Characterization and inheritance of elevated esterases in organophosphorus and carbamate insecticide resistant Culex quinquefasciatus (Diptera: Culicidae) from Sri Lanka

1993 ◽  
Vol 83 (1) ◽  
pp. 127-132 ◽  
Author(s):  
H.T.R. Peiris ◽  
J. Hemingway
Keyword(s):  
Sri Lanka ◽  
Culex Quinquefasciatus ◽  
Sri Lankan ◽  
Relative Importance ◽  
Glutathione S Transferase ◽  
Carbamate Insecticide ◽  
A Minor ◽  
Hydrolysis Of ◽  
Naphthyl Acetate

AbstractCulex quinquefasciatus Say from Peliyagoda, Sri Lanka, has elevated esterases A2 and B2. In vitro insecticide metabolism studies on the temephos-selected Sri Lankan Cutex quinquefasciatus strain, Pel RR, showed that fenitrothion was hydrolysed more rapidly than malathion. A significantly larger amount of fenitrothion was metabolized in Pel RR compared to the insecticide susceptible Pel SS strain, but the amount of malathion metabolized in the two strains was not significantly different. There was more esterase hydrolysis of fenitrothion than oxidase or glutathione S-transferase metabolism in Pel RR, which suggests that the elevated esterases in this strain have both metabolic and sequestering functions and that the relative importance of the two roles depends on the insecticide used. Genetic crosses of the temephos resistant and susceptible strains, showed that both resistance and elevated esterase activity were inherited as semi-dominant multi-genic characters. Hydrolysis of 2-naphthyl acetate was highest in the Pel RR strain, lowest in the Pel SS and intermediate in the F1 cross of the two strains. A minor maternal effect on resistance occurred with backcrosses involving resistant (F1) females, which gave consistently and significantly lower mortalities than those involving resistant (F1) males.

Mechanisms of insecticide resistance in a temephos selected Culex quinquefasciatus (Diptera: Culicidae) strain from Sri Lanka

1990 ◽  
Vol 80 (4) ◽  
pp. 453-457 ◽  
Author(s):  
H.T.R. Peiris ◽  
J. Hemingway
Keyword(s):  
Cytochrome P450 ◽  
Sri Lanka ◽  
Culex Quinquefasciatus ◽  
Resistant Strain ◽  
Resistance Mechanism ◽  
Transferase Activity ◽  
Glutathione S Transferase ◽  
Biochemical Assays ◽  
Significant Difference ◽  
Naphthyl Acetate

AbstractCulex quinquefasciatus Say from Peliyagoda, Sri Lanka, has larval resistance to temephos, malathion, fenitrothion and chlorpyrifos. Biochemical assays on individual resistant and susceptible mosquitoes of this strain showed that there was a good correlation between this resistance and increased esterase activity with both 1-and 2-naphthyl acetate, which appears to be the major resistance mechanism in this multiple organophosphate resistant strain. There was no significant difference in malaoxon, bendiocarb or propoxur sensitivity of the acetylcholinesterase from the resistant and susceptible strains, indicating that the sensitivity of the target site has not been altered. Biochemical assays on mass homogenates of the resistant and susceptible strains showed no correlation between resistance and the level of glutathione s-transferase activity, or the amount of cytochrome P450 present.

An active immunization approach to generate protective catalytic antibodies

2001 ◽  
Vol 360 (1) ◽  
pp. 151-157 ◽  
Author(s):  
Jun WANG ◽  
Yunqing HAN ◽  
Miles F. WILKINSON
Keyword(s):  
Active Immunization ◽  
Catalytic Antibodies ◽  
Toxic Substances ◽  
Mouse Blood ◽  
Physiological Conditions ◽  
Catalytic Function ◽  
Carbamate Insecticide ◽  
Hydrolysis Of

We report that mice immunized with a phosphate immunogen produced polyclonal catalytic antibodies (PCAbs) that catalysed the hydrolysis of carbaryl, a widely used broad-spectrum carbamate insecticide that exerts toxic effects in animals and humans. The reaction catalysed by the PCAbs (IgGs) obeyed Michaelis–Menten kinetics in vitro with the following values at pH8.0 and 25°C: Km≈ 8.0μM, kcat = 4.8×10−3–5.8×10−1, kcat/knon-cat = 5.6×101–6.8×103 (where knon-cat is the rate constant of the reaction in the absence of added catalyst). The PCAbs were also active in whole sera under physiological conditions in vitro. The PCAbs induced in vivo were also active in vivo, as immunization with the phosphate immunogen decreased the mouse blood concentration of carbaryl. To our knowledge, this is the first report demonstrating that active immunization generates antibodies possessing therapeutic catalytic function in vivo. We propose that active immunization schemes that induce enzymically active antibodies may provide a highly specific therapeutic approach for degrading toxic substances.

Malathion-specific resistance in a strain of the rust red grain beetle Cryptolestes ferrugineus (Coleoptera: Cucujidae)

1998 ◽  
Vol 88 (2) ◽  
pp. 199-206 ◽  
Author(s):  
A.G. Spencer ◽  
N.R. Price ◽  
A. Callaghan
Keyword(s):  
Resistant Strain ◽  
Specific Resistance ◽  
Strain Differences ◽  
Gas Chromatography Mass Spectrometry ◽  
Cryptolestes Ferrugineus ◽  
Tributyl Phosphorotrithioate ◽  
Inhibition Studies ◽  
Hydrolysis Of ◽  
Naphthyl Acetate

AbstractA strain of Cryptolestes ferrugineus (Stephens) bred for malathion-specific resistance was found to be 650 fold resistant at LD50 when compared with a susceptible strain bred from the same stock. Resistance was more than 98% synergized by triphenyl phosphate and S,S,S-tributyl phosphorotrithioate, but unaffected by piperonyl butoxide. AChE inhibition by malaoxon varied slightly between the strains. Non-specific esterase activity as measured by the hydrolysis of α-naphthyl acetate was slightly reduced in the resistant strain whereas there were no inter-strain differences in the hydrolysis of β-naphthyl acetate. Products of in vitro metabolism of malathion were identified by thin-layer chromatography and gas chromatography-mass spectrometry as α- and β-malathion mono-acids. It was therefore concluded that resistance was due to the hydrolytic breakdown of malathion by a malathion-specific carboxylesterase. The rate of in vitro malathion hydrolysis was found to be 31 times greater in the resistant strain. In vitro inhibition studies indicated that resistance is attributable to a carboxylesterase unique to the resistant strain. The implications of these results are discussed in relation to work recently carried out on malathion-specific resistance in dipterous species.

Buddhist Law Against the State? Representing Religion, Law, and Conflict

2019 ◽  
Vol 87 (3) ◽  
pp. 662-692 ◽  
Author(s):  
Benjamin Schonthal
Keyword(s):  
Sri Lanka ◽  
Legal Regulation ◽  
The State ◽  
Popular Media ◽  
Sri Lankan ◽  
State Law ◽  
Naturally Occurring ◽  
Normative Systems ◽  
Religious Law ◽  
A Minor

AbstractPublic disputes over the legal regulation of religion are often portrayed as naturally occurring conflicts between competing normative systems: religious law and state law. What, then, explains why some normative frictions become the focus of major controversies, whereas others do not? This article tries to answer this question, while examining a genre of religious law that has not received much attention by scholars of law and religion, Buddhist law in Sri Lanka. Drawing on monastic disciplinary texts, legal archives, and representations of law taken from online and popular media, this article analyzes how and why a minor, routine friction between Buddhist ecclesiastical rules and Sri Lankan statutory regulations—a dispute over whether a monk may wear his robes in prison—came to be portrayed as a grand contest between two incompatible regimes: “Buddhist law” and “state law.”

A multiple basis for insecticide resistance in a strain of Culex quinquefasciatus (Diptera: Culicidae) from Muheza, Tanzania, studied as resistance declined

1993 ◽  
Vol 83 (1) ◽  
pp. 75-85 ◽  
Author(s):  
A. Khayrandish ◽  
R.J. Wood
Keyword(s):  
Culex Quinquefasciatus ◽  
Polyacrylamide Gel Electrophoresis ◽  
Laboratory Culture ◽  
Dominant Effect ◽  
Level Of Activity ◽  
Standard Level ◽  
Minor Influence ◽  
Initial Resistance ◽  
A Minor

AbstractEvidence from observing resistance in decline in fourth instar larvae of the multiple resistant MUHEZA strain of Culex quinquefasciatus Say from Tanzania (MUHEZA), showed that the major mechanisms for chlorpyrifos and propoxur resistance were different. Resistance to chlorpyrifos declined more than 400-fold (from an initial resistance ratio (RR) of 14285) while resistance to propoxur remained stable for at least 30 generations of laboratory culture. Significant synergism was found between propoxur and piperonyl butoxide (PB), propoxur and s,s,s-tributyl trithiophosphate (DEF), and permethrin and PB, but antagonism occurred between chlorpyrifos and PB, and no synergism between chlorpyrifos and DEF. Nine esterase isozymes active against naphthyl acetates on polyacrylamide gel electrophoresis (PAGE), were identified, four (A2, A3, B2, B3) showing polymorphism in activity, with very intense expression at one or other position in more than 32% of larvae, and null expression in less than 30%. The frequency of intense bands and of nulls both declined as resistance declined. A selected substrain (MUHEZA-fb), breeding true for A2, A3, B2 and B3 at the standard level of activity, showed almost stable chlorpyrifos resistance (RR=1428–1785) for approximately 35 generations. In mass larval assays of in vitro sensitivity of acetylcholinesterase (AChE) to propoxur, the I50 in MUHEZA was 950-fold greater than in a reverted resistant strain (RANGOON). Single larval assays indicated an AChE resistance allele (AceR) at frequency 0.43. PAGE of AChE revealed nine isozymes in MUHEZA and five in RANGOON, three of which were in common. It is concluded that propoxur resistance was due principally to AceR with a minor influence from oxidases and non-specific esterases, while chlorpyrifos resistance was due to an interaction between AceR and non-specific esterases, the latter exerting the dominant effect.

scholarly journals Effect of Indian Polyvalent Antivenom in the Prevention and Reversal of Local Myotoxicity Induced by Common Cobra (Naja naja) Venom from Sri Lanka In Vitro

Toxins ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 308
Author(s):  
Umesha Madhushani ◽  
Prabhani Thakshila ◽  
Wayne C. Hodgson ◽  
Geoffrey K. Isbister ◽  
Anjana Silva
Keyword(s):  
Sri Lanka ◽  
Time Scale ◽  
Sri Lankan ◽  
Cellular Injury ◽  
Muscle Preparation ◽  
Naja Naja ◽  
Target Sites ◽  
Lag Period ◽  
Nerve Muscle

Bites by many Asiatic and African cobras (Genus: Naja) cause severe local dermonecrosis and myonecrosis, resulting in permanent disabilities. We studied the time scale in which two Indian polyvalent antivenoms, VINS and Bharat, remain capable of preventing or reversing in vitro myotoxicity induced by common cobra (Naja naja) venom from Sri Lanka using the chick biventer cervicis nerve-muscle preparation. VINS fully prevented while Bharat partially prevented (both in manufacturer recommended concentrations) the myotoxicity induced by Naja naja venom (10 µg/mL) when added to the organ baths before the venom. However, both antivenoms were unable to reverse the myotoxicity when added to organ baths 5 and 20 min post-venom. In contrast, physical removal of the venom from the organ baths by washing the preparation 5 and 20 min after the venom resulted in full and partial prevention of the myotoxicity, respectively, indicating the lag period for irreversible cellular injury. This suggests that, although the antivenoms contain antibodies against cytotoxins of the Sri Lankan Naja naja venom, they are either unable to reach the target sites as efficiently as the cytotoxins, unable to bind efficiently with the toxins at the target sites, or the binding with the toxins simply fails to prevent the toxin-target interactions.

Temephos resistance and the associated cross-resistance spectrum in a strain of Culex quinquefasciatus Say (Diptera: Culicidae) from Peliyagoda, Sri Lanka

1990 ◽  
Vol 80 (1) ◽  
pp. 49-55 ◽  
Author(s):  
H.T.R Peiris ◽  
J Hemingway
Keyword(s):  
Culex Quinquefasciatus ◽  
Cross Resistance ◽  
Single Family ◽  
Parental Population ◽  
Pirimiphos Methyl ◽  
Bendiocarb Resistance ◽  
Low Levels ◽  
Resistance Spectrum ◽  
Hydrolysis Of ◽  
Naphthyl Acetate

AbstractA heterogeneous population (Pel) of Culex quinquefasciatus Say was selected, by single family rearing, to give a strain, Pel SS, which had low levels of hydrolysis of the esterase substrates α and β-naphthyl acetate. The level of temephos resistance was three-fold lower in this strain than the original parental population, and the levels of resistance to malathion, fenitrothion, pirimiphos-methyl, chlorpyrifos and permethrin were also reduced. In contrast, temephos selection increased the temephos-resistance in the Pel-RR strain ten-fold compared to the original parental population and 29-fold compared to Pel SS. The level of temephos-resistance in Pel RR compared to Pel SS at the LC50 level was 37-fold. Larval cross-resistance, at different levels, was observed to the organophosphorus insecticides, malathion, fenitrothion, parathion, pirimiphos-methyl, chlorpyrifos, fenthion and phoxim, and to the carbamates, propoxur and bendiocarb, but the level of fenthion, propoxur and bendiocarb resistance was less than three-fold. Adults showed cross-resistance to malathion and fenitrothion, but not to propoxur. There was negative cross-resistance to permethrin in both the larvae and adults of Pel RR compared to the Pel and Pel SS strains.

The Role of Music and Allied Arts in Public Writings on Cultural Diversity: “People of Sri Lanka”

2020 ◽  
Vol 6 ◽  
pp. 93-100
Author(s):  
Gisa Jähnichen
Keyword(s):  
Sri Lanka ◽  
Cultural Diversity ◽  
South Asia ◽  
Case Studies ◽  
Sri Lankan ◽  
Culturally Different ◽  
The World ◽  
Official Languages ◽  
The Way

The Sri Lankan Ministry of National Coexistence, Dialogue, and Official Languages published the work “People of Sri Lanka” in 2017. In this comprehensive publication, 21 invited Sri Lankan scholars introduced 19 different people’s groups to public readers in English, mainly targeted at a growing number of foreign visitors in need of understanding the cultural diversity Sri Lanka has to offer. This paper will observe the presentation of these different groups of people, the role music and allied arts play in this context. Considering the non-scholarly design of the publication, a discussion of the role of music and allied arts has to be supplemented through additional analyses based on sources mentioned by the 21 participating scholars and their fragmented application of available knowledge. In result, this paper might help improve the way facts about groups of people, the way of grouping people, and the way of presenting these groupings are displayed to the world beyond South Asia. This fieldwork and literature guided investigation should also lead to suggestions for ethical principles in teaching and presenting of culturally different music practices within Sri Lanka, thus adding an example for other case studies.

Blood Pressure values of Sri Lankan Tamils in Jaffna District, Sri Lanka

2015 ◽  
Vol 2 (3) ◽  
pp. 66-71
Author(s):  
Balasubramaniam M ◽  
◽  
Sivapalan K ◽  
Tharsha J ◽  
Sivatharushan V ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Sri Lanka ◽  
Sri Lankan ◽  
Sri Lankan Tamils

Total Synthesis and Antibacterial Screening of (±)-6,8-Dihydroxy-3- undecyl-3,4-dihydroisochromen-1-one: A Structural Analogue of Metabolites from Ononis natrix

2019 ◽  
Vol 16 (3) ◽  
pp. 245-248
Author(s):  
Hummera Rafique ◽  
Aamer Saeed ◽  
Ehsan Ullah Mughal ◽  
Muhammad Naveed Zafar ◽  
Amara Mumtaz ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Structural Analog ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Antibacterial Screening ◽  
Maximum Inhibition ◽  
Bacillus Subtilus ◽  
Hydrolysis Of ◽  
Direct Condensation

Background: (±)-6,8-Dihydroxy-3-undecyl-3,4-dihydroisochromen-1-one is one of the structural analog of several substituted undecylisocoumarins isolated from Ononis natrix (Fabaceae), has been successfully synthesized by direct condensation of homopthalic acid (1) with undecanoyl chloride yields isochromen-1-one (2). Methods: Alkaline hydrolysis of (2) gave the corresponding keto-acid (3), which is then reduced to hydroxy acid (4) then its cyclodehydration was carried out with acetic anhydride to afford 3,4- dihydroisochromen-1-one (5). Followed by demethylation step, the synthesis of target 6,8- dihydroxy-7-methyl-3-undecyl-3,4-dihydroisocoumarin (6) was achieved. Results: In vitro antibacterial screening of all the synthesized compounds were carried out against ten bacterial strains by agar well diffusion method. Conclusion: Newly synthesized molecules exhibited moderate antibacterial activity and maximum inhibition was observed against Bacillus subtilus and Salmonella paratyphi.

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