Environmental fate of 2,4-dinitroanisole (DNAN) and its reduced products.

Several defense departments intend to replace 2,4,6-trinitrotoluene (TNT) in munitions formulations by the less sensitive 2,4-dinitroanisole (DNAN). To help understand environmental behavior and ecological risk associated with DNAN we investigated its key initial abiotic and biotic reaction routes and determined relevant physicochemical parameters (pKa, logKow, aqueous solubility (Sw), partition coefficient (Kd)) for the chemical and its products. Reduction of DNAN with either zero valent iron or bacteria regioselectively produced 2-amino-4-nitroanisole (2-ANAN) which, under strict anaerobic conditions, gave 2,4-diaminoanisole (DAAN). Hydrolysis under environmental conditions was insignificant whereas photolysis gave photodegradable intermediates 2-hydroxy-4-nitroanisole and 2,4-dinitrophenol. Physicochemical properties of DNAN and its amino products drastically depended on the type and position of substituent(s) on the aromatic ring. Sw followed the order (TNT

Bronchoprotection in conscious guinea pigs by budesonide and the NO-donating analogue, TPI 1020, alone and combined with tiotropium or formoterol.

BACKGROUND AND PURPOSE: Inhaled corticosteroids, anticholinergics and ß2-adrenoceptor agonists are frequently combined for treating chronic respiratory diseases. We examine the corticosteroid, budesonide, and novel NO-donating derivative, TPI 1020, against histamine- and methacholine-induced bronchoconstriction and whether they enhance the ß2-adrenoceptor agonist formoterol or muscarinic antagonist tiotropium in conscious guinea pigs. EXPERIMENTAL APPROACH: Dunkin-Hartley guinea pigs received inhaled histamine (3 mM) or methacholine (1.5 mM) and specific airway conductance (sG(aw)) was measured before and 15 or 75 min after treatment with budesonide, TPI 1020, tiotropium or formoterol alone or in combinations. KEY RESULTS: Formoterol (0.7-10 µM) and budesonide (0.11-0.7 mM) inhibited histamine-induced bronchoconstriction and tiotropium (2-20 µM) inhibited methacholine-induced bronchoconstriction by up to 70.8 ± 16.6%, 34.9 ± 4.4% and 85.1 ± 14.3%, respectively. Formoterol (2.5 µM) or tiotropium (2 µM) alone exerted small non-significant bronchoprotection. However, when co-administered with TPI 1020 0.11 mM, which alone had no significant effect, there was significant inhibition of the bronchoconstriction (45.7 ± 12.2% and 79.7 ± 21.4%, respectively). Co-administering budesonide (0.11 mM) with tiotropium (2 µM), which alone had no effect, also significantly inhibited the methacholine bronchoconstriction (36.5 ± 13.0%), but there was no potentiation of formoterol against histamine. The NO scavenger, CPTIO, prevented the bronchoprotection by SNAPand TPI 1020. CONCLUSIONS AND IMPLICATIONS: TPI 1020 potentiated the bronchoprotection by formoterol and tiotropium. Budesonide also enhanced the effects of tiotropium but not formoterol. Combination of TPI 1020 with a long-acting ß2-adrenoceptor agonist or muscarinic receptor antagonist may therefore be a more potent therapeutic approach for treatment of chronic respiratory diseases.

Guideline adaptation: an approach to enhance efficiency in guideline development and improve utilisation.

BACKGROUND: Developing and updating high-quality guidelines requires substantial time and resources. To reduce duplication of effort and enhance efficiency, we developed a process for guideline adaptation and assessed initial perceptions of its feasibility and usefulness. METHODS: Based on preliminary developments and empirical studies, a series of meetings with guideline experts were organised to define a process for guideline adaptation (ADAPTE) and to develop a manual and a toolkit made available on a website (http://www.adapte.org). Potential users, guideline developers and implementers, were invited to register and to complete a questionnaire evaluating their perception about the proposed process. RESULTS: The ADAPTE process consists of three phases (set-up, adaptation, finalisation), 9 modules and 24 steps. The adaptation phase involves identifying specific clinical questions, searching for, retrieving and assessing available guidelines, and preparing the draft adapted guideline. Among 330 registered individuals (46 countries), 144 completed the questionnaire. A majority found the ADAPTE process clear (78%), comprehensive (69%) and feasible (60%), and the manual useful (79%). However, 21% found the ADAPTE process complex. 44% feared that they will not find appropriate and high-quality source guidelines. DISCUSSION: A comprehensive framework for guideline adaptation has been developed to meet the challenges of timely guideline development and implementation. The ADAPTE process generated important interest among guideline developers and implementers. The majority perceived the ADAPTE process to be feasible, useful and leading to improved methodological rigour and guideline quality. However, some de novo development might be needed if no high quality guideline exists for a given topic.

Exploring cancer treatment decision-making by patients: a descriptive study.

OBJECTIVE: Using an interview-guided survey, our descriptive study aimed to document the extent to which cancer patients perceive they are involved in making treatment decisions and the factors that influence patient involvement. PATIENTS AND METHODS: Our study enrolled patients from a Canadian ambulatory oncology program who were undergoing chemotherapy or radiation therapy, or both, for cancer. The adapted Control Preferences Scale was used to survey perceived and preferred roles in decision-making. The study survey also included items from the Decisional Conflict Scale and the Preparation for Decision-Making Scale. RESULTS: Of 192 participants, 98 (51%) perceived that they were offered treatment choices. Of those 98, 47 (48%) thought that the options were presented equally. Compared with the patients not offered choices, those who were given choices were less passive (4% vs. 29%, p < 0.001) and more satisfied (100% vs. 95%, p < 0.03) in decision-making. Participants whose preferred and perceived roles were different would have preferred more involvement in decision-making. To attain the preferred involvement, patients wanted to receive more information on treatment options, to be given a choice, to have more discussion with the health care team, and to have providers better listen to their needs. CONCLUSIONS: Only half of surveyed patients thought that they were offered choices for their cancer treatment. When offered choices, patients were more active in decision-making. Further initiatives are required to determine approaches for supporting patients with cancer so that they can be more involved in decision-making.

Multitargeted approach using antisense oligonucleotides for the treatment of asthma.

Asthma is characterized by inflammation and hyperresponsiveness related to the accumulation of inflammatory cells, particularly eosinophils, within the airways. We tested the hypothesis that a multitargeted approach is better than a single-targeted approach in a rat model of asthma. We simultaneously delivered oligonucleotides (ODNs) targeting the chemokine receptor CCR3 and the common beta chain subunit of the receptors for IL-3, IL-5, and GM-CSF at the time of ovalbumin challenge in sensitized Brown Norway rats. Fewer eosinophils were detected in bronchoalveolar lavage (BAL) of rats treated with both ODNs as compared to each ODN alone. Moreover, airway responsiveness to LTD(4) was significantly decreased at lower doses in the 2 ODN-treated groups compared to a single ODN. As ODN therapy has raised concerns of toxicity we therefore examined ODNs prepared with modified DNA bases, specifically 2'amino, 2'deoxyadenosine (DAP) in place of adenosine. In vivo, administration of individual DAP-ODN was efficacious in inhibiting airway hyperresponsiveness, whereas delivery of 2 DAP-ODNs (targeting CCR3 and common beta chain) reduced the influx not only of eosinophils but also lymphocytes and macrophages in the lungs of rats as compared to the unmodified ODNs. Blocking multiple inflammatory pathways simultaneously is more effective in preventing eosinophilia and airway hyperresponsiveness than inhibiting either pathway alone. The challenges associated with the development of a product containing two oligonucleotides in humans are discussed.

Metabolism of hexahydro-1,3,5-trinitro-1,3,5-triazine through initial reduction to hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine followed by denitration in Clostridium bifermentans HAW-1.

A fast hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX)-degrading [28.1 micromol h(-1) g (dry weight) cells(-1); biomass, 0.16 g (dry weight) cells(-1)] and strictly anaerobic bacterial strain, HAW-1, was isolated and identified as Clostridium bifermentans using a 16S-rRNA-based method. Based on initial rates, strain HAW-1 transformed RDX to hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX), hexahydro-1,3-dinitroso-5-nitro-1,3,5-triazine (DNX), and hexahydro-1,3,5-trinitroso-1,3,5-triazine (TNX) with yields of 56, 7.3 and 0.2%, respectively. Complete removal of RDX and its nitroso metabolites produced (%, of total C or N) methanol (MeOH, 23%), formaldehyde (HCHO, 7.4%), carbon dioxide (CO2, 3.0%) and nitrous oxide (N2O, 29.5%) as end products. Under the same conditions, strain HAW-1 transformed MNX separately at a rate of 16.9 micromol h(-1) g (dry weight) cells(-1) and produced DNX (25%) and TNX (0.4%) as transient products. Final MNX transformation products were (%, of total C or N) MeOH (21%), HCHO (2.9%), and N2O (17%). Likewise strain HAW-1 degraded TNX at a rate of 7.5 micromol h(-1) g (dry weight) cells(-1 )to MeOH and HCHO. Furthermore, removal of both RDX and MNX produced nitrite (NO2-) as a transient product, but the nitrite release rate from MNX was quicker than from RDX. Thus, the predominant pathway for RDX degradation is based on initial reduction to MNX followed by denitration and decomposition. The continued sequential reduction to DNX and TNX is only a minor route.

Phytotoxicity of 2,4,6-trinitrotoluene (TNT) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) in spiked artificial and natural forest soils.

Toxicity of 2,4,6-trinitrotoluene (TNT) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) using two terrestrial plant species, lettuce (Lactuca sativa) and barley (Hordeum vugare), was assessed in artificial soil (silica) and forest soil. Lettuce emergence was significantly decreased after 5 days of exposure to TNT nominal spiked concentrations >/= 1,040 mg/kg dry soil in silica. Barley emergence was significantly reduced after 14 days of exposure at initial (t = 0) TNT concentrations >/= 55.9 +/- 4.5 mg/kg dry soil in silica and at >/= 291.9 +/- 42.8 mg/kg dry forest soil. Biomasses of shoot and roots of barley seeds were significantly reduced after 14 days of exposure at TNT initial exposure concentrations >/= 55.9 +/- 4.5 (LOEC) mg/kg dry soil in silica. Results were similar with the forest soil (LOEC = 91.4 +/- 7.9 mg TNT/kg dry soil) using the root growth parameter, but the shoot biomass was reduced only at concentrations >/= 291.9 +/- 42.8 mg TNT/kg dry soil. Plants were not affected by an HMX exposure up to 3,320 +/- 1,019 mg/kg dry soil using silica or 1,866 +/- 438 mg/kg dry soil using a forest soil. During the 14-day experiments, TNT was partially transformed in the spiked soil samples, as indicated by the presence of its amino metabolites (2-ADNT and 4-ADNT). Higher quantities of metabolites were detected in forest soils having higher initial TNT concentrations (

TNT, RDX, and HMX decrease earthworm (Eisenia andrei) life-cycle responses in a spiked natural forest soil.

Sublethal and chronic toxicities of 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) on earthworm Eisenia andrei in a sandy forest soil were assessed. Various reproduction parameters of fecundity (total and hatched number of cocoons, number of juveniles, and their biomass) were significantly decreased by TNT (> or = 58.8 +/- 5.1 mg/kg dry soil), RDX (> or = 46.7 +/- 2.6 mg/kg), and HMX (> or = 15.6 +/- 4.6 mg/kg). These effects occurred at much lower concentrations than those reported earlier using artificial soil preparations. Growth of adults was significantly decreased in the TNT-spiked natural soils at 136.2 +/- 25.6 mg/kg dry soil, the highest concentration having no significant mortality. In contrast, survival and growth were not significantly reduced at relatively high measured concentrations of RDX (167.3 mg/kg) and HMX (711.0 mg/kg). Although TNT, RDX, and HMX share a common life-cycle response ( i.e., decreased juvenile counts), a number of differences related to other reproduction parameters (e.g., productivity of cocoons) was observed. These results indicate that the tested explosives do not support a common mechanism of toxicity, at least in the earthworm, probably due to differences in their physical-chemical properties as well as metabolites formed during exposure.

Detection of explosives and their degradation products in soil environments.

Polynitro organic explosives [hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) and 2,4,6-trinitrotoluene (TNT)] are typical labile environmental pollutants that can biotransform with soil indigenous microorganisms, photodegrade by sunlight and migrate through subsurface soil to cause groundwater contamination. To be able to determine the type and concentration of explosives and their (bio)transformation products in different soil environments, a comprehensive analytical methodology of sample preparation, separation and detection is thus required. The present paper describes the use of supercritical carbon dioxide (SC-CO2), acetonitrile (MeCN) (US Environmental Protection Agency Method 8330) and solid-phase microextraction (SPME) for the extraction of explosives and their degradation products from various water, soil and plant tissue samples for subsequent analysis by either HPLC-UV, capillary electrophoresis (CE-UV) or GC-MS. Contaminated surface and subsurface soil and groundwater were collected from either a TNT manufacturing facility or an anti-tank firing range. Plant tissue samples were taken fromplants grown in anti-tank firing range soil in a greenhouse experiment. All tested soil and groundwater samples from the former TNT manufacturing plant were found to contain TNT and some of its amino reduced and partially denitrated products. Their concentrations as determined by SPME-GC-MS and LC-UV depended on the location of sampling at the site. In the case of plant tissues, SC-CO2 extraction followed by CE-UV analysis showed only the presence of HMX. The concentrations of HMX (<200 mg/kg) as determined by supercritical fluid extraction (SC-CO2)-CE-UV were comparable to those obtained by MeCN extraction, although the latter technique was found to be more efficient at higher concentrations (>300 mg/kg). Modifiers such as MeCN and water enhanced the SC-CO2 extractability of HMX from plant tissues.

Photodegradation of RDX in aqueous solution: a mechanistic probe for biodegradation with Rhodococcus sp.

Recently we demonstrated that Rhodococcus sp. strain DN22 degraded hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) (1) aerobically via initial denitration followed by ring cleavage. Using UL 14C-[RDX] and ring labeled 15N-[RDX] approximately 30% of the energetic chemical mineralized (one C atom) and 64% converted to a dead end product that was tentatively identified as 4-nitro-2,4-diaza-butanal (OHCHNCH2NHNO2). To have further insight into the role of initial denitration on RDX decomposition, we photolyzed the energetic chemical at 350 nm and pH 5.5 and monitored the reaction using a combination of analytical techniques. GC/ MS-PCI showed a product with a [M+H] at 176 Da matching a molecular formula of C3H5N5O4 that was tentatively identified as the initially denitrated RDX product pentahydro-3,5-dinitro-1,3,5-triazacyclohex-1-ene (II). LC/MS (ES-) showed that the removal of RDX was accompanied by the formation of two other key products, each showing the same [M-H] at 192 Da matching a molecular formula of C3H7N5O5. The two products were tentatively identified as the carbinol (III) of the enamine (II) and its ring cleavage product O2NNHCH2NNO2CH2NHCHO (IV). Interestingly, the removal of III and IV was accompanied by the formation and accumulation of OHCHNCH2NHNO2 that we detected with strain DN22. At the end of the experiment, which lasted 16 h, we detected the following products HCHO, HCOOH, NH2CHO, N2O, NO2-, and NO3-. Most were also detected during RDX incubation with strain DN22. Finally, we were unable to detect any of RDX nitroso products during both photolysis and incubation with the aerobic bacteria, emphasizing that initial denitration in both cases was responsible for ring cleavage and subsequent decomposition in water.

Protein kinase C isoform expression and activity in the mouse heart.

The expression of protein kinase C (PKC) isoforms in the developing murine ventricle was studied using Western blotting, assays of PKC activity, and immunoprecipitations. The abundance of two Ca2+-dependent isoforms, PKCalpha and PKCbetaII, as well as two Ca2+-independent isoforms, PKCdelta and PKCepsilon, decreased during postnatal development to <15% of the levels detected at embryonic day 18. The analysis of the subcellular distribution of the four isoforms showed that PKCdelta and PKCepsilon were associated preferentially with the particulate fraction in fetal ventricles, indicating a high intrinsic activation state of these isoforms at this developmental time point. The expression of PKCalpha in cardiomyocytes underwent a developmental change. Although preferentially expressed in neonatal cardiomyocytes, this isoform was downregulated in adult cardiomyocytes. In fast-performance liquid chromatography-purified ventricular extracts, the majority of PKC activity was Ca2+-independent in both fetal and adult ventricles. Immunoprecipitation assays indicated that PKCdelta and PKCepsilon were responsible for the majority of the Ca2+-independent activity. These studies indicate a prominent role for Ca2+-independent PKC isoforms in the mouse heart.

Eliminating flanker effects and negative priming in the flankers task: evidence for early selection.

Reports of negative priming in the absence of flanker effects (Fox, 1995) provide support for the notion that unattended stimuli are identified. I evaluated the hypothesis that such results are the outcome of attentional leakage to the flanker location. In Experiment 1, I assessed flanker effects and negative priming as a function of target-flanker proximity (.9 degrees and 2.7 degrees for near and far flankers, respectively) and of attention cuing to the target location (precued vs. uncued) on the prime trials. I report larger flanker effects in uncued than in precued conditions, and larger effects for near than for far flankers. More critically, when attention was precued, both flanker effects and negative priming vanished for far flankers. In Experiment 2, I show that the latter result was not linked to prime-probe contextual similarity (Neill, 1997). These results demonstrate that selective target processing is possible when attention is optimally focused to the target location.

Explosive biodegradation in soil slurry batch reactors amended with exogenous microorganisms.

The present study explores the feasibility of biotreatment of 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro- 1,3,5-triazine (RDX)-contaminated soils in slurry batch reactors. Radiorespirometric assays showed that anaerobic sludge was able to mineralize 59% RDX to CO2 although significant mineralization of TNT was not observed in all cases. TNT and RDX at concentrations higher than 50 and 100 mg/L respectively were inhibitory to methanogenesis (used as a bioindicator), however, methanogenesis recovered after TNT was transformed into less toxic triaminotoluene. Bioslurry batch reactors containing 40% of contaminated soil (2000 mg RDX and 1000 mg TNT/kg dry soil) were operated under various conditions. Both TNT and RDX were persistent to soil indigenous microbes. Degradation of both TNT and RDX was enhanced by the municipal sludge amendment, although degradation of RDX was only achieved under anaerobic conditions.

Biotransformation routes of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine by municipal anaerobic sludge.

Recently we demonstrated that hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), a trimer of methylene nitramine (CH2=N-NO2) undergoes spontaneous decomposition following an initial microbial attack using a mixed microbial culture at pH 7 in the presence of glucose as carbon source. The present study describes whether the second cyclic nitramine octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), a more strained tetramer of CH2=N-NO2, degrades similarly using sludge of the same source. Part of HMX biotransformed to give products that are tentatively identified as the nitroso derivatives octahydro-1-nitroso-3,5,7-trinitro-1,3,5,7-tetrazocine (mNs-HMX) and octahydro-1,3-dinitroso-5,7-dinitro-1,3,5,7-tetrazocine and its isomer octahydro-1,5-dinitroso-3,7-dinitro-1,3,5,7-tetrazocine (dNs-HMX). Another fraction of HMX biotransformed, apparently via ring cleavage, to produce products that are tentatively identified as methylenedinitramine (O2NNHCH2-NHNO2) and bis(hydroxymethyl)nitramine ((HOCH2)2NNO2). None of the above intermediates accumulated indefinitely; they disappeared to predominantly form nitrous oxide (N2O) and formaldehyde (HCHO). Formaldehyde biotransformed further to eventually produce carbon dioxide (14CO2). Nitrous oxide persisted in HMX microcosms containing glucose but denitrified rapidly to nitrogen in the absence of glucose. The presence of nitrous oxide was accompanied by the presence of appreciable amounts of hydrogen sulfide, a known inhibitor of denitrification.

The fate of the cyclic nitramine explosive RDX in natural soil.

The sorption-desorption behavior and long-term fate of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) was examined in sterilized and nonsterilized topsoil. Results of this study indicate that although RDX is not extensively sorbed by the topsoil (Ks(d) of 0.83 L/kg), sorption is nearly irreversible. Furthermore, there was no difference in the sorption behavior for sterile and nonsterile topsoil. However, over the longterm, RDX completely disappeared within 5 weeks in nonsterile topsoil, and hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX), hexahydro-1,3-dinitroso-5-nitro-1,3,5-triazine (DNX), and hexahydro-1,3,5-trinitroso-1,3,5-triazine (TNX) metabolites formed in the aqueous phase. Over the same period, recovery of RDX from sterile topsoil was high (55-99%), and the nitroso metabolites were not detected. Only traces of RDX were mineralized to CO2 and N2O by the indigenous microorganisms in nonsterile topsoil. Of the RDX that was mineralized to N2O, one N originated from the ring and the other from the nitro group substituent, as determined using N15 ring-labeled RDX. However, N2O from RDX represented only 3% of the total N2O that formed from the process of nitrification/denitrification.

Dominant-negative c-Jun promotes neuronal survival by reducing BIM expression and inhibiting mitochondrial cytochrome c release.

Sympathetic neurons require nerve growth factor for survival and die by apoptosis in its absence. Key steps in the death pathway include c-Jun activation, mitochondrial cytochrome c release, and caspase activation. Here, we show that neurons rescued from NGF withdrawal-induced apoptosis by expression of dominant-negative c-Jun do not release cytochrome c from their mitochondria. Furthermore, we find that the mRNA for BIM(EL), a proapoptotic BCL-2 family member, increases in level after NGF withdrawal and that this is reduced by dominant-negative c-Jun. Finally, overexpression of BIM(EL) in neurons induces cytochrome c redistribution and apoptosis in the presence of NGF, and neurons injected with Bim antisense oligonucleotides or isolated from Bim(-/-) knockout mice die more slowly after NGF withdrawal.

Detection of the cyclic nitramine explosives hexahydro-1,3,5-trinitro- 1,3,5-triazine (RDX) and octahydro- 1,3,5,7-tetranitro- 1,3,5,7-tetrazine (HMX) and their degradation products in soil environments.

The cyclic nitramine explosives hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazine (HMX) were examined in field and microcosm soil samples to determine their patterns of degradation and environmental fates. A number of analytical techniques, including solid-phase microextraction with on-fiber derivatization, gas chromatography-mass spectrometry, gas chromatography with electron-capture detection, liquid chromatography-mass spectrometry, and micellar electrokinetic chromatography were required for the analyses. Two different classes of intermediates were detected, both of which lead ultimately to the formation of nitrous oxide (N2O) and carbon dioxide (CO2). The first class was identified as the nitroso derivatives formed by the sequential reduction of -NO2 functional groups. The second class of intermediates, which was favored at higher humidities and in the presence of anaerobic sludge amendments, consisted of ring cleavage products including bis-(hydroxymethyl)-nitramine and methylenedinitramine. Rye-grass (Lolium perenne) present in field samples was found to extract and accumulate HMX from soil without further degradation. In all cases (excepting the plant samples), the indigenous microbes or amended domestic anaerobic sludge consortia degraded the cyclic nitramine explosives eventually to produce N2O and CO2.

Characterization of metabolites during biodegradation of hexahydro-1, 3,5-trinitro-1,3,5-triazine (RDX) with municipal anaerobic sludge.

The biodegradation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in liquid cultures with municipal anaerobic sludge showed that at least two degradation routes were involved in the disappearance of the cyclic nitramine. In one route, RDX was reduced to give the familiar nitroso derivatives hexahydro-1-nitroso-3,5-dinitro-1,3, 5-triazine (MNX) and hexahydro-1,3-dinitroso-5-nitro-1,3,5-triazine (DNX). In the second route, two novel metabolites, methylenedinitramine [(O(2)NNH)(2)CH(2)] and bis(hydroxymethyl)nitramine [(HOCH(2))(2)NNO(2)], formed and were presumed to be ring cleavage products produced by enzymatic hydrolysis of the inner C---N bonds of RDX. None of the above metabolites accumulated in the system, and they disappeared to produce nitrous oxide (N(2)O) as a nitrogen-containing end product and formaldehyde (HCHO), methanol (MeOH), and formic acid (HCOOH) that in turn disappeared to produce CH(4) and CO(2) as carbon-containing end products.