo treatment with dasatinib in a CML transgenic mouse model. The over-expression of FOXO3a in CML cells combined with TKIs to reduce proliferation, with similar results seen for inhibitors of PI3K/AKT/mTOR signaling. While stable expression of an active FOXO3a mutant induced a similar level of quiescence to TKIs alone, shRNA-mediated knockdown of FOXO3a drove CML cells into cell cycle and potentiated TKI-induced apoptosis. These data demonstrate that TKI-induced G1 arrest in CML cells is mediated through inhibition of the PI3K/AKT pathway and reactivation of FOXOs. This enhanced understanding of TKI activity and induced progenitor cell quiescence suggests that new therapeutic strategies for CML should focus on manipulation of this signaling network.


Assuntos
Fatores de Transcrição Forkhead/biossíntese , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Animais , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Dasatinibe/farmacologia , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Fase G1/efeitos dos fármacos , Perfilação da Expressão Gênica , Humanos , Células K562 , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Camundongos , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/patologia , Fosforilação , Transdução de Sinais , Transfecção
7.
Infect Immun ; 82(12): 4989-96, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25225246

RESUMO

Clostridium difficile is an important nosocomial pathogen and the leading cause of antibiotic-associated diarrhea. Multilocus sequence typing indicates that C. difficile strains belong to five distinct genetic clades encompassing several PCR ribotypes (RT). Since their emergence in 2003, hypervirulent RT027 strains have been a major focus of research; in contrast, our current understanding of RT017-mediated disease pathogenesis lags far behind. In this study, we aimed to characterize host immunity to CF5 and M68, two genetically well-defined RT017 strains. Both strains engaged with host Toll-like receptor 2/6 (TLR2/6), TLR2-CD14, and TLR5 to similar extents in a model cell line. Despite this, CF5 mediated significantly greater dendritic cell (DC) interleukin-12 (IL-12), IL-27, and IL-10 immunity than M68. Both strains elicited similar IL-1ß mRNA levels, and yet only M68 caused a marked increase in secretory IL-1ß. A CF5 cocultured-DC cytokine milieu drove an equipotent Th1 and Th17 response, while M68 promoted greater Th17 immunity. Human gastrointestinal ex vivo cytokine responses to both strains were characterized. Taken together, our data suggest that C. difficile strains mediate overlapping and yet distinct mucosal and DC/T cell immunity. Finally, toxin-driven IL-1ß release supports the hypothesis that this cytokine axis is a likely target for therapeutic intervention for C. difficile infection.


Assuntos
Clostridioides difficile/classificação , Clostridioides difficile/imunologia , Citocinas/metabolismo , Células Dendríticas/imunologia , Ribotipagem , Linfócitos T/imunologia , Animais , Células Cultivadas , Clostridioides difficile/genética , Técnicas de Cocultura , Humanos , Camundongos Endogâmicos C57BL
8.
Blood ; 119(6): 1501-10, 2012 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-22184410

RESUMO

Recent evidence suggests chronic myeloid leukemia (CML) stem cells are insensitive to kinase inhibitors and responsible for minimal residual disease in treated patients. We investigated whether CML stem cells, in a transgenic mouse model of CML-like disease or derived from patients, are dependent on Bcr-Abl. In the transgenic model, after retransplantation, donor-derived CML stem cells in which Bcr-Abl expression had been induced and subsequently shut off were able to persist in vivo and reinitiate leukemia in secondary recipients on Bcr-Abl reexpression. Bcr-Abl knockdown in human CD34(+) CML cells cultured for 12 days in physiologic growth factors achieved partial inhibition of Bcr-Abl and downstream targets p-CrkL and p-STAT5, inhibition of proliferation and colony forming cells, but no reduction of input cells. The addition of dasatinib further inhibited p-CrkL and p-STAT5, yet only reduced input cells by 50%. Complete growth factor withdrawal plus dasatinib further reduced input cells to 10%; however, the surviving fraction was enriched for primitive leukemic cells capable of growth in a long-term culture-initiating cell assay and expansion on removal of dasatinib and addition of growth factors. Together, these data suggest that CML stem cell survival is Bcr-Abl kinase independent and suggest curative approaches in CML must focus on kinase-independent mechanisms of resistance.


Assuntos
Proteínas de Fusão bcr-abl/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Células-Tronco Neoplásicas/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Antígenos CD34/metabolismo , Apoptose/efeitos dos fármacos , Western Blotting , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Dasatinibe , Relação Dose-Resposta a Droga , Citometria de Fluxo , Proteínas de Fusão bcr-abl/antagonistas & inibidores , Proteínas de Fusão bcr-abl/genética , Regulação Leucêmica da Expressão Gênica , Técnicas de Inativação de Genes , Células HEK293 , Humanos , Células K562 , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Camundongos , Camundongos Transgênicos , Células-Tronco Neoplásicas/patologia , Proteínas Nucleares/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/farmacologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Transcrição STAT5/metabolismo , Tiazóis/farmacologia
9.
ACS Omega ; 9(6): 7154-7162, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38371809

RESUMO

Superhydrophobic surfaces have been studied extensively over the past 25 years. However, many industries interested in the application of hydrophobic properties are yet to find a suitable solution to their needs. This paper looks at the rapid functionalization of nanoparticles and the fabrication of superhydrophobic surfaces with contact angles > 170°. This was achieved by simply mixing commercial products and applying the new formulation with scalable techniques. First, inexpensive and nontoxic superhydrophobic nanoparticles were made by functionalizing nanoparticles with fatty acids in under an hour. A similar methodology was then used to functionalize a commercial polymer coating to express superhydrophobic properties on it by lowering the coating's surface energy. The coating was then applied to a surface by the spray technique to allow for the formation of hierarchical surface structures. By combining the low surface energy with the necessary roughness, the surface was able to express superhydrophobic properties. Both the particles and the surfaces then underwent characterization and functional testing, which, among other things, allowed for clear differentiation between the functionalization properties of the zinc oxide (ZnO) and the silica (SiO2) nanoparticles. This paper shows that suitable superhydrophobic solutions may be found by simple additions to already optimized commercial products.

10.
J Antimicrob Chemother ; 68(1): 17-22, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22941900

RESUMO

OBJECTIVES: To identify the genes responsible for tetracycline resistance in a strain of Streptococcus australis isolated from pooled saliva from healthy volunteers in France. S. australis is a viridans Streptococcus, originally isolated from the oral cavity of children in Australia, and subsequently reported in the lungs of cystic fibrosis patients and as a cause of invasive disease in an elderly patient. METHODS: Agar containing 2 mg/L tetracycline was used for the isolation of tetracycline-resistant organisms. A genomic library in Escherichia coli was used to isolate the tetracycline resistance determinant. In-frame deletions and chromosomal repair were used to confirm function. Antibiotic susceptibility was determined by agar dilution and disc diffusion assay. RESULTS: The tetracycline resistance determinant from S. australis FRStet12 was isolated from a genomic library in E. coli and DNA sequencing showed two open reading frames predicted to encode proteins with similarity to multidrug resistance-type ABC transporters. Both genes were required for tetracycline resistance (to both the naturally occurring and semi-synthetic tetracyclines) and they were designated tetAB(46). CONCLUSIONS: This is the first report of a predicted ABC transporter conferring tetracycline resistance in a member of the oral microbiota.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Antiporters/genética , Proteínas de Bactérias/genética , Boca/microbiologia , Multimerização Proteica/genética , Streptococcus/genética , Resistência a Tetraciclina/genética , Transportadores de Cassetes de Ligação de ATP/química , Adulto , Antiporters/química , Proteínas de Bactérias/química , Humanos , Testes de Sensibilidade Microbiana/métodos , Valor Preditivo dos Testes , Proteínas e Peptídeos Salivares/química , Proteínas e Peptídeos Salivares/genética , Streptococcus/isolamento & purificação
11.
Int J Integr Care ; 23(1): 11, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36845871

RESUMO

Introduction: International policies and legislation set a precedence of person-centred sustainable integrated Health and Social Care (HSC) that meets the health and wellbeing needs of service users through improved experiences. However, current research focuses on service models, with fewer studies investigating experiences and needs. Methods: This qualitative multi-case [n = 7] study was co-designed with key stakeholders and aimed to explore experiences and needs of people who access and provide HSC at home. Data were collected in a regional area of Scotland (UK) via single [n = 10] or dyad [n = 4] semi-structured interviews with service users [n = 6], informal carers [n = 5] and HSC staff [n = 7] and synthesised using Interpretive Thematic Analysis. Findings: Interpersonal connections and supportive relationships were instrumental in helping all participant groups feel able to cope with their changing HSC needs and roles. They promoted reassurance, information sharing and reduced anxiety; when they were lacking, it negatively impacted upon experiences of HSC. Discussion: Promoting inter-personal connections that encourage supportive relationships between people who access and provide HSC and their communities, could promote person-centred Relationship-based care and improve HSC experiences. Conclusions: This study identifies indicators for improved HSC, advocating co-produced community-driven services to meet the self-defined needs of those who access and provide care.

12.
J Funct Biomater ; 15(1)2023 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-38248680

RESUMO

With the phase-out of amalgam and the increase in minimally invasive dentistry, there is a growing need for high-strength composite materials that can kill residual bacteria and promote tooth remineralization. This study quantifies how antibacterial polylysine (PLS) and re-mineralizing monocalcium phosphate monohydrate (MCPM) affect Streptococcus mutans biofilms and the strength of dental composites. For antibacterial studies, the MCPM-PLS filler percentages were 0-0, 8-4, 12-6, and 16-8 wt% of the composite filler phase. Composite discs were immersed in 0.1% sucrose-supplemented broth containing Streptococcus mutans (UA159) and incubated in an anaerobic chamber for 48 h. Surface biomass was determined by crystal violet (CV) staining. Growth medium pH was measured at 24 and 48 h. Biofilm bacterial viability (CFU), exo-polysaccharide (water-soluble glucan (WSG) and water-insoluble glucan (WIG)), and extracellular DNA (eDNA) were quantified. This was by serial dilution plate counting, phenol-sulfuric acid microassay, and fluorometry, respectively. The biaxial flexural strengths were determined after water immersion for 1 week, 1 month, and 1 year. The MCPM-PLS wt% were 8-4, 8-8, 16-4 and 16-8. The normalized biomass, WSG, and WIG showed a linear decline of 66%, 64%, and 55%, respectively, as the PLS level increased up to 8%. The surrounding media pH (4.6) was all similar. A decrease in bacterial numbers with the 12-6 formula and a significant reduction with 16-8 compared to the 0-0 formulation was observed. The eDNA concentrations in biofilms formed on 12-6 and 16-8 formulations were significantly less than the 0-0 control and 8-4 formulations. Doubling MCPM and PLS caused a 14 and 19% reduction in strength in 1 week, respectively. Average results were lower at 1 month and 1 year but affected less upon doubling MCPM and PLS levels. Moreover, a 4% PLS may help to reduce total biomass and glucan levels in biofilms on the above composites. Higher levels are required to reduce eDNA and provide bactericidal action, but these can decrease early strength.

13.
J Bacteriol ; 194(8): 2125-6, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22461557

RESUMO

Here we report the draft genome sequence of Clostridium difficile strain CD37, the first nontoxigenic strain sequenced. Every sequenced strain of Clostridium difficile has been shown to contain multiple different mobile genetic elements. The draft genome sequence of strain CD37 reveals the presence of two putative conjugative transposons.


Assuntos
Clostridioides difficile/genética , Genoma Bacteriano , Sequência de Bases , Elementos de DNA Transponíveis/genética , Regulação Bacteriana da Expressão Gênica , Dados de Sequência Molecular
15.
Appl Environ Microbiol ; 78(7): 2147-53, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22267673

RESUMO

The insertion sites of the conjugative transposon Tn916 in the anaerobic pathogen Clostridium difficile were determined using Illumina Solexa high-throughput DNA sequencing of Tn916 insertion libraries in two different clinical isolates: 630ΔE, an erythromycin-sensitive derivative of 630 (ribotype 012), and the ribotype 027 isolate R20291, which was responsible for a severe outbreak of C. difficile disease. A consensus 15-bp Tn916 insertion sequence was identified which was similar in both strains, although an extended consensus sequence was observed in R20291. A search of the C. difficile 630 genome showed that the Tn916 insertion motif was present 100,987 times, with approximately 63,000 of these motifs located in genes and 35,000 in intergenic regions. To test the usefulness of Tn916 as a mutagen, a functional screen allowed the isolation of a mutant. This mutant contained Tn916 inserted into a gene involved in flagellar biosynthesis.


Assuntos
Proteínas de Bactérias/genética , Clostridioides difficile/genética , Conjugação Genética , Elementos de DNA Transponíveis/genética , Mutagênese Insercional , Bacillus subtilis/genética , Proteínas de Bactérias/metabolismo , Sequência de Bases , Mapeamento Cromossômico , Clostridioides difficile/classificação , Clostridioides difficile/isolamento & purificação , Clostridioides difficile/ultraestrutura , DNA Bacteriano/genética , Flagelos/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Mutação , Ribotipagem , Especificidade da Espécie
16.
Blood ; 115(11): 2241-50, 2010 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-20068223

RESUMO

Chronic myeloid leukemia (CML) is treated effectively with tyrosine kinase inhibitors (TKIs); however, 2 key problems remain-the insensitivity of CML stem and progenitor cells to TKIs and the emergence of TKI-resistant BCR-ABL mutations. BCR-ABL activity is associated with increased proteasome activity and proteasome inhibitors (PIs) are cytotoxic against CML cell lines. We demonstrate that bortezomib is antiproliferative and induces apoptosis in chronic phase (CP) CD34+ CML cells at clinically achievable concentrations. We also show that bortezomib targets primitive CML cells, with effects on CD34+38(-), long-term culture-initiating (LTC-IC) and nonobese diabetic/severe combined immunodeficient (NOD/SCID) repopulating cells. Bortezomib is not selective for CML cells and induces apoptosis in normal CD34+38(-) cells. The effects against CML cells are seen when bortezomib is used alone and in combination with dasatinib. Bortezomib causes proteasome but not BCR-ABL inhibition and is also effective in inhibiting proteasome activity and inducing apoptosis in cell lines expressing BCR-ABL mutations, including T315I. By targeting both TKI-insensitive stem and progenitor cells and TKI-resistant BCR-ABL mutations, we believe that bortezomib offers a potential therapeutic option in CML. Because of known toxicities, including myelosuppression, the likely initial clinical application of bortezomib in CML would be in resistant and advanced disease.


Assuntos
Apoptose/efeitos dos fármacos , Ácidos Borônicos/farmacologia , Técnicas de Cultura de Células/métodos , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Pirazinas/farmacologia , Animais , Antígenos CD34/metabolismo , Bortezomib , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Dasatinibe , Sinergismo Farmacológico , Proteínas de Fusão bcr-abl/metabolismo , Humanos , Camundongos , Camundongos SCID , Proteínas Mutantes/metabolismo , Inibidores de Proteassoma , Pirimidinas/farmacologia , Tiazóis/farmacologia , Fatores de Tempo , Ensaio Tumoral de Célula-Tronco , Ensaios Antitumorais Modelo de Xenoenxerto
17.
Biomed Chromatogr ; 26(5): 545-7, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-21830228

RESUMO

Omacetaxine is a natural product extract originating from Chinese medicine and finding therapeutic use as a potent myelosuppressive agent in leukemia. When planning in vitro cell biology experiments to assess omacetaxine activity against primary leukemic stem cells, it became apparent that the literature rarely describes the in vitro stability of the molecule, although accessible chromatographic methods have been published. Clearly whole organisms vs their component cells will differ in the way in which they handle xenobiotics, with the latter more dependent on physiochemical parameters such as pH and temperature in the absence of active metabolism or excretion. This could impact on the cells' experience of drug in culture. We therefore report here on examination of a modified, high-performance liquid chromatography (HPLC) method with assessment of degradant production from a 72 h solution stability study, clearly demonstrating that omacetaxine is highly stable in representative cell culture conditions (37 °C, neutral pH) and persists for many days in marked contrast to its short-half life in vivo.


Assuntos
Harringtoninas/química , Cromatografia Líquida de Alta Pressão , Estabilidade de Medicamentos , Mepesuccinato de Omacetaxina , Concentração de Íons de Hidrogênio , Soluções/química , Espectrofotometria Ultravioleta , Temperatura
18.
Jpn Dent Sci Rev ; 58: 298-315, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36247748

RESUMO

Purpose: To systematically review in vitro studies that incorporated MMP inhibitors into adhesive systems in terms of the effect on immediate and aged bond strength of dental composite to dentine. Materials and methods: Independently, two reviewers conducted an electronic search in three databases (MEDLINE, EMBASE, and Google Scholar) following the Preferred Reporting Items for Systematic Review and Meta-Analyses Protocols (PRISMA-P), up to 6 March 2022. Results: The search resulted in 894 papers, 33 of which were eligible to be included in the review; of those, 13 fulfilled the meta-analysis eligibility criteria. Nineteen inhibitors were used among the studies, and those included in the meta-analysis were 2%, 0.2% chlorhexidine (CHX), 5 µM GM1489, and 0.5%, 1% benzalkonium chloride (BAC). In the meta-analysis, while above inhibitors showed no adverse effect on bond strength, 0.2% CHX and 5 µM GM1489 caused a significant increase in immediate and 12-months bond strength. All other inhibitors resulted in a significant increase in bond strength at six months of ageing. Conclusions: Incorporation of MMP inhibitors into the adhesive system has no unfavourable effect on immediate bond strength but a favourable effect on longer-term bond strength. Additionally, inhibitors other than CHX could have similar or better effects on bond strength.

19.
Blood ; 2009 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-19965658

RESUMO

Chronic Myeloid Leukaemia (CML) is initiated and maintained by the tyrosine kinase BCR-ABL. ABL-specific tyrosine kinase inhibitors (TKIs), whilst effective against mature CML cells, induce little apoptosis in stem/progenitor cells. However, in stem/progenitor cells TKIs exert potent anti-proliferative effects through a poorly understood mechanism. We showed that in CD34(+) CML cells FOXO1, 3a and 4 (FOXOs) were phosphorylated, predominantly cytoplasmic and inactive, consequent to BCR-ABL expression. TKIs decreased phosphorylation of FOXOs, leading to their re-localisation from cytoplasm (inactive) to nucleus (active), thus inducing G1 arrest. Of key importance, despite BCR-ABL activity, primitive quiescent CML stem cells showed low levels of FOXO phosphorylation and predominant nuclear localisation, resembling the pattern in normal stem cells. These results demonstrate for the first time that TKI-induced G1 arrest in CML progenitor cells is mediated by re-activation of FOXOs, whilst quiescence of CML stem cells is regulated by sustained FOXO activity. These data contribute to our understanding of CML stem cell quiescence and TKI activity, suggesting new strategies to target CML stem/progenitor cells by preventing or reversing this effect.

20.
Health Soc Care Community ; 29(4): 1145-1168, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33058359

RESUMO

A need for people-centred health and social support systems is acknowledged as a global priority. Most nations face challenges in providing safe, effective, timely, affordable, coordinated care around the needs and preferences of people who access integrated health and social care (IHSC) services. Much of the current research in the field focuses on describing and evaluating specific models for delivering IHSC. Fewer studies focus on person-centred experiences, needs and preferences of people who use these services. However, current international guidance for integrated care sets a precedence of person-centred integrated care that meets the health and well-being needs of people who access IHSC services. This integrative literature review synthesises empirical literature from six databases (CINAHL; MEDLINE; AMED; TRIP; Web of Science and Science Direct; 2007-2019). This review aims to better understand the experiences and health and well-being needs of people who use IHSC services in a community setting. Twenty studies met the inclusion criteria and results were thematically analysed. Three overarching themes were identified, including relationships, promoting health and well-being and difficulty understanding systems. Findings of this review indicate that relationships hold significance in IHSC. People who access IHSC services felt that they were not always involved in planning their care and that there was a lack of clarity in navigating integrated systems; subsequently, this impacted upon their experiences of those services. However, service user and informal carer voices appear to be underrepresented in current literature and studies that included their views were found to be of low quality overall. Collectively, these findings support the need for further research that explores the person-centred experiences and needs of people who access IHSC.


Assuntos
Cuidadores , Apoio Social , Atenção à Saúde , Humanos
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