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Recently, polymer composite material has shown excellent performance in a wide range of technological applications, such as renewable energy, biomedical applications, optoelectronic devices ...etc. As the knowledge-base on this emergent material continues to grow, a new kind of hybrid sensors fabricated with semiconducting metal oxides and conducting polymers had been synthesized and had demonstrated high sensing capability for several poisonous gases and chemical warfare agents at room temperature. This research work introduces the synthesis and the characterization of a novel polymer P-DSBT composite consisting of ZnO nanoparticles (P-DSBT/ZNO). The composite films P-DSBT/ZNO are prepared by spin coating technique and then studied using different spectroscopic characterization techniques, i.e., FTIR, XRD, SEM, TEM, AFM and UV–Vis to further investigate on the structure and the morphology of this material. For assessing the P-DSBT/ZNO selectivity, different oxidizing and reducing gases were applied and it was found that the nanocomposite has the best selectivity for methane (CH4). The obtained P-DSBT/ZNO shows a wide sensing range (0–200 ppm) and a very high response magnitude, i.e., relative resistance changes of approximately 40% per 60 ppm of CH4. The key finding of this work is that sensitivity for gas detection is greatly improved by the interaction of ZnO-based hybrid materials at room temperature. [ABSTRACT FROM AUTHOR]

Background: Amongst the chemical warfare agents, blistering (vesicant) agents can be significant materials. The most important agent in this group is sulfur mustard (mustard gas) which is known as "King of chemical warfare (CW) agents ". Exposure to this agent, seriously causes damages in several organs, such as the eyes. This article reviews the ophthalmological aspects of sulfur mustard with reference of its management. Methods: A wide-ranging search in PubMed databases, Thomson Reuters and Scopus was done and different aspects of chemical properties of sulfur mustard, its mechanism of action and effects on eyes, clinical finding, diagnostic evaluation, initiate actions, pharmaceutical and surgical interventions was reported. Results: Sulfur mustard can alkylate DNA and RNA strands and break down structures of protein and lipid of cell membrane. This may impair cell energy production, and leads to cell death. Exposure to sulfur mustard, therefore, causes such problems for organs, including irreversible damage to the eyes. Conclusion: Understanding the mechanism of the sulfur mustard effect and the early training in prevention injuries will cause fewer complications and damage to organs, including the eyes. Washing the eyes with tap water or eyewash solutions, using mydriatic drops, anti-inflammatory drugs, matrix metalloproteinase inhibitors and antibiotics may help to the management of poisoning. Surgical interventions including tarsorrhaphy, amniotic membrane transplantation, stem cell transplantation and corneal transplantation could reduce the harm to the victims. [ABSTRACT FROM AUTHOR]

In World War I, sulfur mustard or mustard gas was used as a chemical weapon for the first time. Years later, during the imposed war (eight years of holy defense) against the Islamic Republic of Iran, Iraq used this poisonous gas against the soldiers and people of Iranian cities. Many years after the war, many chemical veterans still suffer from its effects. Mustard gas is a strong alkylating substance with cytotoxic and mutagenic properties, which causes blisters in mucous membranes and skin when it comes in contact with the skin. It is usually a colorless or amber-yellow oily liquid. In high concentrations, it has a disgusting smell similar to horseradish, onion, or garlic, which is mostly due to contamination with ethyl sulfide and other byproducts of its synthesis. Various studies have proven that long-term exposure to this toxic gas can lead to respiratory disorders and lung cancer. Considering the drug resistance and special conditions of chemical veterans with lung cancer, one of the new methods proposed for their treatment is the use of oncolytic viruses. The purpose of this study is to review the therapeutic potential of oncolytic viruses in the treatment of lung cancer caused by chemical warfare agents. [ABSTRACT FROM AUTHOR]

Provides information on lewisite, a poison gas developed by the U.S. in 1917 in response to Germany's mustard gas. Discovery and cleanup of lewisite in Spring Valley, Washington D.C.; History of lewisite; Articles about the debate on the effectiveness of lewisite; Production and use of lewisite by Japan, Great Britain and the Soviet Union.

Chemical agents; is the general name of substances known to have toxic effects on the environment, which cause a large number of deaths and disabilities in a short period of time. These agents are divided into subclasses such as blister, nerve, choking, incapacitating/behavior altering, and asphyxiants/blood agents. In addition to the short-term effects of these agents there may be long-term reflections which affect the next generation. The previous century has been an important period in terms of observing the problems arising from the usage of the agents during wars. Deaths only due to nerve agents are thought to exceed 5 millions in recent wars. Especially the situation that the World War II has emerged shows the magnitude of the use of chemical agents. Due to these detrimental effects, their usage is restricted or prohibited by various international organizations. Despite these obstacles, chemical agents have been used by some countries and terrorist groups. Effects of these agents can take part vary from basic symptoms such as nose irritation to serious problems such as respiratory arrest. Healthcare professionals working in the management of exposure to these agents should have sufficient knowledge and be aware of their effects on the body. For this purpose; we discussed the serious effects of chemical warfare agents on human health and environment, post-exposure applications and pharmacological treatment options. [ABSTRACT FROM AUTHOR]

Sulfur mustard, in a chemical name bis(2-chloroethyl) sulfide, is a chemical warfare agent. It is cytotoxic and blister forming once spread over the skin. Though exact molecular mechanism of sulfur mustard toxic action remains unknown, inflammation and oxidative stress development are considered as the most relevant pathological consequences. Applications of either low-molecular weight antioxidants or cofactors for enzymatic antioxidants are considered as suitable ways how to ameliorate the poisoning. In this article, survey of literature on countermeasures against sulfur mustard poisoning are given and evidence of oxidative stress role during sulfur mustard poisoning and availability of antioxidants for the therapy are discussed. [ABSTRACT FROM AUTHOR]

Pulmonary complications due to mustard gas exposure range from no effect to severe bronchial stenosis. Pulmonary function tests (PFTs) and respiratory symptoms in chemical war victims were studied 23–25 years after exposure to sulfur mustard (SM). Respiratory symptoms were evaluated in a sample of 142 chemical war victims and 120 control subjects with similar age from the general population using a questionnaire including questions on respiratory symptoms in the past year. PFT values were also measured in chemical war victims before and 15 min after the inhalation of 200 µg salbutamol and baseline PFT in controls. All chemical war victims (100%) reported respiratory symptoms. Wheezing (66.19%), cough (64.78%), and chest tightness (54.4%) were the most common symptoms and only 15.5% of chemical war victims reported sputum (p < 0.01 for sputum and p < 0.001 for other symptoms compared with control group). In addition, 49.3% of chemical war victims had wheeze in chest examination, which were significantly higher than control group (p < 0.001). The severity of respiratory symptoms was also significantly higher than control subjects (p < 0.05 for sputum and p < 0.001 for other symptoms). All the PFT values were also significantly lower in chemical war victims than that in control subjects (p < 0.001 for all cases). In addition, all the PFT values improved significantly after the inhalation of 200 µg salbutamol (p < 0.05–p < 0.001). These results showed that chemical war victims, 23–25 years after exposure to chemical warfare have higher frequencies and severity of respiratory symptoms. PFT values were also significantly reduced among chemical war victims, which showed reversibility due to the inhalation of 200 µg salbutamol. [ABSTRACT FROM PUBLISHER]

The synthesis, characterization and sensing features of a novel probe 1 for the selective chromogenic recognition of diisopropylfluorophosphate (DFP), a sarin and soman mimic, in 99:1 ( v/ v) water/acetonitrile and in the gas phase is reported. Colour modulation is based on the combined reaction of phosphorylation of 1 and fluoride-induced hydrolysis of a silyl ether moiety. As fluoride is a specific reaction product of the reaction between DFP and the −OH group, the probe shows a selective colour modulation in the presence of this chemical. Other nerve agent simulants, certain anions, oxidant species and other organophosphorous compounds were unable to induce colour changes in 1. This is one of the very few examples of a selective detection, in solution and in the gas phase, of a sarin and soman simulant versus other reactive derivatives such as the tabun mimic diethylcyanophosphate (DCNP). [ABSTRACT FROM AUTHOR]

A turn-on signal from zero background allows sensitive detection of a weak signal and is highly desired. The "covalent-assembly" probe design principle is powerful in this regard. Herein, we report an embodiment of this principle (NA570) for detection of Sarin related threats, based on a phenylogous Vilsmeier-Haack reaction. NA570 bears a concise molecular construct, exhibits a colorimetric and a fluorimetric signal, and has potential for real applications. [ABSTRACT FROM AUTHOR]

We report a turn-on sensor framework with enhanced vapor sensitivity by increasing the sensor's response dynamic range via rational design of the sensor formulation. Using a fluorescent dye as the reporter, our approach begins by reducing sensor background fluorescence through the use of selected quenchers. Analyte interaction induces the onset of emission by interrupting the quenching interaction, thereby turning on the sensor. We demonstrate over an order of magnitude increase in vapor sensitivity for dimethyl methylphosphonate (a Sarin simulant) detection using a sensor containing inorganic oxides as a quencher for Nile Red dye. This approach was also used to develop a new sensor with improved sensitivity for methyl benzoate (a hydrolysis byproduct of cocaine, used to train drug-sniffing dogs). By generalization, additional candidate quenchers for Nile Red were identified based on Lewis acid/base interactions. This framework can be applied in parallel with other amplification strategies including mass transport incentive, one-analyte-to-multiple-reporter schemes or signal lasing to further increase sensor response amplitude. [ABSTRACT FROM AUTHOR]

The purpose of our study was to evaluate the late ocular, pulmonary, and cutaneous complications of mustards, 19 years after exposure in 600 patients of the city of Sardasht, Iran. In this case study, we evaluated 600 warfare patients aged 19 to 80 years whose mustard gas injury dated back to 19 years before evaluation in Sardasht. Our results showed that 5.2% of our cases were aged 19-20 years, 18.5% were aged 21-30 years, 31.7% were aged 31-40 years, 23.5% were aged 41-50 years, 12.2% were aged 51-60 years, 5.5% were aged 61-70 years, and 3.4% were aged 71-80 years. There were 50.3% male patients in our study, and 83.2% of the patients were married. Primary ocular manifestations were present in 96.2% of the cases, respiratory manifestations in 80.7%, and cutaneous manifestations in 83.8%, with a hospitalization rate of 64.7%. Ophthalmic, respiratory, and dermal medications were administered in 72.8%, 66.7%, and 61.8% of cases, respectively. The degree of ocular complications was mild in 36.7% and moderate in 1%. Respiratory complications were mild in 45% and moderate in 0.8%. Cutaneous complications were mild in 31.3% and moderate in 0.2.%. Late mild respiratory complications were significantly more frequent than ocular and cutaneous complications. In conclusion, late mild pulmonary complications were more frequent than mild ocular and cutaneous complications; however, moderate ocular complications were more frequent than moderate pulmonary and cutaneous complications. [ABSTRACT FROM AUTHOR]

Abstract: Application of human antidotes against nerve agent intoxications to microcrustacean Daphnia magna (Crustacea, Cladocera) intoxicated by a nerve agent tabun (O-ethyl-N,N-dimethylphosphoramidocyanidate) and their efficacy was investigated. It was found that antidotes can be successfully applied to intoxicated daphnids. Three different treatment regimens were tested: the combination of atropine and acetylcholinesterase reactivator (trimedoxime was chosen), atropine only and trimedoxime alone, too. The most efficient was the combination of atropine and trimedoxime followed by treatment with atropine only. The proportion of recovered animals increased with time not only in treated groups but also in the control as well. This can be explained by a spontaneous reactivation of tabun-inhibited cholinesterase in daphnids probably indicating a difference between mammalian and crustacean cholinesterases. [Copyright &y& Elsevier]

The article examines whether intoxication with nerve agent triggers the molecular events that underlie the acute-phase (AP) response, where the induced AP proteins stand out in alleviating the pathophysiological effects of paraoxon and soman. It noted that both soman and paraoxon poisoning were described by increased synthesis of α1-acid glycoprotein (AGP) that displayed an immunomodulatory effect in vitro. However, it inferred that AGP could be a participant in a feedback control mechanism that prevents an overload by the organism's immune response during the AP response.

Acetylcholinesterase reactivators are crucial antidotes for the treatment of organophosphate intoxication. Among the organophosphates, with the exception of soman, tabun (GA) intoxications are the least responsive to treatment with commercially available therapeutics. A rational design was used to increase reactivation ability and decrease the toxicity of the novel reactivator. (E)-1-(4-carbamoylpyridinium)-4-(4-hydroxyiminomethylpyridinium)-but-2-ene dibromide (K203) has better properties than previously tested compounds in vitro and, therefore, is a potential candidate for the treatment of GA intoxication in vivo. [ABSTRACT FROM AUTHOR]

Abstract: Six novel AChE reactivators with a (Z)-but-2-ene linker were synthesized using the known synthetic pathways. Their ability to reactivate AChE, which had been previously inhibited by nerve agent tabun or pesticide paraoxon, was tested in vitro and compared to pralidoxime, HI-6, obidoxime, and K075. The novel synthesized compounds were found to be ineffective against GA-inhibited AChE but the ability of (Z)-1,4-bis(4-hydroxyiminomethylpyridinium)-but-2-ene dibromide to reactivate paraoxon-inhibited AChE was comparable with that of oxime K075. Notably, the oxime group in position four substantially increased the ability of the novel compounds to reactivate paraoxon-inhibited AChE. [Copyright &y& Elsevier]

Breakthrough behaviour of sulphur mustard, the deadliest of persistent chemical warfare agents, on carbon systems such as NaOH/CrO3/C, NaOH/CrO3/EDA/C and RuCl3/C has been studied and the data were compared with that of active carbon. Effects of bed lengths of carbons on breakthrough time have also been correlated. Thereafter, the effects of flow rate of air–sulphur mustard mixture, concentration and temperature on the kinetic parameters such as rate constant (k v) and kinetic saturation capacity (W e) were analyzed and interpreted by means of modified Wheeler equation. Rate constant was found to be increasing while W e was found to be invariable with the increase in air flow rate. Both k v and W e decreased with the increase of temperature, however, no significant effect on W e and k v was observed due to concentration change (0. 3–0. 6mg/l). The values of kinetic saturation capacity were used to predict the service lives/breakthrough times of carbon beds (when used in filtration systems). [Copyright &y& Elsevier]

Although sulfur mustard (SM) has been used as a chemical warfare agent since the early twentieth century, it has reemerged in the past decade as a major threat around the world. This agent injured over 100,000 Iranians and one-third is suffering from late effects until today. Mustard affects many organs such as the skin, eyes, and lungs, as well as the gastrointestinal, endocrine, and hematopoietic system. In this study we focused on review of the late Cutaneous and ocular complications caused by exposure to SM. All studies regarding long-term ocular and cutaneous effects, which have been done on Iranian population, were collected from domestic and international sources. Pruritus is the most common complain and a malignant change is the most important lesion, which has to be considered. Also this agent is causes of chronic and delayed destructive lesions in the ocular surface and cornea, leading to progressive visual deterioration and ocular irritation. [ABSTRACT FROM AUTHOR]

Abstract: Currently fielded treatments for nerve agent intoxication promote survival, but do not afford complete protection against either nerve agent-induced motor and cognitive deficits or neuronal pathology. The use of human plasma-derived butyrylcholinesterase (HuBuChE) to neutralize the toxic effects of nerve agents in vivo has been shown to both aid survival and protect against decreased cognitive function after nerve agent exposure. Recently, a commercially produced recombinant form of human butyrylcholinesterase (r-HuBuChE; PharmAthene Inc.) expressed in the milk of transgenic goats has become available. This material is biochemically similar to plasma-derived HuBuChE in in vitro assays. The pharmacokinetic characteristics of a polyethylene glycol coated (pegylated) form of r-HuBuChE were determined in guinea pigs; the enzyme was rapidly bioavailable with a half-life (t 1/2) and pharmacokinetic profile that resembled that of plasma-derived huBuChE. Guinea pigs were injected with 140mg/kg (i.m.) of pegylated r-HuBuChE 18h prior to exposure (sc) to 5.5×LD50 VX or soman. VX and soman were administered in a series of three injections of 1.5×LD50, 2.0×LD50, and 2.0×LD50, respectively, with injections separated by 2h. Pretreatment with pegylated r-HuBuChE provided 100% survival against multiple lethal doses of VX and soman. Guinea pigs displayed no signs of nerve agent toxicity following exposure. Assessments of motor activity, coordination, and acquisition of spatial memory were performed for 2 weeks following nerve agent exposure. There were no measurable decreases in motor or cognitive function during this period. In contrast, animals receiving 1.5×LD50 challenges of soman or VX and treated with standard atropine, 2-PAM, and diazepam therapy showed 50 and 100% survival, respectively, but exhibited marked decrements in motor function and, in the case of GD, impaired spatial memory acquisition. The advances in this field have resulted in the decision to select both the plasma-derived and the recombinant form of BuChE for advanced development and transition to clinical trials. Efforts have now been expanded to identify a catalytic protein capable of not only binding, but also rapidly hydrolyzing the standard threat nerve agents. Recent work has focused on paraoxonase-1 (PON1), a naturally occurring human serum enzyme with the capacity to catalyze the hydrolysis of nerve agents, albeit too slowly to afford dramatic protection. Using rational design, several amino acids involved in substrate binding have been identified and site-directed mutations have revealed that residue H115 plays an important role in binding. In addition, the stereospecificity of PON1 for the catalytic hydrolysis of soman has been examined. The enzyme exhibits a slight stereospecificity for the C+P+ isomer of soman, which is due more to preferential binding than to selective hydrolysis of this isomer. The results suggest that it may be possible to engineer a mutant form of PON1 with enhanced activity and stereospecificity for the most toxic nerve agent isoforms. [Copyright &y& Elsevier]

Abstract: Interactions of tabun (GA) with non-hydroxylated and hydroxylated CaO clusters have been studied using density functional (DFT) and Møller–Plesset second order perturbation (MP2) levels of theory. The nature of interactions has been further investigated from the topology of charge distribution (using Atoms in Molecules formalism) and molecular electrostatic potential (MEP) surfaces. These adsorption studies indicate that GA adsorbs strongly on the non-hydroxylated CaO cluster through its Phile interactions of GA on the hydroxylated cluster are weak. These model studies could thus be useful to characterize inorganic oxides for efficient detection and disposal of GA. [Copyright &y& Elsevier]

The article investigates the fate of sarin on several types of activated carbons, particularly on metal-impregnated activated carbons, using P magic-angle-spinning (MAS) nuclear magnetic resonance spectroscopy. Results of the study show that majority of the adsorbed OP nerve agent isopropyl methylphosphonofluoridate (sarin) on dried carbons have decomposed, with a half life of 5-12 days. The degradation time of sarin on activated carbon shortens by approximately an order of magnitude when BPL and ASC carbons were exposed to air of 53 percent humidity. Sarin's half life on BPL carbon was also shorten by wetting to approximately two hours.

Abstract: Three asymmetrical AChE reactivators with cyano-moiety and propane linker were synthesized using modification of currently known synthetic pathways. Their potency to reactivate AChE inhibited by nerve agent tabun and insecticide paraoxon was tested in vitro and compared to pralidoxime, HI-6, obidoxime, K027, and K048. According to the results, three compounds seem to be promising against paraoxon-inhibited AChE. Better results were obtained for bisquaternary substances at least with one oxime group in position four. None of tested substances was able to satisfactorily reactivate tabun-inhibited AChE at concentration applicable for in vivo experiments. [Copyright &y& Elsevier]

Preparation and analysis of tabun (GA) solutions are necessary for the continued development of countermeasures to this nerve agent. GA solutions must be stable and compatible for use in the test systems chosen for study; however, GA is very unstable in saline solutions. In the past we have found GA in saline at 2 mg/mL to be stable for a month or less at -70°C, whereas saline solutions of sarin (GB), soman (GD), and cyclosarin (GF) were stable for many months. Previous studies have shown that Multisol (48.5% H 2 O, 40% propylene glycol, 10% ethanol, and 1.5% benzyl alcohol) provides stable solutions of GA. We confirmed the stability of GA in Multisol with phosphorus nuclear magnetic resonance (P─NMR) and developed a method for the analysis of GA in Multisol using gas chromatographic flame photometric detection (GCFPD) in the phosphorus mode. The GC method used acetonitrile (CH 3 CN) for a dilution solvent because of its miscibility with GA in chloroform (CHCl 3 ) standards and GA in Multisol samples at 1% (v/v). Furthermore, the dilutions with CH 3 CN made the phosphorus mode interference peak present in CHCl 3 analytically manageable, reduced the interferences of Multisol in the GC separation, and contributed to a safe and reliable analysis of GA at 20 μg/mL. We demonstrated the stability of GA in Multisol stored for more than a year at 70°C. This method contributes a suitable technique for the preparation and analysis of reliable solutions of GA in nerve agent medical research and demonstrates the extended stability of GA in Multisol. [ABSTRACT FROM AUTHOR]

A novel method for the rapid screening of degradation products derived from nerve agents by matrix-assisted laser desorption ionization time-of-flight mass spectrometry is described. Five standard products were selected as model compounds, including isopropyl methylphosphonic acid (IMPA), pinacolyl methylphosphonic acid (PMPA), ethyl methylphosphonic acid (EMPA), isobutyl methylphosphonic acid (i-BuMPA), and cyclohexyl methylphosphonic acid (CHMPA), which are degradation products of Sarin (GB), Soman (GD), VX, Russian VX (RVX), and GF, respectively. For comparison, CHCA (α-cyano-4-hydroxycinnamic acid) and DCCA (7-(diethylamino)coumarin-3-carboxylic acid) were used as the MALDI-matrix when the third harmonic generation (355 nm) of a Nd:YAG laser and a hydrogen Raman laser (multifrequency laser) were used, respectively. The method permitted the five nerve agent degradation products to be screened rapidly and successfully, suggesting that it has the potential for use as a routine monitoring tool. [ABSTRACT FROM AUTHOR]

Abstract: Conformational studies have been carried out on the two different enantiomers of tabun at the density functional and second order Møller–Plesset perturbation levels of theory to generate low energy potential energy surfaces in the gas phase as well as in aqueous environment. The structures of the low energy conformers together with their molecular electrostatic potential surfaces have been compared with those of the non-aged acetylcholinesterase–tabun complex to locate the active conformer of this molecule. [Copyright &y& Elsevier]

Sulphur mustard (SM) is an alkylating chemical warfare agent that was widely used during the World War I and in the Iran–Iraq conflict. Delayed complications of SM in different organs and their severity correlations have not previously been reported. Dermatological, ophthalmological, neurological and respiratory examinations, as well as spirometry, gasometry, high resolution computed tomography scanning of the chest, electromyography, nerve conduction velocity, cell blood counts, flow-cytometric analyses, and measurement of serum immunoglobulins and complement factors were performed on all severely SM poisoned veterans in the province of Khorasan, Iran. Haematological and immunological studies were also performed on a control group consisting of 35 healthy male subjects. The severity of dermal, ocular and respiratory complications were classified into four grades and their correlations with each other as well as with the haematological and immunological parameters were determined, using Spearman's rank correlation test. Forty male patients (aged 43.8 ± 9.8 years) with confirmed SM poisoning 16–20 years after the exposure were studied. The most common complications were found in the lungs (95%), peripheral nerves (77.5%), skin (75%), and eyes (65%). WBC, RBC, haematocrit (HCT), IgM, C3, and the percentages of monocytes and CD3+ lymphocytes were significantly ( P < 0.042) higher and the percentage of CD16 + 56 positive cells was significantly ( P = 0.006) lower in the patients than in the control group. The severity of respiratory complications revealed a significant correlation with the severity of ocular complications ( r = 0.322, P = 0.043), as well as with the haemoglobin ( r = 0.369, P = 0.024) and HCT ( r = 0.470, P =0.003). Although late complications of SM poisoning in the skin, eyes, and respiratory system are mainly due to its direct toxic effects, the neuromuscular, haematological and immunological complications are probably the result of systemic toxicity. [ABSTRACT FROM AUTHOR]

Mustard gas or sulfur mustard (SM) is an alkylating chemical warfare agent that was widely used during the World War I and in the Iran-Iraq conflict. We aimed to study late toxic effects of SM on the respiratory system of severely intoxicated Iranian veterans. Respiratory examination, spirometry, arterial blood gas (ABG) analysis, and high resolution computed tomograpghy (HRCT) of the chest were performed on all severely SM-poisoned veterans in the province of Khorasan, Iran. HRCT abnormalities were classified into four grades based on the number of lung lobes involved. ABG and spirometric results were compared with each other, as well as, with the severity grades of HRCT abnormalities, using Spearman's rank correlation test. Forty male subjects with confirmed SM poisoning 16 to 20 years ago, were studied. Main respiratory complications were diagnosed as chronic obstructive pulmonary disease (COPD) (35%), bronchiectasis (32.5%), asthma (25%), large airway narrowing (15%), pulmonary fibrosis (7.5%), and simple chronic bronchitis (5%) patients. While there was a significant correlation (p 2 . We concluded that SM-induced respiratory complications tend to progress over the years. While spirometry is a valuable diagnostic tool for evaluation of pulmonary impairment during regular follow-ups, ABG and HRCT are more objective and should be more considered for evaluation of the severity and for diagnosis of the respiratory complications. [ABSTRACT FROM AUTHOR]

Respiratory tract lesions induced by the chemical warfare agent sulfur mustard (SM) are characterized by epithelial damages associated with inflammatory cell infiltration. Here we evaluated the imbalance between gelatinase and tissue inhibitors of metalloproteinases (TIMPs), and we tested pretreatment with the protease inhibitor doxycycline. Guinea pigs were intoxicated intratracheally with SM and evaluated 24 h after exposure. Matrix metalloproteinase (MMP) gelatinase activity of bronchial lavage (BL) fluid from SM-exposed guinea pigs was high compared with controls, as shown by both zymography and biotinylated substrate degradation, whereas TIMP-1 and -2 levels by immunoblotting were similar. Extensive areas of lysis were evidenced by in situ zymography, indicating imbalance between gelatinases and inhibitors towards net proteolytic activity. Doxycycline pretreatment resulted in 1) decreased gelatinase activity (zymography, free gelatinase activity assay, and in situ zymography); 2) decreased inflammation (BL fluid cellularity and protein level); and 3) dramatic decrease in histological epithelial lesions. Our results suggest inadequate levels of TIMP to counteract increased gelatinase activity and further support a role for MMP gelatinases in SM-induced respiratory lesions. They also suggest that doxycycline may hold promise as a therapeutic tool. [ABSTRACT FROM AUTHOR]

Sorption rate parameters were determined for three organophosphorus (OP) compounds [dimethyl methylphosphonate (DMMP), diethyl ethylphosphonate (DEEP), and triethyl phosphate (TEP)] as surrogates for the 6-type nerve agents sarin (GB), soman (GD), and tabun (GA). OP surrogates were injected and vaporized with additional volatile organic compounds into a 50 m³ chamber finished with painted wallboard. Experiments were conducted at two furnishing levels: (i) chamber containing only hard surfaces including a desk, a bookcase, tables, and chairs and (ii) with the addition of plush materials including carpet with cushion, draperies, and upholstered furniture. Each furnishing level was studied with aged and new painted wallboard. Gas-phase concentrations were measured during sealed chamber adsorb and desorb phases and then fit to three mathematical variations of a previously proposed sorption model having a surface sink and allowing for an embedded sink. A four-parameter model allowing unequal transport rates between surface and embedded sinks provided excellent fits for all conditions. To evaluate the potential effect of sorption, this model was incorporated into an indoor air quality simulation model to predict indoor concentrations of a 6-type agent and a nonsorbing agent for hypothetical outdoor releases with shelter-in- place (SIP) response. Sorption was simulated using a range of parameters obtained experimentally. Simulations considered outdoor Gaussian plumes of 1- and 5-h duration and infiltration rates of 0.1, 0.3, and 0.9 h-1. Indoor toxic loads (TL) for a 10-h SIP were calculated as ∫C² dtfor a G-type agent For the 5-h plume, sheltering reduced TLs for the nonsorbing agent to ∼10-65% of outdoor levels. Analogous TLs for a 6-type agent were 2-31% or 0.3- 12% of outdoor levels assuming slow or moderate sorption. The relative effect of sorption was more pronounced for the longer plume and higher infiltration rates. [ABSTRACT FROM AUTHOR]

BACKGROUND: Sulfur mustard has been a popular chemical warfare agent in the twentieth century. This agent was used in the Iraqi–Iranian conflict in 1983–88. The casualties exposed to sulfur mustard have exhibited acute and chronic complications in the eye, lungs, and skin. Around 15 years post exposure to sulfur mustard, we performed this study to evaluate the severity of the delayed complications in the eyes and the respiratory system. Material and METHODS: In this descriptive study, we evaluated 500 male subjects in the age range of 30–50 years, in 2001. These soldiers'first in toxification to sulfur mustard was confirmed by the Department of Medical Consultation of the Janbazan Organization(the Iranian Veterans'Affairs Agency). Complete ocular and pulmonary examinations were performed. The complications were divided into three grades of mild, moderate, and severe. In order to be classified in a certain grade of severity, the patient must have exhibited at least 50% of the designated signs and symptoms in that category. The frequencies of the patients in each grade were reported and chi-square analysis was performed. RESULTS: The distribution of the subjects within each grade of the complications was as follows: mild ocular, 80%; moderate ocular, 13.2%; severe ocular, 6.8%; mild pulmonary, 69.2%; moderate pulmonary, 19.6%; and severe pulmonary, 11.6%. The distribution of the patients within the different grades of the ocular and pulmonary complications concurrently was as follows: mild ocular and pulmonary complications, 57.2%; moderate ocular and pulmonary complications, 2%; and severe ocular and pulmonary complications, 1.4%. Of all the patients, 14.8% had more severe ocular complications and 24.6% had more severe pulmonary complications. The pulmonary complications were present in higher severity than the ocular complications and statistically the relationship was significant(P < 0.005). CONCLUSION: In this study, all of the subjects exhibited at least mild ocular and pulmonary complications, around 15 years post exposure to sulfur mustard. The severity of the pulmonary complications is higher than the ocular complications. We conclude that these chronic complications are rising. The subjects with no or mild complications in earlier years might develop more severe complications in the future. From the previous cytological studies, it is apparent that the changes induced due to exposure to sulfur mustard are at the cellular structural levels. These changes are not easily reversible or treatable. The proper management of these individuals, with the possible rise in the severity of their complications, remains a major health concern. [ABSTRACT FROM AUTHOR]

Provides information on VX nerve agent, a dangerous manufactured chemical. Development of the chemical in Wiltshire, England; Significant threat of chemical weapons such as the nerve agents to the world's population; Accidental release of the VX at the Dugway Proving Ground in Utah in 1968. INSET: Key Terms.

Human butyrylcholinesterase (HuBChE) is a drug candidate for protection against organophosphates (OP) intoxication. A mathematically based model was validated and employed to better understand the role of the endogenous HuBChE in detoxification of OPs and to estimate the dose of exogenous HuBChE required for enhancing protection of humans from lethal exposure to OPs. The model addresses the relationship between the HuBChE dose needed to maintain a certain residual activity of human acetylcholinesterase (HuAChE) and the following parameters: (1) level and duration of exposure, (2) bimolecular rate constants of inhibition of HuAChE (kA) and HuBChE (kB) by OPs, and (3) time elapsed from enzyme load. The equation derived for the calculation of HuBChE dose requires the knowledge of kA/kB in human blood and the rate constant of HuBChE elimination. Predictions of HuBChE doses were validated by in vitro experiments and data of published human studies. These predictions highlight two parameters that are likely to decrease the calculated dose: (1) the rapid consumption of the less toxic isomers of OPs in human plasma, and (2) the volume of distribution of HuBChE that appears significantly greater than the volume of plasma. The first part of the analysis of the proposed model was focused on acute bolus exposures and suggests that upper limit doses of 134, 115, and 249 mg/70 kg are sufficient to protect RBC AChE above 30% of baseline activity following a challenge with 1 LD50 VX, soman, and sarin, respectively. The principles of the validated model should be applicable for advanced predictions of HuBChE dose for protection against continuous exposures to OPs. [ABSTRACT FROM AUTHOR]

The chemical nerve agent sarin (o-isopropyl methylphosphonofluoridate) was hydrolyzed at 7.18 eight percent in aqueous sodium hydroxide yielding primarily o-isopropyl methylphosphonic acid (IMPA). This hydrolysate was diluted and fed as sole carbon source to activated sludge in an aerobic sequencing batch reactor. Feed chemical oxygen demand (COD) concentrations ranged from approximately 2500 mg/L (initial) to 5000 mg/L (final). The reactor was operated essentially on a 15-day hydraulic residence time. Overall COD removal efficiency was 86.2% and the IMPA in the feed was converted to methylphosphonic acid. MICROTOX ® and Daphnia magna aquatic toxicity testing showed the effluent to be of very low toxicity to aquatic test organisms. The final MPA product was effectively absorbed by Phoslock ™, which is a lanthanide modified clay. [ABSTRACT FROM AUTHOR]

The article focuses on sulfur mustard, and offers information on its characteristics, clinical effects and treatment. Sulfur mustard, which is an agent of chemical warfare since World War I, is an alkylating agent that is toxic to poorly differentiated cells. The first clinical signs of exposure involve local effects on organ systems including the eyes, skin and respiratory tract. Prompt decontamination is the most important and effective treatment for victims for sulfur mustard.

The article assesses the potentialities of chemical agents for military purposes. Despite primitive means of transmitting poisonous gases to the enemy in the First World War, results obtained in the implementation of chemical weapons at that time proved no more effective than those obtained in the use of explosive weapons. By the beginning of the Second World War, the productive capacities and stockpiles of war gases had increased tremendously, particularly in the countries with a high chemical potential.

We report high-sensitivity detection of chemical warfare agents (nerve gases) with very low probability of false positives (PFP). We demonstrate a detection threshold of 1.2 ppb (7.7 μg/m3 equivalent of Sarin) with a PFP of <1:106 in the presence of many interfering gases present in an urban environment through the detection of diisopropyl methylphosphonate, an accepted relatively harmless surrogate for the nerve agents. For the current measurement time of ∼60 s, a PFP of 1:106 corresponds to one false alarm approximately every 23 months. The demonstrated performance satisfies most current homeland and military security requirements. [ABSTRACT FROM AUTHOR]

Synthesis of Ni doped ZnO/polyaniline nanocomposites with optimization of Ni content for maximum sensor response towards NO 2 at room temperature. • A room temperature high response NO 2 sensor based on doped ZnO/polyaniline nanocomposite. • Synthesis of Ni doped ZnO nanorods using wet chemical synthesis. • Effect of Ni doping on structural, thermal, optical and sensing behavior. • Optimization of Ni content for maximum sensor response. • Optimization of ZnO content in nanocomposites for maximum sensor response. Hybrid sensors consisting of semiconducting metal oxides and conducting polymers have immense capability of sensing various poisonous gases and chemical warfare agents at room temperature. The hybrid sensor has tunable properties, which leads to high sensing response with lower detection limits. In the present work, Ni doped ZnO nanorods were synthesized using a wet chemical synthesis and their nanocomposite with polyaniline was prepared using in-situ oxidative polymerization technique. The structure, morphology and surface composition properties were studied using XRD, FTIR, XPS and FESEM. Response of the nanocomposites towards various oxidizing and reducing gases was studied and was found to be more selective towards NO 2. Amount of doping for maximum sensor response was optimized and it was found that with 10 mol% Ni doping, sensor response of 75% was obtained towards 100 ppm with response time of 82 s and recovery time of 399 s. Further, recovery time reduced significantly from 1096 s (ZnO/PANi) to 399 s (Ni@ZnO/PANi). This hybrid sensor shows better sensitivity, selectivity, and higher response compared to pure PANi and ZnO/PANi nanocomposites. Doping of Ni over ZnO nanorods leads to higher surface area, maximum adsorption of gases resulting into a very effective NO 2 gas sensor at room temperature. [ABSTRACT FROM AUTHOR]

The article shares the author's thoughts about the hearing conducted by the Senate Committee on Foreign Relations concerning the Geneva protocol. The author notes that the U.S. has declared that there is a distinction between asphyxiating poisonous and harassing agents. He said that the effects of a chemical agent will depend on its mode of application. He also said that the lethal human inhalation of chloraceptophenoe (CN) is almost the same of cyanogen chloride, lethal gas used in World War I. He points out that when the Geneva Protocol was drawn up, the term poisonous have still had the connotation of immediate lethality that include long -term poisonous effects, mutagenic, teratological and carcinogenic.

Comments on a research on mustard gas and its alleged use during World War II. Characterization of the gas; Physiological effects; Signs and symptoms of exposure to the gas; Historical overview of chemical warfare agents and poison gases.