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1.
BMJ Open ; 13(12): e078703, 2023 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-38110374

RESUMO

OBJECTIVES: Aspirin could be offered for colorectal cancer prevention for the UK general population. To ensure the views of the general population are considered in future guidance, we explored public perceptions of aspirin for preventive therapy. DESIGN: We conducted an online survey to investigate aspirin use, and awareness of aspirin for cancer prevention among the UK general population. We conducted semistructured interviews with a subsample of survey respondents to explore participants' acceptability towards aspirin for cancer preventive therapy. We analysed the interview data using reflexive thematic analysis and mapped the themes onto the Theoretical Domains Framework, and the Necessity and Concerns Framework. SETTING: Online survey and remote interviews. PARTICIPANTS: We recruited 400 UK respondents aged 50-70 years through a market research company to the survey. We purposefully sampled, recruited and interviewed 20 survey respondents. RESULTS: In the survey, 19.0% (76/400) of respondents were aware that aspirin can be used to prevent cancer. Among those who had previously taken aspirin, 1.9% (4/216) had taken it for cancer prevention. The interviews generated three themes: (1) perceived necessity of aspirin; (2) concerns about side effects; and (3) preferred information sources. Participants with a personal or family history of cancer were more likely to perceive aspirin as necessary for cancer prevention. Concerns about taking aspirin at higher doses and its side effects, such as gastrointestinal bleeding, were common. Many described wanting guidance and advice on aspirin to be communicated from sources perceived as trustworthy, such as healthcare professionals. CONCLUSIONS: Among the general population, those with a personal or family history of cancer may be more receptive towards taking aspirin for preventive therapy. Future policies and campaigns recommending aspirin may be of particular interest to these groups. Multiple considerations about the benefits and risks of aspirin highlight the need to support informed decisions on the medication.


Assuntos
Aspirina , Neoplasias , Humanos , Aspirina/uso terapêutico , Pesquisa Qualitativa , Inquéritos e Questionários , Neoplasias/prevenção & controle , Neoplasias/tratamento farmacológico , Reino Unido
2.
Br J Gen Pract ; 73(729): e302-e309, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36997217

RESUMO

BACKGROUND: The National Institute for Health and Care Excellence (NICE) 2020 guidelines recommends aspirin for colorectal cancer prevention for people with Lynch syndrome. Strategies to change practice should be informed by understanding the factors influencing prescribing. AIM: To investigate the optimal type and level of information to communicate with GPs to increase willingness to prescribe aspirin. DESIGN AND SETTING: GPs in England and Wales (n = 672) were recruited to participate in an online survey with a 23 factorial design. GPs were randomised to one of eight vignettes describing a hypothetical patient with Lynch syndrome recommended to take aspirin by a clinical geneticist. METHOD: Across the vignettes, the presence or absence of three types of information was manipulated: 1) existence of NICE guidance; 2) results from the CAPP2 trial; 3) information comparing risks/benefits of aspirin. The main effects and all interactions on the primary (willingness to prescribe) and secondary outcomes (comfort discussing aspirin) were estimated. RESULTS: There were no statistically significant main effects or interactions of the three information components on willingness to prescribe aspirin or comfort discussing harms and benefits. In total, 80.4% (540/672) of GPs were willing to prescribe, with 19.7% (132/672) unwilling. GPs with prior awareness of aspirin for preventive therapy were more comfortable discussing the medication than those unaware (P = 0.031). CONCLUSION: It is unlikely that providing information on clinical guidance, trial results, and information comparing benefits and harms will increase aspirin prescribing for Lynch syndrome in primary care. Alternative multilevel strategies to support informed prescribing may be warranted.


Assuntos
Aspirina , Neoplasias Colorretais Hereditárias sem Polipose , Humanos , Aspirina/uso terapêutico , Neoplasias Colorretais Hereditárias sem Polipose/tratamento farmacológico , Neoplasias Colorretais Hereditárias sem Polipose/prevenção & controle , Inglaterra , Inquéritos e Questionários , Medição de Risco
3.
Hered Cancer Clin Pract ; 20(1): 30, 2022 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-35999639

RESUMO

BACKGROUND: The National Institute for Health and Care Excellence (NG151) recommends considering daily aspirin for people with Lynch syndrome to reduce colorectal cancer risk. However, deciding whether to initiate aspirin could be a complex decision for patients and their healthcare providers, as both the potential benefits and harms need to be considered. METHODS: We conducted semi-structured interviews to explore the barriers and facilitators to using aspirin for preventive therapy. We recruited 15 people with Lynch syndrome, and 23 healthcare providers across multiple professions in primary, and specialist care (e.g. clinical genetics) in the United Kingdom. Interview schedules were informed by the Theoretical Domains Framework. RESULTS: There were three themes: 1) Considering potential harms and benefits; 2) Healthcare pathway; 3) Patients' level of interest in aspirin. All healthcare providers, across primary and specialist care, viewed general practitioners (GPs) as being responsible for prescribing and overseeing the use of aspirin. However, GPs were unfamiliar with aspirin for preventive therapy, and concerned about prescribing at higher doses (300-600 mg). To support decision-making, GPs wanted clarification from specialist clinicians on the evidence and dose to prescribe. Not all participants with Lynch syndrome received information on aspirin from their healthcare provider, and several were unsure who to discuss aspirin with. GPs were more inclined to prescribe aspirin for patients with expressed preferences for the medication, however several patients were uncertain and wanted further guidance. CONCLUSIONS: Coordinated and multilevel strategies are needed, addressing the needs of both GPs and people with Lynch syndrome, to ensure consistent implementation of national guidance on aspirin for preventive therapy.

4.
Int J Clin Pract ; 2022: 5229702, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35693549

RESUMO

Objectives: Assessment of erectile dysfunction (ED) burden could improve health outcomes associated with underlying cardiometabolic and psychological causes of ED. This study provided updated real-world evidence (RWE) on ED epidemiology and quantified healthcare resource utilization (HCRU) and health-related quality of life (HRQoL) burden among men with ED in the UK. Methods: This cross-sectional, prospective real-world evidence study was conducted via a self-reported Internet survey in 2018 in the UK general population. Prevalence of ED was estimated; HCRU and HRQoL were compared between men with ED versus without ED via bivariate analysis. Results: Of 12,490 men included, 41.5% reported ED; 7.5% of men reported severe ED; ED was most prevalent in Wales (44.3%). Men with ED were older (54.1 ± 14.5 vs. 46.8 ± 14.1 years) and often reported modifiable lifestyle risk factors, including smoking (32.8% vs. 26.3%), drinking alcohol (76.1% vs. 71.0%), not exercising (21.7% vs. 19.4%), and being overweight or obese (64.9% vs. 54.6%). Additionally, men with ED more often reported ≥1 comorbid chronic conditions (73.7% vs. 47.7%), including hypertension (31.8% vs. 16.3%), hyperlipidemia (27.6% vs. 14.0%), depression (24.3% vs. 14.6%), anxiety (23.3% vs. 16.6%), and diabetes (15.9% vs. 6.1%) versus men without ED (all, p < 0.001). Nearly half of men with ED (45.3%) were not undergoing treatment for cardiometabolic or psychological comorbidities. Furthermore, men with ED more often reported ≥1 visit to physicians/nurse practitioners and pharmacists in the past year and had significantly lower SEAR total and domain scores than men without ED (all, p < 0.001). Conclusion: ED was highly prevalent in the UK affecting over a quarter of younger men. Cardiometabolic and psychological conditions were common among men with ED and often remained untreated. Higher proportions of modifiable lifestyle risk factors observed among men with ED present an opportunity for healthcare providers to help mitigate the risk of cardiometabolic diseases and incidence of ED.


Assuntos
Disfunção Erétil , Hipertensão , Estudos Transversais , Disfunção Erétil/epidemiologia , Disfunção Erétil/etiologia , Humanos , Hipertensão/complicações , Hipertensão/epidemiologia , Masculino , Prevalência , Estudos Prospectivos , Qualidade de Vida/psicologia , Fatores de Risco
5.
Prev Med ; 154: 106872, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34762964

RESUMO

We undertook a systematic review to synthesise the data on attitudes and behaviour towards the use of aspirin for cancer prevention, and healthcare providers' attitudes towards implementing aspirin in practice. Searches were carried out across 12 databases (e.g. MEDLINE, EMBASE). We used the Mixed Methods Appraisal Tool to evaluate study quality, and conducted a narrative synthesis of the data. The review was pre-registered (PROSPERO: CRD42018093453). Thirty-eight studies were identified. Uptake and adherence data were all from trials. Trials recruited healthy participants, those at higher risk of cancer, and those with cancer. Four studies reported moderate to high (40.9-77.7%) uptake to an aspirin trial among people who were eligible. Most trials (18/22) reported high day-to-day adherence (≥80%). Three trials observed no association between gender and adherence. One trial found no association between adherence and colorectal cancer risk. Three studies reported moderate to high (43.6-76.0%) hypothetical willingness to use aspirin. Two studies found that a high proportion of healthcare providers (72.0-76.0%) perceived aspirin to be a suitable cancer prevention option. No qualitative studies were identified. The likelihood that eligible users of aspirin would participate in a trial evaluating the use of aspirin for preventive therapy was moderate to high. Among participants in a trial, day-to-day adherence was high. Further research is needed to identify uptake and adherence rates in routine care, the factors affecting aspirin use, and the barriers to implementing aspirin into clinical care.


Assuntos
Aspirina , Neoplasias , Aspirina/uso terapêutico , Atitude do Pessoal de Saúde , Pessoal de Saúde , Humanos , Neoplasias/prevenção & controle
6.
Drug Discov Today ; 25(12): 2149-2160, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32920059

RESUMO

Drug discoveries can, when used appropriately, save lives. Since 1970, cancer death rates among people aged under 65 have halved in countries such as the USA and the UK. Despite pharmaceutical market imperfections and fears about the prices of new treatments, further progress should be possible during the 2020s. Anticancer medicine outlays account for 0.1-0.2% of the gross domestic product (GDP) of developed countries. Total cancer service spending typically stands at ∼0.8% of GDP. The affordability of these sums is a political calculation. Improvements in the efficiency of drug development and global access to effective therapies are desirable. However, from a public interest perspective, these goals should not be pursued in ways that understate the value of better treatment outcomes and threaten the funding available for ongoing innovation.


Assuntos
Antineoplásicos/economia , Descoberta de Drogas , Neoplasias/economia , Antineoplásicos/uso terapêutico , COVID-19 , Custos e Análise de Custo , Humanos , Neoplasias/terapia , Anos de Vida Ajustados por Qualidade de Vida , SARS-CoV-2
7.
Antibiotics (Basel) ; 9(4)2020 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-32340387

RESUMO

Antimicrobial resistance (AMR) is a major concern facing global health today, with the greatest impact in developing countries where the burden of infectious diseases is much higher. The inappropriate prescribing and use of antibiotics are contributory factors to increasing antibiotic resistance. Antimicrobial stewardship programmes (AMS) are implemented to optimise use and promote behavioural change in the use of antimicrobials. AMS programmes have been widely employed and proven to improve antibiotic use in many high-income settings. However, strategies to contain antimicrobial resistance have yet to be successfully implemented in low-resource settings. A recent toolkit for AMS in low- and middle-income countries by the World Health Organisation (WHO) recognizes the importance of local context in the development of AMS programmes. This study employed a bottom-up approach to identify important local determinants of antimicrobial prescribing practices in a low-middle income setting, to inform the development of a local AMS programme. Analysis of prescribing practices and interviews with prescribers highlighted priorities for AMS, which include increasing awareness of antibiotic resistance, development and maintenance of guidelines for antibiotic use, monitoring and surveillance of antibiotic use, ensuring the quality of low-cost generic medicines, and improved laboratory services. The application of an established theoretical model for behaviour change guided the development of specific proposals for AMS. Finally, in a consultation with stakeholders, the feasibility of the plan was explored along with strategies for its implementation. This project provides an example of the design, and proposal for implementation of an AMS plan to improve antibiotic use in hospitals in low-middle income settings.

8.
Res Social Adm Pharm ; 15(5): 591-599, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30057329

RESUMO

Erectile dysfunction (ED), which worldwide is likely to affect in excess of 300 million men by 2025, is often either untreated or insufficiently treated. It can be a prelude to other serious illnesses and may be a cause or consequence of depression in affected individuals. Among men younger than 60 years of age, ED can be a robust early-stage indicator of vascular disease and type 2 diabetes. Untreated or inadequately treated ED can also be a sign of poor communication between health professionals and service users of all ages. Improved treatment of ED could cost-effectively prevent premature deaths and avoidable morbidity. The extension of community pharmacy‒based health care would enable more men living with ED to safely access effective medications, along with appropriate diagnostic services and support for beneficial lifestyle changes such as smoking cessation in conveniently accessible settings. The task of introducing improved methods of affordably addressing problems linked to ED exemplifies the strategic challenges now facing health care systems globally. Promoting professionally supported self-care in pharmacies has the potential to meet the needs of aging populations in progressively more effective ways.


Assuntos
Disfunção Erétil/tratamento farmacológico , Farmacêuticos/organização & administração , Papel Profissional , Doenças Cardiovasculares , Humanos , Masculino , Política Pública , Autocuidado
10.
ANZ J Surg ; 2018 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-29510462

RESUMO

BACKGROUND: Over one-third of primary rectal cancers are locally advanced at diagnosis, and local recurrence of rectal cancer occurs at a rate of 3-10% following primary curative resection. Extended resectional surgery, including pelvic exenteration, is the only proven therapy with curative potential in the treatment of these cancers along with many other pelvic malignancies. A microscopically clear resection margin (R0 resection) is the predominant prognostic factor affecting overall and disease-free survival. The extent and complexity of surgery required to achieve an R0 resection is associated with significant risk of morbidity and mortality. The aim of this paper is to show that pelvic exenterations can be performed with acceptable oncological and safe perioperative results in an appropriately resourced specialist centre. METHODS: Data was collected retrospectively for 61 consecutive patients treated between June 2012 and February 2017. This included patient demographics, tumour characteristics, operative, clinical and histological data, length of hospital stay, morbidity and mortality data. RESULTS: A total of 61 patients underwent surgery. Median age was 57 years (range 27-78 years). Median length of stay was 41 days (range 6-288 days). Median operative time was 624 min (range 239-1035 min); 30-day mortality was 3.3% (n = 2). Resection rates were 91.5% - R0, 6.8% - R1 and 1.7% - R2 resections. Histologically, 86.9% - adenocarcinomas, 3.3% - squamous cell carcinomas and 9.8% - represented by leiomyosarcoma, melanoma, myxoid chondrosarcoma, non-neoplastic processes and undifferentiated carcinoma. CONCLUSION: Our experience confirms that radical resectional pelvic surgery can be safely performed with acceptable results during the establishment phase of a dedicated tertiary service.

11.
Biochem Biophys Res Commun ; 495(4): 2547-2552, 2018 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-29288665

RESUMO

Mouse embryos that lack the ability to produce the adrenergic hormones, norepinephrine (NE) and epinephrine (EPI), due to disruption of the dopamine beta-hydroxylase (Dbh-/-) gene inevitably perish from heart failure during mid-gestation. Since adrenergic stimulation is well-known to enhance calcium signaling in developing as well as adult myocardium, and impairments in calcium signaling are typically associated with heart failure, we hypothesized that adrenergic-deficient embryonic hearts would display deficiencies in cardiac calcium signaling relative to adrenergic-competent controls at a developmental stage immediately preceding the onset of heart failure, which first appears beginning or shortly after mouse embryonic day 10.5 (E10.5). To test this hypothesis, we used ratiometric fluorescent calcium imaging techniques to measure cytosolic calcium transients, [Ca2+]i in isolated E10.5 mouse hearts. Our results show that spontaneous [Ca2+]i oscillations were intact and robustly responded to a variety of stimuli including extracellular calcium (5 mM), caffeine (5 mM), and NE (100 nM) in a manner that was indistinguishable from controls. Further, we show similar patterns of distribution (via immunofluorescent histochemical staining) and activity (via patch-clamp recording techniques) for the major voltage-gated plasma membrane calcium channel responsible for the L-type calcium current, ICa,L, in adrenergic-deficient and control embryonic cardiac cells. These results demonstrate that despite the absence of vital adrenergic hormones that consistently leads to embryonic lethality in vivo, intracellular and extracellular calcium signaling remain essentially intact and functional in embryonic mouse hearts through E10.5. These findings suggest that adrenergic stimulation is not required for the development of intracellular calcium oscillations or extracellular calcium signaling through ICa,L and that aberrant calcium signaling does not likely contribute to the onset of heart failure in this model.


Assuntos
Adrenérgicos/metabolismo , Sinalização do Cálcio/fisiologia , Cálcio/metabolismo , Epinefrina/metabolismo , Coração/embriologia , Miocárdio/metabolismo , Norepinefrina/metabolismo , Animais , Camundongos , Camundongos Knockout
12.
Lancet Oncol ; 15(6): e205-12, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24731885

RESUMO

Cancer can have profound social and economic consequences for people in India, often leading to family impoverishment and societal inequity. Reported age-adjusted incidence rates for cancer are still quite low in the demographically young country. Slightly more than 1 million new cases of cancer are diagnosed every year in a population of 1.2 billion. In age-adjusted terms this represents a combined male and female incidence of about a quarter of that recorded in western Europe. However, an estimated 600,000-700,000 deaths in India were caused by cancer in 2012. In age-standardised terms this figure is close to the mortality burden seen in high-income countries. Such figures are partly indicative of low rates of early-stage detection and poor treatment outcomes. Many cancer cases in India are associated with tobacco use, infections, and other avoidable causes. Social factors, especially inequalities, are major determinants of India's cancer burden, with poorer people more likely to die from cancer before the age of 70 years than those who are more affluent. In this first of three papers, we examine the complex epidemiology of cancer, the future burden, and the dominant sociopolitical themes relating to cancer in India.


Assuntos
Neoplasias/epidemiologia , Distribuição por Idade , Efeitos Psicossociais da Doença , Feminino , Humanos , Índia/epidemiologia , Masculino , Neoplasias/etiologia , Distribuição por Sexo , Fatores Socioeconômicos
14.
Prim Health Care Res Dev ; 14(2): 164-74, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23031628

RESUMO

AIM: This study aims to evaluate changes in the durations of English National Health Service prescriptions, as indicated by the volumes of unit doses supplied between 1998 and 2009, and consider relevant policy implications. BACKGROUND: Around the world, countries are seeking to manage the increase in medicines prescribing. In England, many primary care organisations, using limited supporting evidence of cost-effectiveness and clinical improvement, have sought to restrict the number of dosage units on a prescription to 28 days supply. This is based on a conviction that this reduces wastage costs. METHODS: Prescription Cost Analysis (PCA) statistics for England for the period January 1998 to December 2009 were used to analyse trends in the average number of unit doses (tablets or capsules) supplied per prescription for 11 drugs supplied in 34 different presentations. FINDINGS: The changes in prescription lengths observed between 1999 and 2009 ranged from +4.2% in the case of Amoxicillin 500 mg capsules to -41.3% in the case of Levothyroxine 50 µg tablets. All but four of the medicines selected showed statistically significant negative correlations (r > 0.8, P < 0.001) between the year of prescribing and the prescription length. If prescription lengths had been the same in 2009 as they were in 1999, then 33 million fewer prescription items would have been written for the preparations in this analysis. This shift across a range of medications suggests a generalised change in prescribing behaviour. The full balance of benefits and costs associated with this trend, as expressed via drug wastage avoided, patient (in)convenience experienced, professional time costs incurred or saved and positive or negative health outcome impacts, is not known. Although this study does not provide a definitive answer favouring prescription duration individualisation as opposed to standardisation, the available evidence indicates that policies that rigidly favour 28-day standard periods may require review.


Assuntos
Custos de Medicamentos/tendências , Política de Saúde/tendências , Medicamentos sob Prescrição/provisão & distribuição , Atenção Primária à Saúde/normas , Medicina Estatal/tendências , Doença Crônica , Custos de Medicamentos/estatística & dados numéricos , Inglaterra , Política de Saúde/economia , Humanos , Modelos Lineares , Padrões de Prática Médica/tendências , Medicamentos sob Prescrição/economia , Atenção Primária à Saúde/tendências , Medicina Estatal/economia , Medicina Estatal/estatística & dados numéricos
15.
Biochem Biophys Res Commun ; 423(3): 536-41, 2012 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-22683331

RESUMO

To determine if adrenergic hormones play a critical role in the functional development of the cardiac pacemaking and conduction system, we employed a mouse model where adrenergic hormone production was blocked due to targeted disruption of the dopamine ß-hydroxylase (Dbh) gene. Immunofluorescent histochemical evaluation of the major gap junction protein, connexin 43, revealed that its expression was substantially decreased in adrenergic-deficient (Dbh-/-) relative to adrenergic-competent (Dbh+/+ and Dbh+/-) mouse hearts at embryonic day 10.5 (E10.5), whereas pacemaker and structural protein staining appeared similar. To evaluate cardiac electrical conduction in these hearts, we cultured them on microelectrode arrays (8×8, 200 µm apart). Our results show a significant slowing of atrioventricular conduction in adrenergic-deficient hearts compared to controls (31.4±6.4 vs. 15.4±1.7 ms, respectively, p<0.05). To determine if the absence of adrenergic hormones affected heart rate and rhythm, mouse hearts from adrenergic-competent and deficient embryos were cultured ex vivo at E10.5, and heart rates were measured before and after challenge with the ß-adrenergic receptor agonist, isoproterenol (0.5 µM). On average, all hearts showed increased heart rate responses following isoproterenol challenge, but a significant (p<0.05) 225% increase in the arrhythmic index (AI) was observed only in adrenergic-deficient hearts. These results show that adrenergic hormones may influence heart development by stimulating connexin 43 expression, facilitating atrioventricular conduction, and helping to maintain cardiac rhythm during a critical phase of embryonic development.


Assuntos
Arritmias Cardíacas/embriologia , Arritmias Cardíacas/genética , Dopamina beta-Hidroxilase/genética , Condutividade Elétrica , Coração/embriologia , Coração/fisiopatologia , Animais , Conexina 43/biossíntese , Canais de Cátion Regulados por Nucleotídeos Cíclicos/metabolismo , Embrião de Mamíferos/enzimologia , Embrião de Mamíferos/fisiopatologia , Frequência Cardíaca Fetal/genética , Frequência Cardíaca Fetal/fisiologia , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização , Camundongos , Camundongos Knockout
16.
Methods Mol Biol ; 843: 329-38, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22222542

RESUMO

The study of the embryonic development of the cardiac conduction system and its congenital and toxicological defects requires protocols to measure electrical conduction through the myocardium. However, available methods either lack spatial information, necessitate the hearts to be sliced and mounted, or require specialized equipment. Microelectrode arrays (MEAs) are plates with embedded surface electrodes to measure localized extracellular ionic currents (field potentials) created by the depolarization and repolarization of cultured cells and tissue slices. Here we describe a protocol using MEAs to examine electrical conduction through intact and beating cultured hearts isolated from mouse embryos at 10.5 days postcoitus. This method allows measurements of conduction time, estimates of conduction velocity, atrioventricular conduction delay and block, and heart rate and rhythmicity.


Assuntos
Condutividade Elétrica , Espaço Extracelular , Coração/embriologia , Coração/fisiologia , Microeletrodos , Animais , Camundongos , Fatores de Tempo
17.
Endocrinol Metab Clin North Am ; 39(3): 499-512, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20723816

RESUMO

This article reviews economic methodologies developed for estimating cost of illness, examines the current literature on diabetes costs, and presents the latest estimates of the economic impact of type 1 diabetes in terms of direct medical costs (ie, treatment costs) and indirect costs (eg, lost wages).


Assuntos
Diabetes Mellitus Tipo 1/economia , Efeitos Psicossociais da Doença , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/terapia , Custos de Cuidados de Saúde , Humanos
18.
Stem Cells Dev ; 19(9): 1437-48, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20109065

RESUMO

Stem cell therapies offer the potential for repair and regeneration of cardiac tissue. To facilitate evaluation of stem cell activity in vivo, we created novel dual-reporter mouse embryonic stem (mES) cell lines that express the firefly luciferase (LUC) reporter gene under the control of the cardiac sodium-calcium exchanger-1 (Ncx-1) promoter in the background of the 7AC5-EYFP mES cell line that constitutively expresses the enhanced yellow fluorescent protein (EYFP). We compared the ability of recombinant clonal cell lines to express LUC before and after induction of cardiac differentiation in vitro. In particular, one of the clonal cell lines (Ncx-1-43LUC mES cells) showed markedly enhanced LUC expression (45-fold increase) upon induction of cardiac differentiation in vitro. Further, cardiac differentiation in these cells was perpetuated over a period of 2-4 weeks after transplantation in a neonatal mouse heart model, as monitored by noninvasive bioluminescence imaging (BLI) and confirmed via postmortem immunofluorescence and histological assessments. In contrast, transplantation of undifferentiated pluripotent Ncx-1-43LUC mES cells in neonatal hearts did not result in detectable levels of cardiac differentiation in these cells in vivo. These results suggest that prior induction of cardiac differentiation in vitro enhances development and maintenance of a cardiomyocyte-like phenotype for mES cells following transplantation into neonatal mouse hearts in vivo. We conclude that the Ncx-1-43LUC mES cell line is a novel tool for monitoring early cardiac differentiation in vivo using noninvasive BLI.


Assuntos
Diferenciação Celular , Genes Reporter , Imagem Molecular/métodos , Miócitos Cardíacos/fisiologia , Células-Tronco/fisiologia , Engenharia Tecidual/métodos , Animais , Animais Recém-Nascidos , Diferenciação Celular/fisiologia , Linhagem Celular , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Células-Tronco Embrionárias/transplante , Genes Reporter/fisiologia , Coração/crescimento & desenvolvimento , Luciferases de Vaga-Lume/genética , Luciferases de Vaga-Lume/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Modelos Biológicos , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/ultraestrutura , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/metabolismo , Células-Tronco Pluripotentes/transplante , Trocador de Sódio e Cálcio/genética , Trocador de Sódio e Cálcio/metabolismo , Células-Tronco/metabolismo
19.
J Biol Chem ; 285(9): 6811-25, 2010 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-20038578

RESUMO

The Notch signaling pathway plays an essential role in the regulation of cell specification by controlling differentiation, proliferation, and apoptosis. Numb is an intrinsic regulator of the Notch pathway and exists in four alternative splice variants that differ in the length of their phosphotyrosine-binding domain (PTB) and proline-rich region domains. The physiological relevance of the existence of the Numb splice variants and their exact regulation are still poorly understood. We previously reported that Numb switches from isoforms containing the insertion in PTB to isoforms lacking this insertion in neuronal cells subjected to trophic factor withdrawal (TFW). The functional relevance of the TFW-induced switch in Numb isoforms is not known. Here we provide evidence that the TFW-induced switch in Numb isoforms regulates Notch signaling strength and Notch target gene expression. PC12 cells stably overexpressing Numb isoforms lacking the PTB insertion exhibited higher basal Notch activity and Notch-dependent transcription of the transient receptor potential channel 6 (TRPC6) when compared with those overexpressing Numb isoforms with the PTB insertion. The differential regulation of TRPC6 expression is correlated with perturbed calcium signaling and increased neuronal vulnerability to TFW-induced death. Pharmacological inhibition of the Notch pathway or knockdown of TRPC6 function ameliorates the adverse effects caused by the TFW-induced switch in Numb isoforms. Taken together, our results indicate that Notch and Numb interaction may influence the sensitivity of neuronal cells to injurious stimuli by modulating calcium-dependent apoptotic signaling cascades.


Assuntos
Proteínas de Membrana/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Receptores Notch/metabolismo , Canais de Cátion TRPC/genética , Animais , Sinalização do Cálcio , Morte Celular , Humanos , Neurônios/metabolismo , Células PC12 , Isoformas de Proteínas , Ratos , Transdução de Sinais , Estresse Fisiológico , Regulação para Cima/genética
20.
Can J Physiol Pharmacol ; 87(1): 69-75, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19142218

RESUMO

The sarcoplasmic reticular Ca2+ pump (SERCA) is thought to be the primary determinant of heart rate-dependent increases in myocardial contractile [Ca2+]i and force (force-frequency relationship (FFR)), an important mechanism to increase cardiac output. This report demonstrates a rate-dependent role for inward Ca2+ current (ICa) in the human and rat FFR. Human action potential plateau height increased linearly with contractility when heart rate increased in vivo, as measured by monophasic action potential catheter and echocardiography. Rat rate-dependent developed force and cytosolic [Ca2+]i transients were quantified in isolated left ventricular papillary muscles, and ICa and action potential duration in cardiomyocytes. ICa and SERCA measurements better reflected [Ca2+]i and force transients than SERCA activity alone. These data support a direct and (or) indirect contribution to myocardial contractility by ICa at heart rates from approximately 1 to 3-4 Hz (60 to 180-240 bpm) in tandem with SERCA to sustain the typical 'bell shape' of the FFR across species.


Assuntos
Canais de Cálcio/fisiologia , Frequência Cardíaca/fisiologia , Contração Miocárdica , Potenciais de Ação , Adulto , Animais , Cálcio/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ratos , Ratos Endogâmicos WKY , Retículo Sarcoplasmático/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/fisiologia
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