Biochemical basis of resistance in laboratory selected fenazaquin resistant strain of Two-spotted spider mite, Tetranychus urticae Koch

The Two-spotted spider mite, Tetranychus urticae Koch is a serious pest in many cropping systems worldwide including fruits, vegetables and ornamental plants in both closed and open area. T. urticae has developed resistance against different groups of acaricides and no biochemical studies have been conducted to assess the basis/mechanisms of acaricide resistance in T. urticae populations of North India. Therefore, mechanism of acaricide resistance in T. urticae through enzyme assays was investigated. Field population of T. urticae showing resistance to fenazaquin (24.65 fold) was selected with fenazaquin successively for 15 generations to develop fenazaquin resistant strain leading to 6.83 fold increase in the resistance level. There was significant increase in specific activity of the MFO enzymes in resistant strain (534.65 nmol of p-nitrophenol formed min-1 mg-1 of protein) as compared to susceptible strain (166.35 nmol of p-nitrophenol formed min-1 mg-1 of protein). There was 3.21 fold higher MFO activity in resistant strain. Similarly, there was significant increase in GST activity by 1.40 fold and esterase activity by 1.13 and 1.27 fold with α-naphthyl acetate and β-naphthyl acetate as substrate in resistant population. The biochemical experiments conducted in the present study suggested that enhanced metabolic detoxification might be the major mechanism responsible for imparting resistance to fenazaquin in T. Urticae.

Recent advances in pre-eclampsia management: an anesthesiologist's perspective

Pre-eclampsia is an important cause of mortality and morbidity in parturients with varied presentations and controversial pathophysiology. The central pathology is a profound vasoconstriction in the vasculature leading to volume contraction and placental hypoperfusion. The management mainly involves a multi-disciplinary approach with the anesthesiologist playing a significant role for a positive outcome. Anesthesia for such parturients remains a challenge and starts with provision of labor analgesia which should be offered to all preeclamptic parturients. The neuraxial techniques of analgesia are most favourable for adequate pain relief and if contraindicated, intravenous PCA technique with the use of opioids should be used. Recent studies show favourable maternal and fetal outcomes with the use of patient controlled epidural analgesia technique with the combination of lower concentrations of local anesthetics with opioids. Regional anesthesia should be preferred in these parturients for cesarean section if not contraindicated. If general anesthesia is indicated, the techniques should be modified to prevent any stress response. A careful and prompt use of oxytocics should be done in all cases as the incidence of postpartum hemorrhage is high in these parturients