Displaying publications 61 - 80 of 90 in total

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  1. Fulltext Targeting SWI/SNF ATPases in enhancer-addicted prostate cancer
    Xiao L, Parolia A, Qiao Y, Bawa P, Eyunni S, Mannan R, et al.
    Nature, 2022 Jan;601(7893):434-439.
    PMID: 34937944 DOI: 10.1038/s41586-021-04246-z
    The switch/sucrose non-fermentable (SWI/SNF) complex has a crucial role in chromatin remodelling1 and is altered in over 20% of cancers2,3. Here we developed a proteolysis-targeting chimera (PROTAC) degrader of the SWI/SNF ATPase subunits, SMARCA2 and SMARCA4, called AU-15330. Androgen receptor (AR)+ forkhead box A1 (FOXA1)+ prostate cancer cells are exquisitely sensitive to dual SMARCA2 and SMARCA4 degradation relative to normal and other cancer cell lines. SWI/SNF ATPase degradation rapidly compacts cis-regulatory elements bound by transcription factors that drive prostate cancer cell proliferation, namely AR, FOXA1, ERG and MYC, which dislodges them from chromatin, disables their core enhancer circuitry, and abolishes the downstream oncogenic gene programs. SWI/SNF ATPase degradation also disrupts super-enhancer and promoter looping interactions that wire supra-physiologic expression of the AR, FOXA1 and MYC oncogenes themselves. AU-15330 induces potent inhibition of tumour growth in xenograft models of prostate cancer and synergizes with the AR antagonist enzalutamide, even inducing disease remission in castration-resistant prostate cancer (CRPC) models without toxicity. Thus, impeding SWI/SNF-mediated enhancer accessibility represents a promising therapeutic approach for enhancer-addicted cancers.
    Matched MeSH terms: Nitriles
  2. Fulltext Bioactive Markers Based Pharmacokinetic Evaluation of Extracts of a Traditional Medicinal Plant, Piper sarmentosum
    Hussain K, Ismail Z, Sadikun A, Ibrahim P
    Evid Based Complement Alternat Med, 2011;2011:980760.
    PMID: 19770264 DOI: 10.1093/ecam/nep143
    In vitro assays are economical and easy to perform but to establish relevance of their results to real clinical outcome in animals or human, pharmacokinetics is prerequisite. Despite various in vitro pharmacological activities of extracts of Piper sarmentosum, there is no report of pharmacokinetics. Therefore, the present study aimed to evaluate ethanol extract of fruit of the plant in dose of 500 mg kg(-1) orally for pharmacokinetics. Sprague-Dawley rats were randomly divided into groups 1, 2, and 3 (each n = 6) to study absorption, distribution and excretion, respectively. High performance liquid chromatography (HPLC) with ultraviolet detection was applied to quantify pellitorine, sarmentine and sarmentosine in plasma, tissues, feces and urine to calculate pharmacokinetic parameters. Pellitorine exhibited maximum plasma concentration (C(max)) 34.77 ng mL(-1) ± 1.040, time to achieve C(max) (T(max)) 8 h, mean resident time (MRT) 26.00 ± 0.149 h and half life (t(1/2)) 18.64 ± 1.65 h. Sarmentine showed C(max) 191.50 ± 12.69 ng mL(-1), T(max) 6 h, MRT 11.12 ± 0.44 h and t(1/2) 10.30 ± 1.98 h. Sarmentosine exhibited zero oral bioavailability because it was neither detected in plasma nor in tissues, and in urine. Pellitorine was found to be distributed in intestinal wall, liver, lungs, kidney, and heart, whereas sarmentine was found only in intestinal wall and heart. The cumulative excretion of pellitorine, sarmentine and sarmentosine in feces in 72 h was 0.0773, 0.976, and 0.438 μg, respectively. This study shows that pellitorine and sarmentine have good oral bioavailability while sarmentosine is not absorbed from the gastrointestinal tract.
    Matched MeSH terms: Nitriles
  3. Nylon 6,6 modified screen printed carbon electrodes as electrochemical sensors for rapid chlorothalonil determination in water samples using differential pulse cathodic stripping voltammetry
    Thanalechumi P, Mohd Yusoff AR, Yusop Z
    J Environ Sci Health B, 2019;54(4):294-302.
    PMID: 30729855 DOI: 10.1080/03601234.2018.1561057
    A newly developed electrochemical sensor for chlorothalonil based on nylon 6,6 film deposited onto screen printed electrode (SPE) with electrochemical modulation of pH at the electrode/solution interface was studied for the first time. Differential pulse cathodic stripping voltammetry (DPCSV) was used to carry out the electrochemical and analytical studies. Experimental parameters such as accumulation potential, initial potential, accumulation time and pH of Britton-Robinson buffer have been optimized. Chlorothalonil gave optimum analytical signal in a medium of 0.04 M Britton-Robinson buffer at pH 6.0. A well-defined reduction peak was observed, at Ep= -0.851 and -0.938 V vs. Ag/AgCl (3.0 M KCl) for both bare SPE and modified SPE, respectively. The peak currents of modified SPE were significantly increased as compared to bare SPE. At the modified SPE, a linear relationship between the peak current and chlorothalonil concentration was obtained in the range from 0.1 to 2.8 × 10-6 M with a detection limit of 1.53 × 10-8 M (S/N= 3). The practical applicability of the newly developed method has been demonstrated on analyses of real water samples. The newly developed sensor shows good reproducibility with RSD of 3.92%. The nylon 6,6 modified SPE showed itself as promising sensor with good selectivity for chlorothalonil determination.
    Matched MeSH terms: Nitriles/analysis*
  4. Fulltext Low efficacy of delthamethrin-treated net against Singapore Aedes aegypti is associated with kdr-type resistance
    Pang SC, Chiang LP, Tan CH, Vythilingam I, Lam-Phua SG, Ng LC
    Trop Biomed, 2015 Mar;32(1):140-50.
    PMID: 25801264 MyJurnal
    There has been a worldwide surge in the number and severity of dengue in the past decades. In Singapore, relentless vector control efforts have been put in to control the disease since the 1960's. Space spraying, fogging, chemical treatment and source reduction are some commonly used methodologies for controlling its vectors, particularly Aedes aegypti. Here, as we explored the use of a commercially available delthamethrin-treated net as an alternative strategy and the efficacy of the treated net was found to be limited. Through bioassays and molecular studies, the failure of the treated net to render high mortality rate was found to be associated with the knockdown resistance (kdr) mutation. This is the first report of kdr- mutations in Singapore's Ae. aegypti. At least one point mutation, either homozygous or heterozygous, at amino acid residue V1016G of DIIS6 or F1269C of DIIIS6 was detected in 93% of field strains of Ae. aegypti. Various permutations of wild type and mutant amino acids of the four alleles were found to result in varying degree of survival rate among local field Ae. aegypti when exposed to the deltamethrin treated net. Together with the association of higher survival rate with the presence of both V1016G and F1269C, the data suggest the role of these mutations in the resistance to the deltamethrin. The high prevalence of these mutations were confirmed in a country wide survey where 70% and 72% of the 201 Ae. aegypti analysed possessed the mutations at residues 1016 and 1269 respectively. The highest mutated frequency combination was found to be heterozygous alleles (VG/FC) at both residues 1016 and 1269 (37.8%), followed by homozygous mutation at allele 1269 (24.4%) and homozygous mutation at allele 1016 (22.9%). The kdr- type of resistance among the vector is likely to undermine the effectiveness of pyrethroids treated materials against these mosquitoes.
    Matched MeSH terms: Nitriles/pharmacology*
  5. Fulltext Current insecticide susceptibility status of Malaysian Anopheles maculatus Theobald to malathion, permethrin, DDT and deltamethrin
    Rohani A, Aziz I, Zurainee MN, Rohana SH, Zamree I, Lee HL
    Trop Biomed, 2014 Mar;31(1):159-65.
    PMID: 24862056 MyJurnal
    Chemical insecticides are still considered as important control agents for malaria vector control. However, prolonged use of these chemicals may select mosquito vectors for resistance. In this study, susceptibility status of adult Anopheles maculatus collected from 9 localities in peninsular Malaysia, viz., Jeli, Temerloh, Pos Banun, Senderut, Jeram Kedah, Segamat, Kota Tinggi, Kluang and Pos Lenjang were determined using the standard WHO bioassay method in which the adult mosquitoes were exposed to standard insecticide impregnated papers malathion, permethrin, DDT and deltamethrin--at pre-determined diagnostic dosage. Deltamethrin was most effective insecticide among the four insecticides tested, with the LT50 of 29.53 min, compared to malathion (31.67 min), DDT (47.76 min) and permethrin (48.01 min). The effect of all insecticides on the laboratory strain was greater (with all insecticides demonstrated LT50 < 1 hour) than the field strains (deltamethrin 32.7, malathion 53.0, permethrin 62.0, DDT 67.4 min). An. maculatus exhibited low degree of resistance to all test insecticides, indicating that these chemical insecticides are still effective in the control of malaria vector.
    Matched MeSH terms: Nitriles/pharmacology
  6. Fulltext Temporal and spatial trends in insecticide resistance in Anopheles arabiensis in Sudan: outcomes from an evaluation of implications of insecticide resistance for malaria vector control
    Ismail BA, Kafy HT, Sulieman JE, Subramaniam K, Thomas B, Mnzava A, et al.
    Parasit Vectors, 2018 03 02;11(1):122.
    PMID: 29499751 DOI: 10.1186/s13071-018-2732-9
    BACKGROUND: Long-lasting insecticidal nets (LLINs) (with pyrethroids) and indoor residual spraying (IRS) are the cornerstones of the Sudanese malaria control program. Insecticide resistance to the principal insecticides in LLINs and IRS is a major concern. This study was designed to monitor insecticide resistance in Anopheles arabiensis from 140 clusters in four malaria-endemic areas of Sudan from 2011 to 2014. All clusters received LLINs, while half (n = 70), distributed across the four regions, had additional IRS campaigns.

    METHODS: Anopheles gambiae (s.l.) mosquitoes were identified to species level using PCR techniques. Standard WHO insecticide susceptibility bioassays were carried out to detect resistance to deltamethrin (0.05%), DDT (4%) and bendiocarb (0.1%). TaqMan assays were performed on random samples of deltamethrin-resistant phenotyped and pyrethrum spray collected individuals to determine Vgsc-1014 knockdown resistance mutations.

    RESULTS: Anopheles arabiensis accounted for 99.9% of any anopheline species collected across all sites. Bioassay screening indicated that mosquitoes remained susceptible to bendiocarb but were resistance to deltamethrin and DDT in all areas. There were significant increases in deltamethrin resistance over the four years, with overall mean percent mortality to deltamethrin declining from 81.0% (95% CI: 77.6-84.3%) in 2011 to 47.7% (95% CI: 43.5-51.8%) in 2014. The rate of increase in phenotypic deltamethrin-resistance was significantly slower in the LLIN + IRS arm than in the LLIN-only arm (Odds ratio 1.34; 95% CI: 1.02-1.77). The frequency of Vgsc-1014F mutation varied spatiotemporally with highest frequencies in Galabat (range 0.375-0.616) and New Halfa (range 0.241-0.447). Deltamethrin phenotypic-resistance correlated with Vgsc-1014F frequency.

    CONCLUSION: Combining LLIN and IRS, with different classes of insecticide, may delay pyrethroid resistance development, but the speed at which resistance develops may be area-specific. Continued monitoring is vital to ensure optimal management and control.

    Matched MeSH terms: Nitriles/pharmacology
  7. Fulltext Cytotoxicity anticancer activities of anastrozole against breast, liver hepatocellular, and prostate cancer cells
    Hassan F, El-Hiti GA, Abd-Allateef M, Yousif E
    Saudi Med J, 2017 Apr;38(4):359-365.
    PMID: 28397941 DOI: 10.15537/smj.2017.4.17061
    OBJECTIVES: To investigate the cytotoxic effect of anastrozole on breast (MCF7), liver hepatocellular (HepG2), and prostate (PC3) cancer cells. Methods: This is a prospective study. Anastrozole's mechanism of apoptosis in living cells was also determined by high content screening (HCS) assay. Methylthiazol tetrazolium (MTT) assay was carried out at the Centre of Biotechnology Research's, Al-Nahrain University, Baghdad, Iraq between July 2015 and October 2015. The HCS assay was performed at the Centre for Natural Product Research  and Drug Discovery, Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia between November 2015 and February 2016. Results: The most significant cytotoxic effect of anastrozole towards 3 cancer cell lines was obtained when its concentration was 400 µg/mL. The MCF7 cells were more sensitive to anastrozole compared with the HepG2 and PC-3 cells. There was a significant increase in membrane permeability, cytochrome c and nuclear intensity when anastrozole (200 µg/mL) was used compared with doxorubicin (20 µg/mL) as a standard. Also, there was a significant decrease in cell viability and mitochondrial membrane permeability when anastrozole (200 µg/mL) was used compared with positive control. Conclusion: Anastrozole showed cytotoxic effects against the MCF7, HepG2, and PC3 cell lines as determined in-vitro by the MTT assay. The HCS technique also showed toxic effect towards MCF7. It is evident that anastrozole inhibits the aromatase enzyme preventing the aromatization mechanism; however, it has a toxic effect.
    Matched MeSH terms: Nitriles/pharmacology*
  8. Fulltext Inhibition of Janus Kinase 1 synergizes docetaxel sensitivity in prostate cancer cells
    Nalairndran G, Chung I, Abdul Razack AH, Chung FF, Hii LW, Lim WM, et al.
    J Cell Mol Med, 2021 Sep;25(17):8187-8200.
    PMID: 34322995 DOI: 10.1111/jcmm.16684
    Prostate cancer (PCa) is the second most common malignancy and is the fifth leading cause of cancer mortality among men globally. Docetaxel-based therapy remains the first-line treatment for metastatic castration-resistant prostate cancer. However, dose-limiting toxicity including neutropenia, myelosuppression and neurotoxicity is the major reason for docetaxel dose reductions and fewer cycles administered, despite a recent study showing a clear survival benefit with increased total number of docetaxel cycles in PCa patients. Although previous studies have attempted to improve the efficacy and reduce docetaxel toxicity through drug combination, no drug has yet demonstrated improved overall survival in clinical trial, highlighting the challenges of improving the activity of docetaxel monotherapy in PCa. Herein, we identified 15 lethality hits for which inhibition could enhance docetaxel sensitivity in PCa cells via a high-throughput kinome-wide loss-of-function screen. Further drug-gene interactions analyses identified Janus kinase 1 (JAK1) as a viable druggable target with existing experimental inhibitors and FDA-approved drugs. We demonstrated that depletion of endogenous JAK1 enhanced docetaxel-induced apoptosis in PCa cells. Furthermore, inhibition of JAK1/2 by baricitinib and ruxolitinib synergizes docetaxel sensitivity in both androgen receptor (AR)-negative DU145 and PC3 cells, but not in the AR-positive LNCaP cells. In contrast, no synergistic effects were observed in cells treated with JAK2-specific inhibitor, fedratinib, suggesting that the synergistic effects are mainly mediated through JAK1 inhibition. In conclusion, the combination therapy with JAK1 inhibitors and docetaxel could be a useful therapeutic strategy in the treatment of prostate cancers.
    Matched MeSH terms: Nitriles/pharmacology*
  9. Fulltext Indoor and outdoor residual spraying of a novel formulation of deltamethrin K-Othrine® (Polyzone) for the control of simian malaria in Sabah, Malaysia
    Rohani A, Fakhriy HA, Suzilah I, Zurainee MN, Najdah WMAW, Ariffin MM, et al.
    PLoS One, 2020;15(5):e0230860.
    PMID: 32413033 DOI: 10.1371/journal.pone.0230860
    Since 2000, human malaria cases in Malaysia were rapidly reduced with the use of insecticides in Indoor Residual Spray (IRS) and Long-Lasting Insecticide Net (LLIN). Unfortunately, monkey malaria in humans has shown an increase especially in Sabah and Sarawak. The insecticide currently used in IRS is deltamethrin K-Othrine® WG 250 wettable granule, targeting mosquitoes that rest and feed indoor. In Sabah, the primary vector for knowlesi malaria is An. balabacensis a species known to bite outdoor. This study evaluates an alternative method, the Outdoor Residual Spray (ORS) using a novel formulation of deltamethrin K-Othrine® (PolyZone) to examine it suitability to control knowlesi malaria vector in Sabah, compared to the current method. The study was performed at seven villages in Sabah having similar type of houses (wood, bamboo and concrete). Houses were sprayed with deltamethrin K-Othrine® (PolyZone) at two different dosages, 25 mg/m2 and 30 mg/m2 and deltamethrin K-Othrine® WG 250 wettable granule at 25 mg/m2, sprayed indoor and outdoor. Residual activity on different walls was assessed using standard cone bioassay techniques. For larval surveillances, potential breeding sites were surveyed. Larvae were collected and identified, pre and post spraying. Adult survey was done using Human Landing Catch (HLC) performed outdoor and indoor. Detection of malaria parasite in adults was conducted via microscopy and molecular methods. Deltamethrin K-Othrine® (PolyZone) showed higher efficacy when sprayed outdoor. The efficacy was found varied when sprayed on different types of wall surfaces. Deltamethrin K-Othrine® (PolyZone) at 25 mg/m2 was the most effective with regards to ability to high mortality and effective knock down (KD). The vector population was reduced significantly post-spraying and reduction in breeding sites as well. The number of simian malaria infected vector, human and simian malaria transmission were also greatly reduced.
    Matched MeSH terms: Nitriles/chemistry
  10. The selective cytotoxicity of the alkenyl glucosinolate hydrolysis products and their presence in Brassica vegetables
    Kadir NH, David R, Rossiter JT, Gooderham NJ
    Toxicology, 2015 Aug 6;334:59-71.
    PMID: 26066520 DOI: 10.1016/j.tox.2015.06.002
    Cruciferous vegetable consumption correlates with reduced risk of cancer. This chemopreventative activity may involve glucosinolates and their hydrolysis products. Glucosinolate-derived isothiocyanates have been studied for their toxicity and chemopreventative properties, but other hydrolysis products (epithionitriles and nitriles) have not been thoroughly examined. We report that these hydrolysis products differ in their cytotoxicity to human cells, with toxicity most strongly associated with isothiocyanates rather than epithionitriles and nitriles. We explored mechanisms of this differential cytotoxicity by examining the role of oxidative metabolism, oxidative stress, mitochondrial permeability, reduced glutathione levels, cell cycle arrest and apoptosis. 2-Propenylisothiocyanate and 3-butenylisothiocyanate both inhibited cytochome P450 1A (CYP1A) enzyme activity in CYP expressing MCL-5 cells at high cytotoxic doses. Incubation of MCL-5 cells with non-cytotoxic doses of 2-propenylisothiocyanate for 24h resulted in a dose-dependent inhibition of ethoxyresorufin O-deethylase, yet failed to affect CYP1A1 mRNA expression indicating interference with enzyme activity rather than inhibition of transcription. Increased reactive oxygen species (ROS) production was observed only for 2-propenylisothiocyanate treatment. 2-Propenylisothiocyanate treatment lowered reduced glutathione levels whereas no changes were noted with 3,4-epithiobutylnitrile. Cell cycle analysis showed that 2-propenylisothiocyanate induced a G2/M block whereas other hydrolysis products showed only marginal effects. We found that 2-propenylisothiocyanate and 3-butenylisothiocyanate induced cell death predominantly via necrosis whereas, 3,4-epithiobutylnitrile promoted both necrosis and apoptosis. Thus the activity of glucosinolate hydrolysis products includes cytotoxicity that is compound-class specific and may contribute to their putative chemoprotection properties.
    Matched MeSH terms: Nitriles/metabolism; Nitriles/pharmacology*
  11. Fulltext Transient prenatal ruxolitinib treatment suppresses astrogenesis during development and improves learning and memory in adult mice
    Lee HC, Hamzah H, Leong MP, Md Yusof H, Habib O, Zainal Abidin S, et al.
    Sci Rep, 2021 Feb 15;11(1):3847.
    PMID: 33589712 DOI: 10.1038/s41598-021-83222-z
    Ruxolitinib is the first janus kinase 1 (JAK1) and JAK2 inhibitor that was approved by the United States Food and Drug Administration (FDA) agency for the treatment of myeloproliferative neoplasms. The drug targets the JAK/STAT signalling pathway, which is critical in regulating the gliogenesis process during nervous system development. In the study, we assessed the effect of non-maternal toxic dosages of ruxolitinib (0-30 mg/kg/day between E7.5-E20.5) on the brain of the developing mouse embryos. While the pregnant mice did not show any apparent adverse effects, the Gfap protein marker for glial cells and S100β mRNA marker for astrocytes were reduced in the postnatal day (P) 1.5 pups' brains. Gfap expression and Gfap+ cells were also suppressed in the differentiating neurospheres culture treated with ruxolitinib. Compared to the control group, adult mice treated with ruxolitinib prenatally showed no changes in motor coordination, locomotor function, and recognition memory. However, increased explorative behaviour within an open field and improved spatial learning and long-term memory retention were observed in the treated group. We demonstrated transplacental effects of ruxolitinib on astrogenesis, suggesting the potential use of ruxolitinib to revert pathological conditions caused by gliogenic-shift in early brain development such as Down and Noonan syndromes.
    Matched MeSH terms: Nitriles/administration & dosage*; Nitriles/adverse effects
  12. On-line preconcentration and chiral separation of propiconazole by cyclodextrin-modified micellar electrokinetic chromatography
    Wan Ibrahim WA, Hermawan D, Sanagi MM
    J Chromatogr A, 2007 Nov 2;1170(1-2):107-13.
    PMID: 17915239
    A method for the chiral separation of propiconazole using cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) with hydroxypropyl-gamma-cyclodextrin (HP-gamma-CD) as chiral selector is reported. The use of a mixture of 30 mM HP-gamma-CD, 50mM SDS, methanol-acetonitrile 10%:5% (v/v) in 25 mM phosphate buffer solution was able to separate two enantiomeric pairs of propiconazole. Stacking- and sweeping-CD-MEKC under neutral pH (pH 7) and under acidic condition (pH 3.0) were used as two on-line preconcentration methods to increase detection sensitivity of propiconazole. Good repeatabilities in the migration time, peak area and peak height were obtained in terms of relative standard deviation (RSD). A sensitivity enhancement factor of 100-fold was achieved using sweeping-CD-MEKC at acidic pH. This is the first report on the separation of two pairs of propiconazole enantiomers and all the enantiomers of fenbuconazole and tebuconazole using sweeping-CD-MEKC. The limit of detection (S/N=3) for the three triazole fungicides ranged from 0.09 to 0.1 microg/mL, which is well below the maximum residue limits (MRL) set by Codex Alimentarius Commission (CAC). Combination of solid-phase extraction (SPE) pretreatment and sweeping-CD-MEKC procedure was applied to the determination of selected triazole fungicides in grapes samples spiked at concentration 10-40 times lower than the MRL established by the CAC. The average recoveries of the selected fungicides in spiked grapes samples were good, ranging from 73% to 109% with RSD of 9-12% (n=3).
    Matched MeSH terms: Nitriles/analysis
  13. An investigation of the effect of prolonged glove wearing on the hand skin health of dental healthcare workers
    Boyle DK, Forsyth A, Bagg J, Stroubou K, Griffiths CE, Burke FJ
    J Dent, 2002 Jul-Aug;30(5-6):233-41.
    PMID: 12450714
    Glove wearing during patient treatment has been central to dental surgery infection control for over 15 years. However, little is known about the cutaneous effects of glove wearing on the hands of dental healthcare workers (DHCWs). The objective of this project was to assess the hand skin health of DHCWs before and after wearing gloves of two types and to compare this with a control group of non-DHCWs.
    Matched MeSH terms: Nitriles/chemistry
  14. Surface contact toxicity and synergism of several insecticides against different stages of the tropical bed bug, Cimex hemipterus (Hemiptera: Cimicidae)
    How YF, Lee CY
    Pest Manag Sci, 2011 Jun;67(6):734-40.
    PMID: 21370390 DOI: 10.1002/ps.2123
    Five formulated insecticides (lambda-cyhalothrin at 10 mg m⁻², bifenthrin at 50 mg m⁻², fipronil at 10 mg m⁻², fenitrothion at 50 mg m⁻², imidacloprid at 5 mg m⁻²) and one active ingredient (DDT at 500 mg m⁻²) were evaluated using a surface contact method against early and late instars and adults of two strains of the tropical bed bug, Cimex hemipterus (F.). Synergism of lambda-cyhalothrin and fipronil using piperonyl butoxide (PBO) was also assessed.
    Matched MeSH terms: Nitriles/pharmacology
  15. Cross-resistance between a Bacillus thuringiensis Cry toxin and non-Bt insecticides in the diamondback moth
    Sayyed AH, Moores G, Crickmore N, Wright DJ
    Pest Manag Sci, 2008 Aug;64(8):813-9.
    PMID: 18383197 DOI: 10.1002/ps.1570
    Bacillus thuringiensis Berliner (Bt) crystal (Cry) toxins are expressed in various transgenic crops and are also used as sprays in integrated pest management and organic agricultural systems. The diamondback moth (Plutella xylostella L.) is a major worldwide pest of crucifer crops and one that has readily acquired field resistance to a broad range of insecticides.
    Matched MeSH terms: Nitriles/pharmacology
  16. Standardization of a bottle assay--an indigenous method for laboratory and field monitoring of insecticide resistance and comparison with WHO adult susceptibility test
    Elamathi N, Barik TK, Verma V, Velamuri PS, Bhatt RM, Sharma SK, et al.
    Parasitol Res, 2014 Oct;113(10):3859-66.
    PMID: 25098343 DOI: 10.1007/s00436-014-4054-y
    The WHO adult susceptibility test is in use for insecticide resistance monitoring. Presently, materials are being imported from the Universiti Sains Malaysia, Malaysia and sometimes it is cost prohibitive. As an alternative, we present here a method of bottle bioassay using indigenous material. Different aspects related to the assay were studied and validated in the field. Bottle assay was standardized in the laboratory by using locally sourced material and laboratory-maintained insecticide-susceptible Anopheles stephensi and Aedes aegypti strains against technical grade deltamethrin and cyfluthrin insecticides dissolved in ethanol in a range of different concentrations. The frequency of use of the deltamethrin-coated bottles and shelf-life were determined. Discriminating dose for deltamethrin and cyfluthrin was 10 μg against An. stephensi and 2 μg against Ae. aegypti females. Insecticide-coated bottles stored at 25 to 35 °C can be used for three exposures within 7 days of coating. The study carried out in the laboratory was validated on wild caught An. culicifacies in the states of Odisha and Chhattisgarh against deltamethrin-coated bottles in comparison to WHO adult susceptibility test. Results of the study indicated that deltamethrin-coated bottles were effective up to three exposures within 7 days of coating for field population and 100% mortality was recorded within 35 min as observed in laboratory studies for field collected susceptible population. Also in the WHO adult susceptibility test, 100% knock-down within 35 min and 100% mortality after 24 h holding period were observed in susceptible population, while in it was 50% knock-down in 1 h and 64% mortality after 24 h holding period for resistant population (50% mortality in bottle assay in 60 min). The bottle assay can be used as an alternative to the WHO adult susceptibility test both in the laboratory and field for monitoring insecticide resistance in mosquito vectors using locally sourced material.
    Matched MeSH terms: Nitriles
  17. Fulltext Laboratory evaluation of lambda-cyhalothrin a microencapsulated formulation on mosquito nets for control of vector mosquitos
    Vythilingam I, Zainal AR, Hamidah T
    Southeast Asian J. Trop. Med. Public Health, 1999 Mar;30(1):177-83.
    PMID: 10695808
    Two formulations of lambda-cyhalothrin (EC-Emulsion concentrate and MC-Microencapsulated) were impregnated into bednets made of polyethylene and polyester. The nets were treated at a dosage of 15 mg/m2. For bioassay of insecticidal efficacy, female Anopheles maculatus and Aedes aegypti were exposed to the nets for two minutes and mortality was scored 24 hours later. The nets were also tested after repeated washings with water and with soap and water. Microencapsulated (2.5CS) formulation was more effective than emulsion concentrate (2.5EC) formulation on both net materials--polyethylene and polyester. Repeated washing with water and soap reduces the efficacy of all bednet treatment combinations. Microencapsulated formulation on polyethylene gave best results; it could sustain up to five washes with water and two with soap and water.
    Matched MeSH terms: Nitriles
  18. Adulticidal effect of cyfluthrin against mosquitos of public health importance in Malaysia
    Vythilingam I, Chiang GL, Amatachaya C
    Southeast Asian J. Trop. Med. Public Health, 1992 Mar;23(1):111-5.
    PMID: 1355928
    The efficacy of two formulations, wettable powder and emulsifiable concentrate, of cyfluthrin sprayed on plywood [10 mg (ai)/m2] was assessed against six species of mosquitos. The bioassay followed the WHO standard method, with some modification for the bioassay of insecticidal deposits on wall surfaces. The results indicated that these two formulations of cyfluthrin were effective against Anopheles dirus and Mansonia uniformis, moderately toxic to Aedes aegypti and Ae. albopictus in decreasing mortality through out the study period. It was least effective against Culex quinquefasciatus and An. maculatus, respectively. There was no statistically significant difference between these two formulations.
    Matched MeSH terms: Nitriles
  19. Fulltext Lambdacyhalothrin impregnated bednets control malaria in Sabah, Malaysia
    Hii J, Alexander N, Chuan CK, Rahman HA, Safri A, Chan M
    Southeast Asian J. Trop. Med. Public Health, 1995 Jun;26(2):371-4.
    PMID: 8629079
    Matched MeSH terms: Nitriles
  20. Fulltext Residual activity of cyhalothrin 20% EC on cattle as determined by mosquito bioassays
    Vythilingam I, Ridhawati, Sani RA, Singh KI
    Southeast Asian J. Trop. Med. Public Health, 1993 Sep;24(3):544-8.
    PMID: 7909171
    The residual effectiveness of 0.005mg/ml of cyhalothrin applied to cattle was determined against three species of mosquitos: Anopheles maculatus Theobald. Anopheles dirus Peyton and Harrison Mansonia uniformis Theobald. Twenty-four hour post exposure mortality and the degree of successful blood engorgement were determined by exposing mosquitos for 10 minutes to cattle. Three replicated assays were conducted and mortality determined at 1, 2, 7, 14 and 21 days after each treatment. An initial mortality of 92-94% for An. dirus and Ma. uniformis and 79% for An. maculatus was obtained. Percentage mortality declined to 10%, 18% and 31% for An. maculatus, An. dirus and Ma. uniformis respectively on day 7 post application. On day 21 post application, percentage mortality was 2-3% for the three species of mosquitos.
    Matched MeSH terms: Nitriles
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