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Objectives: In a cohort of 21,816 Brazilian steelworkers we found mortality from motor-vehicle injury was twice that in the State population. A nested case-control study was therefore undertaken to investigate possible socio-demographic, medical and occupational risk factors for this increased risk.Methods: Cases were defined as all steelworkers in the cohort who died of motor-vehicle injury during employment in the period 1977-1992. For each case, four controls were selected at random from workers in the cohort who were employed at the time of death of the case, and who were born in the same year as the case. Data on socio-demographic factors, and medical and occupational histories were obtained from personnel, industrial hygiene and medical records, and the relation of these factors to risk of motor-vehicle injury was analysed using conditional logistic regression.Results: In a multivariate analysis, the risk of death from motor-vehicle injury was independently associated with being unmarried (odds ratio [OR] compared to married = 3.21, 95% confidence interval [CI]: 1.84-5.59), having a hearing defect (OR = 2.28, 95% CI: 1.10-4.74) and exposure to moderate (OR = 1.71, 95% CI: 1.03-2.83) or high (OR = 2.00, 95% CI: 1.18-3.39) levels of noise at work. The risk of fatal motor-vehicle injury increased with intensity of occupational noise exposure (P = 0.004).Conclusions: The raised risk of motor-vehicle injury death associated with single marital status is likely to relate to selective factors in the types of individual who remain single, and behaviours associated with being unmarried. The raised risks in relation to hearing defects and exposure to occupational noise, factors that do not appear to have been examined previously, imply that occupational noise exposures might be a cause of fatal motor-vehicle accidents outside the workplace. This finding may have widespread public health consequences since high levels of noise in the workplace and occupationally acquired hearing deficits are prevalent in several occupations. Further investigation is needed to confirm the associated and its mechanisms and, if it is causal, to develop preventive strategies. [ABSTRACT FROM AUTHOR]

Public transport disruptions caused by the COVID-19 pandemic had wide-ranging impacts on the ability of individuals to access health care. Individuals with opioid use disorder represent an especially vulnerable population due to the necessity of frequent, supervised doses of opioid agonists. Focused on Toronto, a major Canadian city suffering from the opioid epidemic, this analysis uses novel realistic routing methodologies to quantify how travel times to individuals\220 nearest clinics changed due to public transport disruptions from 2019 to 2020. Individuals seeking opioid agonist treatment face very constrained windows of access due to the need to manage work and other essential activities. We find that thousands of households in the most materially and socially deprived neighbourhoods crossed 30 and 20-minute travel time thresholds to their nearest clinic. As even small changes to travel times can lead to missed appointments and heighten the chances of overdose and death, understanding the distribution of those most impacted can help inform future policy measures to ensure adequate access to care., Competing Interests: Declarations of Interest None., (Copyright © 2023 Elsevier B.V. All rights reserved.)

One of the most common cell shape changes driving morphogenesis in diverse animals is the constriction of the apical cell surface. Apical constriction depends on contraction of an actomyosin network in the apical cell cortex, but such actomyosin networks have been shown to undergo continual, conveyor belt-like contractions before the shrinking of an apical surface begins. This finding suggests that apical constriction is not necessarily triggered by the contraction of actomyosin networks, but rather can be triggered by unidentified, temporally-regulated mechanical links between actomyosin and junctions. Here, we used C. elegans gastrulation as a model to seek genes that contribute to such dynamic linkage. We found that α-catenin and β-catenin initially failed to move centripetally with contracting cortical actomyosin networks, suggesting that linkage is regulated between intact cadherin-catenin complexes and actomyosin. We used proteomic and transcriptomic approaches to identify new players, including the candidate linkers AFD-1/afadin and ZYX-1/zyxin, as contributing to C. elegans gastrulation. We found that ZYX-1/zyxin is among a family of LIM domain proteins that have transcripts that become enriched in multiple cells just before they undergo apical constriction. We developed a semi-automated image analysis tool and used it to find that ZYX-1/zyxin contributes to cell-cell junctions' centripetal movement in concert with contracting actomyosin networks. These results identify several new genes that contribute to C. elegans gastrulation, and they identify zyxin as a key protein important for actomyosin networks to effectively pull cell-cell junctions inward during apical constriction. The transcriptional upregulation of ZYX-1/zyxin in specific cells in C. elegans points to one way that developmental patterning spatiotemporally regulates cell biological mechanisms in vivo. Because zyxin and related proteins contribute to membrane-cytoskeleton linkage in other systems, we anticipate that its roles in regulating apical constriction in this manner may be conserved., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Slabodnick et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Accessibility indicators are widely used in transportation, urban and healthcare planning, among many other applications. These measures are weighted sums of reachable opportunities from a given origin, conditional on the cost of movement, and are estimates of the potential for spatial interaction. Over time, various proposals have been forwarded to improve their interpretability: one of those methodological additions have been the introduction of competition. In this paper we focus on competition, but first demonstrate how a widely used measure of accessibility with congestion fails to properly match the opportunity-seeking population. We then propose an alternative formulation of accessibility with competition, a measure we call spatial availability. This measure relies on proportional allocation balancing factors (friction of distance and population competition) that are equivalent to imposing a single constraint on conventional gravity-based accessibility. In other words, the proportional allocation of opportunities results in a spatially available opportunities value which is assigned to each origin that, when all origin values are summed, equals the total number of opportunities in the region. We also demonstrate how Two-Stage Floating Catchment Area (2SFCA) methods are equivalent to spatial availability and can be reconceptualized as singly-constrained accessibility. To illustrate the application of spatial availability and compare it to other relevant measures, we use data from the 2016 Transportation Tomorrow Survey of the Greater Golden Horseshoe area in southern Ontario, Canada. Spatial availability is an important contribution since it clarifies the interpretation of accessibility with competition and paves the way for future applications in equity analysis (e.g., spatial mismatch, opportunity benchmarking, policy intervention scenario analysis)., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Soukhov et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

As the COVID-19 pandemic continues, understanding connections between economic pressures and mental health experiences is critical in comprehending how stressful global events can affect families. Although economic pressures and stress can negatively impact mental health, approach coping strategies may provide reductions in negative mental health experiences for parents compared to avoidant coping strategies. Despite recent work showing that stress resulting from the pandemic can have negative implications for the mental health of parents with young children, there is little known about the mental health of parents with adolescents. This study utilized a longitudinal sample of 198 parents (194 biological parents; 103 Fathers, and 91 Mothers) of adolescents and examined the mediating impact of COVID-19 stress on the relationship between economic pressure and subsequent depressive and anxious symptoms. Additionally, approach and avoidant coping strategies were examined as potential moderators between COVID-19 stress and later mental health. Results indicated that parents who experienced economic pressure reported worsening mental health across the school semester, with COVID-19 stress mediating this pathway. Further, approach coping strategies moderated the association between COVID-19 stress and later anxiety symptoms such that higher levels of coping associated with greater rates of later anxiety symptoms, while lower levels of coping associated with less anxiety symptoms later. Avoidant coping strategies also moderated these associations, such that greater use associated with greater depressive and anxious symptomology later. These findings emphasize that parents are experiencing worsening mental health following the onset of the pandemic and that there is an urgent need for increased mental health services to assist families during this time., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Morgan, Higgins, Ingram and Rogers.)

In this paper we analyze the changes in accessibility to emergency and community food services before and during the COVID-19 pandemic in the City of Hamilton, Ontario. Many of these food services are the last line of support for households facing food insecurity; as such, their relevance cannot be ignored in the midst of the economic upheaval caused by the pandemic. Our analysis is based on the application of balanced floating catchment areas and concentrates on households with lower incomes (

The constitutional t(11;22)(q23;q11) translocation is the only recurrent non-Robertsonian translocation known in humans. Carriers are phenotypically normal and are usually referred for cytogenetic testing because of multiple miscarriages, infertility, or having aneuploidy in offspring. A breast cancer predisposition has been suggested, but previous studies have been small and had methodological shortcomings. We therefore conducted a long-term prospective study of cancer and mortality risk in carriers. We followed 65 male and 101 female carriers of t(11;22)(q23;q11) diagnosed in cytogenetic laboratories in Britain during 1976-2005 for cancer and deaths for an average of 21.4 years per subject. Standardised mortality (SMR) and incidence (SIR) ratios were calculated comparing the numbers of observed events with those expected from national age-, sex-, country- and calendar-period-specific population rates. Cancer incidence was borderline significantly raised for cancer overall (SIR = 1.56, 95% CI: 0.98-2.36, n = 22), and significantly raised for invasive breast cancer (SIR = 2.74, 95% CI: 1.18-5.40, n = 8) and in situ breast cancer (SIR = 13.0, 95% CI: 3.55-33.4, n = 4). Breast cancer risks were particularly increased at ages <50 (SIR = 4.37, 95% CI: 1.42-10.2 for invasive, SIR = 22.8, 95% CI: 2.76-82.5 for in situ). Mortality was borderline significantly raised for breast cancer (SMR = 4.82, 95% CI: 0.99-14.1) but not significantly raised for other cancers or causes. Individuals diagnosed with t(11;22)(q23;q11) appear to be at several-fold increased breast cancer risk, with the greatest risks at premenopausal ages. Further research is required to understand the genetic mechanism involving 11q23 and 22q11 and there may be a need for enhanced breast cancer surveillance among female carriers., (© 2018 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.)

Floating Catchment Area (FCA) methods are a popular tool to investigate accessibility to public facilities, in particular health care services. FCA approaches are attractive because, unlike other accessibility measures, they take into account the potential for congestion of facilities. This is done by 1) considering the population within the catchment area of a facility to calculate a variable that measures level of service, and then 2) aggregating the level of service by population centers subject to catchment area constraints. In this paper we discuss an effect of FCA approaches, an artifact that we term demand and level of service inflation. These artifacts are present in previous implementations of FCA methods. We argue that inflation makes interpretation of estimates of accessibility difficult, which has possible deleterious consequences for decision making. Next, we propose a simple and intuitive approach to proportionally allocate demandand and level of service in FCA calculations. The approach is based on a standardization of the impedance matrix, similar to approaches popular in the spatial statistics and econometrics literature. The result is a more intiuitive measure of accessibility that 1) provides a local version of the provider-to-population ratio; and 2) preserves the level of demand and the level of supply in a system. We illustrate the relevant issues with some examples, and then empirically by means of a case study of accessibility to family physicians in the Hamilton Census Metropolitan Area (CMA), in Ontario, Canada. Results indicate that demand and supply inflation/deflation affect the interpretation of accessibility analysis using existing FCA methods, and that the proposed adjustment can lead to more intuitive results., Competing Interests: The authors have declared that no competing interests exist.

A balanced robertsonian translocation (rob) results from fusion of 2 acrocentric chromosomes. Carriers are phenotypically normal and are often diagnosed because of recurrent miscarriages, infertility, or aneuploid offspring. Mortality and site-specific cancer risks in carriers have not been prospectively investigated. We followed 1,987 carriers diagnosed in Great Britain for deaths and cancer risk, over an average of 24.1 years. Standardized mortality and incidence ratios were calculated comparing the number of observed events against population rates. Overall mortality was higher for carriers diagnosed before age 15 years (standardized mortality ratio (SMR) = 2.00, 95% confidence interval (CI): 1.09, 3.35), similar for those diagnosed aged 15-44 years (SMR = 1.06, 95% CI: 0.86-1.28), and lower for those diagnosed aged 45-84 years (SMR = 0.81, 95% CI: 0.68, 0.95). Cancer incidence was higher for non-Hodgkin lymphoma (standardized incidence ratio (SIR) = 1.90, 95% CI: 1.01, 3.24) and childhood leukemia (SIR = 14.5, 95% CI: 1.75, 52.2), the latter particularly in rob(15;21) carriers (SIR = 447.8, 95% CI: 11.3, 2,495). Rob(13;14) carriers had a higher breast cancer risk (SIR = 1.58, 95% CI: 1.12, 2.15). Mortality risks relative to the population in diagnosed carriers depend on age at cytogenetic diagnosis, possibly reflecting age-specific cytogenetic referral reasons. Carriers might be at greater risk of childhood leukemia and non-Hodgkin lymphoma and those diagnosed with rob(13;14) of breast cancer., (© The Author(s) 2019. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health.)

Little work has accounted for congestion, using data that reflects driving patterns, traffic volume, and speed, to examine the association between traffic emissions and human health. In this study, we performed a health risk assessment of PM 2.5 emissions during congestion periods in the Greater Toronto and Hamilton Area (GTHA), Canada. Specifically, we used a micro-level approach that combines the Stochastic User Equilibrium Traffic Assignment Algorithm with a MOVES emission model to estimate emissions considering congestion conditions. Subsequently, we applied a concentration-response function to estimate PM 2.5 -related mortality, and the associated health costs. Our results suggest that traffic congestion has a substantial impact on human health and the economy in the GTHA, especially at the most congested period (7:00am). Considering daily mortality, our results showed an impact of 206 (boundary test 95%: 116; 297) and 119 (boundary test 95%: 67; 171) deaths per year (all-cause and cardiovascular mortality, respectively). The economic impact from daily mortality is approximately $1.3 billion (boundary test 95%: 0.8; 1.9), and $778 million (boundary test 95%: 478; 981), for all-cause and cardiovascular mortality, respectively. Our study can guide reliable projections of transportation and air pollution levels, improving the capability of the medical community to prepare for future trends., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Fluorescent protein tags are fundamental tools used to visualize gene products and analyze their dynamics in vivo. Recent advances in genome editing have expedited the precise insertion of fluorescent protein tags into the genomes of diverse organisms. These advances expand the potential of in vivo imaging experiments and facilitate experimentation with new, bright, photostable fluorescent proteins. Most quantitative comparisons of the brightness and photostability of different fluorescent proteins have been made in vitro, removed from biological variables that govern their performance in cells or organisms. To address the gap, we quantitatively assessed fluorescent protein properties in vivo in an animal model system. We generated transgenic Caenorhabditis elegans strains expressing green, yellow, or red fluorescent proteins in embryos and imaged embryos expressing different fluorescent proteins under the same conditions for direct comparison. We found that mNeonGreen was not as bright in vivo as predicted based on in vitro data but is a better tag than GFP for specific kinds of experiments, and we report on optimal red fluorescent proteins. These results identify ideal fluorescent proteins for imaging in vivo in C. elegans embryos and suggest good candidate fluorescent proteins to test in other animal model systems for in vivo imaging experiments., (© 2016 Heppert et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).)

Apical constriction is a change in cell shape that drives key morphogenetic events including gastrulation and neural tube formation. Apical force-producing actomyosin networks drive apical constriction by contracting while connected to cell-cell junctions. The mechanisms by which developmental patterning regulates these actomyosin networks and associated junctions with spatial precision are not fully understood. Here we identify a myosin light-chain kinase MRCK-1 as a key regulator of C. elegans gastrulation that integrates spatial and developmental patterning information. We show that MRCK-1 is required for activation of contractile actomyosin dynamics and elevated cortical tension in the apical cell cortex of endoderm precursor cells. MRCK-1 is apically localized by active Cdc42 at the external, cell-cell contact-free surfaces of apically constricting cells, downstream of cell fate determination mechanisms. We establish that the junctional components α-catenin, β-catenin, and cadherin become highly enriched at the apical junctions of apically constricting cells and that MRCK-1 and myosin activity are required in vivo for this enrichment. Taken together, our results define mechanisms that position a myosin activator to a specific cell surface where it both locally increases cortical tension and locally enriches junctional components to facilitate apical constriction. These results reveal crucial links that can tie spatial information to local force generation to drive morphogenesis., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

A central goal in the development of genome engineering technology is to reduce the time and labor required to produce custom genome modifications. Here we describe a new selection strategy for producing fluorescent protein (FP) knock-ins using CRISPR/Cas9-triggered homologous recombination. We have tested our approach in Caenorhabditis elegans. This approach has been designed to minimize hands-on labor at each step of the procedure. Central to our strategy is a newly developed self-excising cassette (SEC) for drug selection. SEC consists of three parts: a drug-resistance gene, a visible phenotypic marker, and an inducible Cre recombinase. SEC is flanked by LoxP sites and placed within a synthetic intron of a fluorescent protein tag, resulting in an FP-SEC module that can be inserted into any C. elegans gene. Upon heat shock, SEC excises itself from the genome, leaving no exogenous sequences outside the fluorescent protein tag. With our approach, one can generate knock-in alleles in any genetic background, with no PCR screening required and without the need for a second injection step to remove the selectable marker. Moreover, this strategy makes it possible to produce a fluorescent protein fusion, a transcriptional reporter and a strong loss-of-function allele for any gene of interest in a single injection step., (Copyright © 2015 by the Genetics Society of America.)

The coiled-coil is one of the most ubiquitous and well studied protein structural motifs. Significant effort has been devoted to dissecting subtle variations of the typical heptad repeat sequence pattern that can designate larger topological features such as relative α-helical orientation and oligomer size. Here we report the X-ray structure of a model coiled-coil peptide, HA2-Del-L2seM, which forms an unanticipated core antiparallel dimer with potential sites for discrete higher-order multimerization (trimer or tetramer). In the X-ray structure, a third, partially-ordered α-helix is weakly associated with the antiparallel dimer and analytical ultracentrifugation experiments indicate the peptide forms a well-defined tetramer in solution. The HA2-Del-L2seM sequence is closely related to a parent model peptide, HA2-Del, which we previously reported adopts a parallel trimer; HA2-Del-L2seM differs by only hydrophobic leucine to selenomethione mutations and thus this subtle difference is sufficient to switch both relative α-helical topology and number of α-helices participating in the coiled-coil. Comparison of the X-ray structures of HA2-Del-L2seM (reported here) with the HA2-Del parent (reported previously) reveals novel interactions involving the selenomethionine residues that promote antiparallel coiled-coil configuration and preclude parallel trimer formation. These novel atomic insights are instructive for understanding subtle features that can affect coiled-coil topology and provide additional information for design of antiparallel coiled-coils., (© 2015 Wiley Periodicals, Inc.)

Little is known about the main routes of human cytomegalovirus (HCMV) transmission in young adult populations. This study investigated risk factors for HCMV transmission in young adults attending university over a 3-year period. Blood samples were tested for HCMV specific viral capsid antigen IgG by enzyme immunoassay. Being born in a developing country and having lived in Africa were associated with HCMV seropositivity at study onset. No risk factors were associated with HCMV seroconversion over the 3-year follow-up. In contrast to previous reports, sexual activity was not associated with HCMV seroprevalence or seroconversion.

The coiled-coil is one of the most common protein structural motifs. Amino acid sequences of regions that participate in coiled-coils contain a heptad repeat in which every third then forth residue is occupied by a hydrophobic residue. Here we examine the consequences of a "stutter," a deviation of the idealized heptad repeat that is found in the central coiled-coil of influenza hemagluttinin HA2. Characterization of a peptide containing the native stutter-containing HA2 sequence, as well as several variants in which the stutter was engineered out to restore an idealized heptad repeat pattern, revealed that the stutter is important for allowing coiled-coil formation in the WT HA2 at both neutral and low pH (7.1 and 4.5). By contrast, all variants that contained idealized heptad repeats exhibited marked pH-dependent coiled-coil formation with structures forming much more stably at low pH. A crystal structure of one variant containing an idealized heptad repeat, and comparison to the WT HA2 structure, suggest that the stutter distorts the optimal interhelical core packing arrangement, resulting in unwinding of the coiled-coil superhelix. Interactions between acidic side chains, in particular E69 and E74 (present in all peptides studied), are suggested to play a role in mediating these pH-dependent conformational effects. This conclusion is partially supported by studies on HA2 variant peptides in which these positions were altered to aspartic acid. These results provide new insight into the structural role of the heptad repeat stutter in HA2., (© 2014 Wiley Periodicals, Inc.)

Vaccines that elicit a protective broadly neutralizing antibody (bNAb) response and monoclonal antibody therapies are critical for the treatment and prevention of viral infections. However, isolation of protective neutralizing antibodies has been challenging for some viruses, notably those with high antigenic diversity or those that do not elicit a bNAb response in the course of natural infection. Here, we discuss recent work that employs protein engineering strategies to design immunogens that elicit bNAbs or engineer novel bNAbs. We highlight the use of rational, computational, and combinatorial strategies and assess the potential of these approaches for the development of new vaccines and immunotherapeutics., (Copyright © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.)

We previously described potent inhibition of Ebola virus entry by a 'C-peptide' based on the GP2 C-heptad repeat region (CHR) targeted to endosomes ('Tat-Ebo'). Here, we report the synthesis and evaluation of C-peptides conjugated to cholesterol, and Tat-Ebo analogs containing covalent side chain-side chain crosslinks to promote α-helical conformation. We found that the cholesterol-conjugated C-peptides were potent inhibitors of Ebola virus glycoprotein (GP)-mediated cell entry (~10(3)-fold reduction in infection at 40 μM). However, this mechanism of inhibition is somewhat non-specific because the cholesterol-conjugated peptides also inhibited cell entry mediated by vesicular stomatitis virus glycoprotein G. One side chain-side chain crosslinked peptide had moderately higher activity than the parent compound Tat-Ebo. Circular dichroism revealed that the cholesterol-conjugated peptides unexpectedly formed a strong α-helical conformation that was independent of concentration. Side chain-side chain crosslinking enhanced α-helical stability of the Tat-Ebo variants, but only at neutral pH. These result provide insight into mechanisms of C-peptide inhibiton of Ebola virus GP-mediated cell entry., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Chronic lymphocytic leukemia (CLL) is a clonal disease of a subset of human B lymphocytes. Although the cause of the disease is unknown, its development and evolution appear to be promoted by signals delivered when B-cell receptors (BCRs) engage (auto)antigens. Here, using a peptide phage display library of enhanced size and diverse composition, we examined the binding specificity of a recombinant monoclonal antibody (mAb) constructed with the heavy chain and light chain variable domains of a CLL BCR that does not exhibit somatic mutations. As determined by testing the peptides identified in the selected peptide phage pool, this CLL-associated unmutated mAb bound a diverse set of sequences, some of which clustered in families based on amino acid sequence. Synthesis of these peptides and characterization of binding with the CLL-associated mAb revealed that mAb-peptide interactions were generally specific. Moreover, the mAb-peptide interactions were of lower affinities (micromolar KD), as measured by surface plasmon resonance, than those observed with a CLL mAb containing somatic mutations (nanomolar KD) and with immunoglobulin heavy chain variable (IGHV)-mutated antibodies selected by environmental antigens. This information may be of value in identifying and targeting B lymphocytes expressing specific BCRs in CLL patients and healthy subjects with monoclonal B lymphocytosis.

Campylobacter jejuni is the leading cause of human bacterial gastroenteritis worldwide, but source attribution of the organism is difficult. Previously, DNA microarrays were used to investigate isolate source, which suggested a non-livestock source of infection. In this study we analysed the genome content of 162 clinical, livestock and water and wildlife (WW) associated isolates combined with the previous study. Isolates were grouped by genotypes into nine clusters (C1 to C9). Multilocus sequence typing (MLST) data demonstrated that livestock associated clonal complexes dominated clusters C1-C6. The majority of WW isolates were present in the C9 cluster. Analysis of previously reported genomic variable regions demonstrated that these regions were linked to specific clusters. Two novel variable regions were identified. A six gene multiplex PCR (mPCR) assay, designed to effectively differentiated strains into clusters, was validated with 30 isolates. A further five WW isolates were tested by mPCR and were assigned to the C7-C9 group of clusters. The predictive mPCR test could be used to indicate if a clinical case has come from domesticated or WW sources. Our findings provide further evidence that WW C. jejuni subtypes show niche adaptation and may be important in causing human infection., (© 2013 John Wiley & Sons Ltd and Society for Applied Microbiology.)

Viral fusion proteins undergo dramatic conformational transitions during membrane fusion. For viruses that enter through the endosome, these conformational rearrangements are typically pH sensitive. Here, we provide a comprehensive review of the molecular interactions that govern pH-dependent rearrangements and introduce a paradigm for electrostatic residue pairings that regulate progress through the viral fusion coordinate. Analysis of structural data demonstrates a significant role for side-chain protonation in triggering conformational change. To characterize this behavior, we identify two distinct residue pairings, which we define as Histidine-Cation (HisCat) and Anion-Anion (AniAni) interactions. These side-chain pairings destabilize a particular conformation via electrostatic repulsion through side-chain protonation. Furthermore, two energetic control mechanisms, thermodynamic and kinetic, regulate these structural transitions. This review expands on the current literature by identification of these residue clusters, discussion of data demonstrating their function, and speculation of how these residue pairings contribute to the energetic controls., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Ebola virus and Sudan virus are members of the family Filoviridae of nonsegmented negative-strand RNA viruses ("filoviruses") that cause severe hemorrhagic fever with fatality rates as high as 90%. Infection by filoviruses requires membrane fusion between the host and the virus; this process is facilitated by the two subunits of the envelope glycoprotein, GP1 (the surface subunit) and GP2 (the transmembrane subunit). The membrane-proximal external region (MPER) is a Trp-rich segment that immediately precedes the transmembrane domain of GP2. In the analogous glycoprotein for HIV-1 (gp41), the MPER is critical for membrane fusion and is the target of several neutralizing antibodies. However, the role of the MPER in filovirus GP2 and its importance in membrane fusion have not been established. Here, we characterize the conformational properties of peptides representing the GP MPER segments of Ebola virus and Sudan virus in the presence of micelle-forming surfactants and lipids, at pH 7 and 4.6. Circular dichroism spectroscopy and tryptophan fluorescence indicate that the GP2 MPER peptides bind to micelles of sodium dodecyl sulfate and dodecylphosphocholine (DPC). Nuclear magnetic resonance spectroscopy of the Sudan virus MPER peptide revealed that residues 644-651 interact directly with DPC, and that this interaction enhances the helical conformation of the peptide. The Sudan virus MPER peptide was found to moderately inhibit cell entry by a GP-pseudotyped vesicular stomatitis virus but did not induce leakage of a fluorescent molecule from a large unilammellar vesicle comprised of 1-palmitoyl-2-oleoylphosphatidylcholine or cause hemolysis. Taken together, this analysis suggests the filovirus GP2 MPER binds and inserts shallowly into lipid membranes.

Optical imaging of the dynamics of living specimens involves tradeoffs between spatial resolution, temporal resolution, and phototoxicity, made more difficult in three dimensions. Here, however, we report that rapid three-dimensional (3D) dynamics can be studied beyond the diffraction limit in thick or densely fluorescent living specimens over many time points by combining ultrathin planar illumination produced by scanned Bessel beams with super-resolution structured illumination microscopy. We demonstrate in vivo karyotyping of chromosomes during mitosis and identify different dynamics for the actin cytoskeleton at the dorsal and ventral surfaces of fibroblasts. Compared to spinning disk confocal microscopy, we demonstrate substantially reduced photodamage when imaging rapid morphological changes in D. discoideum cells, as well as improved contrast and resolution at depth within developing C. elegans embryos. Bessel beam structured plane illumination thus promises new insights into complex biological phenomena that require 4D subcellular spatiotemporal detail in either a single or multicellular context., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Apical constriction changes cell shapes, driving critical morphogenetic events, including gastrulation in diverse organisms and neural tube closure in vertebrates. Apical constriction is thought to be triggered by contraction of apical actomyosin networks. We found that apical actomyosin contractions began before cell shape changes in both Caenorhabitis elegans and Drosophila. In C. elegans, actomyosin networks were initially dynamic, contracting and generating cortical tension without substantial shrinking of apical surfaces. Apical cell-cell contact zones and actomyosin only later moved increasingly in concert, with no detectable change in actomyosin dynamics or cortical tension. Thus, apical constriction appears to be triggered not by a change in cortical tension, but by dynamic linking of apical cell-cell contact zones to an already contractile apical cortex.

Purpose: We investigated the long-term risk of second primary malignancy after chemotherapy for Hodgkin's lymphoma (HL) in a much larger cohort than any yet published, to our knowledge., Patients and Methods: We followed 5,798 patients with HL treated with chemotherapy in Britain from 1963 to 2001--of whom 3,432 also received radiotherapy--to assess second primary malignancy risks compared with general population-based expectations., Results: Second malignancies occurred in 459 cohort members. Relative risk (RR) of second cancer was raised after chemotherapy alone (RR, 2.0; 95% CI, 1.7 to 2.4) but was much lower than after combined modalities (RR, 3.9; 95% CI, 3.5 to 4.4). After chemotherapy alone, there were significantly raised risks of lung cancer, non-HL, and leukemia, each contributing approximately equal absolute excess risk. After combined modalities, there were raised risks of these and several other cancers. Second cancer risk peaked 5 to 9 years after chemotherapy alone, but it remained raised for 25 years and longer after combined modalities. Risk was raised after each common chemotherapy regimen except, based on limited numbers and follow-up, adriamycin, bleomycin, vinblastine, and dacarbazine. The age and time-course relations of lung cancer differed between chemotherapy alone and combined modalities., Conclusion: Although chemotherapy alone leads to raised risk of second malignancy, this risk is lower and affects fewer anatomic sites than that after combined modalities, and it is slight if at all after 15 years follow-up. The mechanism of lung cancer etiology may differ between chemotherapy and radiotherapy.

Ebola virus (EboV) belongs to the Filoviridae family of viruses that causes severe and fatal hemhorragic fever. Infection by EboV involves fusion between the virus and host cell membranes mediated by the envelope glycoprotein GP2 of the virus. Similar to the envelope glycoproteins of other viruses, the central feature of the GP2 ectodomain postfusion structure is a six-helix bundle formed by the protein's N- and C-heptad repeat regions (NHR and CHR, respectively). Folding of this six-helix bundle provides the energetic driving force for membrane fusion; in other viruses, designed agents that disrupt formation of the six-helix bundle act as potent fusion inhibitors. To interrogate determinants of EboV GP2-mediated membrane fusion, we designed model proteins that consist of the NHR and CHR segments linked by short protein linkers. Circular dichroism and gel filtration studies indicate that these proteins adopt stable α-helical folds consistent with design. Thermal denaturation indicated that the GP2 six-helix bundle is highly stable at pH 5.3 (melting temperature, T(m) , of 86.8 ± 2.0°C and van't Hoff enthalpy, ΔH(vH) , of -28.2 ± 1.0 kcal/mol) and comparable in stability to other viral membrane fusion six-helix bundles. We found that the stability of our designed α-helical bundle proteins was dependent on buffering conditions with increasing stability at lower pH. Small pH differences (5.3-6.1) had dramatic effects (ΔT(m) = 37°C) suggesting a mechanism for conformational control that is dependent on environmental pH. These results suggest a role for low pH in stabilizing six-helix bundle formation during the process of GP2-mediated viral membrane fusion., (Copyright © 2011 The Protein Society.)

Ebola virus (EboV) and Marburg virus (MarV) (filoviruses) are the causative agents of severe hemorrhagic fever. Infection begins with uptake of particles into cellular endosomes, where the viral envelope glycoprotein (GP) catalyzes fusion between the viral and host cell membranes. This fusion event is thought to involve conformational rearrangements of the transmembrane subunit (GP2) of the envelope spike that ultimately result in formation of a six-helix bundle by the N- and C-terminal heptad repeat (NHR and CHR, respectively) regions of GP2. Infection by other viruses employing similar viral entry mechanisms (such as HIV-1 and severe acute respiratory syndrome coronavirus) can be inhibited with synthetic peptides corresponding to the native CHR sequence ("C-peptides"). However, previously reported EboV C-peptides have shown weak or insignificant antiviral activity. To determine whether the activity of a C-peptide could be improved by increasing its intracellular concentration, we prepared an EboV C-peptide conjugated to the arginine-rich sequence from HIV-1 Tat, which is known to accumulate in endosomes. We found that this peptide specifically inhibited viral entry mediated by filovirus GP proteins and infection by authentic filoviruses. We determined that antiviral activity was dependent on both the Tat sequence and the native EboV CHR sequence. Mechanistic studies suggested that the peptide acts by blocking a membrane fusion intermediate.

Background: Researchers commonly employ strategies to increase participation in health studies. These include use of incentives and intensive reminders. There is, however, little evidence regarding the quantitative effect that such strategies have on study results. We present an analysis of data from a case-control study of Campylobacter enteritis in England to assess the usefulness of a two-reminder strategy for control recruitment., Methods: We compared sociodemographic characteristics of participants and non-participants, and calculated odds ratio estimates for a wide range of risk factors by mailing wave., Results: Non-participants were more often male, younger and from more deprived areas. Among participants, early responders were more likely to be female, older and live in less deprived areas, but despite these differences, we found little evidence of a systematic bias in the results when using data from early reponders only., Conclusions: We conclude that the main benefit of using reminders in our study was the gain in statistical power from a larger sample size.

It has long been known that cells can divide unequally by shifting the mitotic spindle to one side. Two recent reports identify an alternative way to generate daughter cells of different sizes., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Background: Infectious mononucleosis (IM) is common among university students. We undertook to analyze the clinical features and sequelae of the disease in a cohort of students at Edinburgh University., Methods: Consecutive IM case patients were recruited from 2000 through 2002 at the University Health Service after diagnosis of IM., Results: IM resulted in marked reductions in student study time, physical exercise, and non-exercise-related social activities, and sustained increases in reported number of hours of sleep. The disease profile differed between the sexes, with significantly more females reporting fatigue, which was more likely to be prolonged (P = .003) and to lead to loss of study time (P = .013). Female case patients were more likely to discontinue their studies following IM (16% vs 0%; P = .056). Within the typically elevated lymphocyte counts in IM, we identified an elevated gammadelta T cell component that may contribute to the disease pathogenesis., Conclusions: IM results in substantial morbidity among university students, reported as more profound in females, and affecting academic studies, physical exercise, and social activities. Immunization to prevent IM and strategies to reduce post-IM disability would be beneficial in this population.

In a case-control study of Campylobacter spp. risk factors in England during 2005-2006, we identified recent consumption of commercially prepared chicken as an important risk factor. The risk for illness associated with recent chicken consumption was much lower for persons who regularly ate chicken than in those who did not, which suggests that partial immunologic protection may follow regular chicken preparation or consumption. Chicken-related risk factors accounted for 41% of cases; acid-suppressing medication, for 10%; self-reported past Campylobacter enteritis, 2%; and recent acquisition of a pet dog, 1%. Understanding the risks associated with chicken from different sources will benefit strategies to reduce Campylobacter infections. Better characterization of immune correlates for Campylobacter infection is necessary to assess the relative importance of immunity and behavioral factors in determining risk.

A large number of melanocytic nevi is the strongest known risk factor for melanoma in whites, but its relationship to sun exposure overseas among young white women living in temperate climates is unclear. A total of 754 white English women aged 18-46 years were recruited into a cross-sectional study in 1997-2000 to investigate the effect of ultraviolet exposures on numbers of nevi and atypical nevi, and on skin aging as measured by microtopography. Having ever holidayed in hotter countries was associated with a greater age- and phenotype-adjusted mean number of whole-body nevi (percent increase=74; 95% confidence interval: 24, 144; P=0.001), particularly for holidays taken at ages 18-29 years and for counts of the trunk and lower limbs. Having ever lived overseas was not associated with nevus counts, but was inversely associated with number of atypical nevi (P=0.02). Skin aging was not associated with residence or holidays abroad. The association of holidays overseas with an increased nevus count in young white women, which was stronger in the anatomical sites intermittently exposed to sunlight, supports the hypothesis that intermittent sun exposure is of relevance in the etiology of nevi and, hence, melanoma. The findings are of public health relevance given the growing popularity of foreign holidays.

Context: Turner syndrome is characterized by complete or partial X chromosome monosomy. It is associated with substantial morbidity, but mortality risks and causes of death are not well described., Objectives: Our objective was to investigate mortality and causes of death in women with Turner syndrome., Design and Setting: We constructed a cohort of women diagnosed with Turner syndrome at almost all cytogenetic centers in Great Britain and followed them for mortality., Patients: A total of 3,439 women diagnosed between 1959-2002 were followed to the end of 2006., Outcome Measures: Standardized mortality ratios (SMRs) and absolute excess risks were evaluated., Results: In total, 296 deaths occurred. Mortality was significantly raised overall [SMR = 3.0; 95% confidence interval (CI) = 2.7-3.4] and was raised for nearly all major causes of death. Circulatory disease accounted for 41% of excess mortality, with greatest SMRs for aortic aneurysm (SMR = 23.6; 95% CI = 13.8-37.8) and aortic valve disease (SMR = 17.9; 95% CI = 4.9-46.0), but SMRs were also raised for other circulatory conditions. Other major contributors to raised mortality included congenital cardiac anomalies, diabetes, epilepsy, liver disease, noninfectious enteritis and colitis, renal and ureteric disease, and pneumonia. Absolute excess risks of death were considerably greater at older than younger ages., Conclusions: Mortality in women with Turner syndrome is 3-fold higher than in the general population, is raised for almost all major causes of death, and is raised at all ages, with the greatest excess mortality in older adulthood. These risks need consideration in follow-up and counseling of patients and add to reasons for continued follow-up and preventive measures in adult, not just pediatric, care.

The finding of increased risks of specific cancers in individuals with constitutional deletions of chromosomes 11p and 13q led to the discovery of cancer predisposition genes at these locations, but there have been no systematic studies of cancer risks in patients with constitutional deletions, across the chromosome complement. Therefore, we assessed cancer incidence in comparison with national cancer incidence rates in a follow-up of 2561 patients with constitutional autosomal chromosome deletions diagnosed by microscopy or fluorescence in situ hybridisation in Britain during the period 1965-2002. Thirty cancers other than non-melanoma skin cancer occurred in the cohort (standardised incidence ratio (SIR)=2.4, 95% confidence interval (CI) 1.6-3.5). There were significantly increased risks of renal cancer in persons with 11p deletions (SIR=1869, 95% CI 751-3850; P=4 x 10(-21)), eye cancer with 13q deletions (SIR=1084, 95% CI 295-2775; P=2 x 10(-11)), and anogenital cancer with 11q deletions (SIR=305, 95% CI 63-890; P=3 x 10(-7)); all the three latter cancers were in the 11 subjects with 11q24 deletions. The results strongly suggest that in addition to suppressor genes relating to Wilms' tumour risk on 11p and retinoblastoma on 13q, there are suppressor genes around 11q24 that greatly affect anogenital cancer risk.

Constitutional chromosome deletions result in wide ranging morbidity and often fatality. Information about risks and causes of death in these patients is important for counselling, and may illuminate the functions of the part of the chromosome deleted. There have been no cohort studies analysing mortality risks in persons with specific deletions compared with general population rates. We therefore conducted a cohort study following cause-specific mortality in 2,561 patients with autosomal chromosome deletions diagnosed by light microscopy or fluorescence in situ hybridisation at cytogenetic laboratories across Britain, 1965-2002. The commonest deletions were of 22q (544 patients), 15q (460) and 7q (210) and the least common 19q (0) and 20q (2). The prevalence of visible deletions of different chromosome arms was significantly inversely correlated with gene density of the arm (p < 0.001). Mortality was 11-fold raised in the cohort compared with the general population (standardised mortality ratio = 11.4 (95% confidence interval 10.0-12.8)), was significantly raised for each deletion with > or = 25 subjects in the study, and had a lower confidence limit > 10 for deletions of 1p, 1q, 3p, 4p, 5q and 22q. Overall, 29% of deaths were due to congenital anomalies; significantly raised mortality occurred also from many other causes, varying by chromosome and arm of deletion. The data imply that viability of foetuses with visible chromosome deletions may be inversely related to gene density, and that all visible and fluorescence in situ hybridisation-detectable deletions lead to much raised mortality, but the extent and causes of mortality vary according to the specific deletion.

Background: Turner syndrome, one of the most common cytogenetic abnormalities, is characterised by complete or partial X-chromosome monosomy. Cancer risks in women with Turner syndrome have not been clearly established. We aimed to compare the risk of cancer in women with this syndrome with that of the general population., Methods: We formed a national cohort of 3425 women who were cytogenetically diagnosed with Turner syndrome in Great Britain between 1959 and 2002. Identifying information for these patients was sent to the National Health Service Central Register (NHSCR) for England and Wales and to the NHSCR for Scotland. Individuals who were identified on this register were followed-up for cancer incidence. Standardised incidence ratios (SIRs) and 95% CIs were calculated on the basis of the number of cancers observed compared with that expected based on national incidence rates. Cumulative risk estimates were obtained by use of the Kaplan-Meier method., Findings: A total of 58,299 person-years were accrued during the study, with a mean of 17.0 years (SD 8.6) follow-up per patient. 73 malignancies other than non-melanoma skin cancer occurred (SIR 0.9 [95% CI 0.7-1.2]). Risks were significantly increased for tumours of the CNS (n=13; 4.3 [2.3-7.4]), especially for meningioma (n=7; 12.0 [4.8-24.8]) and childhood brain tumours (n=3; 10.3 [2.1-30.1]), and for cancers of the bladder and urethra (n=5; 4.0 [1.3-9.2]) and eye (n=2; 10.5 [1.3-37.9]), compared with the general population. However, the risk of breast cancer was significantly decreased (n=10; 0.3 [0.2-0.6]). The SIR for cutaneous melanoma was 2.2 (95% CI 1.0-4.4; n=8), and one of the ocular cancers was a melanoma. The risk of corpus uteri cancer was significantly increased at ages 15-44 years (n=3; 8.0 [1.6-23.2]). During follow-up, five women, all with a Y-chromosome lineage, developed gonadoblastoma of the ovary, corresponding to a cumulative risk of 7.9% (95% CI 3.1-19.0) by age 25 years in this group., Interpretation: This study shows that, in addition to having an increased risk of gonadoblastoma, women with Turner syndrome seem to be at increased risk for meningioma and childhood brain tumours, and possibly bladder cancer, melanoma, and corpus uteri cancer, but are at a decreased risk for breast cancer. Reasons for these risks might relate to genetic and hormonal factors or to the effects of hormonal treatments given to women with Turner syndrome.

Infectious mononucleosis (IM) is an immunopathological disease caused by EBV that occurs in young adults and is a risk factor for Hodgkin lymphoma (HL). An association between EBV-positive HL and genetic markers in the HLA class I locus has been identified, indicating that genetic differences in the HLA class I locus may alter disease phenotypes associated with EBV infection. To further determine whether HLA class I alleles may affect development of EBV-associated diseases, we analyzed 2 microsatellite markers and 2 SNPs located near the HLA class I locus in patients with acute IM and in asymptomatic EBV-seropositive and -seronegative individuals. Alleles of both microsatellite markers were significantly associated with development of IM. Specific alleles of the 2 SNPs were also significantly more frequent in patients with IM than in EBV-seronegative individuals. IM patients possessing the associated microsatellite allele had fewer lymphocytes and increased neutrophils relative to IM patients lacking the allele. These patients also displayed higher EBV titers and milder IM symptoms. The results of this study indicate that HLA class I polymorphisms may predispose patients to development of IM upon primary EBV infection, suggesting that genetic variation in T cell responses can influence the nature of primary EBV infection and the level of viral persistence.

Background: Studies suggest that routine variations in public drinking water turbidity may be associated with endemic gastrointestinal illness. We systematically reviewed the literature on this topic., Methods: We searched databases and websites for relevant studies in industrialized countries. Studies investigating the association between temporal variations in drinking water turbidity and incidence of acute gastrointestinal illness were assessed for quality. We reviewed good quality studies for evidence of an association between increased turbidity and gastrointestinal illness., Results: We found six relevant good quality studies. Of five studies investigating effluent water turbidity, two found no association. Two studies from Philadelphia reported increased paediatric and elderly hospital use on specific days after increased turbidity. A fifth study reported more telephone health service calls on specific days after peak turbidity. There were differences between studies affecting their comparability, including baseline turbidity and adjustment for seasonal confounders., Conclusion: It is likely that an association between turbidity and GI illness exists in some settings or over a certain range of turbidity. A pooled analysis of available data using standard methods would facilitate interpretation.

We present the results of a multicenter clinical trial using Epstein-Barr virus (EBV)-specific cytotoxic T lymphocytes (CTLs) generated from EBV-seropositive blood donors to treat patients with EBV-positive posttransplantation lymphoproliferative disease (PTLD) on the basis of the best HLA match and specific in vitro cytotoxicity. Thirty-three PTLD patients who had failed on conventional therapy were enrolled. No adverse effects of CTL infusions were observed and the response rate (complete or partial) in 33 patients was 64% at 5 weeks and 52% at 6 months. Fourteen patients achieved a complete remission, 3 showed a partial response, and 16 had no response at 6 months (5 died before completing treatment). At 5 weeks, there was a significant trend toward better responses with higher numbers of CD4(+) cells in infused CTL lines (P = .001) that were maintained at 6 months (P = .001). Patients receiving CTLs with closer HLA matching responded better at 6 months (P = .048). Female patients responded better than male patients, but the differences were not statistically significant. Our results show that allogeneic CTLs are a safe and rapid therapy for PTLD, bypassing the need to grow CTLs for individual patients. The response rate in this poor prognosis patient group is encouraging.

The mortality and cancer incidence risks among males with Y polysomy are unknown because there have been no large long-term cohort studies carried out of such men. We conducted a cohort study of 667 men diagnosed with the abnormality in Britain since 1959 to compare their mortality and cancer incidence rates with those of the general population. Sixty deaths occurred during follow-up to December 2005, twice the number expected from general population rates (standardised mortality ratio (SMR) = 2.0 (95% confidence interval (CI) 1.5-2.6)). Significantly raised mortality was observed for diseases of the nervous system (SMR = 7.0, 95% CI: 2.3-16.4), circulatory system (SMR = 2.1, 95% CI: 1.3-3.2), respiratory system (SMR = 4.0, 95% CI: 1.8-7.5), genitourinary system (SMR = 10.2, 95% CI: 1.2-36.9), and congenital anomalies (SMR = 11.9, 95% CI: 3.2-30.5). Four of the five nervous system deaths were from epilepsy, the risk of death from this condition being more than 20-fold raised. The rates of cancer incidence and mortality among these men was not significantly different from those in the general population. This study provides evidence that mortality rates from several specific causes are raised among men with Y polysomy. The use of these data in genetic counselling should be cautious particularly for cases of Y polysomy that are detected prenatally. Further investigations are required to confirm these findings and to elucidate the possible role of genes on the Y chromosome in the aetiology of these causes of death.

Background: Risk factors for primary infection with Epstein-Barr virus (EBV) and its subtypes have not been fully investigated., Methods: Questionnaires and serum samples from a total of 2006 students who entered Edinburgh University in 1999-2000 were analyzed to examine risk factors for EBV seropositivity, both overall and by EBV type., Results: The prevalence of EBV seropositivity was significantly increased among females, older students, those who had lived in tropical countries, those with siblings, and those who were sexually active, particularly if they had had numerous sex partners. Risk was lower (1) among students who always used a condom than among those who had sexual intercourse without one and (2) among female oral-contraceptive users than among sexually active nonusers. Risk factors for type 1 EBV infection were similar to those for EBV overall. No associations were found between nonsexual risk factors and type 2 infection. Sexual activity increased the risk of type 2 infection, but the increase in risk with number of sex partners was less consistent than for type 1 infections. Dual infection was uncommon, but the patterns of risk appeared to be similar to those of type 1 infection., Conclusion: This study provides further evidence that EBV may be sexually transmitted and some suggestion that the risk factors for type 1 and type 2 infection differ.

Background: Myocardial infarction is a major cause of excess long-term mortality in survivors of Hodgkin disease, but limited information exists on the effects of specific chemotherapy regimens used to treat these patients on their risk of death from myocardial infarction., Methods: We followed a cohort of 7033 Hodgkin disease patients who were treated in Britain from November 1, 1967, through September 30, 2000, and compared their risk of myocardial infarction mortality with that in the general population of England and Wales. All statistical tests were two-sided., Results: A total of 166 deaths from myocardial infarction occurred in the cohort, statistically significantly more than expected (standardized mortality ratio [SMR] = 2.5, 95% confidence interval [CI] = 2.1 to 2.9), with an absolute excess risk of 125.8 per 100,000 person-years. Standardized mortality ratios decreased sharply with older age at first treatment, but absolute excess risks of death from myocardial infarction increased with older age up to age 65 years at first treatment. The statistically significantly increased risk of myocardial infarction mortality persisted through to 25 years after first treatment. Risks were increased statistically significantly and independently for patients who had been treated with supradiaphragmatic radiotherapy, anthracyclines, or vincristine. Risk was particularly high for patients treated with the doxorubicin, bleomycin, vinblastine, and dacarbazine regimen (SMR = 9.5, 95% CI = 3.5 to 20.6). Risk at 20 or more years after first treatment was particularly great for patients who had received supradiaphragmatic radiotherapy and vincristine without anthracyclines (SMR = 14.8, 95% CI = 4.8 to 34.5)., Conclusions: The risk of death from myocardial infarction after treatment for Hodgkin disease remains high for at least 25 years. The increased risks are related to supradiaphragmatic radiotherapy but may also be related to anthracycline and vincristine treatment.

Epstein-Barr virus is present in the saliva of most persistently infected individuals and is generally thought to be spread by close oral contact. However, there are now several reports of EBV in genital secretions, suggesting the possibility of sexual transmission between adults. The present study was undertaken to investigate the risk of sexual transmission of EBV. PCR analysis was used to examined the degree to which a group (n = 11) of patients with infectious mononucleosis (IM) shared the same viral isolates as their sexual partners, and compare this to the extent of isolate sharing among a different group (n = 18) of IM patients and their non-sexual contacts. There was significantly more sharing of EBV isolates among the IM/sexual-contact pairs than among the IM/non-sexual-contact pairs (P = 0.0012). Female cervical (n = 84), male urethral (n = 55), and semen (n = 30) samples from asymptomatic, unselected volunteers were analyzed for the presence of EBV DNA, revealing 7%, 5%, and 3% to be EBV positive, respectively. Fractionation of cervical and urethral samples into cellular and supernatant fluid components showed EBV to be mainly cell-associated. Quantitation of EBV in these samples gave levels of below 10 EBV genomes per microg of DNA. Overall the findings support the possibility that EBV could on occasions be transmitted sexually, however, the low levels detected in genital secretions compared to saliva suggest that this is not a major transmission route. The finding of small quantities of cell-associated virus suggests a latent infection; thus EBV is probably in the B lymphocyte rather than in the epithelial cell component of the secretions.

Background: A vaccine against Epstein-Barr virus (EBV) infection is in clinical trials. Up-to-date information on risk factors for EBV infection and infectious mononucleosis (IM) among young adults is required to inform a vaccination strategy., Methods: We carried out a prospective study on a cohort of university students. All EBV-seronegative students were asked to report symptoms of IM and were followed up 3 years later to undergo repeat EBV testing and to complete a lifestyle questionnaire. EBV typing was performed for these subjects, as well as for students who were EBV seropositive at enrollment and for additional students with IM., Results: A total of 510 students (25%) who took part in the study were EBV seronegative when they entered the university; of the 241 who donated a second blood sample 3 years later, 110 (46%) had seroconverted to EBV, 27 (25%) of whom developed IM [corrected] Penetrative sexual intercourse was a risk factor for EBV seroconversion (P = .004), but neither condom use nor oral sex significantly altered the rate of seroconversion. EBV type 1 was significantly overrepresented in IM, compared with silent seroconversion (P = .001)., Conclusions: Our findings suggest that acquisition of EBV is enhanced by penetrative sexual intercourse, although transmission could occur through related sexual behaviors, such as "deep kissing." We also found that EBV type 1 infection is significantly more likely to result in IM. Overall, the results suggest that a large EBV type 1 load acquired during sexual intercourse can rapidly colonize the B cell population and induce the exaggerated T cell response that causes IM. Thus, IM could, perhaps, be prevented with a vaccine that reduces the viral load without necessarily inducing sterile immunity.