Chemoproteomic discovery of a covalent allosteric inhibitor of WRN helicase

WRN helicase is a promising target for treatment of cancers with microsatellite instability (MSI) due to its essential role in resolving deleterious non-canonical DNA structures that accumulate in cells with faulty mismatch repair mechanisms1-5. Currently there are no approved drugs directly targeting human DNA or RNA helicases, in part owing to the challenging nature of developing potent and selective compounds to this class of proteins. Here we describe the chemoproteomics-enabled discovery of a clinical-stage, covalent allosteric inhibitor of WRN, VVD-133214. This compound selectively engages a cysteine (C727) located in a region of the helicase domain subject to interdomain movement during DNA unwinding. VVD-133214 binds WRN protein cooperatively with nucleotide and stabilizes compact conformations lacking the dynamic flexibility necessary for proper helicase function, resulting in widespread double-stranded DNA breaks, nuclear swelling and cell death in MSI-high (MSI-H), but not in microsatellite-stable, cells. The compound was well tolerated in mice and led to robust tumour regression in multiple MSI-H colorectal cancer cell lines and patient-derived xenograft models. Our work shows an allosteric approach for inhibition of WRN function that circumvents competition from an endogenous ATP cofactor in cancer cells, and designates VVD-133214 as a promising drug candidate for patients with MSI-H cancers.

Identification of Small Molecule Inhibitors and Ligand Directed Degraders of Calcium/Calmodulin Dependent Protein Kinase Kinase 1 and 2 (CaMKK1/2)

CaMKK2 signals through AMPK-dependent and AMPK-independent pathways to trigger cellular outputs including proliferation, differentiation, and migration, resulting in changes to metabolism, bone mass accrual, neuronal function, hematopoiesis, and immunity. CAMKK2 is upregulated in tumors including hepatocellular carcinoma, prostate, breast, and gastric cancer, and genetic deletion in myeloid cells results in increased antitumor immunity in several syngeneic models. Validation of the biological roles of CaMKK2 has relied on genetic deletion or small molecule inhibitors with activity against several biological targets. We sought to generate selective inhibitors and degraders to understand the biological impact of inhibiting catalytic activity and scaffolding and the potential therapeutic benefits of targeting CaMKK2. We report herein selective, ligand-efficient inhibitors and ligand-directed degraders of CaMKK2 that were used to probe immune and tumor intrinsic biology. These molecules provide two distinct strategies for ablating CaMKK2 signaling in vitro and in vivo.

Novel lamprey antibody recognizes terminal sulfated galactose epitopes on mammalian glycoproteins

The terminal galactose residues of N- and O-glycans in animal glycoproteins are often sialylated and/or fucosylated, but sulfation, such as 3-O-sulfated galactose (3-O-SGal), represents an additional, but poorly understood modification. To this end, we have developed a novel sea lamprey variable lymphocyte receptor (VLR) termed O6 to explore 3-O-SGal expression. O6 was engineered as a recombinant murine IgG chimera and its specificity and affinity to the 3-O-SGal epitope was defined using a variety of approaches, including glycan and glycoprotein microarray analyses, isothermal calorimetry, ligand-bound crystal structure, FACS, and immunohistochemistry of human tissue macroarrays. 3-O-SGal is expressed on N-glycans of many plasma and tissue glycoproteins, but recognition by O6 is often masked by sialic acid and thus exposed by treatment with neuraminidase. O6 recognizes many human tissues, consistent with expression of the cognate sulfotransferases (GAL3ST-2 and GAL3ST-3). The availability of O6 for exploring 3-O-SGal expression could lead to new biomarkers for disease and aid in understanding the functional roles of terminal modifications of glycans and relationships between terminal sulfation, sialylation and fucosylation.

A generalized HIV vaccine design strategy for priming of broadly neutralizing antibody responses

Vaccine induction of broadly neutralizing antibodies (bnAbs) to HIV remains a major challenge. Germline-targeting immunogens hold promise for initiating the induction of certain bnAb classes; yet for most bnAbs, a strong dependence on antibody heavy chain complementarity-determining region 3 (HCDR3) is a major barrier. Exploiting ultradeep human antibody sequencing data, we identified a diverse set of potential antibody precursors for a bnAb with dominant HCDR3 contacts. We then developed HIV envelope trimer-based immunogens that primed responses from rare bnAb-precursor B cells in a mouse model and bound a range of potential bnAb-precursor human naïve B cells in ex vivo screens. Our repertoire-guided germline-targeting approach provides a framework for priming the induction of many HIV bnAbs and could be applied to most HCDR3-dominant antibodies from other pathogens.

Structural Basis of Polyketide Synthase O-Methylation

Modular type I polyketide synthases (PKSs) produce some of the most chemically complex metabolites in nature through a series of multienzyme modules. Each module contains a variety of catalytic domains to selectively tailor the growing molecule. PKS O-methyltransferases ( O-MTs) are predicted to methylate β-hydroxyl or β-keto groups, but their activity and structure have not been reported. We determined the domain boundaries and characterized the catalytic activity and structure of the StiD and StiE O-MTs, which methylate opposite β-hydroxyl stereocenters in the myxobacterial stigmatellin biosynthetic pathway. Substrate stereospecificity was demonstrated for the StiD O-MT. Key catalytic residues were identified in the crystal structures and investigated in StiE O-MT via site-directed mutagenesis and further validated with the cyanobacterial CurL O-MT from the curacin biosynthetic pathway. Initial structural and biochemical analysis of PKS O-MTs supplies a new chemoenzymatic tool, with the unique ability to selectively modify hydroxyl groups during polyketide biosynthesis.

Universal protection against influenza infection by a multidomain antibody to influenza hemagglutinin

Broadly neutralizing antibodies against highly variable pathogens have stimulated the design of vaccines and therapeutics. We report the use of diverse camelid single-domain antibodies to influenza virus hemagglutinin to generate multidomain antibodies with impressive breadth and potency. Multidomain antibody MD3606 protects mice against influenza A and B infection when administered intravenously or expressed locally from a recombinant adeno-associated virus vector. Crystal and single-particle electron microscopy structures of these antibodies with hemagglutinins from influenza A and B viruses reveal binding to highly conserved epitopes. Collectively, our findings demonstrate that multidomain antibodies targeting multiple epitopes exhibit enhanced virus cross-reactivity and potency. In combination with adeno-associated virus-mediated gene delivery, they may provide an effective strategy to prevent infection with influenza virus and other highly variable pathogens.

Massively parallel de novo protein design for targeted therapeutics

De novo protein design holds promise for creating small stable proteins with shapes customized to bind therapeutic targets. We describe a massively parallel approach for designing, manufacturing and screening mini-protein binders, integrating large-scale computational design, oligonucleotide synthesis, yeast display screening and next-generation sequencing. We designed and tested 22,660 mini-proteins of 37-43 residues that target influenza haemagglutinin and botulinum neurotoxin B, along with 6,286 control sequences to probe contributions to folding and binding, and identified 2,618 high-affinity binders. Comparison of the binding and non-binding design sets, which are two orders of magnitude larger than any previously investigated, enabled the evaluation and improvement of the computational model. Biophysical characterization of a subset of the binder designs showed that they are extremely stable and, unlike antibodies, do not lose activity after exposure to high temperatures. The designs elicit little or no immune response and provide potent prophylactic and therapeutic protection against influenza, even after extensive repeated dosing.

Deprotonations in the Reaction of Flavin-Dependent Thymidylate Synthase

Many microorganisms use flavin-dependent thymidylate synthase (FDTS) to synthesize the essential nucleotide 2'-deoxythymidine 5'-monophosphate (dTMP) from 2'-deoxyuridine 5'-monophosphate (dUMP), 5,10-methylenetetrahydrofolate (CH2THF), and NADPH. FDTSs have a structure that is unrelated to the thymidylate synthase used by humans and a very different mechanism. Here we report nuclear magnetic resonance evidence that FDTS ionizes N3 of dUMP using an active-site arginine. The ionized form of dUMP is largely responsible for the changes in the flavin absorbance spectrum of FDTS upon dUMP binding. dUMP analogues also suggest that the phosphate of dUMP acts as the base that removes the proton from C5 of the dUMP-methylene intermediate in the FDTS-catalyzed reaction. These findings establish additional differences between the mechanisms of FDTS and human thymidylate synthase.

Structural basis of substrate specificity and regiochemistry in the MycF/TylF family of sugar O-methyltransferases

Sugar moieties in natural products are frequently modified by O-methylation. In the biosynthesis of the macrolide antibiotic mycinamicin, methylation of a 6'-deoxyallose substituent occurs in a stepwise manner first at the 2'- and then the 3'-hydroxyl groups to produce the mycinose moiety in the final product. The timing and placement of the O-methylations impact final stage C-H functionalization reactions mediated by the P450 monooxygenase MycG. The structural basis of pathway ordering and substrate specificity is unknown. A series of crystal structures of MycF, the 3'-O-methyltransferase, including the free enzyme and complexes with S-adenosyl homocysteine (SAH), substrate, product, and unnatural substrates, show that SAM binding induces substantial ordering that creates the binding site for the natural substrate, and a bound metal ion positions the substrate for catalysis. A single amino acid substitution relaxed the 2'-methoxy specificity but retained regiospecificity. The engineered variant produced a new mycinamicin analog, demonstrating the utility of structural information to facilitate bioengineering approaches for the chemoenzymatic synthesis of complex small molecules containing modified sugars. Using the MycF substrate complex and the modeled substrate complex of a 4'-specific homologue, active site residues were identified that correlate with the 3' or 4' specificity of MycF family members and define the protein and substrate features that direct the regiochemistry of methyltransfer. This classification scheme will be useful in the annotation of new secondary metabolite pathways that utilize this family of enzymes.

Visualization and functional analysis of the oligomeric states of Escherichia coli heat shock protein 70 (Hsp70/DnaK)

The molecular chaperone DnaK binds to exposed hydrophobic segments in proteins, protecting them from aggregation. DnaK interacts with protein substrates via its substrate-binding domain, and the affinity of this interaction is allosterically regulated by its nucleotide-binding domain. In addition to regulating interdomain allostery, the nucleotide state has been found to influence homo-oligomerization of DnaK. However, the architecture of oligomeric DnaK and its potential functional relevance in the chaperone cycle remain undefined. Towards that goal, we examined the structures of DnaK by negative stain electron microscopy. We found that DnaK samples contain an ensemble of monomers, dimers, and other small, defined multimers. To better understand the function of these oligomers, we stabilized them by cross-linking and found that they retained ATPase activity and protected a model substrate from denaturation. However, these oligomers had a greatly reduced ability to refold substrate and did not respond to stimulation by DnaJ. Finally, we observed oligomeric DnaK in Escherichia coli cellular lysates by native gel electrophoresis and found that these structures became noticeably more prevalent in cells exposed to heat shock. Together, these studies suggest that DnaK oligomers are composed of ordered multimers that are functionally distinct from monomeric DnaK. Thus, oligomerization of DnaK might be an important step in chaperone cycling.

A new structural form in the SAM/metal-dependent o‑methyltransferase family: MycE from the mycinamicin biosynthetic pathway

O-linked methylation of sugar substituents is a common modification in the biosynthesis of many natural products and is catalyzed by multiple families of S-adenosyl-L-methionine (SAM or AdoMet)-dependent methyltransferases (MTs). Mycinamicins, potent antibiotics from Micromonospora griseorubida, can be methylated at two positions on a 6-deoxyallose substituent. The first methylation is catalyzed by MycE, a SAM- and metal-dependent MT. Crystal structures were determined for MycE bound to the product S-adenosyl-L-homocysteine (AdoHcy) and magnesium, both with and without the natural substrate mycinamicin VI. This represents the first structure of a natural product sugar MT in complex with its natural substrate. MycE is a tetramer of a two-domain polypeptide, comprising a C-terminal catalytic MT domain and an N-terminal auxiliary domain, which is important for quaternary assembly and for substrate binding. The symmetric MycE tetramer has a novel MT organization in which each of the four active sites is formed at the junction of three monomers within the tetramer. The active-site structure supports a mechanism in which a conserved histidine acts as a general base, and the metal ion helps to position the methyl acceptor and to stabilize a hydroxylate intermediate. A conserved tyrosine is suggested to support activity through interactions with the transferred methyl group from the SAM methyl donor. The structure of the free enzyme reveals a dramatic order-disorder transition in the active site relative to the S-adenosyl-L-homocysteine complexes, suggesting a mechanism for product/substrate exchange through concerted movement of five loops and the polypeptide C-terminus.

Comments on the process and product of the health impacts assessment component of the national assessment of the potential consequences of climate variability and change for the United States

In 1990 Congress formed the U.S. Global Change Research Program and required it to conduct a periodic national assessment of the potential impacts of climate variability and change on all regions and select economic/resource sectors of the United States. Between 1998 and 2000, a team of experts collaborated on a health impacts assessment that formed the basis for the first National Assessment's analysis of the potential impacts of climate on human health. The health impacts assessment was integrated across a number of health disciplines and involved a search for and qualitative expert judgment review of data on the potential links between climate events and population health. Accomplishments included identification of vulnerable populations, adaptation strategies, research needs, and data gaps. Experts, stakeholders, and the public were involved. The assessment is reported in five articles in this issue; a summary was published in the April 2000 issue of Environmental Health Perspectives. The assessment report will enhance understanding of ways human health might be affected by various climate-associated stresses and of the need for further empirical and predictive research. Improved understanding and communication of the significance and inevitability of uncertainties in such an assessment are critical to further research and policy development.

The potential impacts of climate variability and change on air pollution-related health effects in the United States

Climate change may affect exposures to air pollutants by affecting weather, anthropogenic emissions, and biogenic emissions and by changing the distribution and types of airborne allergens. Local temperature, precipitation, clouds, atmospheric water vapor, wind speed, and wind direction influence atmospheric chemical processes, and interactions occur between local and global-scale environments. If the climate becomes warmer and more variable, air quality is likely to be affected. However, the specific types of change (i.e., local, regional, or global), the direction of change in a particular location (i.e., positive or negative), and the magnitude of change in air quality that may be attributable to climate change are a matter of speculation, based on extrapolating present understanding to future scenarios. There is already extensive evidence on the health effects of air pollution. Ground-level ozone can exacerbate chronic respiratory diseases and cause short-term reductions in lung function. Exposure to particulate matter can aggravate chronic respiratory and cardiovascular diseases, alter host defenses, damage lung tissue, lead to premature death, and possibly contribute to cancer. Health effects of exposures to carbon monoxide, sulfur dioxide, and nitrogen dioxide can include reduced work capacity, aggravation of existing cardiovascular diseases, effects on pulmonary function, respiratory illnesses, lung irritation, and alterations in the lung's defense systems. Adaptations to climate change should include ensuring responsiveness of air quality protection programs to changing pollution levels. Research needs include basic atmospheric science work on the association between weather and air pollutants; improving air pollution models and their linkage with climate change scenarios; and closing gaps in the understanding of exposure patterns and health effects.

Comments on the process and product of the health impacts assessment component of the national assessment of the potential consequences of climate variability and change for the United States

In 1990 Congress formed the U.S. Global Change Research Program and required it to conduct a periodic national assessment of the potential impacts of climate variability and change on all regions and select economic/resource sectors of the United States. Between 1998 and 2000, a team of experts collaborated on a health impacts assessment that formed the basis for the first National Assessment's analysis of the potential impacts of climate on human health. The health impacts assessment was integrated across a number of health disciplines and involved a search for and qualitative expert judgment review of data on the potential links between climate events and population health. Accomplishments included identification of vulnerable populations, adaptation strategies, research needs, and data gaps. Experts, stakeholders, and the public were involved. The assessment is reported in five articles in this issue; a summary was published in the April 2000 issue of Environmental Health Perspectives. The assessment report will enhance understanding of ways human health might be affected by various climate-associated stresses and of the need for further empirical and predictive research. Improved understanding and communication of the significance and inevitability of uncertainties in such an assessment are critical to further research and policy development.

Climate variability and change in the United States: potential impacts on water- and foodborne diseases caused by microbiologic agents

Exposure to waterborne and foodborne pathogens can occur via drinking water (associated with fecal contamination), seafood (due to natural microbial hazards, toxins, or wastewater disposal) or fresh produce (irrigated or processed with contaminated water). Weather influences the transport and dissemination of these microbial agents via rainfall and runoff and the survival and/or growth through such factors as temperature. Federal and state laws and regulatory programs protect much of the U.S. population from waterborne disease; however, if climate variability increases, current and future deficiencies in areas such as watershed protection, infrastructure, and storm drainage systems will probably increase the risk of contamination events. Knowledge about transport processes and the fate of microbial pollutants associated with rainfall and snowmelt is key to predicting risks from a change in weather variability. Although recent studies identified links between climate variability and occurrence of microbial agents in water, the relationships need further quantification in the context of other stresses. In the marine environment as well, there are few studies that adequately address the potential health effects of climate variability in combination with other stresses such as overfishing, introduced species, and rise in sea level. Advances in monitoring are necessary to enhance early-warning and prevention capabilities. Application of existing technologies, such as molecular fingerprinting to track contaminant sources or satellite remote sensing to detect coastal algal blooms, could be expanded. This assessment recommends incorporating a range of future scenarios of improvement plans for current deficiencies in the public health infrastructure to achieve more realistic risk assessments.

Climate variability and change in the United States: potential impacts on water- and foodborne diseases caused by microbiologic agents

Exposure to waterborne and foodborne pathogens can occur via drinking water (associated with fecal contamination), seafood (due to natural microbial hazards, toxins, or wastewater disposal) or fresh produce (irrigated or processed with contaminated water). Weather influences the transport and dissemination of these microbial agents via rainfall and runoff and the survival and/or growth through such factors as temperature. Federal and state laws and regulatory programs protect much of the U.S. population from waterborne disease; however, if climate variability increases, current and future deficiencies in areas such as watershed protection, infrastructure, and storm drainage systems will probably increase the risk of contamination events. Knowledge about transport processes and the fate of microbial pollutants associated with rainfall and snowmelt is key to predicting risks from a change in weather variability. Although recent studies identified links between climate variability and occurrence of microbial agents in water, the relationships need further quantification in the context of other stresses. In the marine environment as well, there are few studies that adequately address the potential health effects of climate variability in combination with other stresses such as overfishing, introduced species, and rise in sea level. Advances in monitoring are necessary to enhance early-warning and prevention capabilities. Application of existing technologies, such as molecular fingerprinting to track contaminant sources or satellite remote sensing to detect coastal algal blooms, could be expanded. This assessment recommends incorporating a range of future scenarios of improvement plans for current deficiencies in the public health infrastructure to achieve more realistic risk assessments.

The potential impacts of climate variability and change on health impacts of extreme weather events in the United States

Extreme weather events such as precipitation extremes and severe storms cause hundreds of deaths and injuries annually in the United States. Climate change may alter the frequency, timing, intensity, and duration of these events. Increases in heavy precipitation have occurred over the past century. Future climate scenarios show likely increases in the frequency of extreme precipitation events, including precipitation during hurricanes, raising the risk of floods. Frequencies of tornadoes and hurricanes cannot reliably be projected. Injury and death are the direct health impacts most often associated with natural disasters. Secondary effects, mediated by changes in ecologic systems and public health infrastructure, also occur. The health impacts of extreme weather events hinge on the vulnerabilities and recovery capacities of the natural environment and the local population. Relevant variables include building codes, warning systems, disaster policies, evacuation plans, and relief efforts. There are many federal, state, and local government agencies and nongovernmental organizations involved in planning for and responding to natural disasters in the United States. Future research on health impacts of extreme weather events should focus on improving climate models to project any trends in regional extreme events and as a result improve public health preparedness and mitigation. Epidemiologic studies of health effects beyond the direct impacts of disaster will provide a more accurate measure of the full health impacts and will assist in planning and resource allocation.

The potential impacts of climate variability and change on air pollution-related health effects in the United States

Climate change may affect exposures to air pollutants by affecting weather, anthropogenic emissions, and biogenic emissions and by changing the distribution and types of airborne allergens. Local temperature, precipitation, clouds, atmospheric water vapor, wind speed, and wind direction influence atmospheric chemical processes, and interactions occur between local and global-scale environments. If the climate becomes warmer and more variable, air quality is likely to be affected. However, the specific types of change (i.e., local, regional, or global), the direction of change in a particular location (i.e., positive or negative), and the magnitude of change in air quality that may be attributable to climate change are a matter of speculation, based on extrapolating present understanding to future scenarios. There is already extensive evidence on the health effects of air pollution. Ground-level ozone can exacerbate chronic respiratory diseases and cause short-term reductions in lung function. Exposure to particulate matter can aggravate chronic respiratory and cardiovascular diseases, alter host defenses, damage lung tissue, lead to premature death, and possibly contribute to cancer. Health effects of exposures to carbon monoxide, sulfur dioxide, and nitrogen dioxide can include reduced work capacity, aggravation of existing cardiovascular diseases, effects on pulmonary function, respiratory illnesses, lung irritation, and alterations in the lung's defense systems. Adaptations to climate change should include ensuring responsiveness of air quality protection programs to changing pollution levels. Research needs include basic atmospheric science work on the association between weather and air pollutants; improving air pollution models and their linkage with climate change scenarios; and closing gaps in the understanding of exposure patterns and health effects.

The potential impacts of climate variability and change on health impacts of extreme weather events in the United States

Extreme weather events such as precipitation extremes and severe storms cause hundreds of deaths and injuries annually in the United States. Climate change may alter the frequency, timing, intensity, and duration of these events. Increases in heavy precipitation have occurred over the past century. Future climate scenarios show likely increases in the frequency of extreme precipitation events, including precipitation during hurricanes, raising the risk of floods. Frequencies of tornadoes and hurricanes cannot reliably be projected. Injury and death are the direct health impacts most often associated with natural disasters. Secondary effects, mediated by changes in ecologic systems and public health infrastructure, also occur. The health impacts of extreme weather events hinge on the vulnerabilities and recovery capacities of the natural environment and the local population. Relevant variables include building codes, warning systems, disaster policies, evacuation plans, and relief efforts. There are many federal, state, and local government agencies and nongovernmental organizations involved in planning for and responding to natural disasters in the United States. Future research on health impacts of extreme weather events should focus on improving climate models to project any trends in regional extreme events and as a result improve public health preparedness and mitigation. Epidemiologic studies of health effects beyond the direct impacts of disaster will provide a more accurate measure of the full health impacts and will assist in planning and resource allocation.

The potential health impacts of climate variability and change for the United States: executive summary of the report of the health sector of the U.S. National Assessment

We examined the potential impacts of climate variability and change on human health as part of a congressionally mandated study of climate change in the United States. Our author team, comprising experts from academia, government, and the private sector, was selected by the federal interagency U.S. Global Change Research Program, and this report stems from our first 18 months of work. For this assessment we used a set of assumptions and/or projections of future climates developed for all participants in the National Assessment of the Potential Consequences of Climate Variability and Change. We identified five categories of health outcomes that are most likely to be affected by climate change because they are associated with weather and/or climate variables: temperature-related morbidity and mortality; health effects of extreme weather events (storms, tornadoes, hurricanes, and precipitation extremes); air-pollution-related health effects; water- and foodborne diseases; and vector- and rodent-borne diseases. We concluded that the levels of uncertainty preclude any definitive statement on the direction of potential future change for each of these health outcomes, although we developed some hypotheses. Although we mainly addressed adverse health outcomes, we identified some positive health outcomes, notably reduced cold-weather mortality, which has not been extensively examined. We found that at present most of the U.S. population is protected against adverse health outcomes associated with weather and/or climate, although certain demographic and geographic populations are at increased risk. We concluded that vigilance in the maintenance and improvement of public health systems and their responsiveness to changing climate conditions and to identified vulnerable subpopulations should help to protect the U.S. population from any adverse health outcomes of projected climate change.

Non-Hodgkin's lymphoma: case control epidemiological study in Yorkshire

This paper reports the results of a case control study of non-Hodgkin's lymphoma in the Yorkshire Health Region. In all, 437 cases and 724 controls were interviewed. Risk factors associated with past skin conditions, family history of cancer and infectious mononucleosis, aspects of social life and contact with wood dust and epoxy glues all emerge. A comparison of high and low grade morphological forms of disease reveal contrasting risks and suggest separate aetiologies for these conditions.

Chronic lymphocytic leukaemia: case control epidemiological study in Yorkshire

This is the second report of a large case control study of lymphoma/leukaemia occurring in Yorkshire during 1979-84, and deals with chronic lymphocytic leukaemia presenting either in its haematological (CLL) or more solid lymphomatous (malignant lymphoma-lymphocytic or MLL) forms. In all, 330 cases and 561 controls were interviewed. The results support the concept that CLL/MLL is a condition of multiple aetiologies with evidence for genetic predisposition through an excess of family cases, immune perturbation demonstrated by excessive previous skin diseases and phenylbutazone use, and viral involvement shown by links with infectious diseases and multiple sclerosis.

Hodgkin's disease: case control epidemiological study in Yorkshire

This is the first report of a case-control epidemiological study on lymphomas and leukaemias occurring in Yorkshire during 1979-84. This paper deals with the results of the Hodgkin's disease analysis comprising 248 cases and 489 controls. The results indicate support for previous work with respect to small family size and past history of infectious mononucleosis. Positive observations made in a previous pilot study are also confirmed and extended with respect to associations with certain chronic skin lesions, dental anaesthesia and familial factors. Negative associations are described with respect to X-ray exposures and cigarette smoking. It is proposed that these results fit into a general hypothesis that these conditions are the result of interaction between infectious agents and altered immunity in those persons genetically predisposed.

Aetiologic factors in lymphoid malignancies: a case-control epidemiological study

A prospective case-control study of the aetiologic factors involved in the production of lymphoid malignancies has been conducted within a defined geographical area covering six health districts in the Yorkshire Region. Among the aspects investigated were past medical events, occupations and certain social factors. A number of possible causal relationships have been identified including Jewish religion, past solvent exposure and ingestion of amphetamines, although the latter did not achieve statistical significance in this study. In addition several new associations have been identified, most notably with the occurrence of adult eczema/dermatitis and with treatment by radiation or steroids. The feasibility of conducting such a broadly based epidemiological investigation has been established.

The influence of malignant cell cytology screening on the survival of industrial bladder cancer cases

The influence of urinary malignant cell cytology screening has been explored in an industrial population. Survival was prolonged in the screened group partly because a greater proportion of early stages disease was being diagnosed, and partly because of other differences in the screened group which have yet to be defined.