939 research outputs found

    17β-Estradiol responsiveness of MCF-7 laboratory strains is dependent on an autocrine signal activating the IGF type I receptor

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    BACKGROUND: Human MCF-7 cells have been studied extensively as a model for breast cancer cell growth. Many reports have established that serum-starved MCF-7 cells can be induced to proliferate upon the sole addition of 17β-estradiol (E2). However, the extent of the mitogenic response to E2 varies in different MCF-7 strains and may even be absent. In this study we compared the E2-sensitivity of three MCF-7 laboratory strains. RESULTS: The MCF-7S line is non-responsive to E2, the MCF-7 ATCC has an intermediate response to E2, while the MCF-7 NKI is highly E2-sensitive, although the levels and activities of the estrogen receptor (ER) are not significantly different. Both suramin and IGF type I receptor blocking antibodies are able to inhibit the mitogenic response to E2-treatment in MCF-7 ATCC and MCF-7 NKI cells. From this we conclude that E2-induced proliferation is dependent on IGF type I receptor activation in all three MCF-7 strains. CONCLUSIONS: The results presented in this article suggest that E2-responsiveness of MCF-7 cells is dependent on the secretion of an autocrine factor activating the IGF-IR. All three strains of MCF-7 breast cancer cells investigated do not respond to E2 if the IGF-RI-pathway is blocked. Generally, breast cancer therapy is targeted at inhibiting estrogen action. This study suggests that inhibition of IGF-action in combination with anti-estrogen-treatment may provide a more effective way in treatment or even prevention of breast cancer

    Prophylactic non-steroidal anti-inflammatory drugs for the prevention of macular oedema after cataract surgery.

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    BACKGROUND: Macular oedema (MO) is the accumulation of extracellular fluid in the central retina (the macula). It may occur after cataract surgery and may give rise to poor visual outcome, with reduced visual acuity and distortion of the central vision. MO is often self-limiting with spontaneous resolution, but a small proportion of people with chronic persistent MO may be difficult to treat. Chronic oedema may lead to the formation of cystic spaces in the retina termed 'cystoid macular oedema' (CMO). Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used in cataract surgery and may reduce the chances of developing MO. OBJECTIVES: The aim of this review is to answer the question: is there evidence to support the prophylactic use of topical NSAIDs either in addition to, or instead of, topical steroids postoperatively to reduce the incidence of macular oedema (MO) and associated visual morbidity. SEARCH METHODS: We searched a number of electronic databases including CENTRAL, MEDLINE and Embase. Date last searched 2 September 2016. SELECTION CRITERIA: We included randomised controlled trials (RCTs) in which adult participants had undergone surgery for age-related cataract. We included participants irrespective of their baseline risk of MO, in particular we included people with diabetes and uveitis. We included trials of preoperative and/or postoperative topical NSAIDs in conjunction with postoperative topical steroids. The comparator was postoperative topical steroids alone. A secondary comparison was preoperative and/or postoperative topical NSAIDs alone versus postoperative topical steroids alone. DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies for inclusion, assessed risk of bias and extracted data using standard methods expected by Cochrane. We pooled data using a random-effects model. We graded the certainty of the evidence using GRADE and considered the following: risk of bias of included studies, precision of the effect estimate, consistency of effects between studies, directness of the outcome measure and publication bias. MAIN RESULTS: We identified 34 studies that were conducted in the Americas, Europe, the Eastern Mediterranean region and South-East Asia. Over 5000 people were randomised in these trials. The majority of studies enrolled one eye per participant; a small subset (4 trials) enrolled a proportion of people with bilateral surgery. Twenty-eight studies compared NSAIDs plus steroids with steroids alone. Six studies compared NSAIDs with steroids. A variety of NSAIDs were used, including ketorolac, diclofenac, nepafenac, indomethacin, bromfenac, flurbiprofen and pranopfen. Follow-up ranged from one to 12 months. In general, the studies were poorly reported. We did not judge any of the studies at low risk of bias in all domains. Six studies were funded by industry, seven studies were funded from non-industry sources, and the rest of the studies did not report the source of funding.There was low-certainty evidence that people receiving topical NSAIDs in combination with steroids may have a lower risk of poor vision due to MO at three months after cataract surgery compared with people receiving steroids alone (risk ratio (RR) 0.41, 95% confidence interval (CI) 0.23 to 0.76; eyes = 1360; studies = 5; I2 = 5%). We judged this to be low-certainty evidence because of risk of bias in the included studies and indirectness, as the extent of visual loss was not always clear. Only one study reported poor vision due to MO at 12 months and we judged this to be very low-certainty evidence as there were only two events. Quality of life was only reported in one of the 34 studies comparing NSAIDs plus steroids versus steroids alone, and it was not fully reported, other than to comment on lack of differences between groups. There was evidence of a reduced risk of MO with NSAIDs at three months after surgery, but we judged this to be low-certainty due to risk of bias and publication bias (RR 0.40, 95% CI 0.32 to 0.49; eyes = 3638; studies = 21). There was inconsistent evidence on central retinal thickness at three months (I2 = 87%). Results ranged from -30.9 µm in favour of NSAIDs plus steroids to 7.44 µm in favour of steroids alone. Similarly, data on best corrected visual acuity (BCVA) were inconsistent, but nine out of 10 trials reporting this outcome found between-group differences in visual acuity of less than 0.1 logMAR.None of the six studies comparing NSAIDs alone with steroids reported on poor vision due to MO at three or 12 months. There was low-certainty evidence that central retinal thickness was lower in the NSAIDs group at three months (mean difference (MD) -22.64 µm, 95% CI -38.86 to -6.43; eyes = 121; studies = 2). Five studies reported on MO and showed a reduced risk with NSAIDs, but we judged this evidence to be of low-certainty (RR 0.27, 95% CI 0.18 to 0.41; eyes = 520). Three studies reported BCVA at three months and the results of these trials were inconsistent, but all three studies found differences of less than 0.1 logMAR between groups.We did not note any major adverse events - the main consistent observation was burning or stinging sensation with the use of NSAIDs. AUTHORS' CONCLUSIONS: Using topical NSAIDs may reduce the risk of developing macular oedema after cataract surgery, although it is possible that current estimates as to the size of this reduction are exaggerated. It is unclear the extent to which this reduction has an impact on the visual function and quality of life of patients. There is little evidence to suggest any important effect on vision after surgery. The value of adding topical NSAIDs to steroids, or using them as an alternative to topical steroids, with a view to reducing the risk of poor visual outcome after cataract surgery is therefore uncertain. Future trials should address the remaining clinical uncertainty of whether prophylactic topical NSAIDs are of benefit, particularly with respect to longer-term follow-up (at least to 12 months), and should be large enough to detect reduction in the risk of the outcome of most interest to patients, which is chronic macular oedema leading to visual loss

    Trajectories of self-rated health in people with diabetes: Associations with functioning in a prospective community sample

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    © 2013 Schmitz et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Background: Self-rated health (SRH) is a single-item measure that is one of the most widely used measures of general health in population health research. Relatively little is known about changes and the trajectories of SRH in people with chronic medical conditions. The aims of the present study were to identify and describe longitudinal trajectories of self-rated health (SRH) status in people with diabetes. Methods: A prospective community study was carried out between 2008 and 2011. SRH was assessed at baseline and yearly at follow-ups (n=1288). Analysis was carried out through trajectory modeling. The trajectory groups were subsequently compared at 4 years follow-up with respect to functioning. Results: Four distinct trajectories of SRH were identified: 1) 72.2% of the participants were assigned to a persistently good SRH trajectory; 2) 10.1% were assigned to a persistently poor SRH trajectory; 3) mean SRH scores changed from good to poor for one group (7.3%); while 4) mean SRH scores changed from poor to medium/good for another group (10.4%). Those with a persistently poor perception of health status were at higher risk for poor functioning at 4 years follow-up than those whose SRH scores decreased from good to poor. Conclusions: SRH is an important predictor for poor functioning in diabetes, but the trajectory of SRH seems to be even more important. Health professionals should pay attention to not only SRH per se, but also changes in SRH over time.This work was supported by Operating Grant MOP-84574 from the Canadian Institutes of Health Research (CIHR). GG was supported by a doctoral fellowship from the CIHR. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Optimizing the colour and fabric of targets for the control of the tsetse fly Glossina fuscipes fuscipes

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    Background: Most cases of human African trypanosomiasis (HAT) start with a bite from one of the subspecies of Glossina fuscipes. Tsetse use a range of olfactory and visual stimuli to locate their hosts and this response can be exploited to lure tsetse to insecticide-treated targets thereby reducing transmission. To provide a rational basis for cost-effective designs of target, we undertook studies to identify the optimal target colour. Methodology/Principal Findings: On the Chamaunga islands of Lake Victoria , Kenya, studies were made of the numbers of G. fuscipes fuscipes attracted to targets consisting of a panel (25 cm square) of various coloured fabrics flanked by a panel (also 25 cm square) of fine black netting. Both panels were covered with an electrocuting grid to catch tsetse as they contacted the target. The reflectances of the 37 different-coloured cloth panels utilised in the study were measured spectrophotometrically. Catch was positively correlated with percentage reflectance at the blue (460 nm) wavelength and negatively correlated with reflectance at UV (360 nm) and green (520 nm) wavelengths. The best target was subjectively blue, with percentage reflectances of 3%, 29%, and 20% at 360 nm, 460 nm and 520 nm respectively. The worst target was also, subjectively, blue, but with high reflectances at UV (35% reflectance at 360 nm) wavelengths as well as blue (36% reflectance at 460 nm); the best low UV-reflecting blue caught 3× more tsetse than the high UV-reflecting blue. Conclusions/Significance: Insecticide-treated targets to control G. f. fuscipes should be blue with low reflectance in both the UV and green bands of the spectrum. Targets that are subjectively blue will perform poorly if they also reflect UV strongly. The selection of fabrics for targets should be guided by spectral analysis of the cloth across both the spectrum visible to humans and the UV region

    Low pH immobilizes and kills human leukocytes and prevents transmission of cell-associated HIV in a mouse model

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    BACKGROUND: Both cell-associated and cell-free HIV virions are present in semen and cervical secretions of HIV-infected individuals. Thus, topical microbicides may need to inactivate both cell-associated and cell-free HIV to prevent sexual transmission of HIV/AIDS. To determine if the mild acidity of the healthy vagina and acid buffering microbicides would prevent transmission by HIV-infected leukocytes, we measured the effect of pH on leukocyte motility, viability and intracellular pH and tested the ability of an acidic buffering microbicide (BufferGel(®)) to prevent the transmission of cell-associated HIV in a HuPBL-SCID mouse model. METHODS: Human lymphocyte, monocyte, and macrophage motilities were measured as a function of time and pH using various acidifying agents. Lymphocyte and macrophage motilities were measured using video microscopy. Monocyte motility was measured using video microscopy and chemotactic chambers. Peripheral blood mononuclear cell (PBMC) viability and intracellular pH were determined as a function of time and pH using fluorescent dyes. HuPBL-SCID mice were pretreated with BufferGel, saline, or a control gel and challenged with HIV-1-infected human PBMCs. RESULTS: Progressive motility was completely abolished in all cell types between pH 5.5 and 6.0. Concomitantly, at and below pH 5.5, the intracellular pH of PBMCs dropped precipitously to match the extracellular medium and did not recover. After acidification with hydrochloric acid to pH 4.5 for 60 min, although completely immotile, 58% of PBMCs excluded ethidium homodimer-1 (dead-cell dye). In contrast, when acidified to this pH with BufferGel, a microbicide designed to maintain vaginal acidity in the presence of semen, only 4% excluded dye at 10 min and none excluded dye after 30 min. BufferGel significantly reduced transmission of HIV-1 in HuPBL-SCID mice (1 of 12 infected) compared to saline (12 of 12 infected) and a control gel (5 of 7 infected). CONCLUSION: These results suggest that physiologic or microbicide-induced acid immobilization and killing of infected white blood cells may be effective in preventing sexual transmission of cell-associated HIV

    Sparse, interpretable and transparent predictive model identification for healthcare data analysis

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    Data-driven modelling approaches play an indispensable role in analyzing and understanding complex processes. This study proposes a type of sparse, interpretable and transparent (SIT) machine learning model, which can be used to understand the dependent relationship of a response variable on a set of potential explanatory variables. An ideal candidate for such a SIT representation is the well-known NARMAX (nonlinear autoregressive moving average with exogenous inputs) model, which can be established from measured input and output data of the system of interest, and the final refined model is usually simple, parsimonious and easy to interpret. The performance of the proposed SIT models is evaluated through two real healthcare datasets

    Experiences along the diagnostic pathway for patients with advanced lung cancer in the USA: a qualitative study.

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    BACKGROUND: Most patients with lung cancer are diagnosed at advanced stages. However, the advent of oral targeted therapies has improved the prognosis of many patients with lung cancer. PURPOSE: We aimed to understand the diagnostic experiences of patients with advanced lung cancer with oncogenic mutations. METHODS: Qualitative interviews were conducted with patients with advanced or metastatic non-small cell lung cancer with oncogenic alterations. Patients were recruited from online support groups within the USA. Interviews were conducted remotely or in person. Analysis used an iterative inductive and deductive process. Themes were mapped to the Model for Pathways to Treatment. RESULTS: 40 patients (12 male and 28 female) with a median age of 48 were included. We identified nine distinct themes. During the 'patient interval', individuals became concerned about symptoms, but often attributed them to other causes. Prolonged or more severe symptoms prompted care-seeking. During the 'primary care interval', doctors initially treated for illnesses other than cancer. Discovery of an imaging abnormality was a turning point in diagnostic pathways. Occasionally, severity of symptoms prompted patients to seek emergency care. During the 'secondary care interval', obtaining tissue samples was pivotal in confirming diagnosis. Delays in accessing oncology care sometimes led to patient distress. Obtaining genetic testing was crucial in directing patients to receive targeted treatments. CONCLUSIONS: Patients experienced multiple different routes to their diagnosis. Some patients perceived delays, inefficiencies and lack of coordination, which could be distressing. Shifting the stage of diagnosis of lung cancer to optimise the impact of targeted therapies will require concerted efforts in early detection

    Ischaemic strokes in patients with pulmonary arteriovenous malformations and hereditary hemorrhagic telangiectasia: associations with iron deficiency and platelets.

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    <div><p>Background</p><p>Pulmonary first pass filtration of particles marginally exceeding ∼7 µm (the size of a red blood cell) is used routinely in diagnostics, and allows cellular aggregates forming or entering the circulation in the preceding cardiac cycle to lodge safely in pulmonary capillaries/arterioles. Pulmonary arteriovenous malformations compromise capillary bed filtration, and are commonly associated with ischaemic stroke. Cohorts with CT-scan evident malformations associated with the highest contrast echocardiographic shunt grades are known to be at higher stroke risk. Our goal was to identify within this broad grouping, which patients were at higher risk of stroke.</p><p>Methodology</p><p>497 consecutive patients with CT-proven pulmonary arteriovenous malformations due to hereditary haemorrhagic telangiectasia were studied. Relationships with radiologically-confirmed clinical ischaemic stroke were examined using logistic regression, receiver operating characteristic analyses, and platelet studies.</p><p>Principal Findings</p><p>Sixty-one individuals (12.3%) had acute, non-iatrogenic ischaemic clinical strokes at a median age of 52 (IQR 41–63) years. In crude and age-adjusted logistic regression, stroke risk was associated not with venous thromboemboli or conventional neurovascular risk factors, but with low serum iron (adjusted odds ratio 0.96 [95% confidence intervals 0.92, 1.00]), and more weakly with low oxygen saturations reflecting a larger right-to-left shunt (adjusted OR 0.96 [0.92, 1.01]). For the same pulmonary arteriovenous malformations, the stroke risk would approximately double with serum iron 6 µmol/L compared to mid-normal range (7–27 µmol/L). Platelet studies confirmed overlooked data that iron deficiency is associated with exuberant platelet aggregation to serotonin (5HT), correcting following iron treatment. By MANOVA, adjusting for participant and 5HT, iron or ferritin explained 14% of the variance in log-transformed aggregation-rate (p = 0.039/p = 0.021).</p><p>Significance</p><p>These data suggest that patients with compromised pulmonary capillary filtration due to pulmonary arteriovenous malformations are at increased risk of ischaemic stroke if they are iron deficient, and that mechanisms are likely to include enhanced aggregation of circulating platelets.</p></div
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