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1.
J Hosp Infect ; 145: 142-147, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38272124

RESUMO

BACKGROUND: A recent study confirmed significant contamination of syringe tips following routine anaesthesia practice of at least 6 h in duration. AIM: We assessed the relative efficacy of clinically relevant syringe tip disinfection techniques following contamination with the hyper transmissible and more pathogenic Staphylococcus aureus sequence type 5 (S. aureus ST5) strain characteristic associated with increased strength of biofilm formation and greater desiccation tolerance. METHODS: Syringe tips (N=40) contaminated with S. aureus ST5 were randomized to 70% isopropyl pads with 10 or 60 s of drying time, scrubbing alcohol disinfection caps with 10 or 60 s of dwell time, or to non-scrubbing alcohol disinfection caps with 60 s of dwell time. The primary outcome was residual 24-h colony forming units (cfu) >10. RESULTS: Scrubbing disinfection caps were more effective than alcohol pads (25% (12/48) <10 cfu for scrubbing caps (10- or 60-s dwell times) vs 0% (0/48) <10 cfu for alcohol pads (10 or 60 s of drying time), Holm-Sidak adjusted P=0.0016). Scrubbing disinfection caps were more effective than non-scrubbing alcohol disinfection caps (25% (12/48) <10 cfu for scrubbing alcohol caps (10- or 60-s dwell times) vs 2% (1/48) for non-scrubbing alcohol caps (60-s dwell time), adjusted P=0.0087). CONCLUSIONS: Scrubbing alcohol caps are more effective than alcohol pads or non-scrubbing disinfecting caps for microbial reduction of syringe tips contaminated with the more pathogenic S. aureus ST5.


Assuntos
Desinfecção , Staphylococcus , Humanos , Desinfecção/métodos , Staphylococcus aureus , Seringas , Etanol , Contaminação de Equipamentos
2.
J Hosp Infect ; 143: 186-194, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37451409

RESUMO

BACKGROUND: Staphylococcus aureus sequence type 5 (ST5) is an emerging global threat. AIM: To characterize the epidemiology of ST5 transmission in the anaesthesia work area. METHODS: The retrospective cohort study analysed transmitted, prophylactic antibiotic-resistant Staphylococcus aureus isolates involving anaesthesia work area reservoirs. Using whole-genome analysis, the epidemiology of ST5 transmission was characterized by reservoir(s) of origin, transmission location(s), portal of entry, and mode(s) of transmission. All patients were followed for at least 30 days for surgical site infection (SSI) development. FINDINGS: Forty-one percent (18/44; 95% confidence interval: 28-56%) of isolates were ST5. Provider hands were the reservoir of origin for 28% (5/18) of transmitted ST5 vs 4% (1/26) for other STs. Provider hands were the transmission location for 28% (5/18) of ST5 vs 7% (2/26) of other STs. Stopcock contamination occurred for 8% (1/13) of ST5 isolates vs 12% (3/25) of other STs. Sixty-three percent of transmission events occurring between cases on separate operative dates involved ST5. ST5 was more likely to harbour resistance traits (ST5 median (interquartile range) 3 (2-3) vs 2 (1-2) other STs; P < 0.001) and had greater resistance to cefazolin, piperacillin-tazobactam, and/or ciprofloxacin (ST5: 3 (2-3) vs 2 (1-3) other STs; P = 0.02). ST5 was associated with three of six SSIs. CONCLUSION: ST5 is prevalent among transmitted, prophylactic antibiotic-resistant isolates in the anaesthesia work area. Transmission involves provider hands and one patient to another on future date(s). ST5 is associated with a greater number of resistance traits and reduced in-vitro susceptibility vs other intraoperative meticillin-resistant S. aureus.


Assuntos
Anestesia , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Humanos , Staphylococcus aureus/genética , Epidemiologia Molecular , Estudos Retrospectivos , Infecções Estafilocócicas/prevenção & controle , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana
3.
J Hosp Infect ; 134: 121-128, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36693592

RESUMO

BACKGROUND: The extent to which the transmission of prophylactic-antibiotic-resistant bacteria from the anaesthesia work area increases the risk of surgical site infection (SSI) is unknown. It was hypothesized that the risk of SSI would increase progressively from no transmission to transmission of prophylactic-antibiotic-resistant isolates. METHODS: This was a retrospective analysis of archival samples collected in two previously published studies with similar inclusion criteria and sample collection methodology (observational study 2009-2010 and randomized trial 2018-2019). Archival isolates were linked by barcode to all patient demographic and procedural information, including the prophylactic antibiotic administered, transmission and development of SSI. For this study, all archival isolates underwent prophylactic antibiotic susceptibility testing, and the ordered association of transmission of Staphylococcus aureus (no transmission, transmission of prophylactic-antibiotic-susceptible isolates and transmission of prophylactic-antibiotic-resistant isolates) with SSI was assessed. RESULTS: The risk of development of SSI was 2% (8/406) without S. aureus transmission, 11% (9/84) with transmission of S. aureus isolates that were susceptible to the prophylactic antibiotic used, and 18% (4/22) with transmission of prophylactic-antibiotic-resistant S. aureus isolates. The Cochrane-Armitage two-sided test for ordered association was P<0.0001. Treating these three groups as 0, 1 and 2, by exact logistic regression, the odds of SSI increased by 3.59 with each unit increase (95% confidence interval 1.92-6.64; P<0.0001). CONCLUSIONS: Transmission of S. aureus in the anaesthesia work area reliably increases the risk of SSI, especially when the isolates are resistant to the prophylactic antibiotic administered.


Assuntos
Anestesia , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Humanos , Staphylococcus aureus , Infecção da Ferida Cirúrgica/epidemiologia , Infecção da Ferida Cirúrgica/prevenção & controle , Infecção da Ferida Cirúrgica/tratamento farmacológico , Estudos Retrospectivos , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/prevenção & controle , Infecções Estafilocócicas/tratamento farmacológico , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico
5.
Nat Commun ; 12(1): 2646, 2021 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-33976168

RESUMO

Positron Emission Tomography (PET) is a widely-used imaging modality for medical research and clinical diagnosis. Imaging of the radiotracer is obtained from the detected hit positions of the two positron annihilation photons in a detector array. The image is degraded by backgrounds from random coincidences and in-patient scatter events which require correction. In addition to the geometric information, the two annihilation photons are predicted to be produced in a quantum-entangled state, resulting in enhanced correlations between their subsequent interaction processes. To explore this, the predicted entanglement in linear polarisation for the two photons was incorporated into a simulation and tested by comparison with experimental data from a cadmium zinc telluride (CZT) PET demonstrator apparatus. Adapted apparati also enabled correlation measurements where one of the photons had undergone a prior scatter process. We show that the entangled simulation describes the measured correlations and, through simulation of a larger preclinical PET scanner, illustrate a simple method to quantify and remove the unwanted backgrounds in PET using the quantum entanglement information alone.


Assuntos
Algoritmos , Cádmio/química , Modelos Teóricos , Fótons , Tomografia por Emissão de Pósitrons/métodos , Telúrio/química , Zinco/química , Simulação por Computador , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imagens de Fantasmas , Tomografia por Emissão de Pósitrons/instrumentação
6.
Clin Exp Dermatol ; 43(8): 890-894, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29851132

RESUMO

BACKGROUND: Phosphoinositide 3-kinase (PI3K) inhibitors are a class of small-molecule inhibitors approved for the treatment of certain leukaemias and lymphomas. Their dermatological adverse event profile is poorly described. AIM: To characterize a rare cutaneous adverse event from PI3K inhibitors in order to help dermatologists and oncologists identify and effectively manage such eruptions. METHODS: This was a retrospective analysis of patients receiving PI3K inhibitors referred to the Skin Toxicities Program in The Center for Cutaneous Oncology. RESULTS: Three patients on PI3K inhibitors for treatment of malignancy developed diffuse erythroderma and keratoderma. Clinical and histopathological findings were consistent with pityriasis rubra pilaris (PRP)-like reactions. All patients improved with topical and oral corticosteroids, oral acitretin, and drug discontinuation. CONCLUSIONS: PRP-like cutaneous eruptions may develop secondary to PI3K inhibition. Early dermatological evaluation of cutaneous toxicities to PI3K inhibitors as well as rapid initiation of disease-specific treatments may help keep patients on life-prolonging anti-cancer therapies.


Assuntos
Antineoplásicos/efeitos adversos , Dermatite Esfoliativa/induzido quimicamente , Inibidores de Fosfoinositídeo-3 Quinase , Pitiríase Rubra Pilar/induzido quimicamente , Inibidores de Proteínas Quinases/efeitos adversos , Idoso , Antineoplásicos/uso terapêutico , Dermatite Esfoliativa/patologia , Feminino , Humanos , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Oligodendroglioma/tratamento farmacológico , Pitiríase Rubra Pilar/patologia , Inibidores de Proteínas Quinases/uso terapêutico , Estudos Retrospectivos , Pele/patologia
7.
Leukemia ; 32(1): 83-91, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28592889

RESUMO

In the phase 3 RESONATE study, ibrutinib demonstrated superior progression-free survival (PFS), overall survival (OS) and overall response rate (ORR) compared with ofatumumab in relapsed/refractory CLL patients with high-risk prognostic factors. We report updated results from RESONATE in these traditionally chemotherapy resistant high-risk genomic subgroups at a median follow-up of 19 months. Mutations were detected by Foundation One Heme Panel. Baseline mutations in the ibrutinib arm included TP53 (51%), SF3B1 (31%), NOTCH1 (28%), ATM (19%) and BIRC3 (14%). Median PFS was not reached, with 74% of patients randomized to ibrutinib alive and progression-free at 24 months. The improved efficacy of ibrutinib vs ofatumumab continues in all prognostic subgroups including del17p and del11q. No significant difference within the ibrutinib arm was observed for PFS across most genomic subtypes, although a subset carrying both TP53 mutation and del17p had reduced PFS compared with patients with neither abnormality. Reduced PFS or OS was not evident in patients with only del17p. PFS was significantly better for ibrutinib-treated patients in second-line vs later lines of therapy. The robust clinical activity of ibrutinib continues to show ongoing efficacy and acceptable safety consistent with prior reports, independent of various known high-risk mutations.


Assuntos
Leucemia Linfocítica Crônica de Células B/patologia , Mutação/genética , Adenina/análogos & derivados , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais/uso terapêutico , Anticorpos Monoclonais Humanizados , Antineoplásicos/uso terapêutico , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Leucemia Linfocítica Crônica de Células B/mortalidade , Masculino , Pessoa de Meia-Idade , Mutação/efeitos dos fármacos , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/patologia , Piperidinas , Prognóstico , Pirazóis/uso terapêutico , Pirimidinas/uso terapêutico , Proteína Supressora de Tumor p53/genética
10.
Leukemia ; 31(6): 1348-1354, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28115735

RESUMO

The clinical course of patients with recently diagnosed early stage chronic lymphocytic leukemia (CLL) is highly variable. We examined the relationship between CLL-cell birth rate and treatment-free survival (TFS) in 97 patients with recently diagnosed, Rai stage 0-II CLL in a blinded, prospective study, using in vivo 2H2O labeling. Birth rates ranged from 0.07 to 1.31% new cells per day. With median follow-up of 4.0 years, 33 subjects (34%) required treatment by NCI criteria. High-birth rate was observed in 44% of subjects and was significantly associated with shorter TFS, unmutated IGHV status and expression of ZAP70 and of CD38. In multivariable modeling considering age, gender, Rai stage, expression of ZAP70 or CD38, IGHV mutation status and FISH cytogenetics, only CLL-cell birth rate and IGHV mutation status met criteria for inclusion. Hazard ratios were 3.51 (P=0.002) for high-birth rate and 4.93 (P<0.001) for unmutated IGHV. The association between elevated birth rate and shorter TFS was observed in subjects with either mutated or unmutated IGHVs, and the use of both markers was a better predictor of TFS than either parameter alone. Thus, an increased CLL birth rate in early stage disease is a strong predictor of disease progression and earlier treatment.


Assuntos
Biomarcadores Tumorais/genética , Proliferação de Células , Leucemia Linfocítica Crônica de Células B/patologia , Mutação , Adulto , Idoso , Idoso de 80 Anos ou mais , Progressão da Doença , Feminino , Seguimentos , Humanos , Leucemia Linfocítica Crônica de Células B/genética , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Estudos Prospectivos , Taxa de Sobrevida
11.
Leukemia ; 31(10): 2075-2084, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28111464

RESUMO

Although the BTK inhibitor ibrutinib has transformed the management of patients with chronic lymphocytic leukemia (CLL), it does not induce substantial apoptosis in vitro, and as such the mechanisms underlying its ability to kill CLL cells are not well understood. Acalabrutinib, a more specific BTK inhibitor now in development, also appears to be highly effective in CLL, but the connection of its mechanism with CLL cell death is also unclear. Using dynamic BH3 profiling, we analyzed alterations in the function of the mitochondrial apoptotic pathway induced by ibrutinib and acalabrutinib. We studied CLL patient samples treated ex vivo with both drugs, as well as primary samples from CLL patients on clinical trials of both drugs. We found that BTK inhibition enhances mitochondrial BCL-2 dependence without significantly altering overall mitochondrial priming. Enhancement of BCL-2 dependence was accompanied by an increase in the pro-apoptotic protein BIM. In contrast, treatment with the selective BCL-2 inhibitor venetoclax enhanced overall mitochondrial priming without increasing BCL-2 dependence. Pre-treatment of CLL cells with either BTK inhibitor, whether ex vivo or in vivo in patients, enhanced killing by venetoclax. Our data suggest that BTK inhibition enhances mitochondrial BCL-2 dependence, supporting the ongoing development of clinical trials combining BTK and BCL-2 inhibition.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Benzamidas/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/agonistas , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Terapia de Alvo Molecular , Proteínas de Neoplasias/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-bcl-2/fisiologia , Pirazinas/farmacologia , Pirazóis/farmacologia , Pirimidinas/farmacologia , Sulfonamidas/agonistas , Adenina/análogos & derivados , Tirosina Quinase da Agamaglobulinemia , Apoptose/efeitos dos fármacos , Proteína 11 Semelhante a Bcl-2/biossíntese , Proteína 11 Semelhante a Bcl-2/genética , Benzamidas/administração & dosagem , Benzamidas/uso terapêutico , Compostos Bicíclicos Heterocíclicos com Pontes/administração & dosagem , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Ensaios Clínicos como Assunto , Ensaios de Seleção de Medicamentos Antitumorais , Sinergismo Farmacológico , Humanos , Leucemia Linfocítica Crônica de Células B/patologia , Mitocôndrias/efeitos dos fármacos , Proteínas de Neoplasias/fisiologia , Fragmentos de Peptídeos , Piperidinas , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas , Pirazinas/administração & dosagem , Pirazinas/uso terapêutico , Pirazóis/administração & dosagem , Pirazóis/uso terapêutico , Pirimidinas/administração & dosagem , Pirimidinas/uso terapêutico , Sulfonamidas/administração & dosagem , Sulfonamidas/farmacologia , Sulfonamidas/uso terapêutico
12.
Ecol Appl ; 27(1): 94-104, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27870290

RESUMO

The Conservation Effects Assessment Project (CEAP) was created in response to a request from the Office of Management and Budget that the U.S. Department of Agriculture, Natural Resource Conservation Service (USDA-NRCS) document the societal benefits anticipated to accrue from a major increase in conservation funding authorized by the 2002 Farm Bill. A comprehensive evaluation of the efficacy of rangeland conservation practices cost-shared with private landowners was unable to evaluate conservation benefits because outcomes were seldom documented. Four interrelated suppositions are presented to examine the causes underlying minimal documentation of conservations outcomes. These suppositions are (1) the benefits of conservation practices are considered a certainty so that documentation in not required, (2) there is minimal knowledge exchange between the USDA-NRCS and research organizations, (3) and a paucity of conservation-relevant science, as well as (4) inadequate technical support for land owners following implementation of conservation practices. We then follow with recommendations to overcome potential barriers to documentation of conservation outcomes identified for each supposition. Collectively, this assessment indicates that the existing conservation practice standards are insufficient to effectively administer large conservation investments on rangelands and that modification of these standards alone will not achieve the goals explicitly stated by CEAP. We recommend that USDA-NRCS modify its conservation programs around a more comprehensive and integrative platform that is capable of implementing evidence-based conservation. Collaborative monitoring organized around landowner-agency-scientist partnerships would represent the focal point of a Conservation Program Assessment Network (CPAN). The primary network objective would be to establish missing information feedback loops between conservation practices and their agricultural and environmental outcomes to promote learning, adaptive management, and innovation. Network information would be archived and made available to guide other, related conservation programs in relevant ecoregions. Restructuring conservation programs as we recommend would (1) provide site specific information, learning, and accountability that has been requested by CEAP and (2) further advance balanced delivery of agricultural production and environmental quality goals.


Assuntos
Agricultura/métodos , Conservação dos Recursos Naturais/métodos , Estados Unidos , United States Department of Agriculture
13.
Mol Cell Oncol ; 3(4): e1157667, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27652313

RESUMO

Sequencing studies have been instrumental in understanding the genetic basis of chronic lymphocytic leukemia (CLL). Our recent whole-genome sequencing study focusing on lower cytogenetic risk CLL demonstrated that CLL mutations can be attributed to 3 key mutational processes-2 types of activation induced-cytidine deaminase (AID) signatures and an aging signature-that operate at different times throughout CLL evolution.

14.
Leukemia ; 30(1): 173-81, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26165234

RESUMO

Bruton's tyrosine kinase (BTK) kinase is a member of the TEC kinase family and is a key regulator of the B-cell receptor (BCR)-mediated signaling pathway. It is important for B-cell maturation, proliferation, survival and metastasis. Pharmacological inhibition of BTK is clinically effective against a variety of B-cell malignances, such as mantle cell lymphoma, chronic lymphocytic leukemia (CLL), acute myeloid leukemia (AML) and activated B-cell-diffuse large B-cell lymphoma. MNK kinase is one of the key downstream regulators in the RAF-MEK-ERK signaling pathway and controls protein synthesis via regulating the activity of eIF4E. Inhibition of MNK activity has been observed to moderately inhibit the proliferation of AML cells. Through a structure-based drug-design approach, we have discovered a selective and potent BTK/MNK dual kinase inhibitor (QL-X-138), which exhibits covalent binding to BTK and noncovalent binding to MNK. Compared with the BTK kinase inhibitor (PCI-32765) and the MNK kinase inhibitor (cercosporamide), QL-X-138 enhanced the antiproliferative efficacies in vitro against a variety of B-cell cancer cell lines, as well as AML and CLL primary patient cells, which respond moderately to BTK inhibitor in vitro. The agent can effectively arrest the growth of lymphoma and leukemia cells at the G0-G1 stage and can induce strong apoptotic cell death. These primary results demonstrate that simultaneous inhibition of BTK and MNK kinase activity might be a new therapeutic strategy for B-cell malignances.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Leucemia/tratamento farmacológico , Linfoma/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/antagonistas & inibidores , Tirosina Quinase da Agamaglobulinemia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Desenho de Fármacos , Humanos , Leucemia/patologia , Linfoma/patologia
15.
Nat Commun ; 6: 8866, 2015 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-26638776

RESUMO

Patients with chromosome 13q deletion or normal cytogenetics represent the majority of chronic lymphocytic leukaemia (CLL) cases, yet have relatively few driver mutations. To better understand their genomic landscape, here we perform whole-genome sequencing on a cohort of patients enriched with these cytogenetic characteristics. Mutations in known CLL drivers are seen in only 33% of this cohort, and associated with normal cytogenetics and unmutated IGHV. The most commonly mutated gene in our cohort, IGLL5, shows a mutational pattern suggestive of activation-induced cytidine deaminase (AID) activity. Unsupervised analysis of mutational signatures demonstrates the activities of canonical AID (c-AID), leading to clustered mutations near active transcriptional start sites; non-canonical AID (nc-AID), leading to genome-wide non-clustered mutations, and an ageing signature responsible for most mutations. Using mutation clonality to infer time of onset, we find that while ageing and c-AID activities are ongoing, nc-AID-associated mutations likely occur earlier in tumour evolution.


Assuntos
Citidina Desaminase/genética , Leucemia Linfocítica Crônica de Células B/enzimologia , Envelhecimento/genética , Evolução Biológica , Estudos de Coortes , Citidina Desaminase/metabolismo , Genoma Humano , Estudo de Associação Genômica Ampla , Humanos , Leucemia Linfocítica Crônica de Células B/genética , Mutação
16.
J Hosp Infect ; 91(3): 278-81, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26412395

RESUMO

Using a Collison nebulizer, aerosols of influenza (A/Udorn/307/72 H3N2) were generated within a controlled experimental chamber, from known starting virus concentrations. Air samples collected after variable suspension times were tested quantitatively using both plaque and polymerase chain reaction assays, to compare the proportion of viable virus against the amount of detectable viral RNA. These experiments showed that whereas influenza RNA copies were well preserved, the number of viable viruses decreased by a factor of 10(4)-10(5). This suggests that air-sampling studies for assessing infection control risks that detect only influenza RNA may greatly overestimate the amount of viable virus available to cause infection.


Assuntos
Aerossóis , Microbiologia do Ar , Vírus da Influenza A Subtipo H3N2/fisiologia , Viabilidade Microbiana , Humanos , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A Subtipo H3N2/crescimento & desenvolvimento , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Carga Viral , Ensaio de Placa Viral
17.
Cell Death Dis ; 6: e1807, 2015 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-26158513

RESUMO

Microenvironment-mediated upregulation of the B-cell receptor (BCR) and nuclear factor-κB (NF-κB) signaling in CLL cells resident in the lymph node and bone marrow promotes apoptosis evasion and clonal expansion. We recently reported that MLN4924 (pevonedistat), an investigational agent that inhibits the NEDD8-activating enzyme (NAE), abrogates stromal-mediated NF-κB pathway activity and CLL cell survival. However, the NAE pathway also assists degradation of multiple other substrates. MLN4924 has been shown to induce DNA damage and cell cycle arrest, but the importance of this mechanism in primary neoplastic B cells has not been studied. Here we mimicked the lymph node microenvironment using CD40 ligand (CD40L)-expressing stroma and interleukin-21 (IL-21) to find that inducing proliferation of the primary CLL cells conferred enhanced sensitivity to NAE inhibition. Treatment of the CD40-stimulated CLL cells with MLN4924 resulted in deregulation of Cdt1, a DNA replication licensing factor, and cell cycle inhibitors p21 and p27. This led to DNA damage, checkpoint activation and G2 arrest. Alkylating agents bendamustine and chlorambucil enhanced MLN4924-mediated DNA damage and apoptosis. These events were more prominent in cells stimulated with IL-21 compared with CD40L alone, indicating that, following NAE inhibition, the culture conditions were able to direct CLL cell fate from an NF-κB inhibition to a Cdt1 induction program. Our data provide insight into the biological consequences of targeting NAE in CLL and serves as further rationale for studying the clinical activity of MLN4924 in CLL, particularly in combination with alkylating agents.


Assuntos
Alquilantes/administração & dosagem , Antígenos CD40/biossíntese , Ligante de CD40/genética , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Enzimas Ativadoras de Ubiquitina/genética , Apoptose/efeitos dos fármacos , Linfócitos B/metabolismo , Cloridrato de Bendamustina/administração & dosagem , Antígenos CD40/genética , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ciclopentanos/administração & dosagem , Dano ao DNA/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Interleucinas/biossíntese , Interleucinas/genética , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/patologia , Proteína NEDD8 , NF-kappa B/genética , Pirimidinas/administração & dosagem , Enzimas Ativadoras de Ubiquitina/antagonistas & inibidores , Ubiquitinas/genética
18.
Am J Transplant ; 15(6): 1490-501, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25872977

RESUMO

Less than 10% of corneal allografts undergo rejection even though HLA matching is not performed. However, second corneal transplants experience a threefold increase in rejection, which is not due to prior sensitization to histocompatibility antigens shared by the first and second transplants since corneal grafts are selected at random without histocompatibility matching. Using a mouse model of penetrating keratoplasty, we found that 50% of the initial corneal transplants survived, yet 100% of the subsequent corneal allografts (unrelated to the first graft) placed in the opposite eye underwent rejection. The severing of corneal nerves that occurs during surgery induced substance P (SP) secretion in both eyes, which disabled T regulatory cells that are required for allograft survival. Administration of an SP antagonist restored immune privilege and promoted graft survival. Thus, corneal surgery produces a sympathetic response that permanently abolishes immune privilege of subsequent corneal allografts, even those placed in the opposite eye and expressing a completely different array of foreign histocompatibility antigens from the first corneal graft.


Assuntos
Córnea/inervação , Transplante de Córnea , Denervação/métodos , Rejeição de Enxerto/imunologia , Tolerância Imunológica/imunologia , Células Receptoras Sensoriais , Aloenxertos , Animais , Feminino , Rejeição de Enxerto/fisiopatologia , Sobrevivência de Enxerto/imunologia , Sobrevivência de Enxerto/fisiologia , Antígenos de Histocompatibilidade/imunologia , Tolerância Imunológica/efeitos dos fármacos , Tolerância Imunológica/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Modelos Animais , Substância P/antagonistas & inibidores , Substância P/farmacologia , Substância P/fisiologia , Linfócitos T Reguladores/fisiologia
19.
Gene Ther ; 20(9): 913-21, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23535899

RESUMO

Mucopolysaccharidosis type IIIB (MPS IIIB) or Sanfilippo Syndrome type B is a lysosomal storage disease resulting from the deficiency of N-acetyl glucosaminidase (NAGLU) activity. We previously showed that intracranial adeno-associated virus (AAV)-based gene therapy results in partial improvements of several aspects of the disease. In an attempt to further correct the disease, MPS IIIB mice were treated at 2-4 days of age with intracranial AAV2/5-NAGLU (IC-AAV), intravenous lentiviral-NAGLU (IV-LENTI) or the combination of both (BOTH). The BOTH group had the most complete biochemical and histological improvements of any treatment group. Compared with untreated MPS IIIB animals, all treatments resulted in significant improvements in motor function (rotarod) and hearing (auditory-evoked brainstem response). In addition, each treatment group had a significantly increased median life span compared with the untreated group (322 days). The combination arm had the greatest increase (612 days), followed by IC-AAV (463 days) and IV-LENTI (358 days). Finally, the BOTH group had nearly normal circadian rhythm measures with improvement in time to activity onset. In summary, targeting both the systemic and central nervous system disease of MPS IIIB early in life appears to be the most efficacious approach for this inherited metabolic disorder.


Assuntos
Acetilglucosaminidase/genética , Encéfalo/metabolismo , Encéfalo/patologia , Dependovirus/genética , Terapia Genética , Lentivirus/genética , Mucopolissacaridose III/fisiopatologia , Mucopolissacaridose III/terapia , Acetilglucosaminidase/metabolismo , Animais , Animais Recém-Nascidos , Ritmo Circadiano , Vetores Genéticos , Humanos , Fígado/enzimologia , Fígado/patologia , Pulmão/enzimologia , Pulmão/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Atividade Motora , Mucopolissacaridose III/metabolismo , Mucopolissacaridose III/patologia , Miocárdio/enzimologia , Miocárdio/patologia , Resultado do Tratamento
20.
Leukemia ; 27(2): 362-9, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22955330

RESUMO

Chronic lymphocytic leukemia (CLL) remains incurable with chemoimmunotherapy, and allogeneic hematopoietic stem cell transplantation (HSCT) offers the potential for cure. We assessed the outcomes of 108 CLL patients undergoing first allogeneic HSCTs, 76 with reduced-intensity (RIC) and 32 with myeloablative conditioning (MAC) between 1998 and 2009 at Dana-Farber Cancer Institute. With median follow-up of 5.9 years in surviving patients, the 5-year overall survival (OS) for the entire cohort is 63% for RIC regimens and 49% for MAC regimens (P=0.18). The risk of death declined significantly starting in 2004, and we found that 5-year OS for HSCT between 2004 and 2009 was 83% for RIC regimens compared with 47% for MAC regimens (P=0.003). For RIC transplantation, we developed a prognostic model based on predictors of progression-free survival (PFS), specifically remission status, lactate dehydrogenase, comorbidity score and lymphocyte count, and found 5-year PFS to be 83% for Score 0, 63% for Score 1, 24% for Score 2 and 6% for Score ≥3 (P<0.0001). We conclude that RIC HSCT for CLL in the current era is associated with excellent long-term PFS and OS, and, as potentially curative therapy, should be considered early in the disease course of relapsed high-risk CLL patients.


Assuntos
Doença Enxerto-Hospedeiro/prevenção & controle , Transplante de Células-Tronco Hematopoéticas , Leucemia Linfocítica Crônica de Células B/terapia , Modelos Estatísticos , Recidiva Local de Neoplasia/terapia , Adulto , Idoso , Feminino , Citometria de Fluxo , Seguimentos , Humanos , Cariotipagem , Leucemia Linfocítica Crônica de Células B/mortalidade , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/mortalidade , Prognóstico , Estudos Prospectivos , Taxa de Sobrevida , Condicionamento Pré-Transplante , Transplante Homólogo
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