East Central South African genotype as the causative agent in reemergence of Chikungunya outbreak in India

Chikungunya fever is an important arboviral infection prevalent throughout Africa and Southeast Asia. Recently, in 2006, it has reemerged in many parts of India, affecting more than a million persons. A detail serological, virological, and molecular investigation of this unprecedented outbreak was carried out by collecting and studying 540 samples from all the affected regions of India during this epidemic. An in-depth investigation revealed the presence of anti-Chikungunya antibodies in 68% of the samples and genomic RNA in 49% of them. In addition 32 Chikungunya viruses were isolated from 45 representative polymerase chain reaction-positive samples. The nucleotide sequences of partial E1 gene of 25 representative Chikungunya viruses were deciphered. The sequence analysis indicated that all the isolates of this epidemic belonged to the new Indian Ocean island clade of East Central South (ECS) African genotype. This study conclusively proved the genotype shift from Asian to ECS African as the major factor in the reemergence of Chikungunya in an unprecedented outbreak in India after a gap of 32 years.

Detoxification reactions of sulphur mustard on the surface of zinc oxide nanosized rods

Detoxification reactions of sulphur mustard, a deadliest chemical warfare agent were studied on the surface of zinc oxide nanorods at room temperature (32+/-2 degrees C) and the data was compared with that of the bulk ZnO. Prior to the reaction, the nanorods of zinc oxide were synthesized by the hydrothermal method and subsequently characterized by XRD, SEM, TG, N(2) BET, FT-IR. The data revealed the formation of nanorods with diameter ranging from 100 nm to 500 nm with length in microns. Obtained nanomaterial along with bulk ZnO were tested as reactive sorbent for the detoxification of sulphur mustard. Reaction was monitored by GC-FID technique and the reaction products were characterized by GC-MS. Data explores the role of hydrolysis and elimination reactions in the detoxification of sulphur mustard and it also reveals that zinc oxide nanorods and bulk ZnO show the half lives of 8.48 h, 24.75 h in the first 12h and 122.47 h, 177.29 h from 12h to 48 h of the reaction.

Synthesis and characterization of metal ion imprinted nano-porous polymer for the selective recognition of copper

Selective recognition of metal ions utilizing metal ion-imprinted polymers (MIIPs) received much importance in diverse fields owing to their high selectivity for the target metal ions. In the present study, a copper ion imprinted polymer was synthesized without an additional complexing ligand or complex with a broad aim to avoid the conventional extra metal ion complexing ligand during the synthesis of MIIP. The complete removal of the copper metal ion from the MIIP was confirmed by AAS and SEM-EDX. SEM image of the MIIP exhibited nano-patterns and it was also found to be entirely different from that of non-imprinted polymer and polymer with copper metal ions. BET surface area analysis revealed more surface area (47.96 m(2)/g) for the Cu(II)-MIIP than non-imprinted control polymer (41.43 m(2)/g). TGA result of polymer with copper metal ion indicated more char yield (18.41%) when compared to non-imprinted control polymer (8.3%) and Cu(II)-MIIP (less than 1%). FTIR study confirmed the complexation between Cu(II)-MIIP and Cu(II) metal ion through carbonyl oxygen of acryl amide. The Cu(II)-MIIP exhibited an imprinting efficiency of 2.0 and it was showing 8% interference from a mixture of Zn, Ni and Co ions. A potentiometric ion selective electrode devised with Cu(II)-MIIP showed more potential response for Cu(II) ion than that was fabricated from non-imprinted polymer.

Breakthrough behavior of diethyl sulphide vapor on active carbon systems

Breakthrough behavior of diethyl sulphide vapors on carbon systems such as active carbon, NaOH/CrO3/C, NaOH/CrO3/EDA/C and RuCl3/C has been studied by using modified Wheeler equation and the same was used to calculate the pseudo-first-order rate constant (kv) and kinetic saturation of capacity (W(e)) values. Effects of various parameters such as bed height, air flow rate, concentration and temperature on the above parameters have also been studied. Rate constant was found to be increasing with air flow rate, while W(e) was found to be invariable. Both kv and W(e) decreased with the increase in temperature, however, no significant effect on W(e) and kv was observed due to concentration change. The values of kinetic saturation capacity were used to predict the service lives/breakthrough times of carbon beds (when used in filtration systems).

A Rapid Field Detection Method for Arsenic in Drinking Water

In this study, a rapid colorimetric method for arsenic detection was developed. Different reagents containing magnesium turnings in combination with a series of acids were tested for arsine generation. The arsine was then allowed to react with auric chloride on Whatman filter paper No. 3, which in turn changed color. The detection time and detection limit were measured for each acid. Oxalic acid was found to be the most appropriate acid among all the acids used for detection in this study. It took 10 min to detect 10 ppb arsenic concentration and only 1 min to detect concentrations higher than 50 ppb. This method thus reduced the detection time for arsenic and has the potential to develop better field kit.

Adsorptive removal of water poisons from contaminated water by adsorbents

Adsorptive removal of water poisons such as Pb(II), Cu(II), Mn(II), Hg(II), CN(-), microbes, nerve and blister agents (concentration range from 100 to 1000 mg/L) were studied by using adsorbents such as active carbon, impregnated carbon and bentonite loaded fabric strip. Removal of water poisons (99.5%) could be achieved with an optimum stirring time of 5-15 min and weight of adsorbent of 0.8-8.0 g/100mL contaminated water, respectively. However, 85% bentonite loading was found to be most effective for Pb(II) removal. Effect of contaminants concentration was also studied.

Amplification of LDH gene from indian strains of Plasmodium vivax

BACKGROUND & OBJECTIVES

Plasmodium vivax is geographically widespread and responsible for > 50% of malaria cases in India. Increased drug resistance of the parasite highlights the immediate requirement of early and accurate diagnosis as well as new therapeutics. In view of this, the present study was undertaken to amplify P. vivax (Indian strains) lactate dehydrogenase gene (PvLDH) which has been identified as a good target for antimalarials as well as diagnostics.

METHODS

P. vivax infected clinical blood samples were collected from southern part of India and were tested with established diagnostic parameters (ICT, Giemsa staining). Total DNA was extracted from blood samples and subjected to PCR using two sets of primers, one for the amplification of full PvLDH gene (951 bp) and the other for a partial PvLDH gene fragment (422bp), covering a variable antigenic region (140aa) as compared to other plasmodial species.

RESULTS & CONCLUSION

PCRs for both the full and partial gene targets were optimised and found to be consistent when tested on several P. vivax positive clinical samples. In addition, full gene PCR was found to specifically detect only P. vivax DNA and could be used as a specific molecular diagnostic tool. These amplified products can be cloned and expressed as a recombinant protein that might be useful for the development and screening of antimalarials as well as for diagnostic purposes.

Reemergence of dengue virus type-3 (subtype-III) in India: implications for increased incidence of DHF & DSS

Background

Dengue virus infection has recently taken endemic proportion in India implicating all the four known dengue serotypes. There was a major dengue outbreak in northern India including Delhi in October- December, 2003 and again in 2004. We have carried out a detailed investigation of the 2004 outbreak by Serosurveillance, RT-PCR, nested PCR, virus isolation and genotyping. We also report the molecular epidemiological investigation of these outbreaks.

Results

The serological investigation of 162 suspected serum samples using an in-house dengue dipstick ELISA revealed 11%-IgM, 51%-IgG and 38%-both IgM and IgG antibody positivity. The RT-PCR analysis revealed presence of dengue RNA in 17 samples. Further subtyping and genotyping by nested PCR and nucleotide sequencing of C-prM gene junction revealed the association of subtype III of dengue virus type 3 in the outbreak.

Conclusion

The sudden shifting and dominance of the dengue virus serotype-3 (subtype III) replacing the earlier circulating serotype-2 (subtype IV) is a point of major concern and may be attributed to increased incidence of DHF and DSS in India.

Plastic antibody for the recognition of chemical warfare agent sulphur mustard

Molecularly imprinted polymers (MIPs) known as plastic antibodies (PAs) represent a new class of materials possessing high selectivity and affinity for the target molecule. Since their discovery, PAs have attracted considerable interest from bio- and chemical laboratories to pharmaceutical institutes. PAs are becoming an important class of synthetic materials mimicking molecular recognition by natural receptors. In addition, they have been utilized as catalysts, sorbents for solid-phase extraction, stationary phase for liquid chromatography and mimics of enzymes. In this paper, first time we report the preparation and characterization of a PA for the recognition of blistering chemical warfare agent sulphur mustard (SM). The SM imprinted PA exhibited more surface area when compared to the control non-imprinted polymer (NIP). In addition, SEM image showed an ordered nano-pattern for the PA of SM that is entirely different from the image of NIP. The imprinting also enhanced SM rebinding ability to the PA when compared to the NIP with an imprinting efficiency (alpha) of 1.3.

Acute toxicity and cardio-respiratory effects of 2-deoxy-D-glucose: a promising radio sensitiser

OBJECTIVE

To evaluate the acute toxicity of 2-deoxy-D-glucose (2DG) by oral (p.o.) and intravenous (i.v.) routes, and also the cardio-respiratory effects following high doses of 2DG in animal models.

METHODS

The LD50 of 2DG (in water) was determined in rats and mice by p.o. route and in mice by i.v. route. The effect of 2-DG (250 mg/kg, 500 mg/kg, and 1000 mg/kg, i.v.) was studied on various cardio-respiratory parameters viz., mean arterial blood pressure, heart rate and respiratory rate in anaesthetised rats. The effect of 2DG (500 mg/kg, 1000 mg/kg, and 2000 mg/kg, p.o.) was also studied on various respiratory parameters viz., respiratory rate and tidal volume in conscious rats and mice using a computer program.

RESULTS

The p.o. LD50 of 2DG was found to be >8000 mg/kg in mice and rats, and at this dose no death was observed. The LD50 in mice by i.v. route was found to be 8000 mg/kg. At this dose 2 out of 4 mice died and the death occurred within 6 h. A significant increase in the body weight was observed after p.o. administration of 2DG in rats at 500 mg/kg, 1000 mg/kg, and 2000 mg/kg doses. There was no significant change in the body weight at 4000 mg/kg and 8000 mg/kg by the p.o. route in rats and up to 8000 mg/kg by p.o. as well as i.v. routes in mice. Intravenous administration of 2DG (250 mg/kg, 500 mg/kg, and 1000 mg/kg) in anaesthetised rats showed a time-dependent decrease in the mean arterial blood pressure. There was no change in the heart rate in any of the treatment groups. The tidal volume was not changed significantly by p.o administration in conscious rats, but a significant decrease in the respiratory frequency at 500 mg/kg and 1000 mg/kg doses was observed. In the mice also there was no change in the tidal volume after p.o, administration, but the respiratory frequency decreased significantly at 2000 mg/kg dose.

CONCLUSION

2DG is a safe compound but can cause a fall in the blood pressure and a decrease in respiratory frequency at high doses.

Microemulsion mediated in situ derivatization–extraction and gas chromatography–mass spectrometric analysis of alkylphosphonic acids

Detection and identification of environmental signatures of chemical warfare agents is an important aspect of verification program of Chemical Weapons Convention (CWC). Alkylphosphonic acids (APAs) are ultimate and persistent degradation products of nerve agents. Their identification in a sample submitted for off-site analysis infers possible indication of contamination with nerve agents. This paper describes the development of a new sample preparation method which involves 'in situ derivatization and extraction' (INDEX) of acids from water. Derivatization is performed by alkylation of APAs with alkylbromides in surfactant less microemulsion (SLME). The derivatized analytes were analyzed by gas chromatography coupled with mass spectrometry. The developed method involves simultaneous derivatization (alkylation) and extraction of acidic analytes mediated by surfactant less microemulsion. Various derivatization-extraction parameters such as solvent, reaction time and temperature, base and alkyl bromides were optimized. Pentyl bromide in the presence of potassium carbonate and diisopropylamine at 100 degrees C derivatized the selected acids efficiently. Kinetic data for alkylation of methylphosphonic acids and some carboxylic acids were obtained to assess their relative susceptibility for alkylation in microemulsion. Methylphosphonic acid and isopropyl methylphosphonic acid took 140-150 min to reach completion while carboxylic acids took 100 min to complete the reaction. INDEX could be successfully performed even in the presence of interfering Ca(2+) and Mg(2+) ions.

Electroantennogram and behavioral responses of Culex quinquefasciatus (Diptera: Culicidae) females to chemicals found in human skin emanations

The southern house mosquito, Culex quinquefasciatus Say (Diptera: Culicidae), is closely associated with humans and is a vector of filariasis. Use of semiochemicals for control of mosquitoes is a novel and potentially ecofriendly control approach. Human skin emanations are known to attract mosquitoes. In the current study, olfactory and behavioral responses of host-seeking female Cx. quinquefasciatus to various chemical components of human skin emanations (carboxylic acids, alcohols, and aldehydes) were evaluated separately at three doses (0.01, 0.1, and 1 microg) for electroantennogram (EAG) and three doses (0.1, 1, and 10 microg) for behavioral assay. Results of EAG studies indicated that all carboxylic acids elicited significant olfactory responses except tetradecanoic acid (C14) and octadecanoic acid (C18). In particular, hexanoic acid (C6) elicited a maximum, eight-fold olfactory response compared with the solvent control. Ethylene glycol and benzyl alcohol exhibited significant EAG and behavioral responses, whereas among aldehydes, nonanal elicited high EAG and behavioral responses, but only at all three doses tested compared with control. Some carboxylic acids elicited significant behavioral responses, attracting approximately 75% of females tested toward chemical stimuli in a Y-tube olfactometer.

Sample Preparation of Organic Liquid for Off-Site Analysis of Chemical Weapons Convention Related Compounds

Off-site analysis of chemical warfare agents (CWAs) and related compounds plays a key role in the verification program of the Chemical Weapons Convention (CWC). The analysis results, aiming toward unambiguous identication of compounds, depend on the type of sample preparation method. Development of milder sample preparation methods, which offer good recoveries and do not alter the structure of analytes, is highly desirable. Organic liquid with high hydrocarbon background is a frequently encountered challenge in off-site analysis and in official proficiency tests conducted by OPCW. Sample cleanup procedures, namely, solvent exchange followed by cooling and liquid-liquid extraction were studied to eliminate the hydrocarbons from organic liquid. Acetonitrile, a polar aprotic solvent, was effectively used to remove the background in both methods, and recoveries of spiked CWAs by the two techniques were between 69 and 99%.

Gas chromatography/mass spectrometric analysis of methyl esters of N,N-dialkylaminoethane-2-sulfonic acids for verification of the Chemical Weapons Convention

This paper describes the synthesis and gas chromatography/electron ionization mass spectrometric (GC/EI-MS) analysis of methyl esters of N,N-dialkylaminoethane-2-sulfonic acids (DAESAs). These sulfonic acids are important environmental signatures of nerve agent VX and its toxic analogues, hence GC/EI-MS analysis of their methyl esters is of paramount importance for verification of the Chemical Weapons Convention. DAESAs were prepared by condensation of 2-bromoethane sulfonic acid with dialkylamines, and by condensation of dialkylaminoethyl chloride with sodium bisulfite. GC/EI-MS analysis of methyl esters of DAESAs yielded mass spectra; based on these spectra, generalized fragmentation routes are proposed that rationalize most of the characteristic ions.