Reactions of sulphur mustard and sarin on V 1.02 O 2.98 nanotubes

Reactions of sulphur mustard and sarin were studied on the surface of V(1.02)O(2.98) nanotubes by gas chromatography and gas chromatography-mass spectrometry techniques. The V(1.02)O(2.98) nanotube samples were made by using hydrothermal method and characterized by scanning electron microscopy, nitrogen adsorption, X-ray diffractometry and thermogravimetry. Later, they were exposed to sulphur mustard and sarin separately at ambient temperature (30+/-2 degrees C). The data explored the formation of sulphoxide of sulphur mustard, thiodiglycol for sulphur mustard and isopropyl methyl phosphonic acid for sarin on V(1.02)O(2.98) nanotubes illustrating the role of oxidation and hydrolysis reactions in the decontamination.

Neurobehavioral impairments, generation of oxidative stress and release of pro-apoptotic factors after chronic exposure to sulphur mustard in mouse brain

Recent global events have focused attention on the potential threat of international and domestic chemical terrorism, as well as the possibility of chemical warfare proliferation. Sulphur mustard (SM) is one of the potent chemical warfare agents (CWA), which initiates a cascade of events that converge on the redox mechanisms common to brain injury. The present study was designed to examine the effects of chronic SM exposure on neurobehavioral impairments, mitochondrial oxidative stress in male Swiss Albino mice and its role in inducing apoptotic neuronal cell death. The animals were divided into four groups (control, low, medium and high dose) of 5 animals each. Exposure to SM was given percutaneously daily for 12 weeks. The results demonstrated impairment in neurobehavioral indices viz. rota rod, passive avoidance and water maze tests in a dose dependent manner. There was a significant increase in lipid peroxidation and protein carbonyl content whereas, decrease in the activity of manganese superoxide dismutase (MnSOD), glutathione reductase and glutathione peroxidase suggesting impaired antioxidant defense system. Immunoblotting of cytochrome c, Bcl-2, Bax and activation of caspase-3 suggest induction of apoptosis in a dose dependent manner. Finally, increased p53 expression suggests that it may target the mitochondrial pathway for inducing apoptosis in response to DNA damage signals. In conclusion, chronic SM exposure may have the potential to generate oxidative stress which may trigger the release of cytochrome c as well as caspase-3 activation in neurons leading to cell death by apoptosis in a dose dependent manner which may in the end be responsible for the disruption of cognitive functions in mice.

Photocatalytic inactivation of Bacillus anthracis by titania nanomaterials

Photocatalytic inactivation of Bacillus anthracis was studied by using titania nanomaterials and UVA light. Experimental data clearly indicated that, time of exposure, quantity of catalyst, intensity of light, particle size and Sunlight affected the inactivation. It also demonstrated the pseudo-first order behavior of inactivation kinetics and pointed out the enhanced rate of inactivation in the presence of nano-titania existing as a mixture of anatase and rutile phases. The values of rate constant were found to increase when the quantity of catalyst and intensity of UVA light were increased. Nanosized titania exhibited better inactivation properties than the bulk sized titania materials. Sunlight in the presence of nano-titania (mixture of anatase and rutile phases) displayed better photocatalytic bactericidal activity of B. anthracis than sole treatment of Sunlight.

Nanocrystalline zinc oxide for the decontamination of sarin

Nanocrystalline zinc oxide materials were prepared by sol-gel method and were characterized by X-ray diffraction, scanning electron microscopy, thermogravimetry, nitrogen adsorption and infrared spectroscopy techniques. The data confirmed the formation of zinc oxide materials of zincite phase with an average crystallite size of approximately 55 nm. Obtained material was tested as destructive adsorbent for the decontamination of sarin and the reaction was followed by GC-NPD and GC-MS techniques. The reaction products were characterized by GC-MS and the data explored the role of hydrolysis reaction in the detoxification of sarin. Sarin was hydrolyzed to form surface bound non-toxic phosphonate on the surface of nano-zinc oxide. The data also revealed the values of rate constant and half-life to be 4.12h(-1) and 0.16 h in the initial stages of the reaction and 0.361 h(-1) and 1.9h at the final stages of the reaction for the decontamination reaction on nanocrystalline ZnO.

Molecularly imprinted nanopatterns for the recognition of biological warfare agent ricin

Molecularly imprinted polymer (MIP) for biological warfare agent (BWA) ricin was synthesized using silanes in order to avoid harsh environments during the synthesis of MIP. The synthesized MIP was utilized for the recognition of ricin. The complete removal of ricin from polymer was confirmed by fluorescence spectrometer and SEM-EDAX. SEM and EDAX studies confirmed the attachment of silane polymer on the surface of silica gel matrix. SEM image of Ricin-MIP exhibited nanopatterns and it was found to be entirely different from the SEM image of non-imprinted polymer (NIP). BET surface area analysis revealed more surface area (227 m(2)/g) for Ricin-MIP than that of NIP (143 m(2)/g). In addition, surface area study also showed more pore volume (0.5010 cm(3)/g) for Ricin-MIP than that of NIP (0.2828 cm(3)/g) at 12 nm pore diameter confirming the presence of imprinted sites for ricin as the reported diameter of ricin is 12 nm. The recognition and rebinding ability of the Ricin-MIP was tested in aqueous solution. Ricin-MIP rebound more ricin when compared to the NIP. Chromatogram obtained with Ricin-MIP exhibited two peaks due to imprinting, however, chromatogram of NIP exhibited only one peak for free ricin. SDS-PAGE result confirmed the second peak observed in chromatogram of Ricin-MIP as ricin peak. Ricin-MIP exhibited an imprinting efficiency of 1.76 and it also showed 10% interference from the structurally similar protein abrin.

Comparison of toxicity of selected mustard agents by percutaneous and subcutaneous routes

Comparative toxicity of nitrogen mustards (HN-1, HN-2 and HN-3) and sulphur mustard was carried out in mice. Based on LD50, the toxicity pattern was HN-2 < HN-1 < HN-3 < sulphur mustard by percutaneous route whereas, by subcutaneous route the toxicity pattern was sulphur mustard < HN-3 < HN-2 < HN-1. Single dose of 1 LD50 of nitrogen mustards and sulphur mustard was administered percutaneously and various oxidative stress parameters were also evaluated. The weight loss was more in HN-2 on day 3 and in sulphur mustard on day 7. There was a drastic fall of WBC count on day 3 in all groups with a recovery in nitrogen mustard groups on day 7. The RBC count and haemoglobin content showed a significant increase on day 7 in sulphur mustard group. The plasma enzymes (ALT, AST and ALP) showed an increase in all groups on day 3 and day 7. The hepatic GSH and GSSG contents were reduced and MDA content increased in all groups, with a further change in sulphur mustard on 7 day. Extensive DNA fragmentation was observed in all the nitrogen mustard groups compared to sulphur mustard group, on day 3. However, on the day 7 the DNA fragmentation was same in all groups. This study showed that the nitrogen mustards and sulphur mustard were extremely toxic by percutaneous route and caused oxidative stress. Sulphur mustard was more toxic by the percutaneous route and the effects were delayed and progressive.

Conversion from mycophenolate mofetil to enteric-coated mycophenolate sodium in renal transplant recipients with gastrointestinal tract disorders

OBJECTIVE

The objective of this prospective study was to evaluate the effect of conversion from mycophenolate mofetil (MMF) to enteric-coated mycophenolate sodium (EC-MPS) in renal transplant recipients with gastrointestinal tract (GI) reverse effects using patient-reported outcomes instrument.

METHODS

A multicenter, open-label, prospective study was undertaken in renal transplant recipients treated with MMF. In patients experiencing GI tract symptoms, treatment was changed to equimolar EC-MPS (myfortic). At baseline and visit 2 (4-6 weeks after baseline), patients completed the Gastrointestinal Symptom Rating Scale (GSRS) and Gastrointestinal Quality of Life Index (GIQLI), and physicians completed the Overall Treatment Effect (OTE) scale at visit 2. A difference of 0.5 or greater in the OTE score is indicative of clinical relevance.

RESULTS

Of 154 patients screened, 118 fulfilled the inclusion or exclusion criteria. Eighty-five men and 33 women with a mean age of 41.6 years participated in this study. Median time since transplantation was 12 months. Mean (SD) dose of MMF reported at baseline was 1209.4 (422.89) mg/d. More than 50% of patients reported MMF-associated nausea, dyspepsia, and abdominal pain. After conversion to an equimolar dose of EC-MPS, patients showed improvement in GI symptoms. This benefit was predominantly observed in patients with moderate to severe symptoms at baseline. On the GSRS, patients reported a significant (P < .05) reduction in symptom burden across all parameters (reflux, 36%; diarrhea, 38%; indigestion, 36%; constipation, 28%; and abdominal pain, 40%). On the GIQLI also, significant (P < .05) improvement was reported (symptoms, 18%; emotional status, 22%; physical functioning, 21%, and use of medical treatment, 18%). On the OTE scale, 84.7% of patients reported improvement in GI symptoms.

CONCLUSION

In patients with moderate to severe GI symptoms, changing treatment from MMF to EC-MPS significantly reduces GI-related symptom burden and improves GI-specific quality of life.

Comparative evaluation of some flavonoids and tocopherol acetate against the systemic toxicity induced by sulphur mustard

OBJECTIVE

To evaluate the protective value of quercetin, gossypin, Hippophae rhamnoides (HR) flavone and tocopherol acetate against the systemic toxicity of percutaneously administered sulphur mustard (SM) in mice.

MATERIALS AND METHODS

Quercetin, gossypin, HR flavone or tocopherol acetate (200 mg/kg, i.p.) were administered just before percutaneous administration of SM and protection against the SM lethality was evaluated. In another experiment quercetin, gossypin, HR flavone or tocopherol acetate were administered against 2 LD(50) SM. The animals were sacrificed seven days post SM administration and various biochemical parameters were estimated.

RESULTS

The protection against the lethality of SM was very good with the flavonoids (quercetin = 4.7 folds; gossypin = 6.7 folds and HR flavone = 5.6 folds), compared to no protection with tocopherol acetate (0.7 fold). SM (2 LD(50)) showed decrease in reduced and oxidised glutathione (GSH and GSSG) levels, and an increase in malondialdehyde level (MDA). Oxidative stress enzymes like glutathione peroxidase, glutathione reductase and superoxide dismutase were significantly decreased. The total antioxidant status was also significantly decreased. Additionally, there was a significant increase in red blood corpuscles and hemoglobin content. All the flavonoids significantly protected the GSH, GSSG and MDA, and also the hematological variables. Tocopherol acetate failed to offer any protection in those parameters. Gossypin protected glutathione peroxidase, while HR flavone protected both glutathione reductase and glutathione peroxidase significantly. The decrease in body weight induced by SM and the histological lesions in liver and spleen were also significantly protected by the flavonoids but not by tocopherol acetate.

CONCLUSION

The present study supports that SM induces oxidative stress and flavonoids are promising cytoprotectants against this toxic effect.

Prophylactic effect of gossypin against percutaneously administered sulfur mustard

OBJECTIVE

To evaluate the protective efficacy of gossypin (3,3',4',5,7,8-hexahydroxyflavone 8-glucoside) by administering it intraperitoneally, for dose, time, and vehicle dependent effects against sulphur mustard (SM), administered through percutaneous route in mice.

METHODS

SM (diluted in PEG-300) was administered percutaneously. The protective efficacy of gossypin was evaluated by administering it intraperitoneally (50, 100, 200, and 400 mg/kg), in various vehicles (water, PEG-300 and DMSO), and time intervals (30 min prior, simultaneous and 2 h post). The time dependent protection of gossypin (200 mg/kg in PEG-300; i.p.) was also evaluated using selected biochemical variables (GSH, GSSG, MDA, total antioxidant status, Hb, WBC count, RBC count, glutathione peroxidase, glutathione reductase, and superoxide dismutase) and liver histology. The protection of gossypin by oral route was also evaluated against percutaneously administered SM.

RESULTS

The protection against systemic toxicity of SM (LD50 8.1 mg/kg) was better when gossypin was given with PEG-300 (8.0 folds) than DMSO (5.7 folds). No protection was observed when gossypin was administered with water. Good protection (8.0 folds) was observed when gossypin was administered (200 mg/kg in PEG-300; i.p.) at 30 min prior or simultaneous to SM exposure, but no protection was observed when gossypin was administered 2 h post to SM exposure. A significant weight loss was observed 7 days after SM administration (2 LD50), with a significant increase in RBC and Hb. A significant decrease in total antioxidant status of plasma, liver GSH and GSSG levels, and in the activities of glutathione peroxidase, glutathione reductase and superoxide dismutase was also observed 7 days after SM administration. SM treated mouse liver also showed necrosis. A significant protection was observed when gossypin (200 mg/kg in PEG-300; i.p.) was administered either as a pretreatment (30 min before) or simultaneous treatment, and not as a post treatment (2 h). The protective efficacy of gossypin was better through oral route when administered with DMSO (4.8 folds) than with PEG-300 (2.4 folds). No protection was observed when gossypin was administered orally with water.

CONCLUSION

Percutaneous administration of SM induces oxidative stress and gossypin can protect it as a prophylactic agent by intraperitoneal or oral routes.