1,026 research outputs found

    The Association of Ambient Air Pollution With Cataract Surgery in UK Biobank Participants: Prospective Cohort Study

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    Purpose: Air pollution is associated with chronic diseases of later life. Cataract is the most common cause of blindess globally. It is biologically plausible that cataract risk is increased by pollution exposure. Therefore, the relationship between air pollution and incident cataract surgery was examined. Methods: This was a prospective, observational study involving 433,727 UK Biobank participants. Ambient air pollution measures included particulates, nitrogen dioxide (NO2) and nitrogen oxides (NOx). Outdoor air pollution was estimated based on land use regression models. Participants undergoing cataract surgery in either eye were ascertained via data linkage to the National Health Service procedure statistics. Those undergoing cataract surgery within 1 year of baseline assessment and those reporting cataract at baseline were excluded. Cox proportional hazards models were used to examine the associations between air pollutants and incident cataract surgery, adjusting for sociodemographic and lifestyle factors. Results: There were 16,307 incident cases of cataract surgery. Higher exposure to PM2.5 was associated with a 5% increased risk of incident cataract surgery (per interquartile range [IQR] increase). Compared to the lowest quartile, participants with exposures to PM2.5, NO2, and NOx in the highest quartile were 14%, 11%, and 9% more likely to undergo cataract surgery, respectively. A continuous exposure-response relationship was observed, with the likelihood of undergoing cataract surgery being progressively higher with greater levels of PM2.5, NO2, and NOx (P for trend P < 0.001). Conclusions: Although the results of our study showed a 5% increased risk of future cataract surgery following an exposure to PM2.5, NO2, and NOx, the effect estimates were relatively small. Further research is required to determine if the associations identified are causal

    Being young in a changing world: how temperature and salinity changes interactively modify the performance of larval stages of the barnacle Amphibalanus improvisus

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    The fate of key species, such as the barnacle Amphibalanus improvisus, in the course of global change is of particular interest since any change in their abundance and/or performance may entail community-wide effects. In the fluctuating Western Baltic, species typically experience a broad range of environmental conditions, which may preselect them to better cope with climate change. In this study, we examined the sensitivity of two crucial ontogenetic phases (naupliar, cypris) of the barnacle toward a range of temperature (12, 20, and 28°C) and salinity (5, 15, and 30 psu) combinations. Under all salinity treatments, nauplii developed faster at intermediate and high temperatures. Cyprid metamorphosis success, in contrast, was interactively impacted by temperature and salinity. Survival of nauplii decreased with increasing salinity under all temperature treatments. Highest settlement rates occurred at the intermediate temperature and salinity combination, i.e., 20°C and 15 psu. Settlement success of “naive” cyprids, i.e., when nauplii were raised in the absence of stress (20°C/15 psu), was less impacted by stressful temperature/salinity combinations than that of cyprids with a stress history. Here, settlement success was highest at 30 psu particularly at low and high temperatures. Surprisingly, larval survival was not highest under the conditions typical for the Kiel Fjord at the season of peak settlement (20°C/15 psu). The proportion of nauplii that ultimately transformed to attached juveniles was, however, highest under these “home” conditions. Overall, only particularly stressful combinations of temperature and salinity substantially reduced larval performance and development. Given more time for adaptation, the relatively smooth climate shifts predicted will probably not dramatically affect this species

    Paternal effect on genomic activation, clinical pregnancy and live birth rate after ICSI with cryopreserved epididymal versus testicular spermatozoa

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    <p>Abstract</p> <p>Background</p> <p>This study takes an in depth look at embryonic development, implantation, pregnancy and live birth rates with frozen epididymal and testicular sperm from obstructed (OA) and non-obstructed (NOA) patients.</p> <p>Methods</p> <p>Paternal effect of sperm source on zygote formation, embryonic cleavage, and genomic activation were examined. Additional outcome parameters monitored were clinical pregnancy rate (CPR), implantation rate (IR) and live birth rate.</p> <p>Results</p> <p>In this report, we retrospectively analyzed 156 ICSI cycles using cryopreserved epididymal sperm (ES; n = 77) or testicular sperm (TESE; n = 79). The developmental potential of embryos did not appear to be influenced by the type of surgically retrieved sperm. The average number of blastomeres observed on Day 3 was not different among different groups; 7.5 +/- 1.7 (ES), 7.6 +/- 2.1 (TESE-OA) and 6.5 +/- 2.3 (TESE-NOA). Compaction and blastulation rates, both indicators of paternal genomic activation, were similar in embryos derived from ICSI with ES or TESE from OA as well as NOA men. The only parameter significantly affected in NOA-TESE cases was the fertilization rate. CPR and IR with cryopreserved TESE (TESE-OA 59%, 34%, and TESE-NOA 37%, 20%) were also not statistically different, from that achieved with cryopreserved ES (61% and 39%). Live birth rates also appeared to be independent of sperm type. The 87 clinical pregnancies established using cryopreserved TESE and ES, resulted in the birth of 115 healthy infants. No congenital anomalies were noted.</p> <p>Conclusion</p> <p>Zygotic activation seems to be independent of sperm origin and type of azoospermia.</p

    On the relationship between the reversed hazard rate and elasticity

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    Despite hazard and reversed hazard rates sharing a number of similar aspects, reversed hazard functions are far less frequently used. Understanding their meaning is not a simple task. The aim of this paper is to expand the usefulness of the reversed hazard function by relating it to other well-known concepts broadly used in economics: (linear or cumulative) rates of increase and elasticity. This will make it possible (i) to improve our understanding of the consequences of using a particular distribution and, in certain cases, (ii) to introduce our hypotheses and knowledge about the random process in a more meaningful and intuitive way, thus providing a means to achieving distributions that would otherwise be hardly imaginable or justifiable

    Study circles improve the precision in nutritional care in special accommodations

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    Background: Disease-related malnutrition is a major health problem in the elderly population, but it has until recently received very little attention, especially are management issues under-explored. By identifying residents at the risk of undernutrition, appropriate nutritional care can be provided. Objectives: Do study circles and policy documents improve the precision in nutritional care and decrease the prevalence of low or high BMI? Design: Pre and post intervention study. Setting: Special accommodations (nursing homes) within six municipalities were involved. Participants: In 2005, 1726 (90.4%) out of 1910 residents agreed to participate and in 2007, 1526 (81.8%) out of 1866 residents participated. Intervention: Study circles in one municipality, having a policy document in one municipality and no intervention in four municipalities. Measurements: Risk of undernutrition was defined as involving any of: involuntary weight loss, low BMI, and/or eating difficulties. Overweight was defined as high BMI. Results: In 2005 and 2007, 64% of 1726 and 66% of 1526 residents respectively were at the risk of undernutrition. In 2007 significantly more patients in the study circle municipality were accurately provided protein and energy enriched food compared to in the no intervention municipalities. There was a decrease in the prevalence of low BMI in the study circle municipality and the prevalence of overweight increased in the policy document municipality between 2005 and 2007

    Retinal tissue engineering using mouse retinal progenitor cells and a novel biodegradable, thin-film poly(e-caprolactone) nanowire scaffold

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    Retinal progenitor cells (RPCs) can be combined with nanostructured polymer scaffolds to generate composite grafts in culture. One strategy for repair of diseased retinal tissue involves implantation of composite grafts of this type in the subretinal space. In the present study, mouse retinal progenitor cells (RPCs) were cultured on laminin-coated novel nanowire poly(e-caprolactone)(PCL) scaffolds, and the survival, differentiation, and migration of these cells into the retina of C57bl/6 and rhodospsin −/− mouse retinal explants and transplant recipients were analyzed. RPCs were cultured on smooth PCL and both short (2.5 μm) and long (27 μm) nanowire PCL scaffolds. Scaffolds with adherent mRPCs were then either co-cultured with, or transplanted to, wild-type and rhodopsin −/− mouse retina. Robust RPC proliferation on each type of PCL scaffold was observed. Immunohistochemistry revealed that RPCs cultured on nanowire scaffolds increased expression of mature bipolar and photoreceptor markers. Reverse transcription polymerase chain reaction revealed down-regulation of several early progenitor markers. PCL-delivered RPCs migrated into the retina of both wild-type and rhodopsin knockout mice. The results provide evidence that RPCs proliferate and express mature retinal proteins in response to interactions with nanowire scaffolds. These composite grafts allow for the migration and differentiation of new cells into normal and degenerated retina

    The prevalence of BRCA1 mutations among young women with triple-negative breast cancer

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    <p>Abstract</p> <p>Background</p> <p>Molecular screening for BRCA1 and BRCA2 mutations is now an established component of risk evaluation and management of familial breast cancer. Features of hereditary breast cancer include an early age-of-onset and over-representation of the 'triple-negative' phenotype (negative for estrogen-receptor, progesterone-receptor and HER2). The decision to offer genetic testing to a breast cancer patient is usually based on her family history, but in the absence of a family history of cancer, some women may qualify for testing based on the age-of-onset and/or the pathologic features of the breast cancer.</p> <p>Methods</p> <p>We studied 54 women who were diagnosed with high-grade, triple-negative invasive breast cancer at or before age 40. These women were selected for study because they had little or no family history of breast or ovarian cancer and they did not qualify for genetic testing using conventional family history criteria. BRCA1 screening was performed using a combination of fluorescent multiplexed-PCR analysis, BRCA1 exon-13 6 kb duplication screening, the protein truncation test (PTT) and fluorescent multiplexed denaturing gradient gel electrophoresis (DGGE). All coding exons of BRCA1 were screened. The two large exons of BRCA2 were also screened using PTT. All mutations were confirmed with direct sequencing.</p> <p>Results</p> <p>Five deleterious BRCA1 mutations and one deleterious BRCA2 mutation were identified in the 54 patients with early-onset, triple-negative breast cancer (11%).</p> <p>Conclusion</p> <p>Women with early-onset triple-negative breast cancer are candidates for genetic testing for BRCA1, even in the absence of a family history of breast or ovarian cancer.</p

    Under- and Over-Nutrition Among Refugees in San Diego County, California

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    Resettled refugees often arrive in their host country with little knowledge of nutrition or available food choices. We explored nutrition-related issues of recent refugee arrivals to San Diego County—the second largest California resettlement site. In-depth interviews (n = 40) were conducted with refugees, health care practitioners, and refugee service organizations. Content analysis identified nutrition-related themes. Unhealthy weight gain after arrival was the most common concern and was attributed to social pressures among adolescents, food choices and a more sedentary lifestyle. Conversely, undernutrition remained a concern due to poor diets. Factors influencing nutritional problems included continuation of past habits, acculturation, unfamiliarity with available foods and socio-economic influences. The nutritional concerns encountered by resettled refugees in San Diego are not unique to this group but are aggravated by their past experiences, and abrupt changes to food choices and behavior. Addressing contextual factors of poor food choices may prevent some of the long term health consequences of poor nutrition
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