Global biodiversity data suggest allopolyploid plants do not occupy larger ranges or harsher conditions compared with their progenitors

Understanding the factors determining species' geographical and environmental range is a central question in evolution and ecology, and key for developing conservation and management practices. Shortly after the discovery of polyploidy, just over 100 years ago, it was suggested that polyploids generally have greater range sizes and occur in more extreme conditions than their diploid congeners. This suggestion is now widely accepted in the literature and is attributed to polyploids having an increased capacity for genetic diversity that increases their potential for adaptation and invasiveness. However, the data supporting this idea are mixed. Here, we compare the niche of allopolyploid plants to their progenitor species to determine whether allopolyploidization is associated with increased geographic range or extreme environmental tolerance. Our analysis includes 123 allopolyploid species that exist as only one known ploidy level, with at least one known progenitor species, and at least 50 records in the Global Biodiversity Information Facility (GBIF) database. We used GBIF occurrence data and range modeling tools to quantify the geographic and environmental distribution of these allopolyploids relative to their progenitors. We find no indication that allopolyploid plants occupy more extreme conditions or larger geographic ranges than their progenitors. Data evaluated here generally indicate no significant difference in range between allopolyploids and progenitors, and where significant differences do occur, the progenitors are more likely to exist in extreme conditions. We concluded that the evidence from these data indicate allopolyploidization does not result in larger or more extreme ranges. Thus, allopolyploidization does not have a consistent effect on species distribution, and we conclude it is more likely the content of an allopolyploid's genome rather than polyploidy per se that determines the potential for invasiveness.

Excitatory cholinergic responses in mouse primary bronchial smooth muscle require both Ca2+ entry via l-type Ca2+ channels and store operated Ca2+ entry via Orai channels

Malfunctions in airway smooth muscle Ca²⁺-signalling leads to airway hyperresponsiveness in asthma and chronic obstructive pulmonary disease. Ca²⁺-release from intracellular stores is important in mediating agonist-induced contractions, but the role of influx via l-type Ca²⁺ channels is controversial. We re-examined roles of the sarcoplasmic reticulum Ca²⁺ store, refilling of this store via store-operated Ca²⁺ entry (SOCE) and l-type Ca²⁺ channel pathways on carbachol (CCh, 0.1-10 µM)-induced contractions of mouse bronchial rings and intracellular Ca²⁺ signals of mouse bronchial myocytes. In tension experiments, the ryanodine receptor (RyR) blocker dantrolene (100 µM) reduced CCh-responses at all concentrations, with greater effects on sustained rather than initial components of contraction. 2-Aminoethoxydiphenyl borate (2-APB, 100 μM), in the presence of dantrolene, abolished CCh-responses, suggesting the sarcoplasmic reticulum Ca²⁺ store is essential for contraction. The SOCE blocker GSK-7975A (10 µM) reduced CCh-contractions, with greater effects at higher (e.g. 3 and 10 µM) CCh concentrations. Nifedipine (1 µM), abolished remaining contractions in GSK-7975A (10 µM). A similar pattern was observed on intracellular Ca²⁺-responses to 0.3 µM CCh, where GSK-7975A (10 µM) substantially reduced Ca²⁺ transients induced by CCh, and nifedipine (1 µM) abolished remaining responses. When nifedipine (1 µM) was applied alone it had less effect, reducing tension responses at all CCh concentrations by 25% - 50%, with greater effects at lower (e.g. 0.1 and 0.3 µM) CCh concentrations. When nifedipine (1 µM) was examined on the intracellular Ca²⁺-response to 0.3 µM CCh, it only modestly reduced Ca²⁺ signals, while GSK-7975A (10 µM) abolished remaining responses. In conclusion, Ca²⁺-influx from both SOCE and l-type Ca²⁺ channels contribute to excitatory cholinergic responses in mouse bronchi. The contribution of l-type Ca²⁺ channels was especially pronounced at lower doses of CCh, or when SOCE was blocked. This suggests l-type Ca²⁺ channels might be a potential target for bronchoconstriction under certain circumstances.

Insights from the genomes of 4 diploid Camelina spp

Plant evolution has been a complex process involving hybridization and polyploidization making understanding the origin and evolution of a plant's genome challenging even once a published genome is available. The oilseed crop, Camelina sativa (Brassicaceae), has a fully sequenced allohexaploid genome with 3 unknown ancestors. To better understand which extant species best represent the ancestral genomes that contributed to C. sativa's formation, we sequenced and assembled chromosome level draft genomes for 4 diploid members of Camelina: C. neglecta C. hispida var. hispida, C. hispida var. grandiflora, and C. laxa using long and short read data scaffolded with proximity data. We then conducted phylogenetic analyses on regions of synteny and on genes described for Arabidopsis thaliana, from across each nuclear genome and the chloroplasts to examine evolutionary relationships within Camelina and Camelineae. We conclude that C. neglecta is closely related to C. sativa's sub-genome 1 and that C. hispida var. hispida and C. hispida var. grandiflora are most closely related to C. sativa's sub-genome 3. Further, the abundance and density of transposable elements, specifically Helitrons, suggest that the progenitor genome that contributed C. sativa's sub-genome 3 maybe more similar to the genome of C. hispida var. hispida than that of C. hispida var. grandiflora. These diploid genomes show few structural differences when compared to C. sativa's genome indicating little change to chromosome structure following allopolyploidization. This work also indicates that C. neglecta and C. hispida are important resources for understanding the genetics of C. sativa and potential resources for crop improvement.

Update on the Brassicaceae species checklist

Background

Here we present a revised species checklist for the Brassicaceae, updated from Warwick SI, Francis, A, Al-Shehbaz IA (2006), Brassicaceae: Species checklist and database on CD-ROM, Plant Systematics and Evolution 259: 249─25. This update of the checklist was initiated, based on recent taxonomic and molecular studies on the Brassicaceae that have resulted in new species names, combinations and associated synonyms.

New information

New data have been added indicating tribal affiliations within the family and where type specimens have been designated. In addition, information from many early publications has been checked and added to the database. The database now includes information on 14983 taxa, 4636 of which are currently accepted and divided into 340 genera and 52 tribes. A selected bibliography of recent publications on the Brassicaceae is included.

High gene flow maintains genetic diversity following selection for high EPSPS copy number in the weed kochia (Amaranthaceae)

Kochia, a major weed species, has evolved resistance to four herbicide modes of action. Herbicide resistance appears to spread quickly, which could result in diminished standing genetic variation, reducing the ability of populations to adapt further. Here we used double digest restriction enzyme associated sequencing to determine the level of gene flow among kochia populations and whether selection for glyphosate resistance reduces genetic variation. Canadian Prairie populations show little to no genetic differentiation (FST = 0.01) and no correlation between genetic and geographic distance (r2 = - 0.02 p = 0.56), indicating high gene flow and no population structure. There is some evidence that kochia populations are genetically depauperate compared to other weed species, but genetic diversity did not differ between glyphosate susceptible and resistant populations or individuals. The inbreeding coefficients suggest there are 23% fewer heterozygotes in these populations than expected with random mating, and no variation was found within the chloroplast. These results indicate that any alleles for herbicide resistance can be expected to spread quickly through kochia populations, but there is little evidence this spread will reduce the species' genetic variation or limit the species' ability to respond to further selection pressure.

A chromosome-scale draft sequence of the Canada fleabane genome

BACKGROUND

Due to the accessibility of underlying technologies the 'Omics', in particular genomics, are becoming commonplace in several fields of research, including the study of agricultural pests. The weed community is starting to embrace these approaches; genome sequences have been made available in the past years, with several other sequencing projects underway, as promoted by the International Weed Genome Consortium. Chromosome-scale sequences are essential to fully exploit the power of genetics and genomics.

RESULTS

We report such an assembly for Conyza canadensis, an important agricultural weed. Third-generation sequencing technology was used to create a genome assembly of 426 megabases, of which nine chromosome-scale scaffolds cover more than 98% of the entire assembled sequence. As this weed was the first to be identified with glyphosate resistance, and since we do not have a firm handle on the genetic mechanisms responsible for several herbicide resistances in the species, the genome sequence was annotated with genes known to be associated with herbicide resistance. A high number of ABC-type transporters, cytochrome P450 and glycosyltransferases (159, 352 and 181, respectively) were identified among the list of ab initio predicted genes.

CONCLUSION

As C. canadensis has a small genome that is syntenic with other Asteraceaes, has a short life cycle and is relatively easy to cross, it has the potential to become a model weed species and, with the chromosome-scale genome sequence, contribute to a paradigm shift in the way non-target site resistance is studied. © 2020 Her Majesty the Queen in Right of CanadaPest Management Science © 2020 Society of Chemical Industry.

A Chromosome-Scale Assembly of the Garden Orach (Atriplex hortensis L.) Genome Using Oxford Nanopore Sequencing

Atriplex hortensis (2n = 2x = 18, 1C genome size ∼1.1 gigabases), also known as garden orach and mountain-spinach, is a highly nutritious, broadleaf annual of the Amaranthaceae-Chenopodiaceae alliance (Chenopodiaceae sensu stricto, subfam. Chenopodioideae) that has spread in cultivation from its native primary domestication area in Eurasia to other temperate and subtropical regions worldwide. Atriplex L. is a highly complex but, as understood now, a monophyletic group of mainly halophytic and/or xerophytic plants, of which A. hortensis has been a vegetable of minor importance in some areas of Eurasia (from Central Asia to the Mediterranean) at least since antiquity. Nonetheless, it is a crop with tremendous nutritional potential due primarily to its exceptional leaf and seed protein quantities (approaching 30%) and quality (high levels of lysine). Although there is some literature describing the taxonomy and production of A. hortensis, there is a general lack of genetic and genomic data that would otherwise help elucidate the genetic variation, phylogenetic positioning, and future potential of the species. Here, we report the assembly of the first high-quality, chromosome-scale reference genome for A. hortensis cv. "Golden." Long-read data from Oxford Nanopore's MinION DNA sequencer was assembled with the program Canu and polished with Illumina short reads. Contigs were scaffolded to chromosome scale using chromatin-proximity maps (Hi-C) yielding a final assembly containing 1,325 scaffolds with a N50 of 98.9 Mb - with 94.7% of the assembly represented in the nine largest, chromosome-scale scaffolds. Sixty-six percent of the genome was classified as highly repetitive DNA, with the most common repetitive elements being Gypsy-(32%) and Copia-like (11%) long-terminal repeats. The annotation was completed using MAKER which identified 37,083 gene models and 2,555 tRNA genes. Completeness of the genome, assessed using the Benchmarking Universal Single Copy Orthologs (BUSCO) metric, identified 97.5% of the conserved orthologs as complete, with only 2.2% being duplicated, reflecting the diploid nature of A. hortensis. A resequencing panel of 21 wild, unimproved and cultivated A. hortensis accessions revealed three distinct populations with little variation within subpopulations. These resources provide vital information to better understand A. hortensis and facilitate future study.

Population Genomic Approaches for Weed Science

Genomic approaches are opening avenues for understanding all aspects of biological life, especially as they begin to be applied to multiple individuals and populations. However, these approaches typically depend on the availability of a sequenced genome for the species of interest. While the number of genomes being sequenced is exploding, one group that has lagged behind are weeds. Although the power of genomic approaches for weed science has been recognized, what is needed to implement these approaches is unfamiliar to many weed scientists. In this review we attempt to address this problem by providing a primer on genome sequencing and provide examples of how genomics can help answer key questions in weed science such as: (1) Where do agricultural weeds come from; (2) what genes underlie herbicide resistance; and, more speculatively, (3) can we alter weed populations to make them easier to control? This review is intended as an introduction to orient weed scientists who are thinking about initiating genome sequencing projects to better understand weed populations, to highlight recent publications that illustrate the potential for these methods, and to provide direction to key tools and literature that will facilitate the development and execution of weed genomic projects.

Polyploidization for the Genetic Improvement of Cannabis sativa

Cannabis sativa L. is a diploid species, cultivated throughout the ages as a source of fiber, food, and secondary metabolites with therapeutic and recreational properties. Polyploidization is considered as a valuable tool in the genetic improvement of crop plants. Although this method has been used in hemp-type Cannabis, it has never been applied to drug-type strains. Here, we describe the development of tetraploid drug-type Cannabis lines and test whether this transformation alters yield or the profile of important secondary metabolites: Δ9-tetrahydrocannabinol (THC), cannabidiol (CBD), or terpenes. The mitotic spindle inhibitor oryzalin was used to induce polyploids in a THC/CBD balanced drug-type strain of Cannabis sativa. Cultured axillary bud explants were exposed to a range of oryzalin concentrations for 24 h. Flow cytometry was used to assess the ploidy of regenerated shoots. Treatment with 20-40 μM oryzalin produced the highest number of tetraploids. Tetraploid clones were assessed for changes in morphology and chemical profile compared to diploid control plants. Tetraploid fan leaves were larger, with stomata about 30% larger and about half as dense compared to diploids. Trichome density was increased by about 40% on tetraploid sugar leaves, coupled with significant changes in the terpene profile and a 9% increase in CBD that was significant in buds. No significant increase in yield of dried bud or THC content was observed. This research lays important groundwork for the breeding and development of new Cannabis strains with diverse chemical profiles, of benefit to medical and recreational users.

Hybridization rate and hybrid fitness for Camelina microcarpa Andrz. ex DC (♀) and Camelina sativa (L.) Crantz(Brassicaceae) (♂)

Hybridization between crops and their wild relatives has the potential to introduce novel variation into wild populations. Camelina (Camelina sativa) is a promising oilseed and cultivars with modified seed characteristics and herbicide resistance are in development, prompting a need to evaluate the potential for novel trait introgression into weedy relatives. Little-podded false flax (littlepod; Camelina microcarpa) is a naturalized weed in Canada and the USA. Here we evaluated the hybridization rate between the three cytotypes of littlepod (♀) and camelina (♂), assessed characteristics of hybrids, and evaluated the fitness of hexaploid littlepod and camelina hybrids in the glasshouse and field. In total we conducted, 1,005 manual crosses with diploid littlepod, 1, 172 crosses with tetraploid littlepod, and 896 crosses with hexaploid littlepod. Hybrids were not produced by the diploids, but were produced by the tetraploids and hexaploids at rates of one hybrid for 2,000 ovules pollinated and 24 hybrids for 25 ovules pollinated, respectively. Hybrids between tetraploid littlepod and camelina showed low pollen fertility and produced a small number of seeds. In the glasshouse, hybrids between hexaploid littlepod and camelina also showed significantly lower pollen fertility and seed production than parental lines, but their seeds showed high viability. A similar pattern was observed in field trials, with hybrids showing earlier flowering, reduced biomass, seed production and seed weight. However, seed produced by the hybrids showed greater viability than that produced by hexaploid littlepod and is potentially the result of a shortened lifecycle. The introgression of lifecycle traits into littlepod populations may facilitate range expansion and contribute to crop gene persistence. Consequently, future work should evaluate the hybridization rate in the field, the fitness of advanced generation backcrosses, and the role of time to maturity in limiting hexaploid littlepod's distribution.

Assessment of Antinutritional Compounds and Chemotaxonomic Relationships between Camelina sativa and Its Wild Relatives

We compared the secondary metabolite composition in seeds of Camelina sativa and its wild relatives to identify potential germplasm with reduced levels of antinutritional compounds. Twenty Camelina accessions, from five different species, were analyzed by liquid chromatography mass spectrometry and subjected to principal component analysis, which revealed that Camelina spp. separated into distinct chemotaxonomic groups. Three major glucosinolates (GSs) were identified in our study, namely, 9-methylsulfinylnonyl GS (GS9), 10-methylsulfinyldecyl GS (GS10), and 11-methylsulfinylundecyl GS (GS11). While there were differences in total GS levels, species-specific patterns for GS9 and GS11 were noted. Sinapine content ranged between 1.4 and 5.6 mg/g FW, with the lowest levels observed in  C. laxa and C. sativa. Lignin levels were also lowest in C. sativa, with most accessions containing less than 6 mg/g FW. Our results show that wild Camelina spp. have distinct metabolomes, and based on their levels of major antinutritionals, some could be incorporated into breeding programs with C. sativa.

flowPloidy: An R package for genome size and ploidy assessment of flow cytometry data

PREMISE OF THE STUDY

Despite advantages in terms of reproducibility, histogram analysis based on nonlinear regression is rarely used in genome size assessments in plant biology. This is due in part to the lack of a freely available program to implement the procedure. We have developed such a program, the R package flowPloidy.

METHODS AND RESULTS

flowPloidy builds on the existing statistical tools provided with the R environment. This base provides tools for importing flow cytometry data, fitting nonlinear regressions, and interactively visualizing data. flowPloidy adds tools for building flow cytometry models, fitting the models to histogram data, and producing visual and tabular summaries of the results.

CONCLUSIONS

flowPloidy fills an important gap in the study of plant genome size. This package will enable plant scientists to apply a more powerful statistical technique for assessing genome size. flowPloidy improves on existing software options by providing a no-cost workflow streamlined for genome size and ploidy determination.

Glyphosate resistance reduces kochia fitness: Comparison of segregating resistant and susceptible F2 populations

Glyphosate is considered the world's most important herbicide, but widespread and continual use has resulted in the evolution of resistance. Kochia scoparia (kochia) has evolved resistance via tandem gene amplification of glyphosate's target, 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) and resistant populations have been reported from the Canadian Prairies and the Northern Great Plains. Here, we evaluated the fitness costs of EPSPS amplification in kochia by comparing susceptible and resistant full siblings from segregating F2 populations generated from within six populations. Kochia was expected to be highly diverse because of strong gene flow; however, six of the seven field-collected parents with higher EPSPS copy number were homozygous. Under competitive greenhouse conditions, the EPSPS type of the line's maternal parent showed persistent effects: delayed emergence, delayed flowering, and reductions in viable seed count and weight overall. High EPSPS copy number individuals had reduced seed count and weight, reduced competitive ability, and reduced final height in mixed stands, but better germination of the F3. However, all characteristics were highly variable and fitness costs were not constant across genetic backgrounds. In the absence of selection from glyphosate, kochia with increased EPSPS copy number will be at a competitive disadvantage in some genetic backgrounds.

Genome size variation in the genus Avena

Genome size is an indicator of evolutionary distance and a metric for genome characterization. Here, we report accurate estimates of genome size in 99 accessions from 26 species of Avena. We demonstrate that the average genome size of C genome diploid species (2C = 10.26 pg) is 15% larger than that of A genome species (2C = 8.95 pg), and that this difference likely accounts for a progression of size among tetraploid species, where AB < AC < CC (average 2C = 16.76, 18.60, and 21.78 pg, respectively). All accessions from three hexaploid species with the ACD genome configuration had similar genome sizes (average 2C = 25.74 pg). Genome size was mostly consistent within species and in general agreement with current information about evolutionary distance among species. Results also suggest that most of the polyploid species in Avena have experienced genome downsizing in relation to their diploid progenitors. Genome size measurements could provide additional quality control for species identification in germplasm collections, especially in cases where diploid and polyploid species have similar morphology.

Bidirectional but asymmetrical sexual hybridization between Brassica carinata and Sinapis arvensis (Brassicaceae)

With transgenic crop development it is important to evaluate the potential for transgenes to escape into populations of wild, weedy relatives. Ethiopian mustard (Brassica carinata, BBCC) is easily transformed and is being investigated for uses from biodiesel fuels to biopharmaceuticals. However, little work has been done evaluating its ability to cross with relatives such as wild mustard (Sinapsis arvensis, SrSr), an abundant, cosmopolitan weedy relative. Here we conducted bidirectional crosses with Ethiopian mustard as a maternal parent in 997 crosses and paternal parent in 1,109 crosses. Hybrids were confirmed using flow cytometry and species-specific ITS molecular markers and indicate a high hybridization rate of 6.43 % between Ethiopian mustard (♀) and wild mustard (♂) and a lower, but not insignificant, hybridization rate of 0.01 % in the reverse direction. The majority of the hybrids were homoploid (BCSr) with less than 1 % of pollen production of their parents and low seed production (0.26 seeds/pollination) in crosses and backcrosses indicating a potential for advanced generation hybrids. The accession used had a significant effect on hybrid seed production with different accessions of Ethopian mustard varying in their production of hybrid offspring from 2.69 to 16.34 % and one accession of wild mustard siring almost twice as many hybrid offspring per flower as the other. One pentaploid (BBCCSr) and one hexaploid (BBCCSrSr) hybrid were produced and had higher pollen viability, though no and low seed production, respectively. As wild mustard is self-incompatible and the outcrossing rate of Ethiopian mustard has been estimated as 30 % potential for hybrid production in the wild appears to be high, though the hybridization rate found here represents a worst case scenario as it does not incorporate pre-pollination barriers. Hybridization in the wild needs to be directly evaluated as does the propensity of Ethiopian mustard to volunteer.

Medicinal chemistry of the epigenetic diet and caloric restriction

The pronounced effects of the epigenetic diet (ED) and caloric restriction (CR) have on epigenetic gene regulation have been documented in many pre-clinical and clinical studies. Understanding epigenetics is of high importance because of the concept that external factors such as nutrition and diet may possess the ability to alter gene expression without modifying the DNA sequence. The ED introduces bioactive medicinal chemistry compounds such as sulforaphane (SFN), curcumin (CCM), epigallocatechin gallate (EGCG) and resveratrol (RSV) that are thought to aid in extending the human lifespan. CR, although similar to ED in the target of longevity, mildly reduces the total daily calorie intake while concurrently providing all beneficial nutrients. Both CR and ED may act as epigenetic modifiers to slow the aging process through histone modification, DNA methylation, and by modulating microRNA expression. CR and ED have been proposed as two important mechanisms that modulate and potentially slow the progression of age-related diseases such as cardiovascular disease (CVD), cancer, obesity, Alzheimer's and osteoporosis to name a few. While many investigators have examined CR and ED as separate entities, this review will primarily focus on both as they relate to age-related diseases, their epigenetic effects and their medicinal chemistry.

Synoptic weather typing applied to air pollution mortality among the elderly in 10 Canadian cities

BACKGROUND

Synoptic circulation patterns (large-scale weather systems) affect ambient levels of air pollution, as well as the relationship between air pollution and human health.

OBJECTIVE

To investigate the air pollution-mortality relationship within weather types and seasons, and to determine which combination of atmospheric conditions may pose increased health threats in the elderly age categories.

METHODS

The relative risk of mortality (RR) due to air pollution was examined using Poisson generalized linear models (GLMs) within specific weather types. Analysis was completed by weather type and age group (all ages, ≤64, 65-74, 75-84, ≥85 years) in ten Canadian cities from 1981 to 1999.

RESULTS

There was significant modification of RR by weather type and age. When examining the entire population, weather type was shown to have the greatest modifying effect on the risk of dying due to ozone (O3). This effect was highest on average for the dry tropical (DT) weather type, with the all-age RR of mortality at a population weighted mean (PWM) found to be 1.055 (95% CI 1.026-1.085). All-weather type risk estimates increased with age due to exposure to carbon monoxide (CO), nitrogen dioxide (NO2), and sulphur dioxide (SO2). On average, RR increased by 2.6, 3.8 and 1.5% for the respective pollutants between the ≤64 and ≥85 age categories. Conversely, mean ozone estimates remained relatively consistent with age. Elevated levels of air pollution were found to be detrimental to the health of elderly individuals for all weather types. However, the entire population was negatively effected by air pollution on the hot dry (DT) and hot humid (MT) days.

CONCLUSIONS

We identified a significant modification of RR for mortality due to air pollution by age, which is enhanced under specific weather types. Efforts should be targeted at minimizing pollutant exposure to the elderly and/or all age groups with respect to weather type in question.

Inflammatory and immunological biomarkers are not related to survival in adults with Cystic Fibrosis

BACKGROUND

Chronic Pseudomonas aeruginosa pulmonary infection is associated with a decline in lung function and reduced survival in people with Cystic Fibrosis (CF). Damaging inflammatory and immunological mediators released in the lungs can be used as markers of chronic infection, inflammation and lung tissue damage.

METHODS

Clinical samples were collected from CF patients and healthy controls. Serum IgG and IgA anti-Pseudomonas antibodies, sputum IL-8 and TNFα, plasma IL-6 and urine TNFr1 were measured by ELISA. Sputum neutrophil elastase (NE), cathepsin S and cathepsin B were measured by spectrophotometric and fluorogenic assays. The relationship between IgG and IgA, inflammatory mediators and long-term survival was determined.

RESULTS

IgG and IL-6 positively correlated with mortality. However, multivariate analysis demonstrated that after adjusting for FEV(1), IgG was not independently related to mortality. A relationship was observed between IgG and IL-6, TNFα, TNFr1 and between IgA and IL8, cathepsin S and cathepsin B.

CONCLUSIONS

These data indicate that biomarkers of inflammation are not independent predictors of survival in people with CF.

Whole genome duplication affects evolvability of flowering time in an autotetraploid plant

Whole genome duplications have occurred recurrently throughout the evolutionary history of eukaryotes. The resulting genetic and phenotypic changes can influence physiological and ecological responses to the environment; however, the impact of genome copy number on evolvability has rarely been examined experimentally. Here, we evaluate the effect of genome duplication on the ability to respond to selection for early flowering time in lines drawn from naturally occurring diploid and autotetraploid populations of the plant Chamerion angustifolium (fireweed). We contrast this with the result of four generations of selection on synthesized neoautotetraploids, whose genic variability is similar to diploids but genome copy number is similar to autotetraploids. In addition, we examine correlated responses to selection in all three groups. Diploid and both extant tetraploid and neoautotetraploid lines responded to selection with significant reductions in time to flowering. Evolvability, measured as realized heritability, was significantly lower in extant tetraploids (^b(T) =  0.31) than diploids (^b(T) =  0.40). Neotetraploids exhibited the highest evolutionary response (^b(T)  =  0.55). The rapid shift in flowering time in neotetraploids was associated with an increase in phenotypic variability across generations, but not with change in genome size or phenotypic correlations among traits. Our results suggest that whole genome duplications, without hybridization, may initially alter evolutionary rate, and that the dynamic nature of neoautopolyploids may contribute to the prevalence of polyploidy throughout eukaryotes.

Association of airway cathepsin B and S with inflammation in cystic fibrosis

Irreversible tissue damage within the cystic fibrosis (CF) lung is mediated by proteolytic enzymes during an inflammatory response. Serine proteinases, in particular neutrophil elastase (NE), have been implicated however, members of the cysteine proteinase family may also be involved. The aim of this study was to determine cathepsin B and S levels in cystic fibrosis (CF) sputum and to assess any relationship to recognized markers of inflammation such as sputum NE, interleukin-8 (IL-8), tumor necrosis factor alpha (TNF-alpha), urine TNF receptor 1 (TNFr1), plasma IL-6, and serum C-reactive protein (CRP). Proteinase activities were measured in the sputum of 36 clinically stable CF patients using spectrophotometric and fluorogenic assays. Immunoblots were also used to confirm enzyme activity data. All other parameters were measured by ELISA. Patients had a mean age of 27.2 (8.2) years, FEV. of 1.6 (0.79) L and BMI of 20.7 (2.8). Both cathepsin B and S activities were detected in all samples, with mean concentrations of 18.0 (13.5) microg/ml and 1.6 (0.88) microg/ml, respectively and were found to correlate not only with each other but with NE, TNF-alpha and IL-8 (in all cases . < 0.05). Airway cathepsin B further correlated with circulatory IL-6 and CRP however, no relationship for either cathepsin was observed with urine TNFr1. This data indicates that cathepsin B and S may have important roles in the pathophysiology of CF lung disease and could have potential as markers of inflammation in future studies.

Continuity of adolescent and early adult partner violence victimisation: association with witnessing violent crime in adolescence

BACKGROUND

Although exposure to peer and family violence is a documented risk factor for adolescent dating violence, less is known about the relationship between violent crime exposure and dating violence victimisation.

METHODS

Participants in the National Longitudinal Study of Adolescent Health (n = 4794) aged 13-17 years self-reported witnessing violent crime (someone being shot or stabbed) in the 12 months prior to Wave I interview (1994-95), physical partner violence victimisation within the 18 months prior to Wave II interview (1995-96), and physical and sexual partner violence victimisation within the 18 months prior to Wave III interview (2001).

RESULTS

Twelve per cent of respondents reported dating violence victimisation at Wave II. Witnessing violent crime was positively associated with victimisation in crude (OR = 2.11, 95% CI 1.56 to 2.86) and adjusted (AOR = 1.53, 95% CI 1.09 to 2.15) analyses. Of the adolescent partner violence victims (n = 549), 32% reported continued victimisation into early adulthood; after adjusting for gender, age, urbanicity and childhood maltreatment history, witnessing violent crime in adolescence was negatively associated with having non-violent relationships in early adulthood (AOR = 0.40, 95% CI 0.19 to 0.84). In cross-sectional and longitudinal analyses, associations between violent crime exposure and victimisation did not vary by age, gender or race/ethnicity.

CONCLUSION

Adolescents exposed to violent crime experience an increased risk of partner violence victimisation in adolescence and continuing victimisation into adulthood. Targeting dating violence prevention and intervention programmes to geographic areas with high levels of violent crime may be an efficient strategy to reach higher risk adolescents. Reducing community violent crime may also have spillover effects on partner violence.

Design, fabrication and demonstration of a magnetophoresis chamber with 25 output fractions

Our goal is to develop an instrument for parallel and multiplexed bioassay using magnetic labels. Toward this end we are developing a multi-outlet magnetophoresis instrument incorporating a fluidic flow chamber placed inside a magnetic field gradient. Magnetic microparticles are sorted by their magnetic moment for eventual use as biological labels based on magnetic signature.In this paper we concentrate on developments in our flow chamber fabrication methods that have allowed us to scale the number of sorting channels from 8 to 25. We present data for instrument performance and reproducibility of sorting.

National study of physical and sexual assault among women with disabilities

OBJECTIVE

To examine the association between the level of disability impairment and physical and sexual assault in a sample of US women at least 18 years of age.

DESIGN, SETTING AND PARTICIPANTS

Retrospective longitudinal study of 6273 non-institutionalized US women from 8000 women participating in the 1995-1996 National Violence Against Women (NVAW) Survey.

MAIN OUTCOME MEASURE

Women's experiences of physical and sexual assault in the 12 months before the NVAW interview.

RESULTS

Most women reported having no disability (n = 5008, 79.8%) and/or not experiencing an assault in the year before their interview (n = 6018, 95.9%). Less than 5% (n = 280) reported having a disability that severely limited daily activities, and 15.7% (n = 985) reported having a disability that moderately limited activities. Less than 4% (n = 218) of the women reported a physical-only assault, and less than 1% (n = 37) reported being sexually assaulted. Women with severe disability impairments were four times more likely to be sexually assaulted than women with no reported disabilities (RR = 4.0, 95% CI 1.5 to 10.6). Little difference in the risk of sexual assault was found between women with moderate disability impairments and those reporting no disabilities (RR = 1.0, 95% CI 0.3 to 2.8). Women with severe (RR = 1.6, 95% CI 0.9 to 3.0) and moderate (RR = 1.2, 95% CI 0.8 to 1.9) disability impairments were at greater risk, although not quite significantly so, of physical-only assault than were women without a disability.

CONCLUSION

The findings suggest that women with disabilities that severely limit activities of daily living are at increased risk of sexual assault.

Deaths from violence in North Carolina, 2004: how deaths differ in females and males

OBJECTIVE

To identify gender differences in violent deaths in terms of incidence, circumstances, and methods of death.

DESIGN

Analysis of surveillance data.

SETTING

North Carolina, a state of 8.6 million residents on the eastern seaboard of the US.

SUBJECTS

1674 North Carolina residents who died from violence in the state during 2004.

METHODS

Information on violent deaths was collected by the North Carolina Violent Death Reporting System using data from death certificates, medical examiner reports, and law enforcement agency incidence reports.

RESULTS

Suicide and homicide rates were lower for females than males. For suicides, females were more likely than males to have a diagnosis of depression (55% v 36%), a current mental health problem (66% v 42%), or a history of suicide attempts (25% v 13%). Firearms were the sole method of suicide in 65% of males and 42% of females. Poisonings were more common in female than male suicides (37% v 12%). Male and female homicide victims were most likely to die from a handgun or a sharp instrument. Fifty seven percent of female homicides involved intimate partner violence, compared with 13% of male homicides. Among female homicides involving intimate partner violence, 78% occurred in the woman's home. White females had a higher rate of suicide than African-American females, but African-American females had a higher rate of homicide than white females.

CONCLUSIONS

The incidence, circumstances, and methods of fatal violence differ greatly between females and males. These differences should be taken into account in the development of violence prevention efforts.

Tuberculosis antigen-specific immune responses can be detected using enzyme-linked immunospot technology in human immunodeficiency virus (HIV)-1 patients with advanced disease

There are limited data on the efficacy of T cell-based assays to detect tuberculosis (TB) antigen-specific responses in immune-deficient human immunodeficiency virus (HIV) patients. The aim of this study is to determine whether TB antigen-specific immune responses can be detected in patients with HIV-1 infection, especially in those with advanced disease (CD4 T cell count < 300 cells/microl). An enzyme-linked immunospot (ELISPOT) assay, which detects interferon (IFN)-gamma secreted by T cells exposed to TB antigens, was used to assess specific immune responses in a prospective study of 201 HIV-1-infected patients with risk factors for TB infection, attending a single HIV unit. The performance of the ELISPOT assay to detect TB antigen-specific immune responses is independent of CD4 T cell counts in HIV-1 patients. The sensitivity and specificity of this assay for the diagnosis of active tuberculosis does not differ significantly from values obtained in immunocompetent subjects. The negative predictive value of the TB ELISPOT test is 98.2%. A positive predictive value of 86% for the diagnosis of active tuberculosis was found when the combined number of early secretory antigen target-6 (ESAT-6) and culture filtrate protein-10 (CFP-10) IFN-gamma spots to CD4 T cell count ratio was > 1.5. TB antigen-specific immune responses can be detected in HIV patients with low CD4 T cell counts using ELISPOT technology in a routine diagnostic laboratory and is a useful test to exclude TB infection in immune-deficient HIV-1 patients. A combination of TB antigen-specific IFN-gamma responses and CD4 T cell counts has the potential to distinguish active tuberculosis from latent infection.

The emerging role of serine proteases in apoptosis

Unregulated apoptosis can be due to a disruption in the balance and control of both intra- and inter-cellular proteolytic activities leading to various disease states. Many proteases involved in apoptotic processes are yet to be identified; however, several are already well characterized. Caspases traditionally held the predominant role as prime mediators of execution. However, latterly, evidence has accumulated that non-caspases, including calpains, cathepsins, granzymes and the proteasome have roles in mediating and promoting cell death. Increasingly, research is implicating serine proteases within apoptotic processing, particularly in the generation of nuclear events such as condensation, fragmentation and DNA degradation observed in late-stage apoptosis. Serine proteases therefore are emerging as providing additional or alternative therapeutic targets.

Morgentaler v. The Queen in the Supreme Court of Canada

In Morgentaler v. R., the Supreme Court of Canada struck down the abortion provisions in the Criminal Code. In a five to two split, a majority of the Supreme Court judges found that section 251 offended a pregnant woman's constitutionally protected right not to be deprived of her "life, liberty, and security of the person." Sheilah Martin reviews the three majority judgments and focuses on the decision written by Madame Justice Wilson. She believes that Madame Justice Wilson's opinion merits special attention in several regards: her conclusions on the constitutional rights of pregnant women; her recognition and validation of women's perspectives on abortion; and her approach to balancing women's interests in reproductive self-determination against the state's interest in regulating reproduction. Sheilah Martin concludes that this decision will reverberate far into the future. Even though it fails to establish clear guidelines concerning governmental power to control access to abortion, its principles outline the legal framework in which future litigation will occur, and it will limit and shape the terms of any ensuing political debate. In addition, Madame Justice Wilson's judgment holds great promise for those looking to the Court to promote the rights of women and other historically disadvantaged groups.

The structures of mouse and human L1 elements reflect their insertion mechanism

L1 is an abundant, interspersed repeated DNA element of mammalian genomes. It has achieved its high copy number via retrotransposition. Like other non-LTR retrotransposons, L1 insertion into chromosomal DNA apparently occurs by target-site primed reverse transcription, or TPRT. L1 retrotransposition often generates elements with 5' truncations that are flanked by a duplication of the genomic target site (TSD). It is typically assumed that the 5' truncated elements are the consequence of poor processivity of the L1 reverse transcriptase. However, we find that the majority of young L1 elements from both the human and mouse genomes are truncated at sequences that can basepair with the target site. Thus, to whatever extent truncation is a consequence of poor processivity, we suggest that truncation is likely to occur when target site sequence can basepair with L1 sequence. This finding supports a model for insertion that occurs by two sequential TPRT reactions, the second of which relies upon the homology between the target site and L1. Because perfect heteroduplex formation is not required for all insertions, a dynamic relationship between the primer, template and enzyme during reverse transcription is inferred. 5' truncation may be a successful evolutionary strategy that is exploited by L1 as a means to escape host suppression of transposition.

Cytokine concentrations and neutrophil elastase activity in bronchoalveolar lavage and induced sputum from patients with cystic fibrosis, mild asthma and healthy volunteers

BACKGROUND

Induced sputum (IS) has been proposed as a non-invasive alternative to bronchoalveolar lavage (BAL) for the assessment and monitoring of airways inflammation. The aim of this study was to compare both methods in patients with cystic fibrosis (CF). The possible differences between subjects with CF, mild asthma and healthy volunteers (HV) was also assessed.

METHOD

In a single centre, randomised, two way crossover study, 11 patients with CF, 9 mild asthmatics (MA) and 11 HV underwent BAL and hypertonic saline induction on consecutive days. Free neutrophil elastase (NE), neutrophil elastase/alpha(1)-anti-trypsin complex (NE-AAT), tumour necrosis factor receptor (p55) and interleukin-8 (IL-8) were measured in cell free supernatants.

RESULTS

Three CF patients reported serious adverse events following BAL. NE was usually undetectable in both IS or BAL samples and NE-AAT concentrations did not differ consistently between the two sampling methods. IL-8 and p55 levels in the CF patients tended to be higher in IS samples compared with BAL samples (median 19,860 vs. 3,855 pg/ml and 2.55 vs. 0.29 ng/ml, respectively). There was a significant difference in mean p55 concentrations between CF, MA and HV in IS samples (P=0.003) but not in BAL samples (P=0.36). The difference in mean IL-8 concentrations in IS samples between subject groups was statistically different (P=0.023).

CONCLUSIONS

IS samples can be safely obtained from CF patients. Analysis of IS samples can help to characterize the inflammatory process in the airways of CF patients. The serious adverse events following BAL in 3 CF patients highlight an inherent risk associated with this procedure.

Reversible depression of transcription during hibernation

Mammalian hibernators downregulate processes of energy production and consumption while maintaining cellular homeostasis. Energetic costs of transcription must be balanced with demands for gene products. Data from nuclear run-on assays indicate transcriptional initiation is reduced two fold in torpid golden-mantled ground squirrels ( Spermophilus lateralis) as compared to euthermic animals between bouts of torpor. In addition, elongation rates across the temperature range experienced by hibernators indicate a virtual arrest of transcription at the low body temperatures of torpor. Finally, there is no seasonal compensation or species-specific adaptation for increased elongational capacity in the cold. Thus, it appears that hibernators are not specifically adapted to continue transcription during torpor. Taken together, these data indicate that transcription arrests during torpor because of a moderate depression of initiation and a more severe inhibition of elongation, largely due to temperature effects. Restoration of euthermic body temperatures during the interbout arousals reverses this transcriptional depression and permits gene expression.

The DNA sequence and comparative analysis of human chromosome 20

The finished sequence of human chromosome 20 comprises 59,187,298 base pairs (bp) and represents 99.4% of the euchromatic DNA. A single contig of 26 megabases (Mb) spans the entire short arm, and five contigs separated by gaps totalling 320 kb span the long arm of this metacentric chromosome. An additional 234,339 bp of sequence has been determined within the pericentromeric region of the long arm. We annotated 727 genes and 168 pseudogenes in the sequence. About 64% of these genes have a 5' and a 3' untranslated region and a complete open reading frame. Comparative analysis of the sequence of chromosome 20 to whole-genome shotgun-sequence data of two other vertebrates, the mouse Mus musculus and the puffer fish Tetraodon nigroviridis, provides an independent measure of the efficiency of gene annotation, and indicates that this analysis may account for more than 95% of all coding exons and almost all genes.

PCR-based detection and identification of Burkholderia cepacia complex pathogens in sputum from cystic fibrosis patients

PCR amplification of the recA gene followed by restriction fragment length polymorphism (RFLP) analysis was investigated for the rapid detection and identification of Burkholderia cepacia complex genomovars directly from sputum. Successful amplification of the B. cepacia complex recA gene from cystic fibrosis (CF) patient sputum samples containing B. cepacia genomovar I, Burkholderia multivorans, B. cepacia genomovar III, Burkholderia stabilis, and Burkholderia vietnamiensis was demonstrated. In addition, the genomovar identifications determined directly from sputum were the same as those obtained after selective culturing. Sensitivity experiments revealed that recA-based PCR could reliably detect B. cepacia complex organisms to concentrations of 10(6) CFU g of sputum(-1). To fully assess the diagnostic value of the method, sputum samples from 100 CF patients were screened for B. cepacia complex infection by selective culturing and recA-based PCR. Selective culturing identified 19 samples with presumptive B. cepacia complex infection, which was corroborated by phenotypic analyses. Of the culture-positive sputum samples, 17 were also detected directly by recA-based PCR, while 2 samples were negative. The isolates cultured from both recA-negative sputum samples were subsequently identified as Burkholderia gladioli. RFLP analysis of the recA amplicons revealed 2 patients (12%) infected with B. multivorans, 11 patients (65%) infected with B. cepacia genomovar III-A, and 4 patients (23%) infected with B. cepacia genomovar III-B. These results demonstrate the potential of recA-based PCR-RFLP analysis for the rapid detection and identification of B. cepacia complex genomovars directly from sputum. Where the sensitivity of the assay proves a limitation, sputum samples can be analyzed by selective culturing followed by recA-based analysis of the isolate.

Translational initiation is uncoupled from elongation at 18 degrees C during mammalian hibernation

Cellular and organismal homeostasis must be maintained across a body temperature (Tb) range of 0 to 37 degrees C during mammalian hibernation. Hibernators depress biosynthetic activities including protein synthesis, concordant with limited energy availability and temperature effects on reaction rates. We used polysome analysis to show that initiation of protein synthesis ceases during entrance into torpor in golden-mantled ground squirrels (Spermophilus lateralis) when Tb reaches 18 degrees C. Elongation of preinitiated polypeptides continues slowly throughout the torpor bout. As Tb begins to rise, initiation resumes even at temperatures below 18 degrees C, although the euthermic polysome pattern is not reestablished. At precisely 18 degrees C, there is a large increase in initiation events and a complete restoration of euthermic polysome distribution patterns. These data indicate a role for both passive and active depression of translation during torpor and are consistent with a requirement for new protein biosynthesis during each interbout arousal.

Partner violence among adolescents in opposite-sex romantic relationships: findings from the National Longitudinal Study of Adolescent Health

OBJECTIVES

This report examines (1) the prevalence of psychological and minor physical violence victimization in a nationally representative sample of adolescents and (2) associations between sociodemographic factors and victimization.

METHODS

Analyses are based on 7500 adolescents who reported exclusively heterosexual romantic relationships in the National Longitudinal Study of Adolescent Health. Items from the Conflict Tactics Scale were used to measure victimization. Associations between victimization patterns and sociodemographic characteristics were assessed with polytomous logistic regression.

RESULTS

One third of adolescents reported some type of victimization, and 12% reported physical violence victimization. Although most sociodemographic characteristics were significantly associated with victimization, patterns varied by sex and type of victimization.

CONCLUSIONS

Psychological and minor physical violence victimization is common in opposite-sex romantic relationships during adolescence. The sex-specific associations between sociodemographic characteristics and patterns of partner violence victimization underscore the importance of pursuing longitudinal, theory-driven investigations of the characteristics and developmental histories of both partners in a couple to advance understanding of this public health problem.

Treatment compliance among prenatal care patients with substance abuse problems

There is an insufficient number of substance abuse treatment programs available to pregnant women; however, even when women do enroll in treatment, they often choose not to comply with particular components of their treatment. To better understand what factors are associated with a woman's likelihood of compliance with treatment, this study assesses 244 pregnant, substance-using women enrolled in a specialized substance abuse treatment program. Women who complied with treatment referrals are compared with those who did not comply with referrals on various factors including their sociodemographic characteristics, types of substance use before and during pregnancy, experiences of violence before and during pregnancy, and prior substance use treatment. Bivariate analysis found that outpatient treatment compliance was more likely among women who smoked cigarettes before pregnancy, women who had received previous substance abuse treatment, and women whose partner had received previous substance abuse treatment. Outpatient treatment compliance did not vary by sociodemographic characteristics, any other type of substance use, or the women's experiences of violence. Inpatient treatment compliance was more likely among women who received prior substance abuse treatment; however, no other characteristic was found to be associated with inpatient treatment compliance. Logistic regression analyses, which controlled for various factors, suggested that past experiences with substance abuse treatment by the woman or her partner were significantly associated with treatment referral compliance. These findings suggest that the previous treatment experiences of women and their partners are important factors in shaping a successful substance abuse treatment program for pregnant women.

Stressful life events and physical abuse among pregnant women in North Carolina

OBJECTIVES

This study estimates the prevalence of stressful life events and physical abuse among North Carolina women prior to infant delivery, and examines potential associations between abuse and the other stressors.

METHODS

Data were from the North Carolina Pregnancy Risk Assessment Monitoring System, a statewide representative survey of over 2,600 postpartum women. The survey assessed women's sociodemographic characteristics and their experiences of physical abuse and 13 other stressful life events before delivery. The prevalences of each life event and abuse were estimated. Logistic regression modeled the probability of women having high levels of stressful life events in relation to physical abuse and sociodemographics.

RESULTS

Most women were married, white, high school graduates, aged 20 or older. The most common stressful life events were residential moves, increased arguing with husbands/partners, family member hospitalizations, financial hardship, and deaths of loved ones. Fourteen percent of women had high levels of stressful events (5 or more), and almost 9% were physically abused. Abuse was positively associated with increased arguing with husbands/partners, physical fighting, having someone close with an alcohol/drug problem, becoming separated/divorced, and financial hardship. Logistic regression analysis showed that a high level of stressful life events was significantly more likely among women abused both before and during pregnancy (OR = 11.94) and among women abused before but not during pregnancy (OR = 14.19).

CONCLUSIONS

The high frequency of multiple stressful events and abuse in women's lives suggests that women's care providers should ask their patients about these issues, and offer appropriate referral/interventions to those in need.

Mutation frequency and type during ageing in mouse seminiferous tubules

Mutations arise in the germline by errors of replication, recombination and repair, and the movement of transposable elements. Transgenic mice bearing reporter genes such as lacZ have proven useful for measurements of spontaneous and induced mutation frequencies, as well as studies of the effects of ageing. In this study, testicular DNA from lacZ transgenic mice was examined for age-related effects on mutation frequency and type. The recovered transgene was tested for simple substitutions and rearrangements including transposition of endogenous mobile elements. There was no evidence for either an age-related accumulation of mutations, or for the insertion of retrotransposons into the lacZ reporter gene in the testis. We conclude that the frequency of retrotransposition of several mouse mobile elements into the lacZ reporter gene is less than 3.73x10(-8). This is significantly less than the known frequency of approximately 7% of all spontaneous mutations in the mouse being due to retrotransposition of these elements.

In vivo fucosylation of lacto-N-neotetraose and lacto-N-neohexaose by heterologous expression of Helicobacter pylori alpha-1,3 fucosyltransferase in engineered Escherichia coli

We report here the in vivo production of type 2 fucosylated-N-acetyllactosamine oligosaccharides in Escherichia coli. Lacto-N-neofucopentaose Galbeta1-4GlcNAcbeta1-3Galbeta1-4(Fucalpha1-3)Glc, lacto-N-neodifucohexaose Galbeta1-4(Fucalpha1-3)Glc-NAcbeta1-3Galbeta1-4(Fucalpha1-3)Glc, and lacto-N-neodifucooctaose Galbeta1-4GlcNAcbeta1-3Galbeta1-4(Fucalpha1-3)GlcNAcbeta1-3Galbeta1-4(Fucalpha1-3)Glc were produced from lactose added in the culture medium. Two of them carry the Lewis X human antigen. High cell density cultivation allowed obtaining several grams of fucosylated oligosaccharides per liter of culture. The fucosylation reaction was catalyzed by an alpha-1,3 fucosyltransferase of Helicobacter pylori overexpressed in E. coli with the genes lgtAB of N. meningitidis. The strain was genetically engineered in order to provide GDP-fucose to the system, by genomic inactivation of gene wcaJ involved in colanic acid synthesis and overexpression of RcsA, positive regulator of the colanic acid operon. To prevent fucosylation at the glucosyl residue, lactulose Galbeta1-4Fru was assayed in replacement of lactose. Lactulose-derived oligosaccharides carrying fucose were synthesized and characterized. Fucosylation of the fructosyl residue was observed, indicating a poor acceptor specificity of the fucosyltransferase of H. pylori.

Preventive counseling during prenatal care: Pregnancy Risk Assessment Monitoring System (PRAMS)

BACKGROUND

Prenatal care provides an opportunity for counseling about behaviors and experiences that increase the likelihood of adverse maternal and fetal outcomes.

OBJECTIVE

To document (1) prevalence of preventive health counseling during prenatal care, (2) prevalence of women in higher need of counseling about specific health concerns, and (3) whether women in higher need for counseling were more likely than women in lower need to have received counseling.

METHODS

Analysis of the Pregnancy Risk Assessment Monitoring System (PRAMS), a state-specific, population-based, random sample of postpartum women, was performed by using data from 14 states for births during 1997 or 1998, for a total of 24,620 participants. Outcome measures included report of preventive health counseling during prenatal visits by specific topic as well as behaviors and experiences about cigarette use, alcohol use, breast-feeding, partner violence, and preterm labor.

RESULTS

The percentage of women that report preventive counseling during prenatal care is relatively high (> or =75%) for 9 of 13 topics. However, the percentage of women that report counseling is relatively low (<75%) for partner violence, seat belt use, illegal drug use, and human immunodeficiency virus (HIV) risk. Except for counseling about cigarette and alcohol use, women in higher need, compared with women in lower need, for three other health topics were not significantly more likely to receive counseling.

CONCLUSIONS

Preventive health counseling for partner violence, seat-belt use, illegal drug use, and risk of HIV could be increased across prenatal settings. Counseling should involve assessment of risks, with focused counseling related to those risks.

Synthesis and kinetic evaluation of peptide alpha-keto-beta-aldehyde-based inhibitors of trypsin-like serine proteases

New, synthetic peptide analogues bearing a C-terminal basic alpha-keto-beta-aldehyde moiety were prepared as novel inhibitors of the trypsin-like serine proteases. The compounds, Ac-Leu-Leu-Arg-COCHO, Ac-Arg-Gln-Arg-COCHO and Boc-Val-Leu-Lys-COCHO were evaluated kinetically against trypsin and three other trypsin-like serine proteases, tryptase, plasmin and thrombin, all of which are implicated as mediators of important disease processes. Results illustrate that alpha-keto-beta-aldehydes are potent inhibitors, with similar potency to comparable peptide aldehydes, and intriguingly, appearto act, in some instances, by a novel mechanism of action. Ac-Leu-Leu-Arg-COCHO, an analogue of the natural product leupeptin, is a potent, tight-binding inhibitor of trypsin (Ki(final) = 1.9 microM), plasmin (Ki(final) = 4.9 microM) and tryptase (Ki(final) = 1.2 microM) and an irreversible inactivator of thrombin (k2nd 4,500 M(-1).min(-1)). Boc-Val-Leu-Lys-COCHO was found to be a tight-binding inhibitor of its target protease plasmin (Ki(final) = 3.1 microM) and was inactive against thrombin. Ac-Arg-Gln-Arg-COCHO was a slow-binding inhibitor of tryptase (Ki(final) = 1.6 microM) and also irreversibly inactivated trypsin (k2nd = 8,920 M(-1) min(-1)). Peptides or peptidomimetics with a C-terminal basic alpha-keto-beta-aldehyde function thus provide a useful new molecular template for the development of new therapeutic agents against a wide range of disorders, such as coagulopathies and asthma, which may be mediated by the aberrant activity of trypsin-like serine proteases.

Physical abuse of women before, during, and after pregnancy

CONTEXT

Clinicians who care for new mothers and infants need information concerning postpartum physical abuse of women as a foundation on which to develop appropriate clinical screening and intervention procedures. However, no previous population-based studies have been conducted of postpartum physical abuse.

OBJECTIVES

To examine patterns of physical abuse before, during, and after pregnancy in a representative statewide sample of North Carolina women.

DESIGN, SETTING, AND PARTICIPANTS

Survey of participants in the North Carolina Pregnancy Risk Assessment Monitoring System (NC PRAMS). Of the 3542 women invited to participate in NC PRAMS between July 1, 1997, and December 31, 1998, 75% (n = 2648) responded.

MAIN OUTCOME MEASURES

Prevalence of physical abuse during the 12 months before pregnancy, during pregnancy, and after infant delivery; injuries and medical interventions resulting from postpartum abuse; and patterns of abuse over time in relation to sociodemographic characteristics and use of well-baby care.

RESULTS

The prevalence of abuse before pregnancy was 6.9% (95% confidence interval [CI], 5.6%-8.2%) compared with 6.1% (95% CI, 4.8%-7.4%) during pregnancy and 3.2% (95% CI, 2.3%-4.1%) during a mean postpartum period of 3.6 months. Abuse during a previous period was strongly predictive of later abuse. Most women who were abused after pregnancy (77%) were injured, but only 23% received medical treatment for their injuries. Virtually all abused and nonabused women used well-baby care; private physicians were the most common source of care. The mean number of well-baby care visits did not differ significantly by maternal patterns of abuse.

CONCLUSION

Since well-baby care use is similar for abused and nonabused mothers, pediatric practices may be important settings for screening women for violence.

A study of the anti-invasive properties of N-alpha-phthalimidomethyl-ketomethylene tripeptide-based metalloprotease inhibitors

We have developed matrix metalloprotease (MMP) inhibitors based on synthetic peptides incorporating a non-cleavable peptide-bond isostere at the site of the putative scissile bond. These inhibitors, N-alpha-phthaloyl-Gly-psi(CO-CH2)-Leu-Tyr-Ala-NH2 (Pht-G-CH2-LYA-NH2) and N-alpha-phthaloyl-Gly-psi(CO-CH2)-Leu-Tic-Ala-NH2 (Pht-G-CH2-LTcA-NH2) were kinetically evaluated against the type IV collagenases, gelatinase A (MMP-2) and B (MMP-9), and compared with an exactly analogous chelating-based inhibitor, N-alpha-mercaptoacetyl-Leu-Tyr-Ala-NH2 (HSCH2CO-LYA-NH2). The peptide inhibitors were also tested for their anti-invasive effects on breast carcinoma cell lines using a modification of the Boyden chamber assay. Gelatin zymography was utilized to identify gelatinolytic activities present in media removed from cultured breast cancer cells. Of the two N-alpha-phthalimidomethyl-ketomethylene peptide-based inhibitors, Pht-G-CH2-LYA-NH2 proved the more effective inhibitor of MMP-2 and MMP-9 (Ki 34.27 and 45.75 microM, respectively). However, when tested against two breast cancer cell lines, T47D and MDA-MB-231, both inhibitors were able to effectively reduce tumour cell invasion through a type IV collagen matrix by up to 91.2%. Of particular interest was the observation that Pht-G-CH2-LYA-NH2 was the most potent inhibitor of invasion by the highly aggressive MDA-MB-231 cells, despite the cells' relative lack of active secreted metalloprotease activity. The results obtained from this kinetic and anti-invasive analysis of the new inhibitors suggest that compounds incorporating the N-alpha-phthalimidomethyl-ketomethylene peptide-bond isostere may have potential for development as new agents with anti-metastatic properties.

Local and national uses of a Road to Recovery evaluation

Evaluation fellows from the George Washington University School of Public Health and Health Services conducted an evaluation of the Road to Recovery program of the Mid-Atlantic division of the American Cancer Society. The evaluation included qualitative analysis of program operation, mailed surveys, in-depth interviews with patients and drivers, and interviews with social workers from treatment centers. Results indicated that patients and drivers were satisfied with the program. Patients appreciated the ability of drivers to provide personalized, reliable service. The recruitment of sufficient drivers to meet transportation demand was a problem. High staff turnover and a lack of electronic tracking of standard information hindered program monitoring. A Mid-Atlantic Advisory Transportation Group reviewed the findings and made recommendations for service improvement. The Mid-Atlantic division evaluation contributed to an "evaluation synthesis" in which participants from the three divisions that had conducted Road to Recovery evaluations examined study data and made recommendations for reorganizing the national transportation program. A Transportation Program Design Team then held fact-finding meetings and adopted goals and objectives for a new national transportation program. The primary lesson learned was the far-reaching effects that a single program evaluation may have for various stakeholders and for an organization.

Nucleic acid chaperone activity of the ORF1 protein from the mouse LINE-1 retrotransposon

Non-LTR retrotransposons such as L1 elements are major components of the mammalian genome, but their mechanism of replication is incompletely understood. Like retroviruses and LTR-containing retrotransposons, non-LTR retrotransposons replicate by reverse transcription of an RNA intermediate. The details of cDNA priming and integration, however, differ between these two classes. In retroviruses, the nucleocapsid (NC) protein has been shown to assist reverse transcription by acting as a "nucleic acid chaperone," promoting the formation of the most stable duplexes between nucleic acid molecules. A protein-coding region with an NC-like sequence is present in most non-LTR retrotransposons, but no such sequence is evident in mammalian L1 elements or other members of its class. Here we investigated the ORF1 protein from mouse L1 and found that it does in fact display nucleic acid chaperone activities in vitro. L1 ORF1p (i) promoted annealing of complementary DNA strands, (ii) facilitated strand exchange to form the most stable hybrids in competitive displacement assays, and (iii) facilitated melting of an imperfect duplex but stabilized perfect duplexes. These findings suggest a role for L1 ORF1p in mediating nucleic acid strand transfer steps during L1 reverse transcription.

Inhibition of Escherichia coli glucosamine synthetase by novel electrophilic analogues of glutamine--comparison with 6-diazo-5-oxo-norleucine

A series of electrophilic glutamine analogues based on 6-diazo-5-oxo-norleucine has been prepared, using novel synthetic routes, and evaluated as inhibitors of Escherichia coli glucosamine synthetase. The gamma-dimethylsulphonium salt analogue of glutamine was found to be one of the most potent inactivators of this enzyme yet reported, with an apparent second order rate constant (k2/Ki) of 3.5 x 10(5) M(-1) min(-1).