Keratoplasty After Mustard Gas Injury

PURPOSE

Ocular injury by mustard gas can lead to severe eye damage with a delayed course. We report the corneal histology and follow-up after keratoplasty in a patient with mustard gas injury.

METHODS

The patient presented with recurrent painful corneal inflammation in both eyes not improving under local therapy. Visual acuity impaired to handmovements. A penetrating keratoplasty was performed on the left eye and afterwards an autorotation keratoplasty on the right eye with a later corneal graft.

RESULTS

After the operation of the left eye the patient was immediately painfree and the visual acuity improved to 0,4. So far there have been no signs for transplant rejection or inflammation. Histology of the cornea revealed massive stromal necrosis, and signs of chronic inflammation. Despite denervation of the cornea after autorotation keratoplasty the right eye was still painful and became only painfree after corneal transplantation.

CONCLUSION

There has been not much experience with corneal transplantation after mustard gas injury and there is a high risk for transplant rejection due to inflammation and vascularisation of the cornea. Successful and painfree healing with keratoplasty seems only possible after complete removal of the necrotic material.

The effects of weapons of mass destruction on children

PURPOSE

Children are especially vulnerable to the effects of chemical and biological weapons of mass destruction (WMD) because of physiologic, pharmacologic, and developmental characteristics. Presentation of signs and symptoms of exposure to biological and chemical agents are similar to those seen in adults. Pediatric considerations for decontamination and treatment of child victims of biological and chemical agents are discussed.

CONCLUSION

As front-line providers, nurses need to be aware of potential agents, their uses and effects as WMD, and recommended treatments.

PRACTICE IMPLICATIONS

Understanding the additional physiologic and situational needs of children, nurses can optimize the survival and outcomes of children when disaster strikes.

Upward gaze-evoked nystagmus with organoarsenic poisoning

The authors report assessment of abnormal ocular movements in three patients after organoarsenic poisoning from diphenylarsinic acid. The characteristic and principal sign is upward gaze-evoked nystagmus. Moreover, vertical gaze holding impairment was shown by electronystagmography on direct current recording.

[Studying chronic effects caused by alkaline products of from bituminous-salt masses obtained through destruction of sarin, soman and RVX]

The authors summarized study results on chronic effects caused by products of leaching from bituminous-salt masses obtained through destruction of sarin, soman and RVX. State of experimental rats was evaluated with integral informative tests (physiologic, biochemical, hematologic and morphologic) presenting changes in objective health parameters and revealing every disorder in organs and systems functioning.

Highly sensitive and selective amperometric microbial biosensor for direct determination of p-nitrophenyl-substituted organophosphate nerve agents

We report herein a whole cell-based amperometric biosensor for highly selective, highly sensitive, direct, single-step, rapid, and cost-effective determination of organophosphate pesticides with a p-nitrophenyl substituent. The biosensor was comprised of a p-nitrophenol degrader, Pseudomonas putida JS444, genetically engineered to express organophosphorus hydrolase (OPH) on the cell surface immobilized on the carbon paste electrode. Surface-expressed OPH catalyzed hydrolysis of the p-nitrophenyl substituent organophosphorus pesticides such as paraoxon, parathion, and methyl parathion to release p-nitrophenol, which was subsequently degraded by the enzymatic machinery of P. putida JS444. The electrooxidization current of the intermediates was measured and correlated to the concentration of organophosphates. The best sensitivity and response time were obtained using a sensor constructed with 0.086 mg dry weight of cells operating at 600 mV applied potential (vs Ag/AgCl reference) in 50 mM citrate--phosphate pH 7.5 buffer with 50 microM CoCl2 at room temperature. Under optimum operating conditions the biosensor measured as low as 0.28 ppb of paraoxon, 0.26 ppb of methyl parathion, and 0.29 ppb parathion. These detection limits are comparable to cholinesterase inhibition-based biosensors. Unlike the inhibition-based format, this biosensor manifests a selective response to organophosphate pesticides with a p-nitrophenyl substituent only, has a simplified single-step protocol with short response time, and can be used for repetitive/multiple and on-line analysis. The service life of the microbial amperometric biosensor was 5 days when stored in the operating buffer at 4 degrees C. The new biosensor offers great promise for rapid environmental monitoring of OP pesticides with nitrophenyl substituent.

Mortality in US Army Gulf War veterans exposed to 1991 Khamisiyah chemical munitions destruction

OBJECTIVES

We investigated whether US Army Gulf War veterans who were potentially exposed to nerve agents during the March 1991 weapons demolitions at Khamisiyah, Iraq, are at increased risk of cause-specific mortality.

METHODS

The cause-specific mortality of 100487 exposed US Army Gulf War veterans was compared with that of 224980 unexposed US Army Gulf War veterans. Exposure was determined with the Department of Defense 2000 plume model. Relative risk estimates were derived from Cox proportional hazards models.

RESULTS

The risks of most disease-related mortality were similar for exposed and unexposed veterans. However, exposed veterans had an increased risk of brain cancer deaths (relative risk [RR]=1.94; 95% confidence interval [CI]=1.12, 3.34). The risk of brain cancer death was larger among those exposed 2 or more days than those exposed 1 day when both were compared separately to all unexposed veterans (RR=3.26; 95% CI=1.33, 7.96; RR=1.72; 95% CI=0.95,3.10, respectively).

CONCLUSIONS

Exposure to chemical munitions at Khamisiyah may be associated with an increased risk of brain cancer death. Additional research is required to confirm this finding.

[Chemical weapons and chemical terrorism]

Chemical Weapons are kind of Weapons of Mass Destruction (WMD). They were used large quantities in WWI. Historically, large quantities usage like WWI was not recorded, but small usage has appeared now and then. Chemical weapons are so called "Nuclear weapon for poor countrys" because it's very easy to produce/possession being possible. They are categorized (1) Nerve Agents, (2) Blister Agents, (3) Cyanide (blood) Agents, (4) Pulmonary Agents, (5) Incapacitating Agents (6) Tear Agents from the viewpoint of human body interaction. In 1997 the Chemical Weapons Convention has taken effect. It prohibits chemical weapons development/production, and Organization for the Prohibition of Chemical Weapons (OPCW) verification regime contributes to the chemical weapons disposal. But possibility of possession/use of weapons of mass destruction by terrorist group represented in one by Matsumoto and Tokyo Subway Sarin Attack, So new chemical terrorism countermeasures are necessary.

Capnography as a rapid assessment and triage tool for chemical terrorism

The assessment and triage of victims of chemical terrorism in the emergency department and the prehospital setting has become an important priority. This article proposes the use of capnography as a prehospital assessment and triage tool for monitoring victims of chemical terrorism and for critically ill patients. Capnography provides the ABCs in less than 15 seconds and identifies the common complications of chemical terrorism. Further, the reliability of capnography is not affected by motion artifact or low perfusion and it is accurate and reliable in actively seizing patients. Emergency departments and emergency medical services systems should consider adding capnography to their chemical terrorism education and training.

Nerve Agents

Nerve agents cause a rapidly fatal cholinergic crisis, but rapid, appropriate antidotal treatment saves lives. Survivors of nerve-agent poisoning generally are healthy, unlike survivors of some other chemical agent attacks. Neurologists can assist first responders and mass casualty planners materially by serving as resources for information on nerve agents and the syndromes they cause. They also can help their communities by reinforcing that treatment for nerve-agent poisoning is effective.

A clinicopathological study on acute cutaneous lesions induced by sulfur mustard gas (yperite)

During the Iran-Iraq war (1980-1988), sulfur mustard (as a chemical warfare agent) was launched on several occasions. Thirty-two victims with acute mustard poisoning were referred to our dermatology department, and are basis of this clinicopathologic study. Clinical and laboratory findings of these 32 adult patients exposed to mustard gas were determined. Skin biopsies were obtained from all of the patients and studied after staining of the specimens with routine and special stains. Clinically the most frequently involved areas were genitalia, face and axilla. The most common cutaneous findings were erosions, erythema and hyperpigmentation. The histopathologic changes of skin induced by mustard gas, included four distinct patterns: 1. Interface dermatitis, vacuolar type and lichenoid type; 2. Spongiotic dermatitis and bullous dermatitis (with or without acantholysis); 3. Pigmentary disorder pattern, increase of epidermal melanization. 4. Alteration of dermis/hypodermis, sclerodermoid pattern, vasculopathy and appendageal inflammatory response. Despite some specific characteristics related to sulfur mustard effect, these findings were compatible with histopathological changes of the chemical burns.

Chronic and Delayed-Onset Mustard Gas KeratitisReport of 48 patients and review of literature

PURPOSE

To report the clinical features of 93 eyes of 48 patients with chronic and delayed-onset mustard gas keratitis. Clinicopathologic correlation in 5 eyes and a review of related literature are presented.

DESIGN

Retrospective, noncomparative case series.

PARTICIPANTS

Forty-eight Iranian survivors of Iraqi chemical warfare with chronic or delayed-onset mustard gas keratitis.

METHODS

We reviewed the symptoms, clinical findings, course, and treatment of our patients and reviewed the literature. In 5 patients, histopathologic features of corneal and conjunctival specimens were evaluated.

MAIN OUTCOME MEASURES

Ocular findings, clinical course, treatment measures, and histopathologic studies.

RESULTS

Of 48 patients, 31 (64.6%) had chronic symptomatology, whereas 17 (35.4%) experienced delayed-onset lesions. Visual acuity at referral ranged from hand motions to 20/20. Ocular surface changes included chronic blepharitis and decreased tear meniscus in all patients, limbal ischemia (81.3%), and conjunctival vascular abnormalities (50%). Corneal signs in order of frequency were: scar or opacity (87.5%), neovascularization (70.8%), thinning (58.3%), lipoid deposits (52.1%), amyloid deposits (43.8%), and epithelial defects and irregularity (31.3%). Many patients received conservative treatment; others underwent allograft stem cell transplantation (20 eyes of 17 patients), penetrating keratoplasty (12 eyes of 12 patients), and lamellar keratoplasty (4 eyes of 3 patients). Conjunctival specimens were evaluated by light microscopy. Decreased goblet cell density, attenuated or thickened epithelium, scarring in the substantia propria associated with plasmacytic and lymphocytic infiltration, and dilated lymphatic vessels were noted. Excised corneal buttons disclosed absence of epithelium and Bowman's layer, fibrovascular pannus, stromal scarring, and vascularization.

CONCLUSIONS

Mustard gas causes chronic and delayed destructive lesions in the ocular surface and cornea, leading to progressive visual deterioration and ocular irritation. The pathophysiologic features of these changes are not clearly identified. Excised conjunctival and corneal specimens revealed a mixed inflammatory response without any specific features. Based on the clinical appearance of the lesions and the histopathologic findings, an immune-mediated component seems possible. This article contains additional online-only material available at.

[In-hospital management of victims of chemical weapons of mass destruction]

Emergency situations caused by chemical weapons of mass destruction add a new dimension of risk to those handling and treating casualties. The fundamental difference between a hazardous materials incident and conventional emergencies is the potential for risk from contamination to health care professionals, patients, equipment and facilities of the Emergency Department. Accurate and specific guidance is needed to describe the procedures to be followed by emergency medical personnel to safely care for a patient, as well as to protect equipment and people. This review is designed to familiarize readers with the concepts, terminology and key operational considerations that affect the in-hospital management of incidents by chemical weapons.

Environmental Mimics of Chemical Warfare Agents

There are several natural and artificial factors that mimic the effects of chemical warfare agents, thereby causing unwarranted alarm and confusion on the battlefield. Symptoms associated with chemical warfare include paralysis, muscle tremors, heavy salivation, severe burns, blistering, and corrosive skin injuries among others. Similar symptoms can be produced from a variety of environmental sources, artificial and natural. This article reviews several published and unpublished examples of environmental factors that produce syndromes similar to those caused by these agents. Examples of such mimics include pesticides, blistering exudates from insects and plants, various types of bites, and naturally occurring diseases. The potential for confusion caused by these factors is discussed and means of discriminating between warfare agents and naturally occurring events are identified. Recommendations for the use of this information and for needed research are also discussed.

An in vitro investigation of the effects of the nerve agent pretreatment pyridostigmine bromide on human peripheral blood T-cell function

The current pretreatment against nerve agent poisoning deployed by the UK and US armed forces is the acetylcholinesterase (EC 3.1.1.7) inhibitor pyridostigmine bromide (PB). At higher doses, PB is also used to treat the autoimmune disease myasthenia gravis. In both cases, the therapeutic effect is mediated by inhibition of acetylcholinesterase (AChE) at cholinergic synapses. However, the location of AChE is not restricted to these sites. AChE, acetylcholine (ACh) receptors and choline acetyltransferase have been reported to be expressed by T cells, suggesting that cholinergic signalling may exert some modulatory influence on T-cell function and consequently on the immune system. The aim of this study was to investigate the role of the T-cell cholinergic system in the immunological activation process and to examine whether inhibitors of AChE such as PB affect immune function. To investigate this, human peripheral blood mononuclear cells (PBMC) were stimulated using either mitogen, cross-linking of the T-cell receptor and co-receptors with antibodies (anti-CD3/CD28) or by antigen presentation in the presence of various AChE inhibitors and ACh receptor agonists or antagonist. Several indices were used to assess T-cell activation, including the secretion of IL-2, cell proliferation and expression of CD69. Treatment with PB had no significant effect on the immunological assays selected. Physostigmine (PHY), a carbamate compound similar to PB, consistently showed inhibition of T-cell activation, but only at concentrations in excess of those required to inhibit AChE. No evidence was found to support previously published findings showing muscarinic enhancement of cell proliferation or IL-2 secretion.

Long-term respiratory disorders of claimers with subclinical exposure to chemical warfare agents

It is well documented that inhalation of sulfur mustard causes injury of the respiratory system. While all of the reports and surveys thoroughly document long-term pulmonary effects after significant exposure to mustard, there is no direct evidence that addresses the issue of long-term respiratory effects in individuals who were exposed to very low level of mustard and suffered no acute respiratory tract injury. Our subjects were selected among all those who were in chemically contaminated areas with chemical warfare agents (CWA) and had been registered for an annual checkup. Subclinical exposure's definition is the absence of any acute symptoms at the time of exposure. We used standard respiratory questionnaires, and chest HRCT examinations and a pulmonary function test were done. Based on exclusion criteria from total of 200 patients claiming respiratory problems, just 77 veterans entered the study. After performing HRCT for all our patients there were 13 (38.23%) veterans with no observable defect, 13 (38%) of them had just significant air trapping in their HRCTs. All the others had at least air trapping (AT), which added to other defects. Septal wall thickening was seen in five veterans (14.7%) and bronchiectasis was seen in three (8.8%) cases. This study suggest that exposure to CWA was responsible for the occurrence of the bronchiolitis obliterans syndrome observed in our patients. There are many civilian and military people who have been present in contaminated area without signs and symptoms at the time of exposure, and early detection of such a population could be lifesaving.

Clinical and laboratory assessment of distal peripheral nerves in Gulf War veterans and spouses

BACKGROUND

The prevalence of symptoms suggesting distal symmetric polyneuropathy (DSP) was reported to be higher among deployed veterans (DV) to the Persian Gulf in 1990-1991 than to control non-deployed veterans (NDV). The authors therefore compared the prevalence of DSP by direct examination of DV and their spouses to control NDV and spouses.

METHODS

The authors performed standardized neurologic examinations on 1,061 DV and 1,128 NDV selected from a cohort of veterans who previously participated in a national mail and telephone survey. Presence of DSP was evaluated by history, physical examination, and standardized electrophysiologic assessment of motor and sensory nerves. Similar examinations were performed without electrophysiologic tests in 484 DV spouses and 533 NDV spouses. Statistical analyses were performed with appropriate adjustments for the stratified sampling scheme.

RESULTS

No differences between adjusted population prevalence of DSP in DV and NDV were found by electrophysiology (3.7% vs 6.3%, p = 0.07), by neurologic examination (3.1% vs 2.6%, p = 0.60), or by the methods combined (6.3% vs 7.3%, p = 0.47). Excluding veterans with non-military service related diseases that may cause DSP did not alter outcomes. DV potentially exposed to neurotoxins from the Khamisiyah ammunition depot explosion did not significantly differ in DSP prevalence compared to non-exposed DV. The prevalence of DSP in DV spouses did not differ from NDV spouses (2.7% vs 3.2%, p = 0.64).

CONCLUSIONS

Neither veterans deployed during the Gulf War era nor their spouses had a higher prevalence of DSP compared to NDV and spouses.

Toxic inhalational injury: gas, vapor and vesicant exposure

Terrorism poses a clear and present danger to civilian populations. Although terrorist cells may gain access to traditional chemical weapons,there are literally thousands of other industrial chemicals to choose from. Common chemicals used on a daily basis in an industrialized society can be readily obtained from the local shopping center, rail yard. or from nearby industrial parks. and terrorists may choose to use these agents in an attack. The medical implications of a major incident involving the accidental or intentional release of a dangerous chemical are significant, and all healthcare facilities should have a plan in place to manage the casualties of such an event. This plan should include event recognition, crowd control, primary triage, emergency treatment, decontamination of injured and uninjured patients, and secondary triage. Emergency health care providers should be prepared to respond to classic chemical agents such as mustard,chlorine, and phosgene and must also work carefully with law enforcement and public health agencies to keep abreast of new threats. The ability to recognize an event promptly, triage patients, decontaminate casualties,administer antidotes when available, and provide best supportive care will minimize the adverse outcomes.

Clinical findings in 111 ex-Porton Down volunteers

OBJECTIVE

To determine whether the health of Porton Down volunteers (PDV) has suffered as a result of their participation in medical trials, during which they were exposed to single low dose concentrations of chemical warfare agents.

METHODS

Data were obtained from a self-selected series of ex-Porton Down volunteers who attended the MOD's Porton Down Volunteers' Medical Assessment Programme (PDVMAP). One hundred and eleven men attended with a mean age of 62 (range 37-81) years. Information obtained was analysed to determine whether clinical diagnoses and symptoms reported had any relationship to chemical exposures.

RESULTS

The diagnoses were not unusual for UK nationals with a mean age of 62 years. The majority of volunteers went to Porton Down in the 1950s and then had a mean age of 19. The mean time between volunteers attending Porton Down and coming to MAP was 42 years. We found no correlation between chemical exposures and later development of established diagnoses, a latent period of 30 years.

CONCLUSION

On a clinical basis, no evidence was found to support the hypothesis that participation in Porton Down trials produced any long-term adverse health effects or unusual patterns of disease compared to those of the general population of the same age.

Inhalational exposure to nerve agents

The respiratory system plays a major role in the pathogenesis of nerve agent toxicity. It is the major route of entry and absorption of nerve agent vapor, and respiratory failure is the most common cause of death follow-ing exposure. Respiratory symptoms are mediated by chemical irritation,muscarinic and nicotinic receptor overstimulation, and central nervous system effects. Recent attacks have demonstrated that most patients with an isolated vapor exposure developed respiratory symptoms almost immediately. Most patients had only mild and transient respiratory effects, and those that did develop significant respiratory compromise did so rapidly. These observations have significant ramifications on triage of patients in a mass-casualty situation, because patients with mild-to-moderate exposure to nerve agent vapor alone do not require decontamination and are less likely to develop progressive symptoms following initial antidote therapy. Limited data do not demonstrate significant long-term respiratory effects following nerve agent exposure and treatment. Provisions for effective respiratory protection against nerve agents is a vital consideration in any emergency preparedness or health care response plan against a chemical attack.

Examination of changes in connective tissue macromolecular components of large white pig skin following application of lewisite vapour

The aim of this study was to provide information about the degradative processes that occur in major connective tissue components in skin following exposure of large white pigs to Lewisite vapour. Of particular interest were alterations in glycoproteins, which are known to mediate dermo-epidermal attachment (laminin and type IV collagen) and the main collagen found in the dermis (type III collagen). The immunostaining of transfer blots from skin extracts run on sodium dodecyl sulphate polyacrylamide gel electrophoresis gels revealed no evidence of cross-linking of laminin or of type III or IV collagen. However, there was evidence of a very considerable degradation of laminin and, to a lesser extent, of type IV collagen. Type III collagen did not appear to be degraded in skin exposed to Lewisite. These degradative processes appeared to be more severe than found in previous studies in Yucatan mini-pigs percutaneously exposed to sulphur mustard, in which only laminin was found to undergo partial cleavage rather than wholesale degradation. The results suggest that damage to macromolecular components in the sub-epidermal basement membrane in skin which mediate dermo-epidermal separation processes may be a common feature in the mechanism of action of vesicating agents such as Lewisite and sulphur mustard. It is of interest that the damage to laminin in this study appeared to be more severe than that previously found for sulphur mustard. This suggests that skin can suffer substantial damage yet, in the case of Lewisite exposure, recover relatively quickly. However, Lewisite is not an alkylating agent. Sulphur mustard, in contrast, generates characteristically slow healing lesions, most probably because of its ability to alkylate cell types that normally would be involved in skin regenerative processes.

Chlorine-induced injury to the airways in mice

Exposure to chlorine gas (Cl2) causes occupational asthma that we hypothesized occurs through the induction of airway inflammation and airway hyperresponsiveness by oxidative damage. Respiratory mechanics and airway responsiveness to methacholine were assessed in A/J mice 24 hours after a 5-minute exposure to 100, 200, 400, or 800 ppm Cl2 and 2 and 7 days after inhalation of 400 ppm Cl2. Airway responsiveness was higher 24 hours after 400 and 800 ppm Cl2. Responsiveness after inhalation of 400 ppm Cl2 returned to normal by 2 days but was again elevated at 7 days. Airway epithelial loss, patchy alveolar damage, proteinaceous exudates, and inflammatory cells within alveolar walls were observed in animals exposed to 800 ppm Cl2. Macrophages, granulocytes, epithelial cells, and nitrate/nitrite levels increased in lung lavage fluid. Increased inducible nitric oxide synthase expression and oxidation of lung proteins were observed. Epithelial cells and alveolar macrophages from mice exposed to 800 ppm Cl2 stained for 3-nitrotyrosine residues. Inhibition of inducible nitric oxide synthase with 1400W (1 mg/kg) abrogated the Cl2-induced changes in responsiveness. We conclude that chlorine exposure causes functional and pathological changes in the airways associated with oxidative stress. Inducible nitric oxide synthase is involved in the induction of changes in responsiveness to methacholine.

Chemical warfare and the Gulf War: a review of the impact on Gulf veterans' health

It is unlikely that Gulf War veterans are suffering chronic effects from illnesses caused by chemical warfare nerve agent exposure. Extensive investigation and review by several expert panels have determined that no evidence exists that chemical warfare nerve agents were used during the Gulf War. At no time before, during, or after the war was there confirmation of symptoms among anyone, military or civilian, caused by chemical warfare nerve agent exposure. However, studies of Gulf War veterans have found belief that chemical weapons were used, significantly associated with both severe and mild-moderate illnesses. The psychological impact of a chemical warfare attack, either actual or perceived, can result in immediate and long-term health consequences. The deployment or war-related health impact from life-threatening experiences of the Gulf War, including the perceived exposure to chemical warfare agents, should be considered as an important cause of morbidity among Gulf War veterans.

Evaluations over the medical emergency responding to chemical terrorist attack

The use of chemical warfare agents intentionally has become a great concern in the arena of the cold war. On the other hand, there has always been a threat on civilian population due to their mass destruction effects, including psychological damage and a great deal of discussion how to respond to it in terms of medical management. It is very important to provide the best lifesaving medical care and triage in a chemical-contaminated area. Mass casualties exposed to chemical agents require immediate medical intervention to save their lives and should be classified in accordance to medical care priorities and available medical sources, including antidotes and sophisticated health facilities. Establishing the decontamination area for chemical casualties where it is located at the suitable place with respect to the wind direction is necessary. To overcome the mass destruction effects of chemical warfare agents following the terrorist attack, we must have the emergency medical response plan involving experienced triage officers and medical care providers to be able to perform medical management in the chemical-contaminated area and health facilities.

[Hygienic aspects of elimination of chemical weapons in the Russian Federation]

A specialized and unified package of measures has been developed for hygienic provision of work on the elimination of chemical weapons. The optimum algorithms of hygienic studies have been defined at all stages of the elimination of chemical weapons from the start of design of operations to conversion and transition for national economic needs. Guidelines for safe work at the objects of elimination of chemical weapons and for the protection of the environment and human health in the areas where they are located--have been developed.

Belief in exposure to terrorist agents: reported exposure to nerve or mustard gas by Gulf War veterans

September 11 brought increased awareness that even the threat of chemical and biological terrorism can overwhelm this country's health care system. Belief in exposure to toxic agents, even when none is documented, is not uncommon in crisis and merits vigilant health care evaluation and services. This study examined risk factors (demographics, physical symptoms, clinical diagnosis, exposures, and health status) for belief in exposure to potential terrorist agents (nerve or mustard gas) using a large sample of Gulf War veterans who reported belief in exposure to nerve or mustard gas. We found that females, nonwhites, and those who were older (age 32 to 61 years) were more likely to report exposure. When adjusting for demographics and military service, these veterans reported more exposures (nonnerve or mustard gas) to potentially toxic agents and traumatic events (odds ratio [OR], 6.80; p<.001), reported more physical symptoms during the Gulf War (OR, 2.38; p<.001), were more likely to be diagnosed with a mental disorder (OR, 1.72; p<.001), and reported poorer current health status (OR, 3.47 to 1.22; p<.001). Not unlike previously reported studies of disasters, traumatic exposures, or risk exposures, belief in exposure to toxic agents suggests that certain people are at a greater health care risk. This knowledge will aid in better responding to rapid demands that may be placed on our health care delivery systems in times of potential terrorist activity.

[Scientific principles of sanitary and hygienic basis of chemical weapons demolishment]

The authors designed a set of instructions and methodic documents and universal methodology for sanitary and hygienic follow-up in establishments running chemical weapons demolishment. Those instructions and methodology are aimed to safety of workers and general population.

Long-term health effects of exposure to sarin and other anticholinesterase chemical warfare agents

In a telephone survey of 4,022 military volunteers for a 1955-1975 program of experimental exposures to chemical agents at Edgewood, Maryland, the current health of those exposed to anticholinesterase agents was compared with that of men exposed to no active chemicals (no chemical test) and to two or more other types of chemical agents (other chemical tests). The survey posed questions about general health and about neurological and psychological deficits. There were only two statistically significant differences: volunteers in anticholinesterase agent tests reported fewer attention problems than those in other chemical tests and greater sleep disturbance than those in no chemical tests. In contrast, volunteers who reported exposure to civilian or military chemical agents outside of their participation in the Edgewood program reported many statistically significant adverse neurological and psychological effects, regardless of their experimental exposure. In this study, the health effects of self-reported, nonexperimental exposure, which are subject to recall bias, were greater than the health effects of experimental exposure.

Percutaneous absorption of topical N,N-diethyl-m-toluamide (DEET): effects of exposure variables and coadministered toxicants

Exposure to N,N-diethyl-m-toluamide (DEET) commonly occurs in the general population and has been implicated as a contributory factor to the Gulf War Illness. The focus of the present studies was to determine the effect of coexposure factors, potentially encountered in a military environment, that could modulate transdermal flux of topically applied DEET. Factors investigated were vehicle, dose, coexposure to permethrin, low-level sulfur mustard, occlusion, and simultaneous systemic exposure to pyridostigmine bromide and the nerve agent stimulant diisopropylfluorophosphate (DFP). Studies were conducted using the isolated perfused porcine skin flap (IPPSF), with a few mechanistically oriented studies conducted using in vitro porcine skin and silastic membrane diffusion cells. DEET was quantitated using high-performance liquid chromatography. The vehicle-control transdermal DEET flux in the IPPSF was approximately 2 micrograms/cm2/h for both 7.5 and 75% DEET concentrations, a value similar to that reported in humans. DEET absorption was enhanced by coinfusion of pyridostigmine bromide and DFP, by the presence of sulfur mustard, or by dosing under complete occlusion. The greatest increase in baseline flux was fivefold. In vitro diffusion cell studies indicated that silastic membranes had two orders of magnitude greater permeability than porcine skin, and showed vehicle effects on flux that were not detected in the IPPSF. These results suggest that coexposure to a number of chemicals that potentially could be encountered in a military environment may modulate the percutaneous absorption of topically applied DEET beyond that seen for normal vehicles at typically applied concentrations.

[The agent used to free the hostages in Moscow and the insufficient Dutch preparations in case of a terrorist chemical disaster]

In its attempt to liberate the hostages in Moscow, the government used a gas or vapour. Classical war gases are not appropriate for such a task because they cause irreparable damage, while inhalation anaesthetics are inappropriate because they take too long to take effect, and because hundreds of litres would have been required for a sufficient effect. Following the liberation of the hostages, it was reported that a fentanyl derivative had been used, most likely carfentanyl. From the way that the hostages, in Moscow were liberated, it is clear that terrorist attacks in which chemicals are used may also take place in the future in the Netherlands. In order to be able to react adequately to such situations, additional training for physicians and other health-care personnel is urgently necessary and the hospitals must also be better prepared for this task, especially for the artificial respiration of large numbers of patients and for the administration of large amounts of antidote in easy-to-use dosage units. From now on, on-site treatment and stabilisation will not be reserved only for trauma cases.

Long-term effects of chemical weapons on respiratory tract in Iraq-Iran war victims living in Babol (North of Iran)

In the Iraq-Iran war (1981-1989), extensive use of chemical weapons such as mustard gas caused high mortality, morbidity, injuries, and chronic side effects in vital organs, especially the respiratory tract. This study was performed to evaluate the long-term effects on respiratory tract of victims. Two hundred and twenty victims were referred from the Mostazafan and Janbazan Foundation of Babol from 1994 to 1998. Complete histories, physical examinations, chest X-rays, and PFTs were performed. Nearly all the victims complained of cough, dyspnea, and suffocation. Hemoptysis was found in 6 victims. In 4 patients, respiratory distress with use of accessory muscles was observed. Two-thirds of the subjects had wheezing and coarse rale. For the other third, physical examination revealed no abnormal finding. Radiographic findings were mostly normal. Spirometry revealed an obstructive pattern in all patients and PFT revealed mostly normal and restrictive patterns. The shortlist time from exposure to study was 7 years and the longest was 13 years. Most patients reported mustard gas exposure and a few of them did not know what type of gas exposure they had. The clinical evaluations, radiography, and PFTs revealed that the most prevalent effects of chemical weapons on respiratory tract were chronic obstructive lung disease, presenting as many types of obstructive involvement.

Vesicants and nerve agents in chemical warfare. Decontamination and treatment strategies for a changed world

Vesicants and nerve agents have been used in chemical warfare for ages. They remain a threat in today's altered political climate because they are relatively simple to produce, transport, and deploy. Vesicants, such as mustard and lewisite, can affect the skin, eyes, respiratory system, and gastrointestinal system. They leave affected persons at risk for long-term effects. Nerve agents, such as tabun, sarin, soman, and VX, hyperstimulate the muscarinic and nicotinic receptors of the nervous system. Physicians need to familiarize themselves with the clinical findings of such exposures and the decontamination and treatment strategies necessary to minimize injuries and deaths.

Illness experience of Gulf War veterans possibly exposed to chemical warfare agents

BACKGROUND

During the 1991 Gulf War, some Allied troops were potentially exposed to chemical warfare agents as the result of the detonation of Iraqi munitions at Khamisiyah.

METHODS

In 1999, we conducted a computer-assisted telephone survey of 2918 Gulf War veterans from Oregon, Washington, California, North Carolina, and Georgia to evaluate the prevalence of self-reported medical diagnoses and hospitalizations among this potentially exposed population and among comparison groups of veterans deployed and nondeployed to the Southwest Asia theater of operations.

RESULTS

Troops reported to be within 50 kilometers of the Khamisiyah site did not differ from other deployed troops on reports of any medical conditions or hospitalizations in the 9 years following the Gulf War. Hospitalization rates among deployed and nondeployed troops did not differ. Deployed troops were significantly more likely to report diagnoses of high blood pressure (odds ratio [OR]=1.7); heart disease (OR=2.5); slipped disk or pinched nerve (OR=1.5); post-traumatic stress disorder (OR=14.9); hospitalization for depression (OR=5.1); and periodontal disease (OR=1.8) when compared to nondeployed troops. There was a trend for deployed veterans to report more diagnoses of any cancer (OR=3.0).

CONCLUSIONS

These findings do not provide evidence of any long-term health effect associated with exposure to the detonation of chemical warfare agents, but support findings from other investigations of increased morbidity among deployed troops. The prevalence of cancer among this population of deployed troops merits ongoing attention.

Factor analysis of Gulf War illness: what does it add to our understanding of possible health effects of deployment?

The authors conducted factor analysis on survey data from 1,779 Persian Gulf War veterans. Their purposes were to: 1) determine whether factor analysis identified a unique "Gulf War syndrome" among veterans potentially exposed to chemical warfare agents; 2) compare the findings of factor analysis with those from an epidemiologic analysis of symptom prevalence; and 3) observe the behavior of factor analysis when performed on dichotomous data. The factor analysis identified three factors, but they were not unique to any particular deployment group. A unique pattern of illness was not found for the larger group of veterans potentially exposed to chemical warfare agents; however, veterans who had witnessed the demolition of chemical warfare agents at the Khamisiyah site in Iraq had a greater prevalence of dysesthesia. An analysis of the performance of dichotomous variables in factor analysis showed that the standard criteria used to determine the number of relevant factors and the dominant variables within them may be inappropriate. While Gulf War veterans appear to suffer an increased burden of illness, there is insufficient evidence to identify a unique syndrome in this population of deployed servicemen and women. Furthermore, the results provide evidence that factor analysis may make a limited contribution in this area of research.

Laboratory conditions and safety in a chemical warfare agent analysis and research laboratory

Toxic chemicals have been used as weapons of war and also as means of terrorist attacks on civilian populations. Research focusing on chemical warfare agents (CWAs) may be associated with an increased risk of exposure to and contamination by these agents. This article summarizes some of the regulations concerning designation and safety in a CWA analysis and research laboratory and medical countermeasures in case of an accidental exposure. The design of such a laboratory, coupled with a set of safety guidelines, provides for the safe conduct of research and studies involving CWAs. Thus, a discussion of decontamination and protection means against CWAs is also presented.

Evaluation of risk assessment guideline levels for the chemical warfare agents mustard, GB, and VX

The U.S. Army has estimated acute lethality guideline levels for inhalation of the chemical warfare agents mustard, GB, and VX. These levels are expressed as dosages measured in milligram-minutes per cubic meter (mg-min/m(3)). The National Advisory Council has also proposed acute emergency guideline levels (AEGLs) for the agents. The AEGLs are threshold exposure limits for the general public for mild effects, serious adverse effects, and lethality. They are expressed as air concentrations (in units of mg/m(3)) and are applicable to emergency exposure periods ranging from 10 min to 8 h. The report discusses strengths and deficiencies in the levels, important parameters (i.e., exposure time, breathing rate) that need to be explicitly addressed in deriving the guideline levels, and possible impacts that could result from using AEGLs instead of guideline dosages in future assessments.

Artificial neural networks for modeling electrophoretic mobilities of inorganic cations and organic cationic oximes used as antidote contra nerve paralytic chemical weapons

Electrophoretic mobility of various analytes can be modeled and thus also predicted using artificial neural networks (ANNs) evaluating experiments done according to a suitable experimental design. In contrast to response surfaces modeling which can be used to predict optimal separation conditions, ANNs combined with experimental design were shown to be efficient for modeling and prediction of optimal separation conditions, while no explicit model and any knowledge of the physicochemical constants is needed. Methodology has been developed and demonstrated on separation of inorganic cations and organic oximes while various additives (methanol, complexation agent), pH or buffer concentration were followed. In our approach proposed the number of experiments necessary to find optimal separation conditions can be reduced significantly.

Pyridostigmine bromide and the long-term subjective health status of a sample of over 700 male Reserve Component Gulf War era veterans

Data from a 1996-1997 survey of approximately 700 Reserve Component male veterans indicate that the consumption of pyridostigmine bromide pills, used as a pretreatment for potential exposure to the nerve agent Soman, was a significant predictor of declines in reported subjective health status after the war, even after controlling for a number of other possible factors. Reported reactions to vaccines and other medications also predicted declines in subjective health. While higher military rank generally predicted better health during and after the war, educational attainment, minority status, number of days in theater, and age generally did not predict changes in subjective health. Although servicemembers were directed to take three pills a day, veterans reported a range of compliance--less than a fourth (24%) followed the medical instructions compared to 61% who took fewer than three pills daily and 6% who took six or more pills a day. Implications for use of pyridostigmine bromide are discussed.

The immunostatus of natural killer cells in people exposed to sulfur mustard

Sulfur mustard (2,2-dichloroethyl sulfide, SM) has been documented as an alkylating agent. It has been widely used as a chemical weapon during the last two decades. Despite extensive worldwide research, no effective therapy has yet been devised for the treatment of patients exposed to SM. A severe suppression of the immune system still remains as the major cause of opportunistic infections, septicemia and death in such patients. The aim of this study was to determine the possible effect of SM on natural killer (NK) cells in patients suffering from SM injuries. Patients were classified into three groups: mild, moderate and severe. Blood sample obtained from each patient was examined using flowcytometric technique. Results showed that the percentage of NK cells (CD45+/CD56+) is significantly lower in severe patients than that of the control group (P<0.05). It was also observed that the activity of NK cells (CD56+/CD25+) in severe alkylating group is noticeably higher compared with the control group (P<0.1).

Temporal changes in respiratory dynamics in mice exposed to phosgene

One hallmark of phosgene inhalation toxicity is the latent formation of life-threatening, noncardiogenic pulmonary edema. The purpose of this study was to investigate the effect of phosgene inhalation on respiratory dynamics over 12 h. CD-1 male mice, 25-30 g, were exposed to 32 mg/m(3) (8 ppm) phosgene for 20 min (640 mg min/m(3)) followed by a 5-min air washout. A similar group of mice was exposed to room air for 25 min. After exposure, conscious mice were placed unrestrained in a whole-body plethysmograph to determine breathing frequency (f), inspiration (Ti) and expiration (Te) times, tidal volume (TV), minute ventilation (MV), end inspiratory pause (EIP), end expiratory (EEP) pause, peak inspiratory flows (PIF), peak expiratory flows (PEF), and a measure of bronchoconstriction (Penh). All parameters were evaluated every 15 min for 12 h. Bronchoalveolar lavage fluid (BALF) protein concentration and lung wet/dry weight ratios (W/D) were also determined at 1, 4, 8, and 12 h. A treatment x time repeated-measures two-way analysis of variance (ANOVA) revealed significant differences between air and phosgene for EEP, EIP, PEF, PIF, TV, and MV, p < or =.05, across 12 h. Phosgene-exposed mice had a significantly longer mean Ti, p < or =.05, compared with air-exposed mice over time. Mice exposed to phosgene showed marked increases (approximately double) in Penh across all time points, beginning at 5 h, when compared with air-exposed mice, p < or =.05. BALF protein, an indicator of air/blood barrier integrity, and W/D were significantly higher, 10- to 12-fold, in phosgene-exposed than in air-exposed mice 4-12 h after exposure, p <or =.001 and p < or =.05, respectively. These results indicate that exposure to phosgene causes early bronchoconstriction, a temporal obstructivelike injury pattern, and disruption of mechanical rhythm largely regulated by the progressive production of pulmonary edema on airway flow. Potential therapeutic intervention may include compounds that produce bronchodilation and mechanical ventilation support if warranted.

Responding to chemical, biological, or nuclear terrorism: the indirect and long-term health effects may present the greatest challenge

The possibility of terrorists employing chemical, biological, or nuclear/ radiological (CBN) materials has been a concern since 1995 when sarin gas was dispersed in a Tokyo subway. Contingency planning almost exclusively involved detection. containment, and emergency health care for mass casualties. However, it is clear that even small-scale CBN incidents--like the recent spread of anthrax spores through the mail--can cause widespread confusion, fear, and psychological stress that have lasting effects on the health of affected communities and on a nation's sense of well-being. More emphasis therefore needs to be placed on indirect effects and on the medical, social, economic, and legal consequences that follow months to years afterward. To respond effectively to CBN attacks, a comprehensive strategy needs to be developed that includes not only emergency response, but also long-term health care, risk communication, research, and economic assistance. Organizing an effective response challenges government institutions because the issues involved--eligibility for health care, the effects of low-level exposure to toxic agents. stress-related illnesses, unlicensed therapeutics. financial compensation--are complex and controversial.

Weapons of mass destruction and the role of the neurosurgeon

The desire to assist in a crisis should be tempered by a serious assessment of the technical preparation one has undertaken. Additionally, in the same way that a needs assessment is undertaken before prescribing a course of treatment, one should evaluate the actual staffing requirements of the situation. Many physician volunteers were turned away after the World Trade Center attacks because the overwhelming response of available medical personnel quickly exceeded the requirement. Finally, the duration and intensity of preparation should be based on a realistic evaluation of the likelihood of an event occurring that would necessitate use of the training. Before jumping into action in a situation in which weapons of mass destruction have been used, several issues must be addressed. Prior to the crisis, all professionals, neurosurgeons included, should ask how they can prepare themselves and their communities. During the crisis, neurosurgeons should evaluate their roles based on specialized triage training and experience, personal and equipment decontamination training, and the importance of neurosurgical skills. Finally, one should continually ask if there is anything he/she should be doing during the crisis in addition to performing neurosurgical tasks.

Common chemical agent threats

The events of September 11, 2001, highlight the fact that we live in precarious times. National and global awareness of the resolve and capabilities of terrorists has increased. The possibility that the civilian neurosurgeon may confront a scenario involving the use of chemical warfare agents has heightened. The information reported in this paper serves as a primer on the recognition, decontamination, and treatment of trauma patients exposed to chemical warfare agents.

Intramuscular diazepam pharmacokinetics in soman-exposed guinea pigs

Intramuscular (i.m.) diazepam is included by the US military as an anticonvulsant in the standard therapeutic regimen for organophosphorus nerve agent intoxication. In this study we investigated the pharmacokinetics of diazepam after i.m. administration while monitoring pharmacodynamic (electroencephalogram, EEG) data in soman-exposed guinea pigs. Prior to experiments the animals were surgically implanted with EEG leads to monitor seizure activity. For the study, animals were administered pyridostigmine (0.026 mg x kg(-1) i.m.) 30 min prior to soman (56 microg x kg(-1), 2 x LD50; subcutaneously, s.c.), which was followed in 1 min by atropine sulfate (2 mg x kg(-1) i.m.) and pralidoxime chloride (25 mg x kg(-1) i.m.). All animals receiving this regimen developed seizure activity. Diazepam (10 mg x kg(-1) i.m.) was administered 5 min after onset of seizure activity. Based on EEG data, animals were categorized as either seizure terminated or not terminated at 30 min after diazepam. Serial blood samples were obtained from each animal. Diazepam (10 mg x kg(-1) i.m.) terminated seizure activity in 52% of the animals within 30 min. The pharmacokinetics were characterized by a one-compartment model with first-order absorption and elimination. The maximum plasma concentrations (Cmax) were 991 and 839 ng x ml(-1) for seizure terminated and not terminated, respectively. Mean plasma concentrations of diazepam were significantly different (P < 0.05) for seizure terminated vs not terminated groups at 30 min. The plasma Cmax in seizure-terminated animals in this study is similar to the minimum range of plasma diazepam (200-800 ng x ml(-1)) reported to suppress seizure activity in humans. It has been reported in an earlier study that the minimum effective i.m. dose (0.1 mg x kg(-1)) required to prevent soman-induced convulsions in Rhesus monkeys produces a mean Cmax of 50 ng x ml(-1) for diazepam. The data from our current study suggest that a higher dose (and corresponding Cmax) is necessary to terminate ongoing seizure activity.