Cloning of Two Acetylcholinesterase Genes and Analysis of Point Mutations Putatively Associated with Triazophos Resistance in Chilo auricilius (Lepidoptera: Pyralidae).

Acetylcholinesterase (AChE) is the target of organophosphate (OP) and carbamate insecticides. Mutations in the AChE gene (ace) leading to decreased insecticide susceptibility is the main resistance mechanism in insects. In this study, two Chilo auricilius acetylcholinesterase genes, designated as Caace1 and Caace2, were cloned using RT-PCR and RACE. Caace1 cDNA is 2534 bp, with ORF of 2082 bp, and it encodes an acetylcholinesterase 1 (CaAChE1) protein comprising a calculated 693 amino acid (aa) residues. Caace2 cDNA contains 2280 bp, with a full-length ORF of 1917 bp, encoding acetylcholinesterase 2 (CaAChE2) comprising a calculated 638 aa residues. At the aa level, CaAChE1 displays the highest similarity (97%) with the Chilo suppressalis AChE1, and CaAChE2 shows the highest similarity with the C. suppressalis AChE2 (99%). From the restriction fragment length polymorphism (RFLP) PCR (RFLP-PCR) analysis, one mutation in Caace1, similar to the ace1 mutation associated with triazophos resistance in C. suppressalis, was detected. Detailed examination of field populations of C. auricilius indicated this resistance mutation in C. auricilius is still quite infrequent. Based on the assay of AChE activity and RFLP-PCR testing, an individual that contains resistance mutation has lower AChE activities, while the individual that does not contain the resistance mutation has higher AChE activities. This study provides a basis for future investigations into the mechanism of OP resistance in C. auricilius, as well as a guidance for C. auricilius control with reasonable choice of pesticides.

Safe limits of contrast vary with hydration volume for prevention of contrast-induced nephropathy after coronary angiography among patients with a relatively low risk of contrast-induced nephropathy.

BACKGROUND: Few studies have investigated the safe limits of contrast to prevent contrast-induced nephropathy (CIN) based on hydration data. We aimed to investigate the relative safe maximum contrast volume adjusted for hydration volume in a population with a relatively low risk of CIN. METHODS AND RESULTS: The ratios of contrast volume-to-creatinine clearance (V/CrCl) and hydration volume to body weight (HV/W) were determined in patients undergoing cardiac catheterization. Receiver-operator characteristic curve analysis based on the maximum Youden index was used to identify the optimal cutoff for V/CrCl in all patients and in HV/W subgroups. Eighty-six of 3273 (2.6%) patients with mean CrCl 71.89±27.02 mL/min developed CIN. Receiver-operator characteristic curve analysis indicated that a V/CrCl ratio of 2.44 was a fair discriminator for CIN in all patients (sensitivity, 73.3%; specificity, 70.4%). After adjustment for other confounders, V/CrCl >2.44 continued to be significantly associated with CIN (adjusted odds ratio, 4.12; P<0.001) and the risk of death (adjusted hazard ratio, 2.62; P<0.001). The mean HV/W was 12.18±7.40. We divided the patients into 2 groups (HV/W ≤12 and >12 mL/kg). The best cutoff value for V/CrCl was 1.87 (sensitivity, 67.9%; specificity, 64.4%; adjusted odds ratio, 3.24; P=0.011) in the insufficient hydration subgroup (HV/W, ≤12 mL/kg; CIN, 1.32%) and 2.93 (sensitivity, 69.0%; specificity, 65.0%; adjusted odds ratio, 3.04; P=0.004) in the sufficient hydration subgroup (HV/W, >12 mL/kg; CIN, 5.00%). CONCLUSIONS: The V/CrCl ratio adjusted for HV/W may be a more reliable predictor of CIN and even long-term outcomes after cardiac catheterization. We also found a higher best cutoff value for V/CrCl to predict CIN in patients with a relatively sufficient hydration status, which may be beneficial during decision-making about contrast dose limits in relatively low-risk patients with different hydration statuses.

Preprocedural N-terminal pro-brain natriuretic peptide (NT-proBNP) is similar to the Mehran contrast-induced nephropathy (CIN) score in predicting CIN following elective coronary angiography.

BACKGROUND: N-terminal pro-brain natriuretic peptide (NT-proBNP) has been associated with important risk factors for contrast-induced nephropathy (CIN). However, few studies have investigated the predictive value of NT-proBNP itself. This study investigated whether levels of preprocedural NT-proBNP could predict CIN after elective coronary angiography as effectively as the Mehran CIN score. METHODS AND RESULTS: We retrospectively observed 2248 patients who underwent elective coronary angiography. The predictive value of preprocedural NT-proBNP for CIN was assessed by receiver operating characteristic and multivariable logistic regression analysis. The 50 patients (2.2%) who developed CIN had higher Mehran risk scores (9.5 ± 5.1 versus 4.8 ± 3.8), and higher preprocedural levels of NT-proBNP (5320 ± 7423 versus 1078 ± 2548 pg/mL, P<0.001). Receiver operating characteristic analysis revealed that NT-proBNP was not significantly different from the Mehran CIN score in predicting CIN (C=0.7657 versus C=0.7729, P=0.8431). An NT-proBNP cutoff value of 682 pg/mL predicted CIN with 78% sensitivity and 70% specificity. Multivariable analysis suggested that, after adjustment for other risk factors, NT-proBNP >682 pg/mL was significantly associated with CIN (odds ratio: 4.007, 95% CI: 1.950 to 8.234; P<0.001) and risk of death (hazard ratio: 2.53; 95% CI: 1.49 to 4.30; P=0.0006). CONCLUSIONS: Preprocedural NT-proBNP >682 pg/mL was significantly associated with the risk of CIN and death. NT-proBNP, like the Mehran CIN score, may be another useful and rapid screening tool for CIN and death risk assessment, identifying subjects who need therapeutic measures to prevent CIN.

Contrast Volume-to-Creatinine Clearance Ratio Predicts the Risk of Contrast-Induced Nephropathy After Percutaneous Coronary Intervention in Patients With Reduced Ejection Fraction.

We determined a relatively safe contrast media volume-to-creatinine clearance (V/CrCl) cutoff value to avoid contrast-induced nephropathy (CIN) after percutaneous coronary intervention (PCI) in patients (n = 111) with reduced ejection fraction (<40%). Improved prediction of CIN in these patients would be useful. Multivariate regression models were used to evaluate whether V/CrCl is an independent risk factor for CIN. Nine (8.1%) patients developed CIN. The V/CrCl was significantly (P = .023) higher in patients with CIN than in those without. The incidence of CIN in patients with the highest tertile of V/CrCl was significantly higher than the middle and lowest tertiles (18.4% vs. 2.7% and 2.8%; P = .013). After adjusting for other potential risk factors, a V/CrCl ≥3.87 remained significantly associated with risk of CIN. A V/CrCl <3.87 might be valuable in predicting the risk of CIN in patients with reduced ejection fraction undergoing PCI.

[Association between high-sensitivity C-reactive protein and contrast-induced nephropathy after primary percutaneous coronary intervention].

OBJECTIVE: To explore the association between high-sensitivity C-reactive protein (hs-CRP) and contrast-induced nephropathy (CIN) in patients with ST-segment elevated myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI) . METHODS: A total of 220 STEMI patients undergoing primary PCI from Guangdong general hospital were recruited. Patients were divided into four groups according to the quartile of hs-CRP (Q1 group:hs-CRP < 6.26 mg/L,Q2 group:6.26-14.44 mg/L, Q3 group:14.45-33.08 mg/L, Q4 group:hs-CRP > 33.08 mg/L) . Baseline data, CIN incidence and other in-hospital outcomes were compared among groups. CIN was defined as an increase in serum creatinine of more than 5 mg/L from baseline within 48-72 hours after contrast media exposure. Receiver operator characteristics (ROC) curves and multivariate logistic regression were used to assessed the correlation between hs-CRP and CIN. RESULTS: CIN occurred in 21 (9.8%) patients. CIN incidence of hs-CRP quartitles were 1.8%(1/55), 1.8% (1/55), 14.5% (8/55) and 20.0% (11/55) (P-trend < 0.01), respectively. In-hospital death (P-trend > 0.05) , required renal replace therapy (P-trend > 0.05) were similar among groups. ROC analysis revealed that the optimal cutoff value of hs-CRP to predict the onset of CIN was 16.85 mg/L (sensitivity: 81.0%, specificity: 61.8%, AUC: 0.748). Univariate logistic analysis showed that hs-CRP was strongly related with CIN incidence (OR = 6.88,95%CI:2.23-21.21, P < 0.01). Multivariate logistic regression analysis showed that after adjusting other traditional risk factors including female gender, anemia, ACEI/ARB use, IABP support, LVEF < 40%, age > 75 years, baseline eGFR and diabetes, hs-CRP > 16.85 mg/L was still a significant independent predictor of CIN in patients with STEMI undergoing primary PCI. Additionally, age > 75 years (OR = 7.27,95%CI:1.85-28.63, P < 0.01), eGFR (OR = 6.38,95% CI:1.48-27.41, P < 0.05) were also independent risk factors of CIN. CONCLUSIONS: hs-CRP is positively correlated with CIN incidence. STEMI patients with higher hs-CRP level post PCI is at higher risk of developing CIN.

Use of the contrast volume or grams of iodine-to-creatinine clearance ratio to predict mortality after percutaneous coronary intervention.

BACKGROUND: Few studies have assessed the predictive value of the ratio of the contrast media volume or grams of iodine to the creatinine clearance (V/CrCl or g-I/CrCl, respectively) for the risk of contrast-induced nephropathy (CIN) and mortality after percutaneous coronary intervention (PCI). METHODS: The association between V/CrCl and mortality was prospectively evaluated in 1,135 consecutive patients undergoing PCI. Cox regression models were used to adjust for the V/CrCl ratio and other confounding factors for risk of death within 1 year. RESULTS: Fifty-five patients (4.84%) developed CIN. The 1-year mortality was higher in patients with a V/CrCl ratio >2.62 (g-I/CrCl >0.97) than in others (4.44% vs 0.40%; P < .001). After adjusting for other risk factors, the 1-year mortality risk remained associated with increased V/CrCl ratio. The risk of death was significant for V/CrCl >2.62 (adjusted risk ratio [RR] for death 2.605, 95% CI 1.040-6.529, P = .041), V/CrCl >3.0 (g-I/CrCl >1.11) (adjusted RR 4.338, 95% CI 1.689-11.142, P = .002), and V/CrCl >3.7 (g-I/CrCl >1.37) (adjusted RR 2.557, 95% CI 1.162-5.627, P = .002). CONCLUSION: The data further support the prognostic significance of calculating the V/CrCl ratio to predict the relative maximum contrast volume during PCI. Use of a contrast dose determined based on the estimated renal function with a planned V/CrCl ratio <3.7 (g-I/CrCl <1.37) and preferably <2.62 (g-I/CrCl <0.97) might be valuable in reducing the risks of CIN and even death after PCI.