Role of metabolic enzymes in conferring resistance to synthetic pyrethroids, organophosphates, and phenylpyrazole compounds in Rhipicephalus microplus

2017 ◽  
Vol 44 (1) ◽  
pp. 28-34 ◽  
Author(s):  
Gajanan M. Chigure ◽  
Anil Kumar Sharma ◽  
Sachin Kumar ◽  
Ashutosh Fular ◽  
Sharath V. Sagar ◽  
...  
2021 ◽  
Vol 53 (3) ◽  
Author(s):  
Achille S. Ouedraogo ◽  
Olivier M. Zannou ◽  
Abel S. Biguezoton ◽  
Kouassi Yao Patrick ◽  
Adrien M. G. Belem ◽  
...  

AbstractSince 2011, period of the livestock invasion by the cattle tick Rhipicephalus microplus in Burkina Faso (BF), tick-control problems were exacerbated. Based on farmer’s reports, most commonly used commercial acaricides were found to be ineffective in Western South part of the country. To investigate the occurrence and extent of such acaricidal ineffectiveness, we performed the standardized larval packet test (LPT) with commercial deltamethrin (vectocid) and cypermethrin (cypertop), on two cattle tick species, the native Amblyomma variegatum and the invasive R. microplus. The resistance ratios (RR) were computed with susceptible Hounde strain of Rhipicephalus geigyi as reference. The R. microplus population showed resistance to the two acaricides tested with the highest lethal concentration (LC) values, and different resistance ratios higher than 4 (deltamethrin: RR50 = 28.18 and RR90 = 32.41; cypermethrin: RR50 = 8.79 and RR90 = 23.15). In the contrary, A. variegatum population was found to be highly susceptible to acaricides tested with low lethal concentrations and resistance ratio values (deltamethrin: RR50 = 0.5 and RR90 = 0.48; cypermethrin: RR50 = 0.68 and RR90 = 0.79). These data demonstrate high synthetic pyrethroid resistance in R. microplus strain, leading to conclude that the acaricide ineffectiveness in tick populations control remains a concern in BF.


1994 ◽  
Vol 40 (4) ◽  
pp. 259-264 ◽  
Author(s):  
Joel M. Wierenga ◽  
Robert M. Hollingworth
Keyword(s):  

2014 ◽  
Author(s):  
Ivana Petrovska ◽  
Elisabeth Nüske ◽  
Matthias C Munder ◽  
Gayathrie Kulasegaran ◽  
Liliana Malinovska ◽  
...  

One of the key questions in biology is how the metabolism of a cell responds to changes in the environment. In budding yeast, starvation causes a drop in intracellular pH, but the functional role of this pH change is not well understood. Here, we show that the enzyme glutamine synthetase (Gln1) forms filaments at low pH and that filament formation leads to enzymatic inactivation. Filament formation by Gln1 is a highly cooperative process, strongly dependent on macromolecular crowding, and involves back-to-back stacking of cylindrical homo-decamers into filaments that associate laterally to form higher order fibrils. Other metabolic enzymes also assemble into filaments at low pH. Hence, we propose that filament formation is a general mechanism to inactivate and store key metabolic enzymes during a state of advanced cellular starvation. These findings have broad implications for understanding the interplay between nutritional stress, the metabolism and the physical organization of a cell.


Author(s):  
Hideki Furuya ◽  
Songhwa Choi ◽  
Lina M. Obeid ◽  
Toshihiko Kawamori ◽  
Ashley J. Snider

ISRN Oncology ◽  
2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Shuji Komori ◽  
Shinji Osada ◽  
Kazuhiro Yoshida

5-fluorouracil (5-FU) is widely used in chemotherapy for gastric and colorectal cancer, but gemcitabine (GEM), and not 5-FU, is approved as a standard drug for use in pancreatic cancer. Interindividual variation in the enzyme activity of the GEM metabolic pathway can affect the extent of GEM metabolism and the efficacy of GEM chemotherapy. Human equilibrative nucleoside transporter 1 (hENT1) is recognized as a major transporter of GEM into cells. In addition, a factor that activates hENT1 is the inhibition of thymidylate synthase (TS), one of the 5-FU metabolic enzymes; TS inhibition mediates depleting intracellular nucleotide pools, resulting in the activation of the salvage pathway mediated through hENT1. In this paper, the role of 5-FU in GEM-based chemotherapy for pancreatic cancer is discussed with special emphasis on enzymes involved in the 5-FU and GEM metabolic pathways and in the correlation between GEM responsiveness and the expression of 5-FU and GEM metabolic enzymes.


Author(s):  
Darkiane Fernandes Ferreira ◽  
Jarlei Fiamoncini ◽  
Iryna Hirata Prist ◽  
Suely Kubo Ariga ◽  
Heraldo Possolo de Souza ◽  
...  
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document