178 research outputs found
Nutrient Adequacy of Children Participating in WIC
USDA's Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) provides supplemental foods to participants, in most cases through vouchers for retail purchase of foods designated as approved by the program. WIC food packages were initially designed to include foods rich in nutrients that were lacking in the diets of low-income participants. This brief summarizes two recent ERS-sponsored studies that provide new assessments of nutrient intakes of WIC children, income-eligible children not participating in the program, and children ineligible for the program.Special Supplemental Nutrition Program for Women, Infants and Children, WIC, food assistance programs, nutrient intake, diet quality, CSFII, NHANES, vitamin C, vitamin A, iron, protein, calcium, ERS, USDA, Food Consumption/Nutrition/Food Safety, Food Security and Poverty,
Trogocytosis by Entamoeba histolytica Mediates Acquisition and Display of Human Cell Membrane Proteins and Evasion of Lysis by Human Serum.
We previously showed that Entamoeba histolytica kills human cells through a mechanism that we termed trogocytosis ("trogo-" means "nibble"), due to its resemblance to trogocytosis in other organisms. In microbial eukaryotes like E. histolytica, trogocytosis is used to kill host cells. In multicellular eukaryotes, trogocytosis is used for cell killing and cell-cell communication in a variety of contexts. Thus, nibbling is an emerging theme in cell-cell interactions both within and between species. When trogocytosis occurs between mammalian immune cells, cell membrane proteins from the nibbled cell are acquired and displayed by the recipient cell. In this study, we tested the hypothesis that through trogocytosis, amoebae acquire and display human cell membrane proteins. We demonstrate that E. histolytica acquires and displays human cell membrane proteins through trogocytosis and that this leads to protection from lysis by human serum. Protection from human serum occurs only after amoebae have undergone trogocytosis of live cells but not phagocytosis of dead cells. Likewise, mutant amoebae defective in phagocytosis, but unaltered in their capacity to perform trogocytosis, are protected from human serum. Our studies are the first to reveal that amoebae can display human cell membrane proteins and suggest that the acquisition and display of membrane proteins is a general feature of trogocytosis. These studies have major implications for interactions between E. histolytica and the immune system and also reveal a novel strategy for immune evasion by a pathogen. Since other microbial eukaryotes use trogocytosis for cell killing, our findings may apply to the pathogenesis of other infections.IMPORTANCE Entamoeba histolytica causes amoebiasis, a potentially fatal diarrheal disease. Abscesses in organs such as the liver can occur when amoebae are able to breach the intestinal wall and travel through the bloodstream to other areas of the body. Therefore, understanding how E. histolytica evades immune detection is of great interest. Here, we demonstrate for the first time that E. histolytica acquires and displays human cell membrane proteins by taking "bites" of human cell material in a process named trogocytosis ("trogo-" means "nibble"), and that this allows amoebae to survive in human serum. Display of acquired proteins through trogocytosis has been previously characterized only in mammalian immune cells. Our study suggests that this is a more general feature of trogocytosis not restricted to immune cells and broadens our knowledge of eukaryotic biology. These findings also reveal a novel strategy for immune evasion by a pathogen and may apply to the pathogenesis of other infections
IDENTIFYING PRIORITIES FOR PESTICIDE RESIDUE REDUCTION
Pesticide residues, dietary intakes, dietary risks, fruits and vegetables, Crop Production/Industries,
School Food Service Costs: Does Location Matter?
Over 30 million lunches and 9.8 million breakfasts are served every day to children in participating American schools through the USDA National School Lunch and School Breakfast Programs. It is challenging for participating local school food authorities (SFAs) to serve appealing, healthful meals while covering food, labor, and other operating costs with USDA reimbursements. But it may be more difficult for some SFAs than others due to cost differences across locations. Analysis of data from a large national sample reveals that after controlling for differences in SFA characteristics, sharp differences in costs remained among rural, urban, and suburban SFAs and across regions. The highest costs occurred in Mid-Atlantic, suburban SFAs and the lowest cost existed in southwest, urban SFAs. Differences in food costs explained the largest share of this variation.school meal costs, cost function, SFA, Food Consumption/Nutrition/Food Safety,
A DISTRIBUTIONAL ANALYSIS OF THE COSTS OF FOODBORNE ILLNESS: WHO ULTIMATELY PAYS?
This paper traces the economic impact of the costs of foodborne illness on the U.S. economy using a Social Accounting Matrix (SAM) framework. Previous estimates of the costs of seven foodborne pathogens are disaggregated by type, and distributed across the population using data from the National Health Interview Survey. Initial income losses resulting from premature death cause a decrease in economic activity. Medical costs, in contrast, result in economic growth, though this growth does not outweigh the total costs of premature death. A SAM accounting of how the costs of illness are diffused through the economy provides useful information for policy makers.Cost of illness, Foodborne illness, Social Accounting Matrix, Food Consumption/Nutrition/Food Safety,
Trypanin, a Component of the Flagellar Dynein Regulatory Complex, Is Essential in Bloodstream Form African Trypanosomes
The Trypanosoma brucei flagellum is a multifunctional organelle with critical roles in motility, cellular morphogenesis, and cell division. Although motility is thought to be important throughout the trypanosome lifecycle, most studies of flagellum structure and function have been restricted to the procyclic lifecycle stage, and our knowledge of the bloodstream form flagellum is limited. We have previously shown that trypanin functions as part of a flagellar dynein regulatory system that transmits regulatory signals from the central pair apparatus and radial spokes to axonemal dyneins. Here we investigate the requirement for this dynein regulatory system in bloodstream form trypanosomes. We demonstrate that trypanin is localized to the flagellum of bloodstream form trypanosomes, in a pattern identical to that seen in procyclic cells. Surprisingly, trypanin RNA interference is lethal in the bloodstream form. These knockdown mutants fail to initiate cytokinesis, but undergo multiple rounds of organelle replication, accumulating multiple flagella, nuclei, kinetoplasts, mitochondria, and flagellum attachment zone structures. These findings suggest that normal flagellar beat is essential in bloodstream form trypanosomes and underscore the emerging concept that there is a dichotomy between trypanosome lifecycle stages with respect to factors that contribute to cell division and cell morphogenesis. This is the first time that a defined dynein regulatory complex has been shown to be essential in any organism and implicates the dynein regulatory complex and other enzymatic regulators of flagellar motility as candidate drug targets for the treatment of African sleeping sickness
Communicating absolute fracture risk reduction and the acceptance of treatment for osteoporosis
Healthcare professionals frequently communicate the benefits of treatments as a relative risk reduction (RRR) in the likelihood of an event occurring. Here we evaluated whether presenting the benefits of osteoporosis treatment as a RRR in fractures compared with an absolute risk reduction (ARR) changed the patient’s attitudes towards accepting treatment. We surveyed 160 individuals attending a specialised osteoporosis clinic for face-to-face consultations between May 2018 and Jan 2021. They were presented with information on RRR for the treatment being considered followed by ARR and after each question were asked about how likely they would be to start treatment on a 5-point scale (1 = very likely, 5 = very unlikely). Participants were less likely to accept treatment when it was presented as ARR (mean score 2.02 vs. 2.67, p < 0.001, 95% CI for difference − 0.82 vs − 0.47) and thirty-eight participants (23.7%) declined treatment with knowledge of their ARR when they would have accepted the same treatment based on the RRR. Individuals who declined treatment had a lower 5-year risk of fracture than those who accepted treatment (9.0 vs. 12.5%, p < 0.001, 95% CI − 5.0 to − 1.6) and as fracture risk decreased, the participant was less likely to accept treatment (Spearman r − 0.32, 95% CI − 0.46 to − 0.17, p ≤ 0.001). Whilst presentation of data as ARR more accurately reflects individual benefit and helps facilitate shared decision-making, clinicians should be aware that this will lead to a proportion of patients with lower fracture risk declining treatment for osteoporosis
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