Iraq's Chemical Warfare: Case Proved: A U.N. team found mustard and nerve gas bombs on the battlefield; now the challenge is to prevent the war from spreading

The Role of Magnetic Resonance Spectroscopy in Evaluating the Rate of Brain Metabolic Variations in Chemical Veterans with Respiratory Problem In Comparison To Control Group

BACKGROUND

During the eight years of the imposed war, Iraq used various chemical agents such as sulfur mustard and nerve agents (mainly tabun and sometimes soman) on Iran's soldiers. Using information obtained from specialist sequences and analysing information obtained from magnetic resonance imaging (MRI) in a susceptibility weighted imaging (SWI) sequence and magnetic resonance spectroscopy (MRS) provides valuable information on continuation of treatment and identifying functional disorders.

AIM

The objective of this research was to evaluate the rate of metabolic variations in chemically injured veterans based on chemical neuromarkers using the chemical sequence MRS, which would help patients and physicians in terms of time, economics, and selection of appropriate therapeutic methods, so if the can physician can get complete information about the metabolic properties of the brain through paraclinical (especially MRI) tools before treatment, he might change his treatment program to reduce the complications caused by it.

METHODOLOGY

In this research, 40 chemically injured veterans with brain dysfunction admitted to the screening centre for MRI with specialized MRS sequence participated. Accordingly, we examined the rate of brain metabolic variations about the level of neuromarkers and evaluated the relationship between the level of neuromarkers and brain damages.

RESULTS

The results of this research revealed that while the demographic characteristics such as age of the two groups of chemically injured veterans and control was similar, only the median of the NAA/Cr (N-acetylaspartate to creatine ratio) ratio in PONS of chemically injured patients was significantly lower than that of the control group, and this ratio was similar in other parts of the brain in two groups. The results also showed that the ratio of NAA to total choline and Cr was similar in all parts of the brain in two groups.

CONCLUSION

Based on the research results, using the MR (Magnetic Resonance) spectroscopy device and determination of the value and ratio of markers such as creatinine and N-acetylaspartate and choline, the brain injuries of chemically injured veterans can be examined. By conducting further studies and larger sample size, the brain damages in veterans can be diagnosed early, which would be a great contribution in their treatment.

Destruction of chemical warfare agent simulants by air and moisture stable metal NHC complexes

The cooperative effect of both NHC and metal centre has been found to destroy chemical warfare agent (CWA) simulants. Choice of both the metal and NHC is key to these transformations as simple, monodentate N-heterocyclic carbenes in combination with silver or vanadium can promote stoichiometric destruction, whilst bidentate, aryloxide-tethered NHC complexes of silver and alkali metals promote breakdown under mild heating. Iron-NHC complexes generated in situ are competent catalysts for the destruction of each of the three targetted CWA simulants.

Recoverable amphiphilic polyoxoniobates catalyzing oxidative and hydrolytic decontamination of chemical warfare agent simulants in emulsion

Amphiphilic polyoxoniobates (PONbs), [C_nH_2n+1N(CH₃)₃]₇HNb₆O₁₉ (for 1, n=14; for 2, n=16; and for 3, n=18), were successfully prepared by the electrostatic interaction of hexaniobate anions with quaternary ammoniums containing long alkyl chain, and thoroughly characterized by using various techniques including Fourier transform infrared (FT-IR), ¹H nuclear magnetic resonance (¹H NMR), ¹³C nuclear magnetic resonance (¹³C NMR), thermogravimetric analysis (TGA), and elemental analysis. All three PONbs were used in the emulsion systems to catalytically decontaminate chemical warfare agent simulants and the influences of quaternary ammonium cations, polyanions, and amount of catalyst on the catalytic efficiency have been evaluated. Under optimal conditions, catalyst 3 in emulsion can completely convert both a the nerve agent simulant, diethyl cyanophosphonate (DECP), in 2h by hydrolysis and a sulfur mustard simulant, 2-chloroethyl ethyl sulfide (CEES), in 20min by oxidation using nearly stoichiometric 3% aqueous H₂O₂. Moreover, the amphiphilic catalyst 3 can be simply separated and readily reused for five recycles without obvious losing its activity. To the best of our knowledge, this study represents the first example where the emulsions of PONbs are used in the catalysis.

In vivo protection by amifostine and DRDE-07 against sulphur mustard toxicity

The study was aimed at investigating the prophylactic efficacy of orally administered amifostine and a newly synthesized compound, S-2(2-amino-ethylamino)ethyl phenyl sulphide (DRDE-07), against dermally applied sulphur mustard (SM) in mice and rats. The LD50 values of amifostine and DRDE-07 were determined following oral and intraperitoneal routes and the LD50 of SM diluted in PEG-300 was determined following dermal route. Amifostine or DRDE-07 (equivalent to their 0.05 LD50, 0.10 LD50 and 0.20 LD50) dissolved in water was fed to mice and rats and, after 30 min, various doses of SM were applied to the hair-clipped area of the skin and were observed for 14 days for mortality. The protection index (PI) was calculated as a ratio of LD50 with treatment to LD50 without treatment. The estimated percutaneous LD50 of SM was found to be 8.1 and 2.4 mg///kg for female mice and male rats, respectively. A dose-related protection was observed with all the three doses of both compounds. Thirty minutes prior, the administration of amifostine in female mice offered a PI of 3.0 at the lowest pretreatment dose (52.5 mg// kg) followed by PI of 6.7 and 9.5 at 105 and 210 mg// /kg pretreatment doses, respectively. DRDE-07 offered better protection against SM in female mice, i.e., a PI of 4.8 at pretreatment dose of 62.5 mg// /kg, a PI of 12.0 at the dose of 124.7 mg///kg and a PI of 27.0 at the dose of 249.4 mg/kg. In male rats, DRDE-07 gave a PI of about 3.0 at all the three pretreatment doses (80, 160 and 320 mg///kg), whilst amifostine offered a PI of 3.1 at the highest pretreatment dose (452 mg///kg). The present study showed that oral administration of both amifostine and DRDE-07 was effective as a prophylactic agent for protecting against SM toxicity, and that DRDE-07 offered better protection.

Role of reactive nitrogen species generated via inducible nitric oxide synthase in vesicant-induced lung injury, inflammation and altered lung functioning

Pulmonary toxicity induced by sulfur mustard and related vesicants is associated with oxidative stress. In the present studies we analyzed the role of reactive nitrogen species (RNS) generated via inducible nitric oxide synthase (iNOS) in lung injury and inflammation induced by vesicants using 2-chloroethyl ethyl sulfide (CEES) as a model. C57Bl/6 (WT) and iNOS-/- mice were sacrificed 3 days or 14 days following intratracheal administration of CEES (6 mg/kg) or control. CEES intoxication resulted in transient (3 days) increases in bronchoalveolar lavage (BAL) cell and protein content in WT, but not iNOS-/- mice. This correlated with expression of Ym1, a marker of oxidative stress in alveolar macrophages and epithelial cells. In contrast, in iNOS-/- mice, Ym1 was only observed 14 days post-exposure in enlarged alveolar macrophages, suggesting that they are alternatively activated. This is supported by findings that lung tumor necrosis factor and lipocalin Lcn2 expression, mediators involved in tissue repair were also upregulated at this time in iNOS-/- mice. Conversely, CEES-induced increases in the proinflammatory genes, monocyte chemotactic protein-1 and cyclooxygenase-2, were abrogated in iNOS-/- mice. In WT mice, CEES treatment also resulted in increases in total lung resistance and decreases in compliance in response to methacholine, effects blunted by loss of iNOS. These data demonstrate that RNS, generated via iNOS play a role in the pathogenic responses to CEES, augmenting oxidative stress and inflammation and suppressing tissue repair. Elucidating inflammatory mechanisms mediating vesicant-induced lung injury is key to the development of therapeutics to treat mustard poisoning.

Protective actions of des-aspartate-angiotensin I in mice model of CEES-induced lung intoxication

The present study investigated the protective actions of des-aspartate-angiotensin I (DAA-I) in mice that were intranasally administered 2-chloroethyl ethyl sulfide (CEES), a half sulfur mustard. The protection was dose-dependent, and an oral dose of 75 mg kg⁻¹ per day administered 18 h post exposure and for the following 13 days, offered maximum protection that increased survival by a third. DAA-I attenuated the early processes of inflammation seen in the CEES-inoculated mice. DAA-I attenuated (i) elevated pulmonary ROS, and gp91-phox protein of NADPH oxidase, a non phagocytic enzyme that generates superoxide and subsequent ROS; (ii) intercellular adhesion molecule-1 (ICAM⁻¹) that is involved in the extravasation of circulating leucocytes; and (iii) myeloperoxidase activity, which is a surrogate enzymatic measurement of neutrophil infiltration. These actions led to improved histological lung structures, and survival of type-1 pneumocytes. The action of DAA-I on animal survival was blocked by losartan, a selective angiotensin AT1 receptor blocker, indicting that the AT1 receptor mediates the protection. The presence of elevated PGE2 and PGI2 in lung supernatants of DAA-I treated CEES-inoculated mice indicates that the two prostaglandins are involved in signaling the protective actions of DAA-I. This finding complements earlier studies showing that DAA-I acts on an indomethacin-sensitive angiotensin AT1 receptor. The findings of the present study are the first demonstration of an angiotensin peptide as an effective antidote for CEES intoxication. DAA-I is also an effective therapeutic intervention against CEES that was instituted at 18 h post exposure, and challenges conventional assumptions of limited efficacy with delayed action against alkylating agents.

Dominant lethal study of sulfur mustard in male and female rats

Sulfur mustard (HD) (bis(2-chloroethyl)sulfide) is a strong alkylating agent with known mutagenic and suspected carcinogenic properties, but occupational health standards have not been established. The purpose of this study was to determine the dominant lethal effect in male and female rats dosed orally with HD, for which currently available data are ambiguous. Sprague-Dawley rats of each sex, 6-7 weeks old, were orally administered 0, 0.08, 0.20 or 0.50 mg kg-1 HD 5 days a week for 10 weeks, after which dominant lethal studies were conducted during the post-exposure period. The studies were conducted in two phases: a female dominant lethal phase in which treated or untreated males were mated with treated females and their fetuses were evaluated 14 days after copulation; and a male dominant lethal phase in which treated males cohabited with untreated females for 5 days and fetuses were evaluated 14 days after the mid-point of the week of cohabitation, for each of 10 weeks. In addition, motility, population size and morphology were measured in sperm obtained from the cauda epididymis. Parental growth rates were reduced in both sexes treated with the high level of HD. Female dominant lethal effects were not observed, although significant male dominant lethal effects were observed in HD-exposed male rats mated to untreated females at 2 and 3 weeks' post-exposure. These effects, which included increases of early fetal resorptions and preimplantation losses and decrease in total live embryo implants, were most consistently observed at a dose of 0.50 mg kg-1. A significant P(P < 0.05) increase in the percentage of abnormal sperm was detected in males exposed to 0.50 mg kg-1 HD. The timing of dominant lethal effects is consistent with an effect during the post-meiotic stages of spermatogenesis, possibly involving the generally sensitive spermatids.

Reagan Offers a Chemical Weapons Treaty: But he declines to resume bilateral talks, which might speed agreement

There is remarkably rich diversity in the cultivated rices and their wild relatives. Substantial segments of the diverse germplasm have been collected and conserved during the past two decades by national, regional, and international research centers. Multidisciplinary and interinstitutional evaluation and use have drawn substantial rewards. However, nations in the developing world that grow and consume rice still face enormous challenges to meet the continuous growth of the human population. Further conservation efforts and improved preservation measures are needed to provide security for the irreplaceable rice germplasm. Modest inputs into conservation programs are highly justified by multibillion dollar returns from the improved varieties in the past two decades.