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BACKGROUND: Financial distress is thought to be a key reason why small-medium enterprise (SME) owners experience higher levels of mental health conditions compared with the broader population. Business advisors who form trusting, high-quality relationships with their SME clients, are therefore well placed to: (1) help prevent/reduce key sources of financial distress, (2) better understand the business and personal needs of their clients and, (3) recognise the signs and symptoms of mental health conditions and encourage help-seeking where appropriate. The aim of this study is to compare the effectiveness of relationship building training (RBT) combined with mental health first aid (MHFA) training for business advisors with MHFA alone, on the financial and mental health of their SME-owner clients. METHODS: This is a single blind, two-arm randomised controlled trial. Participants will be business advisors who provide information, guidance and/or assistance to SME owner clients and are in contact with them at least 3 times a year. The business advisors will invite their SME-owner clients to complete 3 online surveys at baseline, 6- and 12-months. Business advisors will be randomised to one of two conditions, using a 1:1 allocation ratio: (1) MHFA with RBT; or (2) MHFA alone, and complete 3 online surveys at baseline, 2- and 6-months. Primary outcomes will be measured in the business advisors and consist of the quality of the relationship, stigmatizing attitude, confidence to offer mental health first aid, quality of life and provision of mental health first aid. Secondary outcomes will be measured in the SME owners and includes trust in their business advisors, the quality of this relationship, financial wellbeing, financial distress, psychological distress, help-seeking behaviour, and quality of life. To complement the quantitative data, we will include a qualitative process evaluation to examine what contextual factors impacted the reach, effectiveness, adoption, implementation, and maintenance of the training. DISCUSSION: As there is evidence for the connections between client trust, quality of relationship and financial and mental wellbeing, we hypothesise that the combined RBT and MHFA training will lead to greater improvements in these outcomes in SME owners compared with MHFA alone. TRIAL REGISTRATION: ClinicalTrials.gov : NCT04982094 . Retrospectively registered 29/07/2021. The study started in February 2021 and the recruitment is ongoing.
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Letramento em Saúde , Saúde Mental , Humanos , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto , Método Simples-Cego , ConfiançaRESUMO
We present the first results of the Fermilab National Accelerator Laboratory (FNAL) Muon g-2 Experiment for the positive muon magnetic anomaly a_{µ}≡(g_{µ}-2)/2. The anomaly is determined from the precision measurements of two angular frequencies. Intensity variation of high-energy positrons from muon decays directly encodes the difference frequency ω_{a} between the spin-precession and cyclotron frequencies for polarized muons in a magnetic storage ring. The storage ring magnetic field is measured using nuclear magnetic resonance probes calibrated in terms of the equivalent proton spin precession frequency ω[over Ë]_{p}^{'} in a spherical water sample at 34.7 °C. The ratio ω_{a}/ω[over Ë]_{p}^{'}, together with known fundamental constants, determines a_{µ}(FNAL)=116 592 040(54)×10^{-11} (0.46 ppm). The result is 3.3 standard deviations greater than the standard model prediction and is in excellent agreement with the previous Brookhaven National Laboratory (BNL) E821 measurement. After combination with previous measurements of both µ^{+} and µ^{-}, the new experimental average of a_{µ}(Exp)=116 592 061(41)×10^{-11} (0.35 ppm) increases the tension between experiment and theory to 4.2 standard deviations.
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AIM: Lipomodelling has been successfully used in reconstructive breast surgery but not yet in patients with permanent stomas. METHOD: A feasibility study of six patients with permanent stomas was undertaken. Patients underwent lipomodelling of the peristomal area. The number of leakages and quality of life were measured before and for 6 months after the procedure. RESULTS: All patients reported an improvement in their stoma-related quality of life and a reduction in the number of leakages experienced (mean: 2.25 leakages/24 h before lipomodelling and 0.5 leakages/24 h after lipomodelling). CONCLUSION: Lipomodelling appears to be an effective method to reduce stoma leakages caused by peristomal skin contour abnormalities.
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Tecido Adiposo/transplante , Fístula Anastomótica/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Estomas Cirúrgicos/efeitos adversos , Idoso , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Qualidade de Vida , Resultado do TratamentoRESUMO
We included six trials with 2524 participants. Capnography reduced hypoxaemic episodes, relative risk (95% CI) 0.71 (0.56-0.91), p = 0.02, but the quality of evidence was poor due to high risks of performance bias and detection bias and substantial statistical heterogeneity. The reduction in hypoxaemic episodes was statistically homogeneous in the subgroup of three trials of 1823 adults sedated for colonoscopy, relative risk (95% CI) 0.59 (0.48-0.73), p < 0.001, although the risks of performance and detection biases were high. There was no evidence that capnography affected other outcomes, including assisted ventilation, relative risk (95% CI) 0.58 (0.26-1.27), p = 0.17.
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Anestesia/métodos , Capnografia/métodos , Colonoscopia , Hipóxia/prevenção & controle , Humanos , Reprodutibilidade dos Testes , RiscoRESUMO
Microfluidic systems enable reactions and assays on the scale of nanoliters. However, at this scale nonuniformities in sample delivery become significant. To determine the fundamental minimum sample volume required for a particular device, a detailed understanding of mass transport is required. Co-flowing laminar streams are widely used in many devices, but typically only in the steady-state. Because establishing the co-flow steady-state consumes excess sample volume and time, there is a benefit to operating devices in the transient state, which predominates as the volume of the co-flow reactor decreases. Analysis of the co-flow transient has been neglected thus far. In this work we describe the fabrication of a pneumatically controlled microfluidic injector constructed to inject a discrete 50nL bolus into one side of a two-stream co-flow reactor. Using dye for image analysis, injections were performed at a range of flow rates from 0.5-10µL/min, and for comparison we collected the co-flow steady-state data for this range. The results of the image analysis were also compared against theory and simulations for device validation. For evaluation, we established a metric that indicates how well the mass distribution in the bolus injection approximates steady-state co-flow. Using such analysis, transient-state injections can approximate steady-state conditions within predefined errors, allowing straight forward measurements to be performed with reduced reagent consumption.
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Relatively few Chinese patients access tertiary cancer services in North West England. We investigated the reasons behind this using a culturally sensitive questionnaire. The questionnaire, completed by 214 Chinese people in English, Cantonese or Mandarin, evaluated the Chinese population's access and satisfaction with primary care, understanding of cancer and awareness of local cancer services. Ninety-five per cent of respondents were registered with a general practitioner (GP) and 75% had accessed primary care in the last year. Satisfaction with GP consultations was high but a third of respondents reported a lack of confidence in local National Health Service (NHS) services. Only 57% of eligible women had attended cervical screening programmes. The overall understanding of the causes and treatment of cancer and cancer services in the North West was poor. Despite registration with primary healthcare, the Chinese population under-utilise cancer prevention programmes and tertiary cancer services because of a lack of awareness and understanding of cancer services in the North West. A significant proportion of the population is dissatisfied with the perceived slow service and lack confidence in services, with 41% considering using healthcare abroad. These data highlight the critical need to engage with, educate and support the Chinese population if they are to access NHS cancer services.
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Acessibilidade aos Serviços de Saúde , Necessidades e Demandas de Serviços de Saúde , Neoplasias/terapia , Atenção Primária à Saúde , Atenção Terciária à Saúde , Adulto , Idoso , China/etnologia , Detecção Precoce de Câncer , Inglaterra , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/prevenção & controle , Adulto JovemRESUMO
We used high-density oligonucleotide microarrays to analyse the genomes and meiotic expression patterns of two yeast strains, SK1 and W303, that display distinct kinetics and efficiencies of sporulation. Hybridization of genomic DNA to arrays revealed numerous gene deletions and polymorphisms in both backgrounds. The expression analysis yielded approximately 1,600 meiotically regulated genes in each strain, with a core set of approximately 60% displaying similar patterns in both strains. Most of these (95%) are MATa/MATalpha-dependent and are not similarly expressed in near-isogenic meiosis-deficient controls. The transcript profiles correlate with the distribution of defined meiotic promoter elements and with the time of known gene function.
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Meiose/genética , Saccharomycetales/citologia , Saccharomycetales/genética , Sítios de Ligação/genética , Deleção de Genes , Regulação Fúngica da Expressão Gênica , Genoma Fúngico , Cinética , Análise de Sequência com Séries de Oligonucleotídeos , Polimorfismo Genético , Regiões Promotoras Genéticas , RNA Fúngico/genética , RNA Mensageiro/genética , Saccharomycetales/fisiologia , Especificidade da Espécie , Esporos Fúngicos/genética , Fatores de Transcrição/metabolismo , Transcrição GênicaRESUMO
BACKGROUND: The UK Multicentre Aneurysm Screening Study (MASS) demonstrated reduced mortality from screening for abdominal aortic aneurysm (AAA). As a result, the National Health Service AAA Screening Programme was introduced in England. This study reports the results from an early-implementation screening centre. METHODS: Men aged 65 years were invited to attend an ultrasound assessment. Data were analysed for 15 months from the onset of the screening programme. RESULTS: A total of 6091 men aged 65 years were invited between April 2009 and June 2010, of whom 2037 (33·4 per cent) failed to attend. There were 162 self-referrals (median age 71·3 years) so that 4216 men were screened. Of those scanned, 4146 (98·3 per cent) had an aortic diameter of less than 3·0 cm, 65 (1·5 per cent) had an aneurysm measuring 3·0-5·4 cm, and five (0·1 per cent) had an aneurysm with a diameter of 5·5 cm and above. The presence of an aneurysm was more common in those who self-referred than in the invited group (P < 0·001). All 70 screen-detected aneurysms were found in white men. CONCLUSION: The prevalence of AAA was lower than expected. This reflects the younger age of this cohort compared with those in published large multicentre studies and the diverse ethnic background of the local population.
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Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aneurisma da Aorta Abdominal/epidemiologia , Programas de Rastreamento , Idoso , Aneurisma da Aorta Abdominal/etnologia , Aneurisma da Aorta Abdominal/etiologia , Humanos , Incidência , Londres/epidemiologia , Masculino , Programas de Rastreamento/métodos , Prevalência , Fatores de Risco , UltrassonografiaRESUMO
AIM: Perianal Mycobacterium tuberculosis is rare, but tuberculosis (TB) is now endemic in many areas of the world. It is essential to recognize TB to institute appropriate management. We report three cases of TB presenting with supralevator abscess. METHOD: We analysed the outcomes of three patients who presented to our unit, from 2004 to 2009, with supralevator abscess caused by TB. RESULTS: The patients presented as emergencies with symptoms of per-anal sepsis. All required multiple drainage procedures. Supralevator extension was confirmed clinically and radiologically (by magnetic resonance imaging in two patients and by computed tomography scanning in one patient). One patient was diagnosed by perianal biopsy, the second by culture of pus and the third by sputum culture. Following drainage, all three patients were given anti-TB medication for 6 months. In all patients, the fistulae had high communication with the anal canal. In one patient, local drainage and medical therapy led to sepsis resolution, the second patient has residual complex fistulae and the third patient has recently commenced antimicrobial therapy. CONCLUSION: As TB is endemic in many parts of Europe, TB should be suspected in patients with complex and/or recurrent perianal sepsis. Samples for histological and bacteriological analyses should be obtained from these patients. Recurrent perianal drainage procedures are likely to be required, and sepsis may persist after anti-TB therapy.
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Abscesso/etiologia , Canal Anal , Fístula Retal/etiologia , Tuberculose/complicações , Adulto , Idoso , Feminino , Humanos , Masculino , Músculo Esquelético , Tuberculose/diagnósticoRESUMO
BACKGROUND: Overdose is a major cause of morbidity and mortality among people who use opioids. Naloxone can reverse opioid overdoses and can be distributed and administered with minimal training. People with experience of overdose are a key population to target for overdose prevention strategies. This study aims to understand if factors associated with recent non-fatal opioid overdose are the same as factors associated with naloxone access and naloxone training in people who recently used opioids or received opioid agonist treatment (OAT). METHODS: ETHOS Engage is an observational study of people who inject drugs in Australia. Logistic regression models were used to estimate odds ratios for non-fatal opioid overdose, naloxone access and naloxone training. RESULTS: Between May 2018-September 2019, 1280 participants who recently used opioids or received OAT were enrolled (62% aged >40 years; 35% female, 80% receiving OAT, 62% injected drugs in the preceding month). Recent opioid overdose (preceding 12 months) was reported by 7% of participants, lifetime naloxone access by 17%, and lifetime naloxone training by 14%. Compared to people receiving OAT with no additional opioid use, recent opioid, benzodiazepine (preceding six months), and hazardous alcohol use was associated with recent opioid overdose (aOR 3.91; 95%CI: 1.68-9.10) and lifetime naloxone access (aOR 2.12; 95%CI 1.29-3.48). Among 91 people who reported recent overdose, 65% had never received take-home naloxone or naloxone training. CONCLUSIONS: Among people recently using opioids or receiving OAT, benzodiazepine and hazardous alcohol use is associated with non-fatal opioid overdose. Not all factors associated with non-fatal overdose correspond to factors associated with naloxone access. Naloxone access and training is low across all groups. Additional interventions are needed to scale up naloxone provision.
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Overdose de Drogas , Overdose de Opiáceos , Transtornos Relacionados ao Uso de Opioides , Analgésicos Opioides/uso terapêutico , Overdose de Drogas/tratamento farmacológico , Overdose de Drogas/epidemiologia , Feminino , Humanos , Masculino , Naloxona/uso terapêutico , Antagonistas de Entorpecentes/uso terapêutico , Transtornos Relacionados ao Uso de Opioides/tratamento farmacológico , Transtornos Relacionados ao Uso de Opioides/epidemiologiaRESUMO
Unabated, worldwide trends in CO2 production project growth to > 43-BMT per year over the next two decades. Efficient power electronics are crucial to fully realizing the CO2 mitigating benefits of a worldwide smart grid (~ 18% reduction for the United States alone). Even state-of-the-art SiC high voltage junction devices are inefficient because of slow transition times (~ 0.5-µs) and limited switching rates at high voltage (~ 20-kHz at ≥ 15-kV) resulting from the intrinsically limited charge carrier drift speed (< 2 × 107-cm-s-1). Slow transition times and limited switch rates waste energy through transition loss and hysteresis loss in external magnetic components. Bulk conduction devices, where carriers are generated and controlled nearly simultaneously throughout the device volume, minimize this loss. Such devices are possible using below bandgap excitation of semi-insulating (SI) SiC single crystals. We explored carrier dynamics with a 75-fs single wavelength pump/supercontinuum probe and a modified transient spectroscopy technique and also demonstrated a new class of efficient, high-speed, high-gain, bi-directional, optically-controlled transistor-like power device. At a performance level six times that of existing devices, for the first time we demonstrated prototype operation at multi-10s of kW and 20-kV, 125-kHz in a bulk conduction transistor-like device using direct photon-carrier excitation with below bandgap light.
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Oligonucleotide microarrays were used to map the detailed topography of chromosome replication in the budding yeast Saccharomyces cerevisiae. The times of replication of thousands of sites across the genome were determined by hybridizing replicated and unreplicated DNAs, isolated at different times in S phase, to the microarrays. Origin activations take place continuously throughout S phase but with most firings near mid-S phase. Rates of replication fork movement vary greatly from region to region in the genome. The two ends of each of the 16 chromosomes are highly correlated in their times of replication. This microarray approach is readily applicable to other organisms, including humans.
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Cromossomos Fúngicos/metabolismo , Replicação do DNA , DNA Fúngico/biossíntese , Genoma Fúngico , Origem de Replicação , Fase S , Saccharomyces cerevisiae/genética , Algoritmos , Sequência de Bases , Centrômero/metabolismo , Cromossomos Fúngicos/genética , DNA Fúngico/genética , DNA Fúngico/metabolismo , DNA Intergênico , Análise de Fourier , Cinética , Hibridização de Ácido Nucleico , Análise de Sequência com Séries de Oligonucleotídeos , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/metabolismo , Telômero/metabolismo , Transcrição GênicaRESUMO
As more genomes are sequenced, the identification and characterization of the causes of heritable variation within a species will be increasingly important. It is demonstrated that allelic variation in any two isolates of a species can be scanned, mapped, and scored directly and efficiently without allele-specific polymerase chain reaction, without creating new strains or constructs, and without knowing the specific nature of the variation. A total of 3714 biallelic markers, spaced about every 3.5 kilobases, were identified by analyzing the patterns obtained when total genomic DNA from two different strains of yeast was hybridized to high-density oligonucleotide arrays. The markers were then used to simultaneously map a multidrug-resistance locus and four other loci with high resolution (11 to 64 kilobases).
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Mapeamento Cromossômico/métodos , Técnicas Genéticas , Variação Genética , Genoma Fúngico , Saccharomyces cerevisiae/genética , Alelos , Cicloeximida/farmacologia , Resistência Microbiana a Medicamentos/genética , Resistência a Múltiplos Medicamentos/genética , Deleção de Genes , Genes Fúngicos , Ligação Genética , Marcadores Genéticos , Genótipo , Hibridização de Ácido Nucleico , Fenótipo , Recombinação GenéticaRESUMO
Scrotal skin is thin and has high steroid permeability, but the pharmacokinetics of testosterone via the scrotal skin route has not been studied in detail. The aim of this study was to define the pharmacokinetics of testosterone delivered via the scrotal skin route. The study was a single-center, three-phase cross-over pharmacokinetic study of three single doses (12.5, 25, 50 mg) of testosterone cream administered in random sequence on different days with at least 2 days between doses to healthy eugonadal volunteers with endogenous testosterone suppressed by administration of nandrolone decanoate. Serum testosterone, DHT and estradiol concentrations were measured by liquid chromatograpy, mass spectrometry in extracts of serum taken before and for 16 h after administration of each of the three doses of testosterone cream to the scrotal skin. Testosterone administration onto the scrotal skin produced a swift (peak 1.9-2.8 h), dose-dependent (p < 0.0001) increase in serum testosterone with the 25 mg dose maintaining physiological levels for 16 h. Serum DHT displayed a time- (p < 0.0001), but not dose-dependent, increase in concentration reaching a peak concentration of 1.2 ng/mL (4.1 nm) at 4.9 h which was delayed by 2 h after peak serum testosterone. There were no significant changes in serum estradiol over time after testosterone administration. We conclude that testosterone administration to scrotal skin is well tolerated and produces dose-dependent peak serum testosterone concentration with a much lower dose relative to the non-scrotal transdermal route.
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Absorção Cutânea , Testosterona/administração & dosagem , Testosterona/farmacocinética , Administração Cutânea , Adolescente , Adulto , Cromatografia Líquida , Estudos Cross-Over , Di-Hidrotestosterona/sangue , Di-Hidrotestosterona/farmacocinética , Relação Dose-Resposta a Droga , Monitoramento de Medicamentos/métodos , Estradiol/sangue , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , New South Wales , Escroto , Espectrometria de Massas em Tandem , Testosterona/sangue , Adulto JovemRESUMO
Acute myeloid leukemia (AML) is a clonal hematologic malignant disease of developing myeloid cells that have acquired aberrant survival, uncontrolled proliferation and a block in normal hematopoietic cell differentiation. Standard chemotherapy often induces remissions in AML patients, but the disease frequently relapses due to incomplete targeting of leukemia-initiating cells (LICs), emphasizing the need for novel effective treatments. Exportin 1 (XPO1)-mediated nuclear export, which is inhibited by the drug selinexor, is an attractive new therapeutic target in AML. Selinexor has shown impressive activity in Phase I/II clinical trials for AML. Here we report the anti-leukemic efficacy and tolerability of KPT-8602, a second-generation XPO1 inhibitor. KPT-8602 demonstrates substantially reduced brain penetration compared to selinexor, with resultant attenuation of the central nervous system mediated side effects of anorexia and weight loss. Due to its improved tolerability profile, KPT-8602 can be given daily compared to the two or three times weekly regimen of selinexor, and exhibits greater anti-leukemic efficacy against both leukemic blasts and LICs in AML patient-derived xenograft models. Importantly, normal hematopoietic stem and progenitor cell (HSPC) frequency is not significantly reduced by KPT-8602, providing a therapeutic window for elimination of relapse-driving LICs while sparing normal HSPCs. These findings strongly endorse clinical testing of KPT-8602 in patients with relapsed and refractory AML.
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Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Carioferinas/antagonistas & inibidores , Leucemia Mieloide Aguda/tratamento farmacológico , Receptores Citoplasmáticos e Nucleares/antagonistas & inibidores , Animais , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Crise Blástica/tratamento farmacológico , Crise Blástica/patologia , Carcinogênese/efeitos dos fármacos , Carcinogênese/patologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Xenoenxertos , Humanos , Hidrazinas , Leucemia Mieloide Aguda/patologia , Camundongos , Triazóis , Proteína Exportina 1RESUMO
BACKGROUND: Traditionally axillary surgery has been used to provide staging information and until recently was thought to improve loco-regional control. However, a more minimal approach to the axilla is now being adopted. The aim of this study was to assess long term outcomes of patients with 'low-risk' breast cancers who did not undergo any axillary surgery. 'Low-risk' criteria were: postmenopausal, <20 mm grade 1 or <15 mm grade 2, LVI-ve, ER +ve. METHODS: Women with invasive breast cancer that did not undergo any axillary surgery were identified. Patients were censored when an event or death occurred or at last follow-up at breast clinic or with their General Practitioner. RESULTS: Between 05/01/1995-20/11/2006, 194 patients (199 tumours) were operated upon without axillary surgery. Median follow-up was 10.4 years. 128 patients met low-risk criteria and 71 did not (patient choice = 42, medical fitness = 29). In the 'low risk' cohort there were two axillary recurrences, with a cumulative incidence of 0.8% and 1.9% at 5 and 10 years respectively. DDFS was 99.2% (94.1-99.9%), and 97% (90.0-99%) at 5 and 10 years respectively and DFS was 96.6% (91.1-98.7%) and 91.2% (82.6-95.6%). OS was 90.3% (95% CI: 83.6-94.4) and 75.5% (95% CI: 65.9-82.8) at 5 and 10 years respectively. CONCLUSION: Axillary recurrence and DDFS in this low-risk cohort is favourable. In the modern era of breast cancer management it is possible to define a group of women in whom axillary surgery can be omitted.
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Neoplasias da Mama/patologia , Neoplasias da Mama/cirurgia , Excisão de Linfonodo , Linfonodos/patologia , Linfonodos/cirurgia , Recidiva Local de Neoplasia/diagnóstico , Conduta Expectante , Adulto , Idoso , Idoso de 80 Anos ou mais , Axila , Neoplasias da Mama/química , Neoplasias da Mama/mortalidade , Registros Eletrônicos de Saúde , Inglaterra/epidemiologia , Feminino , Seguimentos , Humanos , Incidência , Estimativa de Kaplan-Meier , Metástase Linfática , Pessoa de Meia-Idade , Gradação de Tumores , Recidiva Local de Neoplasia/epidemiologia , Recidiva Local de Neoplasia/prevenção & controle , Estudos Retrospectivos , Fatores de Risco , Biópsia de Linfonodo SentinelaRESUMO
Currently available combination chemotherapy for acute myeloid leukemia (AML) often fails to result in long-term remissions, emphasizing the need for novel therapeutic strategies. We reasoned that targeted inhibition of a prominent nuclear exporter, XPO1/CRM1, could eradicate self-renewing leukemia-initiating cells (LICs) whose survival depends on timely XPO1-mediated transport of specific protein and RNA cargoes. Using an immunosuppressed mouse model bearing primary patient-derived AML cells, we demonstrate that selinexor (KPT-330), an oral antagonist of XPO1 that is currently in clinical trials, has strong activity against primary AML cells while sparing normal stem and progenitor cells. Importantly, limiting dilution transplantation assays showed that this cytotoxic activity is not limited to the rapidly proliferating bulk population of leukemic cells but extends to the LICs, whose inherent drug resistance and unrestricted self-renewal capacity has been implicated in the difficulty of curing AML patients with conventional chemotherapy alone.
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Hidrazinas/farmacologia , Carioferinas/antagonistas & inibidores , Leucemia Mieloide Aguda/tratamento farmacológico , Células-Tronco Neoplásicas/efeitos dos fármacos , Receptores Citoplasmáticos e Nucleares/antagonistas & inibidores , Triazóis/farmacologia , Animais , Humanos , Terapia de Imunossupressão , Leucemia Mieloide Aguda/patologia , Camundongos , Ensaios Antitumorais Modelo de Xenoenxerto , Proteína Exportina 1RESUMO
Previous studies have demonstrated that a number of biochemical actions of ceramide are mediated through protein kinase signalling pathways, such as p42/p44 mitogen-activated protein kinase (p42/p44 MAPK) and c-Jun N-terminal directed protein kinase (JNK). Ceramide-activated protein kinases, such as the kinase suppressor of Ras (KSR) and protein kinase Czeta (PKCzeta), are involved in the regulation of c-Raf, which promotes sequential activation of MEK-1 and p42/p44 MAPK in mammalian cells. However, in cultured airway smooth muscle (ASM) cells, neither KSR nor PKCzeta are involved in the C2-ceramide (C2-Cer)-dependent activation of this kinase cascade. Instead, we found that C2-Cer utilises a novel pathway involving tyrosine kinases, phosphoinositide 3-kinase (PI3K) and conventional PKC isoform(s). We also found that despite its ability to stimulate p42/p44 MAPK, C2-Cer inhibited platelet-derived growth factor (PDGF)-stimulated DNA synthesis. The possibility that growth arrest could be mediated by JNK was discounted on the basis that PDGF, as well as ceramide, stimulated JNK in these cells. Therefore, growth arrest in response to ceramide is mediated by an alternative mechanism.