| 1. |
- Böhm, Johann, et al.
(författare)
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Mutation spectrum in the large GTPase dynamin 2, and genotype-phenotype correlation in autosomal dominant centronuclear myopathy.
- 2012
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Ingår i: Human mutation. - : Hindawi Limited. - 1098-1004 .- 1059-7794. ; 33:6, s. 949-59
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Tidskriftsartikel (refereegranskat)abstract
- Centronuclear myopathy (CNM) is a genetically heterogeneous disorder associated with general skeletal muscle weakness, type I fiber predominance and atrophy, and abnormally centralized nuclei. Autosomal dominant CNM is due to mutations in the large GTPase dynamin 2 (DNM2), a mechanochemical enzyme regulating cytoskeleton and membrane trafficking in cells. To date, 40 families with CNM-related DNM2 mutations have been described, and here we report 60 additional families encompassing a broad genotypic and phenotypic spectrum. In total, 18 different mutations are reported in 100 families and our cohort harbors nine known and four new mutations, including the first splice-site mutation. Genotype-phenotype correlation hypotheses are drawn from the published and new data, and allow an efficient screening strategy for molecular diagnosis. In addition to CNM, dissimilar DNM2 mutations are associated with Charcot-Marie-Tooth (CMT) peripheral neuropathy (CMTD1B and CMT2M), suggesting a tissue-specific impact of the mutations. In this study, we discuss the possible clinical overlap of CNM and CMT, and the biological significance of the respective mutations based on the known functions of dynamin 2 and its protein structure. Defects in membrane trafficking due to DNM2 mutations potentially represent a common pathological mechanism in CNM and CMT.
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| 2. |
- Crowe, Jennifer, et al.
(författare)
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A pilot field evaluation on heat stress in sugarcane workers in Costa Rica : what to do next?
- 2009
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Ingår i: Global Health Action. - : Co-action publishing. - 1654-9716 .- 1654-9880. ; 2, s. 71-80
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Climate change is producing major impacts including increasing temperatures in tropical countries, like Costa Rica, where the sugarcane industry employs thousands of workers who are exposed to extreme heat.OBJECTIVES: This article outlines a pilot qualitative evaluation of working conditions and heat in the sugarcane industry.DESIGN: A literature review, direct observations and exploratory interviews with workers were conducted to reach a preliminary understanding of the dimensions of heat-related health issues in the sugarcane industry, as a basis for the design of future studies.RESULTS: The industry employs temporary workers from Nicaragua and Costa Rica as well as year-round employees. Temporary employees work 12-hour shifts during the harvest and processing ('zafra') season. In many cases, sugarcane field workers are required to carry their own water and often have no access to shade. Sugar mill workers are exposed to different levels of heat stress depending upon their job tasks, with the most intense heat and workload experienced by the oven ('caldera') cleaners.CONCLUSIONS: Research is needed to achieve better understanding of the multiple factors driving and interacting with heat exposures in the sugarcane industry in order to improve the health and safety of workers while maintaining worker productivity.
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| 3. |
- Crowe, Jennifer, 1976-
(författare)
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Heat exposure and health outcomes in Costa Rican sugarcane harvesters
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background The remarkably efficient mechanisms of the human body to maintain its core temperature of 37°C can be inadequate when harsh climatic conditions and excessive muscle movement lead to heat stress, dehydration and potential heat illness, ranging from minor symptoms such as fatigue to a potentially fatal heat stroke. Agricultural workers in the tropics are at high risk, which is expected to increase with climate change. Sugarcane harvesting in Costa Rica is largely done by cutting the cane with a machete, by temporary, sub-contracted workers who are often migrants and living in poverty. Sugarcane harvesters are known to be affected by an epidemic of chronic kidney disease of non-traditional origin, currently hypothesized to be related to working conditions.Objectives This work aimed to better understand and document sugarcane harvester exposure to heat and the health consequences of working under such conditions. Specific objectives were to 1) Document working conditions and heat in the Costa Rican sugarcane industry (Paper I); 2) Quantify heat stress exposures faced by sugarcane harvesters in Costa Rica (Paper II); and 3) Quantify the occurrence of heat stress symptoms and abnormal urinary parameters in sugarcane workers in Costa Rica (Papers III and IV).Methods This study took place over three harvests following a pilot assessment prior to the first harvest. Methods included direct observation, semi-structured interviews with 24 individuals and a participatory workshop with 8 harvesters about heat-related perceptions, exposures and coping strategies during the harvest and non-harvest season (Pilot). Researchers accompanied workers in the field during all three harvests, measured wet bulb globe temperature (WBGT) and conducted direct observation. Heat exposure assessment was conducted by calculating metabolic load, WBGT and corresponding limit values based on international guidelines (NTP and OSHA) (Harvest 1). Self-reported symptom data were collected using orally-administered questionnaires from 106 sugarcane harvesters and 63 non-harvesters from the same company (Harvest 2). Chi-square test and gamma statistic were used to evaluate differences in self-reported symptoms and trends over heat exposure categories. Finally, liquid consumption during the work shift was documented and urinalysis was conducted pre-and post-shift in 48 sugarcane harvesters on three days; differences were assessed with McNemar´s test on paired proportions (Harvest 3).Results Sugarcane workers in both the harvest and non-harvest seasons are exposed to heat, but particularly during the harvest season. Field workers have to carry their own water to the field and often have no access to shade. Some plantworkers are also exposed to intense heat. The metabolic load of sugarcane harvesting was determined to be 261 W/m2. The corresponding threshold value is 26 ◦C WBGT, above which workers should decrease work load or take breaks to avoid the risk of heat stress. Harvesters in this study were at risk of heat stress as early as 7:15 am on some mornings and by 9:00 am on all mornings. After 9:15 am, OSHA recommendations would require that harvesters only work at full effort 25% of each hour to avoid heat stress. Heat and dehydration symptoms at least once per week were experienced significantly more frequently among harvesters than non-harvesters (p<0.05): headache, tachycardia, fever, nausea, difficulty breathing, dizziness, and dysuria. Percentages of workers reporting heat and dehydration-related symptoms increased over increasing heat exposure categories. Total liquid consumed ranged from 1 to 9 L and differed over days (median 5.0, 4.0 and 3.25 on days 1, 2 and 3 respectively). On these same days, the two principle indicators of dehydration: high USG (≥1.025) and low pH (≤5), changed significantly from pre to post-shift (p=0.000 and p=0.012).Proportions of workers with proteinuria >30 mg/dL, and blood, leucocytes and casts in urine were also significantly different between pre and post-shift samples at the group level, but unlike USG and pH, these alterations were more frequent in the pre-shift sample. 85% of workers presented with proteinuria at least once and 52% had at least one post-shift USG indicative of dehydration.Conclusion Heat exposure is an important occupational health risk for sugarcane workers according to international standards. A large percentage of harvesters experience symptoms consistent with heat exhaustion throughout the harvest season. Pre and post-shift urine samples demonstrate dehydration and other abnormal findings. The results of this study demonstrate an urgent need to improve working conditions for sugarcane harvesters both under current conditions and in adaptation plans for future climate change.
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| 4. |
- Crowe, Jennifer, et al.
(författare)
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Heat exposure in sugarcane harvesters in Costa Rica
- 2013
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Ingår i: American Journal of Industrial Medicine. - : John Wiley & Sons. - 0271-3586 .- 1097-0274. ; 56:10, s. 1157-1164
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Occupational heat stress is a major concern in sugarcane production and has been hypothesized as a causal factor of a chronic kidney disease epidemic in Central America. This study described working conditions of sugarcane harvesters in Costa Rica and quantified their exposure to heat.METHODS: Non-participatory observation and Wet Bulb Globe Temperatures (WBGT) according to Spanish NTP (Technical Prevention Notes) guidelines were utilized to quantify the risk of heat stress. OSHA recommendations were used to identify corresponding exposure limit values.RESULTS: Sugarcane harvesters carried out labor-intensive work with a metabolic load of 261 W/m(2) (6.8 kcal/min), corresponding to a limit value of 26° WBGT which was reached by 7:30 am on most days. After 9:15 am, OSHA recommendations would require that workers only work 25% of each hour to avoid health risks from heat.CONCLUSIONS: Sugarcane harvesters are at risk for heat stress for the majority of the work shift. Immediate action is warranted to reduce such exposures.
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| 5. |
- Crowe, Jennifer, 1976-, et al.
(författare)
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Heat-Related symptoms in sugarcane harvesters
- 2015
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Ingår i: American Journal of Industrial Medicine. - : John Wiley & Sons. - 0271-3586 .- 1097-0274. ; 58:5, s. 541-548
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Tidskriftsartikel (refereegranskat)abstract
- Background: Exposure to heat stress is a documented risk for Central American sugarcane harvesters. However, little is known about heat-related illness in this population.Methods: This study examined the frequency of heat-related health effects among harvesters (n = 106) exposed to occupational heat stress compared to non-harvesters (n = 63). Chi-square test and gamma statistic were used to evaluate differences in self-reported symptoms and trends over heat exposure categories.Results: Heat and dehydration symptoms (headache, tachycardia, muscle cramps, fever, nausea, difficulty breathing, dizziness, swelling of hands/feet, and dysuria) were experienced at least once per week significantly more frequently among harvesters. Percentages of workers reporting heat and dehydration symptoms increased in accordance with increasing heat exposure categories.Conclusions: A large percentage of harvesters are experiencing heat illness throughout the harvest demonstrating an urgent need for improved workplace practices, particularly in light of climate change and the epidemic of chronic kidney disease prevalent in this population.
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| 6. |
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| 7. |
- Kjellström, Tord, et al.
(författare)
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Climate change, workplace heat exposure, and occupational health and productivity in Central America
- 2011
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Ingår i: International journal of occupational and environmental health. - : Maney Publishing. - 1077-3525 .- 2049-3967. ; 17:3, s. 270-81
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Tidskriftsartikel (refereegranskat)abstract
- Climate change is increasing heat exposure in places such as Central America, a tropical region with generally hot/humid conditions. Working people are at particular risk of heat stress because of the intrabody heat production caused by physical labor. This article aims to describe the risks of occupational heat exposure on health and productivity in Central America, and to make tentative estimates of the impact of ongoing climate change on these risks. A review of relevant literature and estimation of the heat exposure variable wet bulb globe temperature (WBGT) in different locations within the region were used to estimate the effects. We found that heat stress at work is a real threat. Literature from Central America and heat exposure estimates show that some workers are already at risk under current conditions. These conditions will likely worsen with climate change, demonstrating the need to create solutions that will protect worker health and productivity.
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| 8. |
- Lewis, Cathryn M, et al.
(författare)
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Genome scan meta-analysis of schizophrenia and bipolar disorder, part II : Schizophrenia
- 2003
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Ingår i: American Journal of Human Genetics. - 0002-9297 .- 1537-6605. ; 73:1, s. 34-48
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Tidskriftsartikel (refereegranskat)abstract
- Schizophrenia is a common disorder with high heritability and a 10-fold increase in risk to siblings of probands. Replication has been inconsistent for reports of significant genetic linkage. To assess evidence for linkage across studies, rank-based genome scan meta-analysis (GSMA) was applied to data from 20 schizophrenia genome scans. Each marker for each scan was assigned to 1 of 120 30-cM bins, with the bins ranked by linkage scores (1 = most significant) and the ranks averaged across studies (R(avg)) and then weighted for sample size (N(sqrt)[affected casess]). A permutation test was used to compute the probability of observing, by chance, each bin's average rank (P(AvgRnk)) or of observing it for a bin with the same place (first, second, etc.) in the order of average ranks in each permutation (P(ord)). The GSMA produced significant genomewide evidence for linkage on chromosome 2q (PAvgRnk<.000417). Two aggregate criteria for linkage were also met (clusters of nominally significant P values that did not occur in 1,000 replicates of the entire data set with no linkage present): 12 consecutive bins with both P(AvgRnk) and P(ord)<.05, including regions of chromosomes 5q, 3p, 11q, 6p, 1q, 22q, 8p, 20q, and 14p, and 19 consecutive bins with P(ord)<.05, additionally including regions of chromosomes 16q, 18q, 10p, 15q, 6q, and 17q. There is greater consistency of linkage results across studies than has been previously recognized. The results suggest that some or all of these regions contain loci that increase susceptibility to schizophrenia in diverse populations.
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| 10. |
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