249 resultados para age-related macular degeneration


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Heart rate (HR) has been widely studied as a measure of an individual's response to painful stimuli. It remains unclear whether changes in mean HR or the variability of HR are specifically related to the noxious stimulus (i.e. pain). Neither is it well understood how such changes reflect underlying neurologic control mechanisms that produce these responses, or how these mechanisms change during the first year of life. To study the changes in cardiac autonomic modulation that occur with acute pain and with age during early infancy, the relationship between respiratory activity and short-term variations of HR (i.e. respiratory sinus arrhythmia) was quantified in a longitudinal study of term born healthy infants who underwent a finger lance blood collection at 4 months of age (n = 24) and again at 8 months of age (n = 20). Quantitative respiratory activity and HR were obtained during baseline, lance, and recovery periods. Time and frequency domain analyses from 2.2-min epochs of data yielded mean values, spectral measures of low (0.04-0.15 Hz) and high (0.15-0.80 Hz) frequency power (LF and HF), and the LF/HF ratio. To determine sympathetic and parasympathetic cardiac activity, the transfer relation between respiration and HR was used. At both 4 and 8 months, mean HR increased significantly with the noxious event (p > 0.01). There were age-related differences in the pattern of LF, HF, and LF/HF ratio changes. Although these parameters all decreased (p > 0.01) at 4 months, LF and LF/HF increased at 8 months and at 8 months HF remained stable in response to the noxious stimulus. Transfer gain changes with the lance demonstrated a change from predominant vagal baseline to a sympathetic condition at both ages. The primary finding of this study is that a response to an acute noxious stimulus appears to produce an increase in respiratory-related sympathetic HR control and a significant decrease in respiratory-related parasympathetic control at both 4 and 8 months. Furthermore, with increasing age, the sympathetic and parasympathetic changes appear to be less intense, but more sustained.

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Age-related changes in the facial expression of pain during the first 18 months of life have important implications for our understanding of pain and pain assessment. We examined facial reactions video recorded during routine immunization injections in 75 infants stratified into 2-, 4-, 6-, 12-, and 18-month age groups. Two facial coding systems differing in the amount of detail extracted were applied to the records. In addition, parents completed a brief questionnaire that assessed child temperament and provided background information. Parents' efforts to soothe the children also were described. While there were consistencies in facial displays over the age groups, there also were differences on both measures of facial activity, indicating systematic variation in the nature and severity of distress. The least pain was expressed by the 4-month age group. Temperament was not related to the degree of pain expressed. Systematic variations in parental soothing behaviour indicated accommodation to the age of the child. Reasons for the differing patterns of facial activity are examined, with attention paid to the development of inhibitory mechanisms and the role of negative emotions such as anger and anxiety.

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Collagen molecules in articular cartilage have an exceptionally long lifetime, which makes them susceptible to the accumulation of advanced glycation end products (AGEs). In fact, in comparison to other collagen-rich tissues, articular cartilage contains relatively high amounts of the AGE pentosidine. To test the hypothesis that this higher AGE accumulation is primarily the result of the slow turnover of cartilage collagen, AGE levels in cartilage and skin collagen were compared with the degree of racemization of aspartic acid (% d-Asp, a measure of the residence time of a protein). AGE (N(epsilon)-(carboxymethyl)lysine, N(epsilon)-(carboxyethyl)lysine, and pentosidine) and % d-Asp concentrations increased linearly with age in both cartilage and skin collagen (p <0.0001). The rate of increase in AGEs was greater in cartilage collagen than in skin collagen (p <0.0001). % d-Asp was also higher in cartilage collagen than in skin collagen (p <0.0001), indicating that cartilage collagen has a longer residence time in the tissue, and thus a slower turnover, than skin collagen. In both types of collagen, AGE concentrations increased linearly with % d-Asp (p <0.0005). Interestingly, the slopes of the curves of AGEs versus % d-Asp, i.e. the rates of accumulation of AGEs corrected for turnover, were identical for cartilage and skin collagen. The present study thus provides the first experimental evidence that protein turnover is a major determinant in AGE accumulation in different collagen types. From the age-related increases in % d-Asp the half-life of cartilage collagen was calculated to be 117 years and that of skin collagen 15 years, thereby providing the first reasonable estimates of the half-lives of these collagens.

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Chemical, nonenzymatic modification of protein and lipids by reducing sugars, such as glucose, is thought to contribute to age-related deterioration in tissue protein and cellular membranes and to the pathogenesis of diabetic complications. This report describes the synthesis and quantification of N-(glucitol)ethanolamine (GE) and N-(carboxymethyl)serine (CMS), two products of nonenzymatic modification of aminophospholipids. GE is the product of reduction and hydrolysis of glycated phosphatidylethanolamine (PE), while CMS is formed through reaction of phosphatidylserine (PS) with products of oxidation of either carbohydrate (glycoxidation) or lipids (lipoxidation). Gas chromatography/mass spectrometry procedures for quantification of the N,O-acetyl methyl ester derivatives of the modified head groups were developed. GE and CMS were quantified in samples of PE and PS, respectively, following incubation with glucose in vitro; CMS formation was dependent on the presence of oxygen during the incubation. Both GE and CMS were detected and quantified in lipid extracts of human red blood cell membranes. The content of GE, but not CMS, was increased in the lipids from diabetic compared to nondiabetic subjects. Measurement of these modified lipids should prove useful for assessing the role of carbonyl-amine reactions of aminophospholipids in aging and age-related diseases.

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Several studies have assessed changes in frequency of -174 interleukin (IL)-6 single nucleotide polymorphism (SNP) with age. If IL-6 tracks with disability and age-related diseases, then there should be reduction, in the oldest old, of the frequency of homozygous GG subjects, who produce higher IL-6 levels. However, discordant results have been obtained. To explore the relationship between this polymorphism and longevity, we analyzed individual data on long-living subjects and controls from eight case-control studies conducted in Europeans, using meta-analysis. There was no significant difference in the IL-6 genotype between the oldest old and controls (Odds Ratio [OR]=0.96; 95% C.I.: 0.77-1.20; p=0.71), but there was significant between-study heterogeneity (I2=55.5%). In a subgroup analyses when male centenarians from the three Italian studies were included, the frequency of the IL-6 -174 GG genotype was significantly lower than the other genotypes (OR=0.49; 95% C.I.: 0.31-0.80; p=0.004), with no evidence of heterogeneity (I2=0%). Our data supports a negative association between the GG genotype of IL-6 SNP and longevity in Italian centenarians, with males who carry the genotype being two times less likely to reach extreme old age compared with subjects carrying CC or CG genotypes. These findings were not replicated in other European groups suggesting a possible interaction between genetics, sex and environment in reaching longevity.

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Purpose: To evaluate the clinical and histological side effects of a prototype stereotactic radiotherapy system delivering microcollimated external beam radiation through pars plana in porcine eyes.

Methods: Five Yucatan mini-swine (10 eyes) were randomized to five treatment groups. Eight eyes were dosed with X-ray radiation on Day 1, and two eyes served as untreated controls. Treated eyes received doses up to 60 Gy to the retina and up to 130 Gy to the sclera using single or overlapping beams. The treatment beams were highly collimated such that the diameter was approximately 2.5 mm on the sclera and 3 mm on the retinal surface. Fundus photography, fluorescein angiography (FA), and spectral domain optical coherence tomography (SD-OCT) were obtained on days 7, 30, 60, and 110. Images were examined by a masked grader and evaluated for abnormalities. Animals were sacrificed on day 111 and gross and histopathological analysis was conducted.

Results: Histological and gross changes to eye structures including conjunctiva and lens were minimal at all doses. Fundus, FA, and SD-OCT of the targeted region failed to disclose any abnormality in the control or 21 Gy treated animals. In the 42 and 60 Gy animals, hypopigmented spots were noted after treatment on clinical exam, and corresponding hyperfluorescent staining was seen in late frames. No evidence of choroidal hypoperfusion was seen. The histological specimens from the 60 Gy animals showed photoreceptor loss and displacement of cone nuclei.

Conclusion: Transcleral stereotactic radiation dosing in porcine eyes can be accomplished with no significant adverse events as doses less than 42 Gy.

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Background:There are wide international differences in 1-year cancer survival. The UK and Denmark perform poorly compared with other high-income countries with similar health care systems: Australia, Canada and Sweden have good cancer survival rates, Norway intermediate survival rates. The objective of this study was to examine the pattern of differences in cancer awareness and beliefs across these countries to identify where these might contribute to the pattern of survival.Methods:We carried out a population-based telephone interview survey of 19 079 men and women aged =50 years in Australia, Canada, Denmark, Norway, Sweden and the UK using the Awareness and Beliefs about Cancer measure.Results:Awareness that the risk of cancer increased with age was lower in the UK (14%), Canada (13%) and Australia (16%) but was higher in Denmark (25%), Norway (29%) and Sweden (38%). Symptom awareness was no lower in the UK and Denmark than other countries. Perceived barriers to symptomatic presentation were highest in the UK, in particular being worried about wasting the doctor's time (UK 34%; Canada 21%; Australia 14%; Denmark 12%; Norway 11%; Sweden 9%).Conclusion:The UK had low awareness of age-related risk and the highest perceived barriers to symptomatic presentation, but symptom awareness in the UK did not differ from other countries. Denmark had higher awareness of age-related risk and few perceived barriers to symptomatic presentation. This suggests that other factors must be involved in explaining Denmark's poor survival rates. In the UK, interventions that address barriers to prompt presentation in primary care should be developed and evaluated. © 2013 Cancer Research UK. All rights reserved.

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Whilst data recognise both myeloid cell accumulation during choroidal neovascularisation (CNV) as well as complement activation, none of the data has presented a clear explanation for the angiogenic drive that promotes pathological angiogenesis. One possibility that is a pre-eminent drive is a specific and early conditioning and activation of the myeloid cell infiltrate. Using a laser-induced CNV murine model, we have identified that disruption of retinal pigment epithelium (RPE) and Bruch's membrane resulted in an early recruitment of macrophages derived from monocytes and microglia, prior to angiogenesis and contemporaneous with lesional complement activation. Early recruited CD11b(+) cells expressed a definitive gene signature of selective inflammatory mediators particularly a pronounced Arg-1 expression. Accumulating macrophages from retina and peripheral blood were activated at the site of injury, displaying enhanced VEGF expression, and notably prior to exaggerated VEGF expression from RPE, or earliest stages of angiogenesis. All of these initial events, including distinct VEGF (+) Arg-1(+) myeloid cells, subsided when CNV was established and at the time RPE-VEGF expression was maximal. Depletion of inflammatory CCR2-positive monocytes confirmed origin of infiltrating monocyte Arg-1 expression, as following depletion Arg-1 signal was lost and CNV suppressed. Furthermore, our in vitro data supported a myeloid cell uptake of damaged RPE or its derivatives as a mechanism generating VEGF (+) Arg-1(+) phenotype in vivo. Our results reveal a potential early driver initiating angiogenesis via myeloid-derived VEGF drive following uptake of damaged RPE and deliver an explanation of why CNV develops during any of the stages of macular degeneration and can be explored further for therapeutic gain.

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Healthcare systems worldwide are facing an unprecedented demographic change as globally, the number of older people will triple to 2 billion by the year 2050. The resulting pressures on acute services have been instrumental in the development of intermediate care (IC) as a new healthcare model, which has its origins in the National Health Service in the UK. IC is an umbrella term for patient services that do not require the resources of a general hospital but are beyond the scope of a traditional primary care team. IC aims to promote timely discharge from hospital, prevent unnecessary hospital admissions and reduce the need for long-term residential care by optimizing functional independence. Various healthcare providers around the world have adopted similar models of care to manage changing healthcare needs. Polypharmacy, along with age-related changes, places older people at an increased risk of adverse drug events, including inappropriate prescribing, which has been shown to be prevalent in this population in other healthcare settings. Medicines management (the practice of maximizing health through optimal use of medicines) of older people has been discussed in the literature in a variety of settings; however, its place within IC is largely unknown. Despite IC being a multidisciplinary healthcare model, there is a lack of evidence to suggest that enhanced pharmaceutical involvement is core to the service provided within IC. This review article highlights the gap in the literature surrounding medicines management within IC and identifies potential solutions aimed at improving patient outcomes in this setting.

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To determine potential benefits of intensive leisure sports for age-related changes in postural control, we tested 3 activity groups comprising 70 young (M = 21.67 years, SD = 2.80) and 73 older (M = 62.60 years, SD = 5.19) men. Activity groups were martial artists, who held at least 1st Dan (black belt), sportive individuals exercising sports without explicit balance components, and nonsportive controls. Martial artists had an advantage over sportive individuals in dynamic posture tasks (upright stance on a sway-referenced platform), and these 2 active groups showed better postural control than nonsportive participants. Age-related differences in postural control were larger in nonsportive men compared with the 2 active groups, who were similar in this respect. In contrast, negative age differences in other sensorimotor and cognitive functions did not differ between activity groups. We concluded that individuals engaging in intensive recreational sports have long-term advantages in postural control. However, even in older martial artists with years of practice in their sports, we observed considerable differences favoring the young. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

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Although the past two decades have seen concrete attempts to reduce ethnic and racial prejudice, relatively little has been done to diminish age related prejudice. In this paper, we review intergenerational contact interventions have been applied in a real world setting, the results are mixed. While contact interventions are not a panacea, they do constitute a main plank in efforts to redress ageism. We, therefore, examine the types of interventions that are effective, the processes underlying their enhanced impact, and clarifying when and how intergenerational contact can predict more positive attitudes towards the elderly. Finally, we highlight ways in which findings might be applied to the development of more effective interventions aimed at combating a pervasive stereotype of aging, drawing out lessons for theory and implications for practice.

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Few research papers in economics have examined the extent, causes or consequences of physical stature decline in aging populations. Using repeated observations on objectively measured data from the English Longitudinal Study of Ageing (ELSA), we document that reduction in height is an important phenomenon among respondents aged 50 and over. On average, physical stature decline occurs at an annual rate of between 0.08% and 0.10% for males, and 0.12% and 0.14% for females—which approximately translates into a 2cm to 4cm reduction in height over the life course. Since height is commonly used as a measure of long-run health, our results demonstrate that failing to take age-related height loss into account substantially overstates the health advantage of younger birth cohorts relative to their older counterparts. We also show that there is an absence of consistent predictors of physical stature decline at the individual level. However, we demonstrate how deteriorating health and reductions in height occur simultaneously. We document that declines in muscle mass and bone density are likely to be the mechanism through which these effects are operating. If this physical stature decline is determined by deteriorating health in adulthood, the coefficient on measured height when used as an input in a typical empirical health production function will be affected by reverse causality. While our analysis details the inherent difficulties associated with measuring height in older populations, we do not find that significant bias arises in typical empirical health production functions from the use of height which has not been adjusted for physical stature decline. Therefore, our results validate the use of height among the population aged over 50.

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Time features in two key ways in cognition, each of which is discussed in turn in this chapter: time is processed as a dimension of stimuli or events, and time is represented as a framework in which events can be located. Section 1 examines the first of these from a developmental perspective, by reviewing research on age-related changes in the accuracy of duration processing. The Piagetian approach linked changes in duration processing to the development of a concept of time as a dimension of events separable from other event dimensions. This is contrasted with recent research conducted within the framework of Scalar Expectancy Theory, which models development in terms of changes in components of specialized timing mechanisms. Section 2 discusses developmental changes in the temporal frameworks that children use to represent the locations of events. Although as adults, we represent times as locations on a linear framework stretching from the past, to the present, and into the future, this way of representing time is not developmentally basic. A model is proposed of developmental stages in the acquisition of a mature temporal framework. The chapter concludes by considering two themes that cut across Section 1 and 2: the issue of whether there are both qualitative and quantitative change in children’s temporal abilities, and the link between temporal and spatial cognition.

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Aging results in deterioration of the immune system, which is associated with increased susceptibility to infection and impaired wound healing in the elderly. Phagocytosis is an essential process in both wound healing and immune defence. As such, age-related impairments in phagocytosis impact on the health of the elderly population. Phagocytic efficiency in peritoneal macrophages, bone marrow-derived macrophages and bone marrow monocytes from young and old mice was investigated. Aging significantly impaired phagocytosis by peritoneal macrophages, both in vitro and in vivo. However, bone marrow-derived macrophages and bone marrow monocytes did not exhibit age-related impairments in phagocytosis, suggesting no intrinsic defect in these cells. We sought to investigate underlying mechanisms in age-related impairments in phagocytosis by peritoneal macrophages. We hypothesized that microenvironmental factors in the peritoneum of old mice impaired macrophage phagocytosis. Indeed, macrophages from young mice injected into the peritoneum of old mice exhibited impaired phagocytosis. Proportions of peritoneal immune cells were characterized, and striking increases in numbers of T cells, B1 and B2 cells were observed in the peritoneum of old mice compared with young mice. In addition, B cell-derived IL-10 was increased in resting and LPS-activated peritoneal cell cultures from old mice. These data demonstrate that aging impairs phagocytosis by tissue-resident peritoneal macrophages, but not by bone marrow-derived macrophages/monocytes, and suggest that age-related defects in macrophage phagocytosis may be due to extrinsic factors in the tissue microenvironment. As such, defects may be reversible and macrophages could be targeted therapeutically in order to boost immune function in the elderly.