Activated STING in a vascular and pulmonary syndrome

BACKGROUND

The study of autoinflammatory diseases has uncovered mechanisms underlying cytokine dysregulation and inflammation.

METHODS

We analyzed the DNA of an index patient with early-onset systemic inflammation, cutaneous vasculopathy, and pulmonary inflammation. We sequenced a candidate gene, TMEM173, encoding the stimulator of interferon genes (STING), in this patient and in five unrelated children with similar clinical phenotypes. Four children were evaluated clinically and immunologically. With the STING ligand cyclic guanosine monophosphate-adenosine monophosphate (cGAMP), we stimulated peripheral-blood mononuclear cells and fibroblasts from patients and controls, as well as commercially obtained endothelial cells, and then assayed transcription of IFNB1, the gene encoding interferon-β, in the stimulated cells. We analyzed IFNB1 reporter levels in HEK293T cells cotransfected with mutant or nonmutant STING constructs. Mutant STING leads to increased phosphorylation of signal transducer and activator of transcription 1 (STAT1), so we tested the effect of Janus kinase (JAK) inhibitors on STAT1 phosphorylation in lymphocytes from the affected children and controls.

RESULTS

We identified three mutations in exon 5 of TMEM173 in the six patients. Elevated transcription of IFNB1 and other gene targets of STING in peripheral-blood mononuclear cells from the patients indicated constitutive activation of the pathway that cannot be further up-regulated with stimulation. On stimulation with cGAMP, fibroblasts from the patients showed increased transcription of IFNB1 but not of the genes encoding interleukin-1 (IL1), interleukin-6 (IL6), or tumor necrosis factor (TNF). HEK293T cells transfected with mutant constructs show elevated IFNB1 reporter levels. STING is expressed in endothelial cells, and exposure of these cells to cGAMP resulted in endothelial activation and apoptosis. Constitutive up-regulation of phosphorylated STAT1 in patients' lymphocytes was reduced by JAK inhibitors.

CONCLUSIONS

STING-associated vasculopathy with onset in infancy (SAVI) is an autoinflammatory disease caused by gain-of-function mutations in TMEM173. (Funded by the Intramural Research Program of the National Institute of Arthritis and Musculoskeletal and Skin Diseases; ClinicalTrials.gov number, NCT00059748.).

Health of UK servicemen who served in Persian Gulf War

BACKGROUND

Various symptoms in military personnel in the Persian Gulf War 1990-91 have caused international speculation and concern. We investigated UK servicemen.

METHODS

We did a cross-sectional postal survey on a random sample of Gulf War veterans (Gulf War cohort, n=4248) and, stratified for age and rank, servicemen deployed to the Bosnia conflict (Bosnia cohort, n=4250) and those serving during the Gulf War but not deployed there (Era cohort, n=4246). We asked about deployment, exposures, symptoms, and illnesses. We analysed men only. Our outcome measures were physical health, functional capacity (SF-36), the general health questionnaire, the Centers for Disease Control and Prevention (CDC) multisymptom criteria for Gulf War illness, and post-traumatic stress reactions.

FINDINGS

There were 8195 (65.1%) valid responses. The Gulf War cohort reported symptoms and disorders significantly more frequently than those in the Bosnia and Era cohorts, which were similar. Perception of physical health and ability were significantly worse in the Gulf War cohort than in the other cohorts, even after adjustment for confounders. Gulf War veterans were more likely than the Bosnia cohort to have substantial fatigue (odds ratio 2.2 [95% CI 1.9-2.6]), symptoms of post-traumatic stress (2.6 [1.9-3.4]), and psychological distress (1.6 [1.4-1.8]), and were nearly twice as likely to reach the CDC case definition (2.5 [2.2-2.8]). In the Gulf War, Bosnia, and Era cohorts, respectively, 61.9%, 36.8%, and 36.4% met the CDC criteria, which fell to 25.3%, 11.8%, and 12.2% for severe symptoms. Potentially harmful exposures were reported most frequently by the Gulf War cohort. All exposures showed associations with all of the outcome measures in the three cohorts. Exposures specific to the Gulf were associated with all outcomes. Vaccination against biological warfare and multiple routine vaccinations were associated with the CDC multisymptom syndrome in the Gulf War cohort.

INTERPRETATION

Service in the Gulf War was associated with various health problems over and above those associated with deployment to an unfamiliar hostile environment. Since associations of ill health with adverse events and exposures were found in all cohorts, however, they may not be unique and causally implicated in Gulf-War-related illness. A specific mechanism may link vaccination against biological warfare agents and later ill health, but the risks of illness must be considered against the protection of servicemen.

The solution structure of HIV-1 Nef reveals an unexpected fold and permits delineation of the binding surface for the SH3 domain of Hck tyrosine protein kinase

The solution structure of HIV-1 Nef has been solved by multidimensional heteronuclear NMR spectroscopy. The construct employed to circumvent problems associated with aggregation was a double-deletion mutant (delta2-39, delta159-173) in which conformationally disordered regions of the protein at the N terminus and in a long solvent-exposed flexible loop were removed, without affecting the properties or structural integrity of the remainder of the protein. Despite the absence of any sequence similarity, the overall fold of Nef is reminiscent of that of the family of winged helix-turn-helix DNA binding proteins. The binding surface of Nef for the SH3 domain of Hck tyrosine protein kinase has been mapped and reveals a non-contiguous (in terms of amino-acid sequence) interaction surface. This unique feature may suggest possible avenues for drug design aimed at inhibiting the interaction between Nef and SH3 domains.

Domains of the integrase protein of human immunodeficiency virus type 1 responsible for polynucleotidyl transfer and zinc binding

The integrase protein of human immunodeficiency virus type 1 carries out a set of polynucleotidyl transfer reactions that result in the covalent attachment of the retroviral cDNA to host DNA. We have analyzed the activities of a set of deletion derivatives of the integrase protein. The analysis reveals that a central domain of only 137 amino acids is sufficient in vitro to catalyze a subset of the reactions carried out by the complete protein. This polypeptide contains an amino acid sequence motif, Asp-Xaa39-58-Asp-Xaa35-Glu (DX39-58DX35E, where X and the subscript indicate the intervening amino acids between the invariant acidic residues), that is found in the integrases of retroviruses and retrotransposons and also the transposase proteins of some bacterial transposable elements. We also find that the integrase protein can bind Zn2+, and the histidine and cysteine residues of another conserved motif (HX3-7HX23-32CX2C) are required for efficient Zn2+ binding. The activities displayed by deletion mutants suggest to us possible functions for the various parts of integrase.

Refined solution structure and backbone dynamics of HIV-1 Nef

The tendency of HIV-1 Nef to form aggregates in solution, particularly at pH values below 8, together with its large fraction of highly mobile residues seriously complicated determination of its three-dimensional structure, both for heteronuclear solution NMR (Grzesiek et al., 1996a, Nat Struct Biol 3:340-345) and for X-ray crystallography (Lee et al., 1996, Cell 85:931-942). Methods used to determine the Nef structure by NMR at pH 8 and 0.6 mM concentration are presented, together with a detailed description of Nef's secondary and tertiary structure. The described techniques have general applicability for the NMR structure determination of proteins that are aggregating and/or have limited stability at low pH values. Extensive chemical shift assignments are reported for backbone and side chain 1H, 13C, and 15N resonances of the HIV-1 Nef deletion mutants NEF delta 2-39, NEF delta 2-39, delta 159-173, and of NEF delta 2-39, delta 159-173 in complex with the SH3 domain of the Hck tyrosine protein kinase. Besides a type II polyproline helix, Nef's structure consists of three alpha-helices, a 3(10) helix, and a five-stranded anti-parallel beta-sheet. The analysis of 15N relaxation parameters of the backbone amide sites reveals that all the secondary structure elements are non-mobile on the picosecond to nanosecond and on the millisecond time scale. A large number of slowly exchanging amide protons provides evidence for the stability of the Nef core even on the time scale of hours. Significant internal motions on the ps to ns time scale are detected for residues 60 to 71 and for residues 149 to 180, which form solvent-exposed loops. The residues of the HIV-1 protease cleavage site (W57/L58) do not exhibit large amplitude motions on the sub-nanosecond time scale, and their side chains insert themselves into a hydrophobic crevice formed between the C-terminus of helix 1 and the N-terminus of helix 2. A refined structure has been determined based on additional constraints for side-chain and backbone dihedral angles derived from a large number of three-bond J-coupling and ROE data.

Biophysical and functional characterization of full-length, recombinant human tissue inhibitor of metalloproteinases-2 (TIMP-2) produced in Escherichia coli. Comparison of wild type and amino-terminal alanine appended variant with implications for the mechanism of TIMP functions

Matrix metalloproteinases (MMPs) function in the remodeling of the extracellular matrix that is integral for many normal and pathological processes. The tissue inhibitor of metalloproteinases family, including tissue inhibitor of metalloproteinases-2 (TIMP-2), regulates the activity of these multifunctional metalloproteinases. TIMP family members are proteinase inhibitors that contain six conserved disulfide bonds, one involving an amino-terminal cysteine residue that is critical for MMP inhibitor activity. TIMP-2 has been expressed in Escherichia coli, folded from insoluble protein, and functionally characterized. The wild type protein inhibited gelatinase A (MMP-2), whereas a variant with an alanine appended to the amino terminus (Ala+TIMP-2) was inactive. Removal of amino-terminal alanine by exopeptidase digestion restored protease inhibitor activity. This confirms the mechanistic importance of the amino-terminal amino group in the metalloproteinase inhibitory activity, as originally suggested from the x-ray structure of a complex of MMP-3 with TIMP-1 and a complex of TIMP-2 with MT-1-MMP. The Ala+TIMP-2 variant exhibited conformational, pro-MMP-2 complex formation and fibroblast growth modulating properties of the wild type protein. These findings demonstrate that Ala+TIMP-2 is an excellent biochemical tool for examining the specific role of MMP inhibition in the multiple functions ascribed to TIMPs.

Chronic fatigue syndrome. A practical guide to assessment and management

Chronic fatigue and chronic fatigue syndrome (CFS) have become increasingly recognized as a common clinical problem, yet one that physicians often find difficult to manage. In this review we suggest a practical, pragmatic, evidence-based approach to the assessment and initial management of the patient whose presentation suggests this diagnosis. The basic principles are simple and for each aspect of management we point out both potential pitfalls and strategies to overcome them. The first, and most important task is to develop mutual trust and collaboration. The second is to complete an adequate assessment, the aim of which is either to make a diagnosis of CFS or to identify an alternative cause for the patient's symptoms. The history is most important and should include a detailed account of the symptoms, the associated disability, the choice of coping strategies, and importantly, the patient's own understanding of his/her illness. The assessment of possible comorbid psychiatric disorders such as depression or anxiety is mandatory. When the physician is satisfied that no alternative physical or psychiatric disorder can be found to explain symptoms, we suggest that a firm and positive diagnosis of CFS be made. The treatment of CFS requires that the patient is given a positive explanation of the cause of his symptoms, emphasizing the distinction among factors that may have predisposed them to develop the illness (lifestyle, work stress, personality), triggered the illness (viral infection, life events) and perpetuated the illness (cerebral dysfunction, sleep disorder, depression, inconsistent activity, and misunderstanding of the illness and fear of making it worse). Interventions are then aimed to overcoming these illness-perpetuating factors. The role of antidepressants remains uncertain but may be tried on a pragmatic basis. Other medications should be avoided. The only treatment strategies of proven efficacy are cognitive behavioral ones. The most important starting point is to promote a consistent pattern of activity, rest, and sleep, followed by a gradual return to normal activity; ongoing review of any 'catastrophic' misinterpretation of symptoms and the problem solving of current life difficulties. We regard chronic fatigue syndrome as important not only because it represents potentially treatable disability and suffering but also because it provides an example for the positive management of medically unexplained illness in general.

Solution structure of anti-HIV-1 and anti-tumor protein MAP30: structural insights into its multiple functions

We present the solution structure of MAP30, a plant protein with anti-HIV and anti-tumor activities. Structural analysis and subsequent biochemical assays lead to several novel discoveries. First, MAP30 acts like a DNA glycosylase/apurinic (ap) lyase, an additional activity distinct from its known RNA N-glycosidase activity toward the 28S rRNA. Glycosylase/ap lyase activity explains MAP30's apparent inhibition of the HIV-1 integrase, MAP30's ability to irreversibly relax supercoiled DNA, and may be an alternative cytotoxic pathway that contributes to MAP30's anti-HIV/anti-tumor activities. Second, two distinct, but contiguous, subsites are responsible for MAP30's glycosylase/ap lyase activity. Third, Mn2+ and Zn2+ interact with negatively charged surfaces next to the catalytic sites, facilitating DNA substrate binding instead of directly participating in catalysis.

Migration responses of human monocytic cell lines to alpha- and beta-chemokines

The beta-chemokines monocyte chemotactic protein 1 (MCP-1), macrophage inflammatory protein 1 alpha (MIP-1alpha), MIP-1beta and regulated on activation, normal T cells, expressed and secreted (RANTES) induced the in vitro migration of the monocytic cell line MonoMac-6. MCP-1 exhibits the most potent chemotactic effect on this cell line while MIP-1alpha, RANTES and to a lesser extent MIP-1beta were more moderate inducers of cell migration. MonoMac-6 migration in response to chemokines was shown to be a chemotactic and not a chemokinetic response, which was inhibited by pertussis and cholera toxins suggesting a role for G proteins in chemokine receptor-mediated signalling in these cells; chemotaxis of MonoMac-6 cells in response to MCP-1 was abrogated by the addition of anti-MCP-1 antibody. The response of MonoMac-6 cells to the alpha-chemokines IL-8, IP-10, growth-related peptide (Gro) alpha and MIP-2beta was substantially weaker than to the beta-chemokines. MCP-1 caused an alteration in cellular morphology by increasing ruffling at the cell membrane and the number of cells exhibiting extended pseudopodia. The chemotactic response of MonoMac-6 cells to beta-chemokines was compared with less well-differentiated myelomonocytic cell lines. THP-1 showed a similar, but weaker response to the beta-chemokines while both HL60 and U937 failed to respond to any member of this subfamily when tested under the same conditions. These results suggest that the differentiation status of cells of monocytic lineage may affect their response to beta-chemokines.

The effects of crossing porcine renal artery ostia with various endovascular stents

OBJECTIVES

To compare the effects of crossing renal artery ostia with various stents.

METHODS

The renal artery ostia of 24 large white pigs were covered with a Wallstent (nine ostia), a Palmaz stent (nine ostia) and a Memotherm stent (13 ostia). After an interval of 6-15 weeks, aortography, renal pressure and blood samples were performed and the pigs then sacrificed for histological examination.

RESULTS

Histological examination revealed an organised collagen matrix with endothelial cells covering the struts in contact with the aorta. This occurred with all stents but was most organised with the Wallstent. This matrix did not involve the renal artery ostia crossed by Wallstents, but in one Palmaz stent and in 12/13 Memotherm stents, a disorganised acellular matrix caused partial ostial occlusion. There was no mean fall in renal artery pressure but traces were damped in 8/13 cases of partial occlusion. There was a rise in serum creatinine in two cases using the Palmaz stent.

CONCLUSIONS

Covering renal arteries with the Wallstent appears to be safe in the short-term. Placement of stents with larger struts across renal arteries will require imaging methods, such as intravascular ultrasound (IVUS) to ensure that the ostia are not obstructed.

Human ocular melanocytes and retinal pigment epithelial cells differ in their melanogenic properties in vivo and in vitro

PURPOSE

The vertebrate eye contains both melanocytes and retinal pigment epithelial (RPE) cells. Little is known of the pigmentary behaviour of these embryologically dissimilar cells. The aim of this study was to examine aspects of the pigmentary properties of both cell types in vitro and ex vivo to learn more of the function of these cells.

METHODS

Sections of normal adult human eye were stained for tyrosinase related protein 1(TRP1), and cultures of RPE cells and choroidal melanocytes were examined immunocytochemically for TRP1 and 2 and enzymatically for tyrosinase activity (by assaying dopa oxidase activity).

RESULTS

Over half of the choroidal melanocytes expressed TRP1 ex vivo; in contrast, a very small percentage of RPE cells were TRP1 positive. In vitro, passage 1 to 3 ocular melanocytes expressed TRP1 and TRP2 and had tyrosinase activity, which was influenced by the choice of substrate on which the cells were grown. Tyrosinase activity was highest when cells were grown on fibronectin and plastic, intermediate on laminin and lowest on vitreous extracellular matrix (ECM) containing pigment to which they attached and spread out poorly. In contrast, passage 3 RPE cells (which were unpigmented) showed little evidence of tyrosinase activity in short-term culture, irrespective of the substrate on which they were grown, and failed to express TRP1 and TRP2. When cells were grown on plastic for greater than 3 weeks in culture, a very low percentage of cells (< 0.1%) became TRP1 positive and this percentage was increased threefold if cells were cultured on laminin in the presence of bFGF. A few cells were also seen to contain pigment but cultures failed to show any tyrosinase activity. In contrast, RPE cells (but not melanocytes) showed a marked ability to take up pigment granules in vitro.

CONCLUSIONS

The data suggest that normal human ocular melanocytes retain the capacity to produce pigment throughout adult life, and this can be demonstrated both ex vivo and in vitro. In contrast, we were unable to confirm that the majority of RPE cells play any significant role in active pigment production in the adult.

The use of Michel's transport medium for immunofluorescence and immunoelectron microscopy in autoimmune bullous diseases

We report the use of Michel's solution, already a well established transport medium, in the combined use of direct immunofluorescence (IMF) and pre-embedding immunoelectron microscopy in 3 subepidermal bullous diseases--bullous pemphigoid (BP), epidermolysis bullosa acquisita (EBA) and dermal binding linear IgA disease (LABD). Our studies demonstrated that electron microscopy of normal skin maintained in Michel's medium for up to 28 days showed remarkable preservation of all components of the basement membrane zone, including the ultrastructure of the basal keratinocytes, dermoepidermal junction and papillary dermis. However, epidermal cell cytolysis occurred after just 48 hours. Immunoelectron microscopy using a gold probe has enabled us to localise the immunoreactants in bullous pemphigoid, epidermolysis bullosa acquisita and dermal-binding linear IgA bullous dermatoses. Our findings are comparable to and as equally reliable as those on immunoelectron microscopy of fresh skin biopsies with no loss of antigen deposition, and demonstrate an effective new use of a well established transport medium.

Occupational risk factors for ill health in Gulf veterans of the United Kingdom

OBJECTIVES

To study the association between occupational factors specific to the Armed Forces (rank, functional roles, Service, regular or reservist status and deployment factors) and symptomatic health problems in Gulf veterans, after sociodemographic and lifestyle factors have been accounted for.

DESIGN

A postal cross sectional survey of randomly selected UK Gulf veterans was conducted six to seven years after the Gulf conflict. Physical ill health was measured using the Fatigue Questionnaire and a measure of the Centers for Disease Control and Prevention (CDC) multi-symptom syndrome. Psychological ill health was measured using the General Health Questionnaire and a post-traumatic stress measure.

SETTING

Population of servicemen who were serving in the UK Armed Forces during the Gulf conflict between 1 September 1990 and 30 June 1991.

PARTICIPANTS

3297 Gulf veterans.

MAIN RESULTS

In multivariate logistic regression, there was an inverse relation between higher rank and psychological and physical ill health (test of trend: General Health Questionnaire, p=0.004; post-traumatic stress, p=0.002; fatigue, p=0.015; CDC case, p=0.002). Having left the Armed Forces was associated with a two to three times increase in reporting ill health. Of the deployment factors, there was a weak association between being deployed as an individual reinforcement in a combat role and post-traumatic stress but there was no association between receiving pre-deployment training or post-deployment leave and ill health. Marital status and smoking were associated with psychological and physical ill health.

CONCLUSIONS

Rank was the main occupational factor associated with both psychological and physical ill health in Gulf veterans. This may parallel the associations between socioeconomic status and morbidity in civilian populations. Ill health seems to be greater in those who return to civilian life. Sociodemographic factors also seem to be important in ill health in Gulf veterans.

Separation and crystallization of T = 3 and T = 4 icosahedral complexes of the hepatitis B virus core protein

The icosahedral nucleocapsid of human hepatitis B virus is a homopolymer of the dimeric capsid protein also known as hepatitis B core antigen or HBcAg. Purified capsid protein obtained from an Escherichia coli expression system was reassembled into a mixture of T = 3 and T = 4 icosahedral particles consisting of 90 and 120 dimers, respectively. The two types of capsid were separated on a preparative scale by centrifugation through a sucrose gradient. In addition to this heterogeneity, the capsid protein has three cysteines, one of which has a great propensity for forming disulfide bonds between the two subunits, forming a dimer. To eliminate heterogeneity arising from oxidation, alanines were substituted for the cysteines. T = 3 and T = 4 capsids crystallized under similar conditions. Crystals of T = 3 capsids diffracted to approximately 8 A resolution; crystals of T = 4 capsids diffracted to 4 A resolution.

Anti-HIV and anti-tumor protein MAP30, a 30 kDa single-strand type-I RIP, shares similar secondary structure and beta-sheet topology with the A chain of ricin, a type-II RIP

MAP30 is a 30 kDa single-stranded, type-I ribosome inactivating protein (RIP) possessing anti-tumor and anti-HIV activities. It binds both ribosomal RNA and the HIV-1 long-terminal repeat DNA. To understand the structural basis for MAP30 activities, we undertook the study of MAP30 by solution NMR spectroscopy. We report nearly complete 1H, 13C, and 15N chemical shift assignments of its 263 amino acids. Based upon an analysis of secondary 13C chemical shifts, 3J(HNHA) coupling constants, hydrogen exchange data, and nuclear Overhauser effect patterns, we find that the secondary structure and beta-sheet topology of MAP30 are very similar to those of the ricin A chain, a subunit of the well-known type-II RIP, even though two proteins display distinct activities. We therefore suggest that MAP30 and ricin A chain share a similar three-dimensional fold, and that the reported functional differences between two proteins arise primarily from differences in local three-dimensional structure and other structural properties such as surface electrostatic potentials.

The health effects of peace-keeping in the UK Armed Forces: Bosnia 1992-1996. Predictors of psychological symptoms

BACKGROUND

Peace-keeping duties are associated with unique stresses for military personnel. There have been few reports on the effects of peace-keeping on psychological health.

METHOD

We used data from a cross-sectional study originally established to examine health effects of service in the Gulf War, which included a control group who had been deployed in Bosnia (N= 2049). This group was examined to establish which demographic, occupational, and deployment-related risk factors were associated with psychological distress measured on the General Health Questionnaire (GHQ-12) and stress symptoms akin to a post-traumatic stress reactions.

RESULTS

The main risk factors for stress symptoms in the Bosnia group were--lower rank, being deployed early in the campaign, having more deployment-related exposures, and serving on staff duties. There was no protective effect of previous deployments to the Falklands or Northern Ireland, and time off following deployment was not protective. For GHQ-12 cases, the main risk factors were: female gender, lower rank, increased deployment-related exposures and serving on staff duties.

CONCLUSIONS

This study suggests that stress symptoms and GHQ-12 cases, are strongly predicted both by experiences during deployment and demographic factors.

A retrospective analysis of tissue-fixed immunoreactants from skin biopsies maintained in Michel's medium

656 skin biopsies with positive direct immunofluorescence from the UK and overseas were studied over a 2-year period. The length of time biopsies had remained in Michel's medium at pH 7.0 in various diseases (pemphigoid, pemphigus, linear IgA disease, epidermolysis bullosa acquisita, lupus erythematosus, vasculitis, amyloid, lichen planus and dermatitis herpetiformis) was analysed. We concluded that direct immunofluorescence remained positive at 6 months and that Michel's medium is a reliable long-term maintenance medium for skin biopsies.

An audit of study casts used to monitor tooth wear in general practice

OBJECTIVE

To assess the outcome of compliance of advice sent to patients and dentists about monitoring tooth wear in general practice.

METHOD

Postal questionnaires were sent to 70 patients and their dentists requesting information on the outcome of letters of advice sent to general dental practitioners regarding monitoring tooth wear with study casts. They also requested information about the reasons for the patients' referral, the outcome of treatment and whether study models had been taken.

RESULTS

Replies were received from 60 dentists (87%) and 53 patients (75%). Of these, 16 patients and 16 dentists had moved from their recorded address. Study casts were reported as having been taken by 23 dentists (38%) and reported by 18 patients (34%). The most common reason for referral was advice about monitoring the wear and the appearance of their teeth.

CONCLUSIONS

The compliance of the patients and dentists in monitoring tooth wear by using study casts in general practice was not successful. It raises issues regarding the value of consultant advice letters to this common clinical problem.

The Psychological Dimension Of Chemical, Biological, Radiological And Nuclear (CBRN) Terrorism

Terrorism is an increasing feature of the World Scene. In the UK, our perspective has changed from a largely Ireland focused one to a more international view. The United States of America are, for the first time, seen as major terrorist targets. We are now "at war with terrorism". The medical aspects of terrorism have been extensively discussed in this journal and elsewhere, this article specifically addresses the psychological consequences of the use of terror weapons.

Chemical, biological, radiological and nuclear terrorism: an introduction for occupational physicians

BACKGROUND

Chemical, biological, radiological and nuclear terrorism poses considerable threat throughout the world.

AIM

To provide occupational physicians with an understanding of this threat and its main forms and what action can be taken to counter this threat.

METHODS

Presenters at a conference on chemical, biological, radiological and nuclear terrorism were asked to contribute their evidence-based opinions in order to produce a review article.

RESULTS

This paper presents a summary of the different forms of chemical, biological, radiological and nuclear terrorism and the effective counter-measures and also provides a review of current scientific literature.

CONCLUSION

The threat of chemical, biological, radiological and nuclear terrorism is present throughout the world and is one that occupational physicians should be aware of, as well as the action that can be taken to counter it.

Psychological effects of chemical weapons: a follow-up study of First World War veterans

BACKGROUND

Chemical weapons exercise an enduring and often powerful psychological effect. This had been recognized during the First World War when it was shown that the symptoms of stress mimicked those of mild exposure to gas. Debate about long-term effects followed the suggestion that gassing triggered latent tuberculosis.

METHOD

A random sample of 103 First World War servicemen awarded a war pension for the effects of gas, but without evidence of chronic respiratory pathology, were subjected to cluster analysis using 25 common symptoms. The consistency of symptom reporting was also investigated across repeated follow-ups.

RESULTS

Cluster analysis identified four groups: one (n=56) with a range of somatic symptoms, a second (n=30) with a focus on the respiratory system, a third (n=12) with a predominance of neuropsychiatric symptoms, and a fourth (n=5) with a narrow band of symptoms related to the throat and breathing difficulties. Veterans from the neuropsychiatric cluster had multiple diagnoses including neurasthenia and disordered action of the heart, and reported many more symptoms than those in the three somatic clusters.

CONCLUSIONS

Mild or intermittent respiratory disorders in the post-war period supported beliefs about the damaging effects of gas in the three somatic clusters. By contrast, the neuropsychiatric group did not report new respiratory illnesses. For this cluster, the experience of gassing in a context of extreme danger may have been responsible for the intensity of their symptoms, which showed no sign of diminution over the 12-year follow-up.