Realized heritability, cross-resistance and high risk of resistance development to spirotetramat in dusky cotton bug, Oxycarenus hyalinipennis Costa (Hemiptera: Lygaeidae), an emerging threat to BT cotton in Pakistan

2021 ◽  
Author(s):  
Mamuna Ijaz ◽  
Sarfraz Ali Shad
Keyword(s):  
High Risk ◽  
Cross Resistance ◽  
Bt Cotton ◽  
Realized Heritability ◽  
Resistance Development ◽  
Oxycarenus Hyalinipennis

Phase II study of SM-88 in Ewing's and other sarcomas.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e23505-e23505
Author(s):  
Victoria S. Chua ◽  
Sant P. Chawla ◽  
Kitty Zheng ◽  
Ted Kim ◽  
Giuseppe Del Priore ◽  
...  
Keyword(s):  
High Risk ◽  
Prospective Trial ◽  
Median Number ◽  
Cross Resistance ◽  
Duration Of Treatment ◽  
Open Label ◽  
Durable Response ◽  
Phase 2 Trial ◽  
Acid Analogue ◽  
Prior Systemic Therapy

e23505 Background: Sarcomas are rare heterogeneous malignancies. Once recurrent, cure is uncommon. SM-88 (racemetyrosine) is an amino acid analogue with no known cross resistance to typical sarcoma regimens. Based on previous anecdotal experience in Ewing’s (EWS) we initiated a Phase 2 trial (HopES) in EWS and other sarcomas (Ss) after >1 prior systemic therapy. We now report preliminary data after having met prespecified continuation criteria. Methods: Open label prospective trial in 2 separate cohorts (EWS and Ss) of oral SM-88 used with MPS conditioning agents (SM-88 920 mg, methoxsalen 10 mg, phenytoin 50 mg, sirolimus 0.5 mg) all daily until progression. Results: As of Feb 5 2021, 10 pts with incurable sarcomas were enrolled; 4 had high risk but stable EWS. Average age 43.9 yrs (13–77); 70% white; 20% female. Median number of prior regimens 4 (1–9); 70% received prior RT; 50% prior surgery. Median time from initial diagnosis 39.5 months with 50% T2 (40% unknown), 30% M1 (30% unknown). Prespecified futility stopping was exceeded (i.e., >1 of first 5 subjects/cohort) upon achieving clinical benefit in each. Stable disease was achieved in 75.0% (6/8 with available data). Time on treatment (TTx) exceeded last known TTx in 80% (95% CI 44.4–97.5). Median SM-88 TTx was 4.9 vs 2.9 mo for prior TTx (logrank HR 0.53; p=0.12). One EWS subject had unresectable disease that became resectable, was completely resected, and remained disease-free for ≥ 6 months. Prior to SM-88, longest TTx was 12 mo (on IT*) and shortest TTx 1 mo (on IEV*) vs SM-88 TTx of 11.9 mo. An angiosarcoma subject had a 21% reduction in the sum of all target lesions and exceeded all prior TTx (including 8 mo on Ap/N* with 12+ mo duration of treatment of SM-88). There were no serious drug-related AEs. ECOG performance remained stable for all. Conclusions: SM-88 has exceeded pre-specified futility in both cohorts (EWS maintenance and Ss salvage). HopES continues to enroll toward the planned total of 12 subjects to more precisely define its benefit in this ultra-orphan, extremely recalcitrant disease. This trial now confirms the previously reported clinical utility of oral SM-88 in EWS and other high-risk sarcomas. Based on durable response (>6mo), SD and prolonged TTx, SM-88 warrants additional investigation in this setting. Clinical trial information: NCT03778996. [Table: see text]

scholarly journals Comparative Study of the Effect of Solvents on the Efficacy of Neonicotinoid Insecticides Against Malaria Vector Populations Across Africa

2022 ◽  
Author(s):  
Magellan Tchouakui ◽  
Tatiane Assatse ◽  
Leon M. J. Mugenzi ◽  
Benjamin D. Menze ◽  
Daniel Nguiffo-Nguete ◽  
...  
Keyword(s):  
Democratic Republic Of Congo ◽  
Natural Populations ◽  
Resistance Mechanisms ◽  
Lower Mortality ◽  
Malaria Vectors ◽  
Cross Resistance ◽  
Metabolic Resistance ◽  
Resistance Development ◽  
Development Of Resistance ◽  
Bottle Test

Abstract Background New insecticides with a novel mode of action such as neonicotinoids have recently been recommended for public health by WHO. Resistance monitoring of such novel insecticides requires a robust protocol to monitor the development of resistance in natural populations. In this study, we comparatively used three different solvents to assess the susceptibility of malaria vectors to neonicotinoids across Africa.MethodsMosquitoes were collected from May to July 2021 from three agricultural settings in Cameroon (Njombe-Penja, Nkolondom, and Mangoum), the Democratic Republic of Congo (Ndjili-Brasserie), Ghana (Obuasi), and Uganda (Mayuge). Using the CDC bottle test, we compared the effect of three different solvents (ethanol, acetone, MERO) on the efficacy of neonicotinoids against Anopheles gambiae s.l. In addition, TaqMan assays were used to genotype key pyrethroid-resistant markers in An. gambiae and to evaluate potential cross-resistance between pyrethroids and clothianidin.ResultsLower mortality were observed when using absolute ethanol or acetone alone as solvent (11.4- 51.9% mortality in Nkolondom, 31.7- 48.2% in Mangoum, 34.6- 56.1% in Mayµge, 39.4- 45.6% in Obuasi, 83.7- 89.3% in Congo and 71.05- 95.9% in Njombe pendja) compared to acetone + MERO for which 100% mortality were observed for all the populations. Synergist assays (PBO, DEM and DEF) revealed a significant increase of mortality suggesting that metabolic resistance mechanisms are contributing to the reduced susceptibility. A negative association was observed between the L1014F-kdr mutation and clothianidin resistance with a greater frequency of homozygote resistant mosquitoes among the dead than among survivors (OR=0.5; P=0.02). However, the I114T-GSTe2 was in contrast significantly associated with a greater ability to survive clothianidin with a higher frequency of homozygote resistant among survivors than other genotypes (OR=2.10; P=0.013). ConclusionsThis study revealed a contrasted susceptibility pattern depending on the solvents with ethanol/acetone resulting to lower mortality, thus possibly overestimating resistance, whereas the MERO consistently showed a greater efficacy of neonicotinoids but it could prevent to detect early resistance development. Therefore, we recommend monitoring the susceptibility using both acetone alone and acetone+MERO (8-10µg/ml for clothianidin) to capture the accurate resistance profile of the mosquito populations.

scholarly journals Succinate dehydrogenase inhibitor (SDHI) fungicide resistance prevention strategy

2011 ◽  
Vol 64 ◽  
pp. 119-124 ◽  
Author(s):  
A.H. McKay ◽  
G.C. Hagerty ◽  
G.B. Follas ◽  
M.S. Moore ◽  
M.S. Christie ◽  
...  
Keyword(s):  
New Zealand ◽  
High Risk ◽  
Succinate Dehydrogenase ◽  
Fungicide Resistance ◽  
Fungal Pathogens ◽  
Resistance Management ◽  
Resistance Development ◽  
Development Of Resistance ◽  
Action Committee ◽  
Succinate Dehydrogenase Inhibitor

Succinate dehydrogenase inhibitor (SDHI) fungicides are currently represented in New Zealand by eight active ingredients bixafen boscalid carboxin fluaxapyroxad fluopyram isopyrazam penthiopyrad and sedaxane They are either currently registered or undergoing development in New Zealand for use against a range of ascomycete and basiodiomycete pathogens in crops including cereals ryegrass seed apples pears grapes stonefruit cucurbits and kiwifruit These fungicides are considered to have medium to high risk of resistance development and resistance management is recommended by the Fungicide Resistance Action Committee (FRAC) in Europe Guidelines are presented for use of SDHI fungicides in New Zealand to help avoid or delay the development of resistance in the fungal pathogens that they target

scholarly journals Evidence for the Predisposition of Fungicide-Resistant Isolates of Venturia inaequalis to a Preferential Selection for Resistance to Other Fungicides

2001 ◽  
Vol 91 (8) ◽  
pp. 776-781 ◽  
Author(s):  
Wolfram Köller ◽  
W. F. Wilcox
Keyword(s):  
Fungicide Resistance ◽  
Venturia Inaequalis ◽  
Apple Scab ◽  
The United States ◽  
Cross Resistance ◽  
Resistance Development ◽  
Flexible Response ◽  
Sterol Demethylation Inhibitors ◽  
Selection For ◽  
Selection Of

In the United States, populations of the apple scab pathogen Venturia inaequalis have progressed through three consecutive rounds of fungicide resistance development, first to dodine, then to the benzimidazoles, and most recently to the sterol demethylation inhibitors (DMIs). Analysis of extensive monitoring data have to date provided no indication of detectable cross-resistance or partial cross-resistance of V. inaequalis populations to the three unrelated classes of fungicides prior to the selection of resistant subpopulations. However, in this study, resistance to both benomyl and DMIs developed to significantly higher frequencies within the previously established dodine-resistant population than in the population sensitive to dodine. Accelerated selection of phenotypes double resistant to dodine and the DMI fenarimol was apparent over the course of distinct seasons of apple scab management with either dodine or fenarimol. The data provide evidence for an accelerated speed of resistance development among phenotypes of V. inaequalis already resistant to an unrelated fungicide. This finding represents a departure from the previous model, which assumed entirely independent rounds of resistance developments. The data indicate that phenotypes of V. inaequalis might not only be selected for the trait of fungicide resistance but also for traits allowing a more flexible response to changes in the environment where they compete.

Characterization of genetic basis and realized heritability of bifenthrin-resistance selected in dusky cotton bug, Oxycarenus hyalinipennis (Costa) (Hemiptera: Lygaeidae) in Pakistan

2021 ◽  
Vol 141 ◽  
pp. 105441
Author(s):  
Ansa Banazeer ◽  
Hafiz Muhammad Usama Khan ◽  
Muhammad Babar Shahzad Afzal ◽  
Sarfraz Ali Shad
Keyword(s):  
Genetic Basis ◽  
Realized Heritability ◽  
Oxycarenus Hyalinipennis
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