118 research outputs found

    Anti-angiogenesis: making the tumor vulnerable to the immune system

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    Ongoing angiogenesis has been shown to possess immune suppressive activity through several mechanisms. One of these mechanisms is the suppression of adhesion receptors, such as intercellular adhesion molecule-1, vascular cell adhesion molecule-1 and E-selectin—adhesion molecules involved in leukocyte interactions—on the vascular endothelium. This phenomenon, when happening to the tumor endothelium, supports tumor growth due to escape from immunity. Since angiogenesis has this immune suppressive effect, it has been hypothesized that inhibition of angiogenesis may circumvent this problem. In vitro and in vivo data now show that several angiogenesis inhibitors are able to normalize endothelial adhesion molecule expression in tumor blood vessels, restore leukocyte vessel wall interactions, and enhance the inflammatory infiltrate in tumors. It is suggested that such angiogenesis inhibitors can make tumors more vulnerable for the immune system and may therefore be applied to facilitate immunotherapy approaches for the treatment of cancer

    Is there a U-shaped association between physical activity and falling in older persons?

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    Summary: This study tests whether the relationship between physical activity and (recurrent) falling is U-shaped. Among 1,337 community-dwelling older persons, no evidence for a nonlinear association was found. If all older persons increase their physical activity level with 100 units, 4% may be prevented to become recurrent fallers. Introduction: Previous studies suggest a U-shaped relationship between physical activity and falling. This study tests this hypothesis and examines whether this relationship is modified by level of physical functioning. Methods: Community-dwelling persons (65+) from the Longitudinal Aging Study Amsterdam (LASA) were prospectively followed on falls for 3 years after baseline assessment in 1995/1996 (n=1,337). Outcome measures were time to first fall and time to recurrent falling. The LASA Physical Activity Questionnaire was used to calculate physical activity in minutes per day weighted for intensity (range 0-2000). Physical functioning was measured with physical performance tests and self reported functional limitations. Confounders were age, sex, body mass index, chronic diseases, psychotropic medication, cognitive functioning, depressive symptoms, and fear of falling. Results: No evidence for a nonlinear association was found (p for physical activity > 0.20). No significant association was found between physical activity and time to first fall. An increase in physical activity of 100 units led to a 4% decrease in risk of recurrent falling (adjusted hazard ratio 0.96, 95% confidence interval 0.92, 0.99). No interactions with physical performance or functional limitations were found (p>0.50). Conclusions: The hypothesized U-shaped relationship between physical activity and falling could not be confirmed. At higher levels of physical activity, the risk of recurrent falling decreased, while no association was found with fall risk

    The effect of Tai Chi Chuan in reducing falls among elderly people: design of a randomized clinical trial in the Netherlands [ISRCTN98840266]

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    BACKGROUND: Falls are a significant public health problem. Thirty to fifty percent of the elderly of 65 years and older fall each year. Falls are the most common type of accident in this age group and can result in fractures and subsequent disabilities, increased fear of falling, social isolation, decreased mobility, and even an increased mortality. Several forms of exercise have been associated with a reduced risk of falling and with a wide range of physiological as well as psychosocial health benefits. Tai Chi Chuan seems to be the most promising form of exercise in the elderly, but the evidence is still controversial. In this article the design of a randomized clinical trial is presented. The trial evaluates the effect of Tai Chi Chuan on fall prevention and physical and psychological function in older adults. METHODS/DESIGN: 270 people of seventy years and older living at home will be identified in the files of the participating general practitioners. People will be asked to participate when meeting the following inclusion criteria: have experienced a fall in the preceding year or suffer from two of the following risk factors: disturbed balance, mobility problems, dizziness, or the use of benzodiazepines or diuretics. People will be randomly allocated to either the Tai Chi Chuan group (13 weeks, twice a week) or the no treatment control group. The primary outcome measure is the number of new falls, measured with a diary. The secondary outcome measures are balance, fear of falling, blood pressure, heart rate, lung function parameters, physical activity, functional status, quality of life, mental health, use of walking devices, medication, use of health care services, adjustments to the house, severity of fall incidents and subsequent injuries. Process parameters will be measured to evaluate the Tai Chi Chuan intervention. A cost-effectiveness analysis will be carried out alongside the evaluation of the clinical results. Follow-up measurements will be collected at 3, 6 and 12 months after randomization. DISCUSSION: As far as we know this is the first trial in Europe considering Tai Chi Chuan and fall prevention. This project will answer a pragmatic research question regarding the efficacy of Tai Chi Chuan regarding fall reduction

    Genome-Wide Survey and Expression Profiling of CCCH-Zinc Finger Family Reveals a Functional Module in Macrophage Activation

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    Previously, we have identified a novel CCCH zinc finger protein family as negative regulators of macrophage activation. To gain an overall insight into the entire CCCH zinc finger gene family and to evaluate their potential role in macrophage activation, here we performed a genome-wide survey of CCCH zinc finger genes in mouse and human. Totally 58 CCCH zinc finger genes in mouse and 55 in human were identified and most of them have not been reported previously. Phylogenetic analysis revealed that the mouse CCCH family was divided into 6 groups. Meanwhile, we employed quantitative real-time PCR to profile their tissue expression patterns in adult mice. Clustering analysis showed that most of CCCH genes were broadly expressed in all of tissues examined with various levels. Interestingly, several CCCH genes Mbnl3, Zfp36l2, Zfp36, Zc3h12a, Zc3h12d, Zc3h7a and Leng9 were enriched in macrophage-related organs such as thymus, spleen, lung, intestine and adipose. Consistently, a comprehensive assessment of changes in expression of the 58 members of the mouse CCCH family during macrophage activation also revealed that these CCCH zinc finger genes were associated with the activation of bone marrow-derived macrophages by lipopolysaccharide. Taken together, this study not only identified a functional module of CCCH zinc finger genes in the regulation of macrophage activation but also provided the framework for future studies to dissect the function of this emerging gene family

    Teachers' ideas versus experts' descriptions of 'the good teacher' in postgraduate medical education: implications for implementation. A qualitative study

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    Contains fulltext : 96394.pdf (publisher's version ) (Open Access)BACKGROUND: When innovations are introduced in medical education, teachers often have to adapt to a new concept of what being a good teacher includes. These new concepts do not necessarily match medical teachers' own, often strong beliefs about what it means to be a good teacher.Recently, a new competency-based description of the good teacher was developed and introduced in all the Departments of Postgraduate Medical Education for Family Physicians in the Netherlands. We compared the views reflected in the new description with the views of teachers who were required to adopt the new framework. METHODS: Qualitative study. We interviewed teachers in two Departments of Postgraduate Medical Education for Family Physicians in the Netherlands. The transcripts of the interviews were analysed independently by two researchers, who coded and categorised relevant fragments until consensus was reached on six themes. We investigated to what extent these themes matched the new description. RESULTS: Comparing the teachers' views with the concepts described in the new competency-based framework is like looking into two mirrors that reflect clearly dissimilar images. At least two of the themes we found are important in relation to the implementation of new educational methods: the teachers' identification and organisational culture. The latter plays an important role in the development of teachers' ideas about good teaching. CONCLUSIONS: The main finding of this study is the key role played by the teachers' feelings regarding their professional identity and by the local teaching culture in shaping teachers' views and expectations regarding their work. This suggests that in implementing a new teaching framework and in faculty development programmes, careful attention should be paid to teachers' existing identification model and the culture that fostered it

    Detecting referral and selection bias by the anonymous linkage of practice, hospital and clinic data using Secure and Private Record Linkage (SAPREL): case study from the evaluation of the Improved Access to Psychological Therapy (IAPT) service

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    Background: The evaluation of demonstration sites set up to provide improved access to psychological therapies (IAPT) comprised the study of all people identified as having common mental health problems (CMHP), those referred to the IAPT service, and a sample of attenders studied in-depth. Information technology makes it feasible to link practice, hospital and IAPT clinic data to evaluate the representativeness of these samples. However, researchers do not have permission to browse and link these data without the patients’ consent. Objective: To demonstrate the use of a mixed deterministic-probabilistic method of secure and private record linkage (SAPREL) - to describe selection bias in subjects chosen for in-depth evaluation. Method: We extracted, pseudonymised and used fuzzy logic to link multiple health records without the researcher knowing the patient’s identity. The method can be characterised as a three party protocol mainly using deterministic algorithms with dynamic linking strategies; though incorporating some elements of probabilistic linkage. Within the data providers’ safe haven we extracted: Demographic data, hospital utilisation and IAPT clinic data; converted post code to index of multiple deprivation (IMD); and identified people with CMHP. We contrasted the age, gender, ethnicity and IMD for the in-depth evaluation sample with people referred to IAPT, use hospital services, and the population as a whole. Results: The in IAPT-in-depth group had a mean age of 43.1 years; CI: 41.0 - 45.2 (n = 166); the IAPT-referred 40.2 years; CI: 39.4 - 40.9 (n = 1118); and those with CMHP 43.6 years SEM 0.15. (n = 12210). Whilst around 67% of those with a CMHP were women, compared to 70% of those referred to IAPT, and 75% of those subject to indepth evaluation (Chi square p< 0.001). The mean IMD score for the in-depth evaluation group was 36.6; CI: 34.2 - 38.9; (n = 166); of those referred to IAPT 38.7; CI: 37.9 - 39.6; (n = 1117); and of people with CMHP 37.6; CI 37.3- 37.9; (n = 12143). Conclusions: The sample studied in-depth were older, more likely female, and less deprived than people with CMHP, and fewer had recorded ethnic minority status. Anonymous linkage using SAPREL provides insight into the representativeness of a study population and possible adjustment for selection bias

    Serum potassium levels and outcome in acute heart failure (Data from the PROTECT and COACH Trials)

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    Serum potassium is routinely measured at admission for acute heart failure (AHF), but information on association with clinical variables and prognosis is limited. Potassium measurements at admission were available in 1,867 patients with AHF in the original cohort of 2,033 patients included in the Patients Hospitalized with acute heart failure and Volume Overload to Assess Treatment Effect on Congestion and Renal FuncTion trial. Patients were grouped according to low potassium ( 5.0 mEq/l) levels. Results were veri fi ed in a validation cohort of 1,023 patients. Mean age of patients was 71 – 11 years, and 66% were men. Low potassium was present in 115 patients (6%), normal potassium in 1,576 (84%), and high potassium in 176 (9%). Potassium levels increased during hospitalization (0.18 – 0.69 mEq/l). Patients with high potassium more often used angiotensin-converting enzyme inhibitors and mineralo- corticoid receptor antagonists before admission, had impaired baseline renal function and a better diuretic response (p [ 0.005), independent of mineralocorticoid receptor antagonist usage. During 180-day follow-up, a total of 330 patients (18%) died. Potassium levels at admission showed a univariate linear association with mortality (hazard ratio [log] 2.36, 95% con fi dence interval 1.07 to 5.23; p [ 0.034) but not after multivariate adjustment. Changes of potassium levels during hospitalization or potassium levels at discharge were not associated with outcome after multivariate analysis. Results in the validation cohort were similar to the index cohort. In conclusion, high potassium levels at admission are associated with an impaired renal function but a better diuretic response. Changes in po- tassium levels are common, and overall levels increase during hospitalization. In conclu- sion, potassium levels at admission or its change during hospitalization are not associated with mortality after multivariate adjustment

    Evidence for association between the HLA-DQA locus and abdominal aortic aneurysms in the Belgian population: a case control study

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    BACKGROUND: Chronic inflammation and autoimmunity likely contribute to the pathogenesis of abdominal aortic aneurysms (AAAs). The aim of this study was to investigate the role of autoimmunity in the etiology of AAAs using a genetic association study approach with HLA polymorphisms. METHODS: HLA-DQA1, -DQB1, -DRB1 and -DRB3-5 alleles were determined in 387 AAA cases (180 Belgian and 207 Canadian) and 426 controls (269 Belgian and 157 Canadian) by a PCR and single-strand oligonucleotide probe hybridization assay. RESULTS: We observed a potential association with the HLA-DQA1 locus among Belgian males (empirical p = 0.027, asymptotic p = 0.071). Specifically, there was a significant difference in the HLA-DQA1*0102 allele frequencies between AAA cases (67/322 alleles, 20.8%) and controls (44/356 alleles, 12.4%) in Belgian males (empirical p = 0.019, asymptotic p = 0.003). In haplotype analyses, marginally significant association was found between AAA and haplotype HLA-DQA1-DRB1 (p = 0.049 with global score statistics and p = 0.002 with haplotype-specific score statistics). CONCLUSION: This study showed potential evidence that the HLA-DQA1 locus harbors a genetic risk factor for AAAs suggesting that autoimmunity plays a role in the pathogenesis of AAAs

    The PARAChute project: remote monitoring of posture and gait for fall prevention

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    Falls in the elderly are a major public health problem due to both their frequency and their medical and social consequences. In France alone, more than two million people aged over 65 years old fall each year, leading to more than 9 000 deaths, in particular in those over 75 years old (more than 8 000 deaths). This paper describes the PARAChute project, which aims to develop a methodology that will enable the detection of an increased risk of falling in community-dwelling elderly. The methods used for a remote noninvasive assessment for static and dynamic balance assessments and gait analysis are described. The final result of the project has been the development of an algorithm for movement detection during gait and a balance signature extracted from a force plate. A multicentre longitudinal evaluation of balance has commenced in order to validate the methodologies and technologies developed in the project
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