Evaluation of Insecticides Susceptibility and Malaria Vector Potential of Anopheles annularis s.l. and Anopheles vagus in Assam,India

During the recent past, development of DDT resistance and reduction to pyrethroid susceptibility among the malaria vectors has posed a serious challenge in many Southeast Asian countries including India. Current study presents the insecticide susceptibility and knock-down data of field collected Anopheles annularis sensu lato and An. vagus mosquito species from endemic areas of Assam in northeast India. Anopheles annularis s.l. and An. vagus adult females were collected from four randomly selected sentinel sites in Orang primary health centre (OPHC) and Balipara primary health centre (BPHC) areas, and used for testing susceptibility to DDT, malathion, deltamethrin and lambda-cyhalothrin. After insecticide susceptibility tests, mosquitoes were subjected to VectorTest^™ assay kits to detect the presence of malaria sporozoite in the mosquitoes. An. annularis s.l. was completely susceptible to deltamethrin, lambda-cyhalothrin and malathion in both the study areas. An. vagus was highly susceptible to deltamethrin in both the areas, but exhibited reduced susceptibility to lambda-cyhalothrin in BPHC. Both the species were resistant to DDT and showed very high KDT₅₀ and KDT₉₉ values for DDT. Probit model used to calculate the KDT₅₀ and KDT₉₉ values did not display normal distribution of percent knock-down with time for malathion in both the mosquito species in OPHC (p<0.05) and An. vagus in BPHC (χ² = 25.3; p = 0.0), and also for deltamethrin to An. vagus in BPHC area (χ² = 15.4; p = 0.004). Minimum infection rate (MIR) of Plasmodium sporozoite for An. vagus was 0.56 in OPHC and 0.13 in BPHC, while for An. annularis MIR was found to be 0.22 in OPHC. Resistance management strategies should be identified to delay the expansion of resistance. Testing of field caught Anopheles vectors from different endemic areas for the presence of malaria sporozoite may be useful to ensure their role in malaria transmission.     

Pervaporation Aided Esterification of Carboxylic Acids with Ethanol Catalyzed by Porcine Pancreatic Lipase

The results of pervaporation-coupled esterification of various carboxylic acids with ethanol catalyzed by Porcine pancreatic lipase are reported. The effect of lipase and substrate concentrations has been studied and the advantage of pervaporation on the equilibrium conversion has been deduced. The kinetics of reaction were analyzed with a three-parameter model which coupled the effect of pervaporation. The intrinsic kinetic constants for all the reactions were estimated and correlated with the carbon number, an indicator of hydrophobicity of the acids. It was found that the rate constant increases with decrease in carbon number. The experimental concentration profiles were simulated from the model for all the reactions and the model prediction was found to be reasonably good. The water permeability was also correlated well with acid hydrophobicity. The pervaporation coupled reaction efficiency, as represented by the reaction time for equilibrium conversion, was found to bear a profound relation to membrane surface area per unit volume of the reaction mixture (A/V). The time for equilibrium conversion was found to decrease with an increase in A/V value, reaching a minimum and then increasing with a further increase of A/V. A probable explanation has been postulated for such an observation.     

Heterologous expression of <Emphasis Type="Italic">PDH47</Emphasis> confers drought tolerance in <Emphasis Type="Italic">indica</Emphasis> rice

Jerusalem artichoke (Helianthus tuberosus L.) cultivars are conserved in genebanks for use in breeding and horticultural research programs. Jerusalem artichoke collections are particularly vulnerable to environmental and biological threats because they are often maintained in the field. These field collections could be securely conserved in genebanks if improved cryopreservation methods were available. This work used four Jersualem artichoke cultivars (‘Shudi’, ‘M6’, ‘Stampede’, and ‘Relikt’) to improve upon an existing procedure. Four steps were optimized and the resulting procedure is as follows: preculture excised shoot tips (2–3 mm) in liquid MS medium supplemented with 0.4 M sucrose for 3 days, osmoprotect shoot tips in loading solution for 30 min, dehydrate with plant vitrification solution 2 for 15 min before rapid cooling in liquid nitrogen, store in liquid nitrogen, rapidly rewarm in MS liquid medium containing 1.2 M sucrose, and recover on MS medium supplemented with 0.1 mg L^?1 GA₃ for 3–5 days in the dark and then on the same medium for 4–6 weeks in the light (14 h light/10 h dark). After cryopreservation, Jerusalem artichoke cultivar ‘Shudi’ had the highest survival (93%) and regrowth (83%) percentages. Cultivars ‘M6’, ‘Stampede’, and ‘Relikt’ achieved survival and regrowth percentages ranging from 44 to 72%, and 37–53%, respectively. No genetic changes, as assessed by using simple sequence repeat markers, were detected in plants regenerated after LN exposure in Jerusalem artichoke cultivar ‘Shudi’. Differential scanning calorimetry analyses were used to investigate the thermal activities of the tissues during the cryopreservation process and it was determined that loading with 2.0 M sucrose and 0.4 M sucrose dehydrated the shoot tips prior to treatment with PVS2. Histological observations revealed that the optimized droplet vitrification protocol caused minimal cellular damage within the meristem cells of the shoot tips.     

Subacute toxicity of anilofos, a new organophosphorus herbicide, in male rats: effect on some physical attributes and acetylcholinesterase activity

In acute toxicity study, rats showed dose-dependent signs of cholinergic hyperactivity and behavioural alterations. Maximum intensity of symptoms was not associated with mortality. Oral LD50 was 1681 mg/kg. In subacute toxicity study, rats were orally administered 50, 100 or 200 mg/kg of anilofos once daily for 28 days. Signs and symptoms were observed mainly with 200mg/kg. At this dose, anilofos induced hypothermia and progressive weight loss. None of the anilofos-treated rats died. Weight of brain, lung, testis was not altered, while of liver, heart, spleen and kidney increased. Anilofos inhibited cholinesterase (ChE) activities of erythrocyte (41-67%), plasma (36%), blood (37-64%), brain (63-73%) and liver (28-48%). Total protein was decreased in plasma and liver. Results indicate moderate toxic potential of anilofos in mammals, substantial contribution of CNS-mediated effects in causing anilofos toxicity and no direct relationship between hypothermia and level of ChE inhibition.     

Subacute toxicity of anilofos, a new organophosphorus herbicide in male rats: effect on lipid peroxidation and ATPase activity

Effects of anilofos on lipid peroxidation--an index of oxidative stress, ATPase activity--an integral part of active transport mechanisms for cations, GSH level and GST activity were evaluated in blood (erythrocyte/plasma), brain and liver of male rats after daily oral exposure to 50, 100 or 200 mg/kg for 28 days. None of the doses increased lipid peroxidation. The lowest dose, rather, produced marginally significant decrease in peroxidation in liver. Different doses of anilofos decreased GSH content and activities of GST and ATPases. Inhibition of total ATPase (34-44%) and Na+-K+-ATPase (45-52%) activities was maximum in liver, while that of Mg2+-ATPase (46-56%) was more in erythrocyte. Results indicate that anilofos may not cause oxidative damage to cell membrane in repeatedly exposed animals and may cause neuronal/cellular dysfunction by affecting ionic transport across cell membrane.     

Esterification of lauric acid with lauryl alcohol using cross-linked enzyme crystals: Solvent effect and kinetic study

In this paper, we report a comprehensive kinetic study on esterification of lauric acid with lauryl alcohol catalysed by commercial porcine pancreatic lipase (PPL) in the form of cross-linked enzyme crystals (CLEC) using glutaraldehyde as the cross linker. The stability of the CLEC was better than the immobilized enzyme for practical applications. Comparative studies using six different solvents having hydrophobicity (log p) values ranging from 0.70 to 3.50 revealed that the esterification reaction was favoured in hydrophobic solvents. The kinetics of the esterification reaction conformed with the so-called Ping-Pong-Bi-Bi mechanism with alcohol inhibition.     

Mononuclear and dinuclear peroxotungsten complexes with co-ordinated dipeptides as potent inhibitors of alkaline phosphatase activity

New molecular peroxotungstate(VI) complexes with dipeptides as ancillary ligands of the type, [WO(O₂)₂(dipeptide)(H₂O)].3H₂O, dipeptide = glycyl-glycine or glycyl-leucine, have been synthesized and characterized by elemental analysis, spectral and physico-chemical methods including thermal analysis. The complexes contain side-on bound peroxo groups and a peptide zwitterion bonded to the metal centre unidentately through an O(carboxylate) atom. Investigations on certain biologically important key properties of these compounds and a set of dimeric compounds in analogous co-ligand environment, Na₂[W₂O₃(O₂)₄(dipeptide)₂].3H₂O, dipeptide = glycyl-glycine and glycyl-leucine, reported previously by us revealed interesting features of the compounds. Each of the compounds despite having a 7 co-ordinated metal centre exerts a strong inhibitory effect on alkaline phosphatase activity with a potency higher than that of the free dipeptide, tungstate or peroxotungstate. The compounds exhibit remarkable stability in solutions of acidic as well as physiological pH and are weaker as substrate to the enzyme catalase, compared to H₂O₂. The mononuclear and dinuclear peroxotungsten compounds are efficient oxidants of reduced glutathione (GSH), a reaction in which only one of the peroxo groups of a diperoxotungsten moiety of the complexes was found to be active.     

Serologic Prevalence of Toxoplasma gondii in Indian Women of Child Bearing Age and Effects of Social and Environmental Factors

Background

Seroprevalence and incidence of toxoplasmosis in women of child bearing age has remained a contentious issue in the Indian subcontinent. Different laboratories have used different patient recruitment criteria, methods and variable results, making these data difficult to compare.

Aim

To map the point-prevalence and incidence of toxoplasmosis in India.

Material and Methods

In this cross-sectional study, a total of 1464 women of fertile age were recruited from 4 regions using similar recruitment plans. This included women from northern (203), southern (512), eastern (250) and western (501) regions of India. All samples were transported to a central laboratory in Delhi and tested using VIDAS technology. Their age, parity, eating habits and other demographic and clinical details were noted.

Results

Most women were in the 18–25 years age group (48.3%), followed by 26–30 years (28.2%) and 31–35 years (13.66). Few (45) women older than 35 yr. were included. Overall prevalence of anti-Toxoplasma IgG antibodies was seen in 22.40%, with significantly more in married women (25.8%) as compared to single women (4.3%). Prevalence increased steadily with age: 18.1% in the 18–25 yr. age group to 40.5% in women older than 40 yr. The prevalence was high (66%) in those who resided in mud houses. Region-wise, the highest prevalence was observed in South India (37.3%) and the lowest (8.8%) in West Indian women. This difference was highly significant (P<0.001). Prevalence was 21.2% in East India and 19.7% in North India. The IgM positivity rate ranged from 0.4% to 2.9% in four study centers.

Conclusions

This pan-India study shows a prevalence rate of 22.4% with a wide variation in four geographical regions ranging from as low as 8.8% to as high as 37.3%. The overall IgM positivity rate was 1.43%, indicating that an estimated 56,737–176,882 children per year are born in India with a possible risk of congenital toxoplasmosis.     

Potentiality of actinobacteria to combat against biotic and abiotic stresses in tea [Camellia sinensis (L) O. Kuntze]

Tea (Camellia sinensis (L) O. Kuntze) is a long-duration monoculture crop prone to several biotic (fungal diseases and insect pest) and abiotic (nutrient deficiency, drought and salinity) stress that eventually result in extensive annual crop loss. The specific climatic conditions and the perennial nature of the tea crop favour growth limiting abiotic factors, numerous plant pathogenic fungi (PPF) and insect pests. The review focuses on the susceptibility of tea crops to PPF/pests, drought, salinity and nutrient constraints and the potential role of beneficial actinobacteria in promoting tea crop health. The review also focuses on some of the major PPF associated with tea, such as Exobasidium vexans, Pestalotiopsis theae, Colletotrichum acutatum, and pests (Helopeltis theivora). The phylum actinobacteria own a remarkable place in agriculture due to the biosynthesis of bioactive metabolites that assist plant growth by direct nutrient assimilation, phytohormone production, and by indirect aid in plant defence against PPF and pests. The chemical diversity and bioactive significance of actinobacterial metabolites (antibiotics, siderophore, volatile organic compounds, phytohormones) are valuable in the agro-economy. This review explores the recent history of investigations in the role of actinobacteria and its secondary metabolites as a biocontrol agent and proposes a commercial application in tea cultivation.