A whole-genome, radiation hybrid mapping resource of hexaploid wheat.

Generating a contiguous, ordered reference sequence of a complex genome such as hexaploid wheat (2n = 6x = 42; approximately 17 GB) is a challenging task due to its large, highly repetitive, and allopolyploid genome. In wheat, ordering of whole-genome or hierarchical shotgun sequencing contigs is primarily based on recombination and comparative genomics-based approaches. However, comparative genomics approaches are limited to syntenic inference and recombination is suppressed within the pericentromeric regions of wheat chromosomes, thus, precise ordering of physical maps and sequenced contigs across the whole-genome using these approaches is nearly impossible. We developed a whole-genome radiation hybrid (WGRH) resource and tested it by genotyping a set of 115 randomly selected lines on a high-density single nucleotide polymorphism (SNP) array. At the whole-genome level, 26 299 SNP markers were mapped on the RH panel and provided an average mapping resolution of approximately 248 Kb/cR1500 with a total map length of 6866 cR1500 . The 7296 unique mapping bins provided a five- to eight-fold higher resolution than genetic maps used in similar studies. Most strikingly, the RH map had uniform bin resolution across the entire chromosome(s), including pericentromeric regions. Our research provides a valuable and low-cost resource for anchoring and ordering sequenced BAC and next generation sequencing (NGS) contigs. The WGRH developed for reference wheat line Chinese Spring (CS-WGRH), will be useful for anchoring and ordering sequenced BAC and NGS based contigs for assembling a high-quality, reference sequence of hexaploid wheat. Additionally, this study provides an excellent model for developing similar resources for other polyploid species.

Mineral intake and lung cancer risk in the NIH-American Association of Retired Persons Diet and Health study.

BACKGROUND: Using data from a case-control study, we previously reported that low dietary intakes of magnesium (Mg), iron (Fe), zinc (Zn), copper (Cu), but not selenium (Se) and calcium (Ca), were associated with increased lung cancer risk. Due to dietary recall bias in case-control studies, our objective was to assess whether these findings hold in a prospective cohort study. METHODS: We analyzed data from the NIH-American Association of Retired Persons Diet and Health study of 482,875 subjects (288,257 men and 194,618 women) who were cancer-free and completed a food frequency questionnaire at enrollment between 1995 and 2003. Cox proportional hazards models were computed to estimate the relative risk adjusted for potential confounders. RESULTS: During a mean follow-up of 7 years, 7,052 lung cancer cases were identified. For all subjects, we observed no significant associations between total (diet + supplement) Ca, Mg, Fe, Cu, Se, and Zn intakes and lung cancer risk. Total Ca intake was protective (P trend < 0.05) for current smokers and subjects with adenocarcinomas. Total Mg intake increased risk (P trend < 0.05) in men and current smokers. Total Fe intake was inversely associated with risk in women (P trend < 0.01). For dietary minerals, Mg increased risk (P trend < 0.05) in all subjects, among men and current smokers. Increased dietary Ca intake reduced risk in women (P trend = 0.05). Dietary Fe decreased risk in all subjects and among women (P trend < 0.05). Mineral intake from supplements did not affect lung cancer risk. CONCLUSIONS: Dietary minerals are risk factors for lung cancer. IMPACT: Dietary mineral consumption may influence lung cancer risk, but the associations differ by type of mineral and population subgroups.

Skeletal tissue growth, differentiation and mineralization in the NASA rotating wall vessel.

The NASA Rotating Wall Vessel (RWV) is a device that creates a unique environment that supports three-dimensional tissue growth, a heightened level of cell differentiation and randomizes the position of the downward gravitational force on cells. Embryonic bone formation encompasses a cascade of chondrogenic and osteogenic events, which can be altered by changes in gravitational loading. These studies were conducted to determine if the chondrogenic cascade in bone formation would be enhanced or hindered in the unique culture environment of the RWV. Embryonic mouse pre-bone tissues were placed in the RWV at one of four different stages of chondrogenesis, ranging from undifferentiated mesenchyme cells to chondrocytes on the verge of undergoing terminal chondrocyte differentiation. After culture, tissues were analyzed for their size, the amount of alkaline phosphatase (ALP) activity and their ability to form a mineralized matrix. Tissue consisting of cells at the early phase of chondrogenesis grew very little and did not differentiate or mineralize when cultured in the RWV. Some tissues were cultured for short periods in the RWV then cultured in standard culture dishes (SCD). Following this culture regime, the cartilage grew only a small amount, but alkaline phosphatase activity increased, and some mineralized regions formed. The pattern of mineralization was abnormal, with two mineralized zones at each end of the cartilage instead of a single central zone. Tissues that were at the three more advanced stages of chondrogenesis when placed in the RWV showed substantial growth, differentiation and mineralization. Mineralization patterns in these older tissues was normal. Tissues at the oldest stage of chondrogenesis showed more growth and as much or more mineralization as tissue cultured only in SCD. These data suggest that exposure to the RWV at early stages of chondrogenesis severely limits the ability for cartilage growth and yields abnormal downstream morphogenesis. However, at later stages of chondrogenesis, the RWV environment may be beneficial and enhance growth and development. Future studies to characterize intercellular signaling molecules and gene expression activities of chondrocytes in the RWV will be valuable for understanding the mechanism of skeletogenesis.

High noon for U.S. health care reform.

A growing popular movement besieges a health policy status quo near financial as well as moral bankruptcy. A single-payer, Canadian-style national health program would assure universal, egalitarian coverage; democratic, rather than corporate, control of key policy choices; financing based on ability to pay; and cost controls that spare needed care as well as health workers' standard of living. Despite a misinformation campaign (generously funded by insurance and pharmaceutical firms) that slanders the Canadian experience, most Americans favor a national health program. The public health community should fight for no less.

Telling it to Studs Terkel: HMPRG at age five.

After five years, the Health and Medicine Policy Research Group, out of generosity or vain-glory, has come to believe that its health policy interventions are a moveable feast. In what follows, the nation's premier interviewer extracts from three HMPRG stalwarts the history and the style of work which, up to this moment, has proven remarkably productive for us. Please presume this interview is an invitation to readers wherever you may be to inquire and seek counsel about how what we have been able to do might be replicated in your city. The interview was aired on WFMT's Studs Terkel Program of January 6, 1986. Patricia Terrell, Executive Director of HMPRG, John McKnight, Professor of Urban Policy at Northwestern University and a co-founder of the group, and Quentin Young, former Medical Director of Cook County Hospital and President of HMPRG, answered, as best they could, Studs Terkel's interrogatories.

On publicly provided health care.

At a time of greatest need the national examination of health policy is hobbled, nay shackled, by an intellectual blindspot that, neurologically speaking, suggests brain damage. To achieve balance and appeal to reason we present this essay, which celebrates the nation's historic experience with public sector medicine and thereby serves as an antidote to the toxic maxim of received truth: in matters of health, private is good and public is bad.

A proportional mortality ratio study of workers in a construction equipment and diesel engine manufacturing plant.

The mortality of 461 workers who were employed 10 or more years in a Midwest engine and construction equipment plant was examined, using the method of proportional mortality ratios. Both state and national deaths were used as the standard population. Major exposures in this plant included solvents, cutting oils, and metal fumes and dusts. However, precise exposure data were not available. Among white males, no significant deviations from expected deaths were found. Among black males, significant excess deaths were found for all malignant neoplasms combined, for cancer of the pancreas, and for non-Hodgkin's lymphomas. Proportional cancer mortality ratios produced similar results, although the excess of pancreatic cancer in blacks was only significant among those with 20 or more years of service. Although complete occupational histories were not available, these results may provide hypotheses for future studies of workers in heavy machinery production.