Alleles conferring a higher adaptive value in one environment may have a detrimental impact on fitness in another environment. Alleles conferring resistance to pesticides and drugs provide textbook examples of this trade-off as, in addition to conferring resistance to these molecules, they frequently decrease fitness in pesticide/drug-free environments. We show here that resistance to chlorpyrifos, an organophosphate (OP), in Chinese populations of the diamondback moth, Plutella xylostella, is conferred by two mutations of ace1 - the gene encoding the acetylcholinesterase enzyme targeted by OPs - affecting the amino acid sequence of the corresponding protein. These mutations were always linked, consistent with the segregation of a single resistance allele, ace1R, carrying both mutations, in the populations studied. We monitored the frequency of ace1R (by genotyping more than 20 000 adults) and the level of resistance (through bioassays on more than 50 000 individuals) over several generations. We found that the ace1R resistance allele was costly in the absence of insecticide and that this cost was likely recessive. This fitness costs involved a decrease in fecundity: females from resistant strains laid 20% fewer eggs, on average, than females from susceptible strains. Finally, we found that the fitness costs associated with the ace1R allele were greater at high temperatures. At least two life history traits were involved: longevity and fecundity. The relative longevity of resistant individuals was affected only at high temperatures and the relative fecundity of resistant females - which was already affected at temperatures optimal for development - decreased further at high temperatures. The implications of these findings for resistance management are discussed.
Abstract.To gain further insight into the molecular features of the ubiquitous Hsp70 family of conserved heat shock proteins, total nine full-length cDNA sequences of inducible hsp70s and one constitutive hsc70 (Px-hsc70(C)) were isolated and characterized in the diamondback moth (DBM), Plutella xylostella, collected from Fuzhou, China. The nine Px-hsp70s cDNAs encoded the protein of between 629-669 amino acids with molecular weight ranging from 69.00-72.58 kDa and were derived from four hsp70 genes in the genome of DBM. The Px-hsc70(C) cDNA contained 1,953 bp of open reading frame (ORF), which produced a putative protein comprising 650 amino acids with a calculated molecular weight of 71.18 kDa. Whether in adults or larvae of chlorpyrifos-resistant (R R ) and chlorpyrifos-susceptible (S S ) strains of DBM, the basal level (at 25°C) of Px-hsc70(C) mRNA expression was high, but no significant up-regulation expression was found under heat stress. However, heat stress facilitated up-regulation expressions of Px-hsp70s, and S S DBM displayed higher up-regulation expression of Px-hsp70s than R R DBM. We suggest that higher up-regulation expression of Px-hsp70s in S S DBM is probably involved in their higher thermal tolerance.
Objective To examine whether medical decisions regarding evaluation and management of musculoskeletal pain conditions varied systematically by characteristics of the patient or provider. Methods We conducted a balanced factorial experiment among primary care physicians in the U.S. Physicians (N=192) viewed two videos of different patients (actors) presenting with pain: (1) undiagnosed sciatica symptoms or (2) diagnosed knee osteoarthritis. Systematic variations in patient gender, socioeconomic status (SES), race, physician gender and experience (<20 vs. ≥20 years in practice) permitted estimation of unconfounded effects. Analysis of variance was used to evaluate associations between patient or provider attributes and clinical decisions. Quality of decisions was defined based on the current recommendations of the ACR, American Pain Society, and clinical expert consensus. Results Despite current recommendations, under one-third of physicians would provide exercise advice (30.2% for osteoarthritis, 32.8% for sciatica). Physicians with fewer years in practice were more likely to provide advice on lifestyle changes, particularly exercise (P<0.01), and to prescribe NSAIDs for pain relief, both of which were appropriate and consistent with current recommendations for care. Newer physicians ordered fewer tests, particularly basic laboratory investigations or urinalysis. Test ordering decreased as organizational emphasis on business or profits increased. Patient factors and physician gender had no consistent effects on pain evaluation or treatment. Conclusion Physician education on disease management recommendations regarding exercise and analgesics, and implementation of quality measures may be useful, particularly for physicians with more years in practice.
Lactate has long been credited as a by-product, which jeopardizes cell growth and productivity when accumulated over a certain concentration during the manufacturing process of therapeutic recombinant proteins by Chinese hamster ovary (CHO) cells. A number of efforts to decrease the lactate concentration have been developed; however, the accumulation of lactate is still a critical issue by the late stage of fed-batch culture. Therefore, a lactate-tolerant cell line was developed through over-expression of lactate dehydrogenase C (LDH-C). In fed-batch culture, sodium lactate or sodium pyruvate was supplemented into the culture medium to simulate the environment of lactate accumulation, and LDH-C over-expression increased the highest viable cell density by over 30 and 50 %, respectively, on day 5, meanwhile the viability was also improved significantly since day 5 compared with that of the control. The percentages of cells suffering early and late apoptosis decreased by 3.2 to 12.5 and 2.0 to 4.3 %, respectively, from day 6 onwards in the fed-batch culture when 40 mM sodium pyruvate was added compared to the control. The results were confirmed by mitochondrial membrane potential assay. In addition, the expression of cleaved caspases 3 and 7 decreased in cells over-expressing LDH-C, suggesting the mitochondrial pathway was involved in the LDH-C regulated anti-apoptosis. In conclusion, a novel cell line with higher lactate tolerance, lowered lactate production, and alleviated apoptosis response was developed by over-expression of LDH-C, which may potentially represent an efficient and labor-saving approach in generating recombinant proteins.
ObjectiveTo observe and evaluate the effect of a single intravenous injection of low-dose esketamine on post-operative pain and post-partum depression (PPD) in cesarean delivery patients.MethodsA total of 210 patients undergoing elective cesarean delivery under combined spinal-epidural anesthesia were divided into an esketamine group (Group S, n = 105) and a normal saline group (Group L, n = 105) by a random number table. At 5 min after childbirth, patients in the S group were given 0.25 mg/kg esketamine, whereas patients in the L group received an equal volume of saline. The primary outcomes included post-operative pain control according to the Numerical Rating Scale (NRS) and the incidence of PPD according to the Edinburgh Post-partum Depression Scale (EPDS). The secondary outcomes included analgesia-related adverse events and Ramsay sedation scores.ResultsThis clinical study was a prospective, randomized, double-blind trial. A total of 210 patients were enrolled in this study. The NRS pain (cough pain) score was lower in the S group than in the L group at 24 h after surgery (P = 0.016), and there was no significant difference in resting pain and mobilization pain at 4, 8, and 48 h after surgery or resting pain at 24 h after surgery between the two groups. There was no significant difference in the prevalence of PPD between the two groups on the day before delivery, or at the first week, the second week, or the fourth week after childbirth. At 5 min after dosing, the incidence of hallucinations (P < 0.001) and dizziness (P < 0.001) was higher in the S group than in the L group. At 15 min after dosing, the incidence of dizziness (P < 0.001) and nausea (P = 0.011) was higher in the S group than in the L group. The incidence of dizziness (P < 0.001) was higher in the S group than in the L group when leaving the operating room. The Ramsay scores in Group S were lower than in Group L at 5 min (p < 0.001), 15 min (p < 0.001) after dosing and at the time of leaving the operating room (p < 0.001).ConclusionIn this study, a single intravenous injection of 0.25 mg/kg esketamine did not reduce the incidence of depression at 1, 2, or 4 w post-partum but improved pain during exercise at 24 h post-operatively under the conditions of this clinical trial.Clinical trial registration[www.chictr.org.cn], identifier [ChiCTR2100054332].
BackgroudCationic liposomes (CLs) can be used as non-viral vectors in gene transfer and drug delivery. However, the underlying molecular mechanism of its cytotoxicity has not been well elucidated yet.MethodsWe herein report a systems biology approach based on whole-transcriptome sequencing coupled with computational method to identify the predominant genes and pathways involved in the cytotoxicity of CLs in HepG2 cell line.ResultsFirstly, we validated the concentration-dependent cytotoxicity of CLs with an IC50 of 120 μg/ml in HepG2 exposed for 24 h. Subsequently, we used whole-transcriptome sequencing to identify 220 (77 up- and 143 down-regulated) differentially expressed genes (DEGs). Gene ontology (GO) and pathway analysis showed that these DEGs were mainly related to cholesterol, steroid, lipid biosynthetic and metabolic processes. Additionally, “key regulatory” genes were identified using gene act, pathway act and co-expression network analysis, and expression levels of 11 interested altered genes were confirmed by quantitative real time PCR. Interestingly, no cell cycle arrest was observed through flow cytometry.ConclusionsThese data are expected to provide deep insights into the molecular mechanism of CLs cytotoxicity.
Cationic liposomes (CLs) are vital nonviral vectors with a wide range of applications. Although the toxicity of CLs is far lower than that of viral vectors, increasing evidence suggests that there are limited clinical applications of CLs because of their potential toxicity. In the present study, the toxicity of CLs toward L02 cells was investigated and comprehensively analyzed based on proteomics and metabolomics data. Using quantitative iTRAQ-LC-MS/MS proteomics coupled with UHPLC-Q-TOF-MS based metabolomics, we determined that exposure to CLs generated 90 significantly altered proteins and 65 altered metabolites in cells. Metabolomic analysis also showed significant alterations in metabolic pathways, including small molecules involved in energy and lipid metabolism. Proteomics revealed that exposure to CLs significantly influenced multiple proteins, including those involved in the folding of proteins and metabolism. Furthermore, the proteins participated in oxidative stress, which also influenced lipid metabolism. Overall, our findings indicate that high-throughput metabolomics and proteomics can provide insight into the toxicological mechanisms of CLs using high-resolution mass spectrometry. To our knowledge, this is the first study combining proteomics and metabolomics to investigate the potential effects of CLs on any cells. Specifically, we integrated quantitative iTRAQ-based proteomics with UHPLC-Q-TOF-MS-based metabolomics datasets to comprehensively assess the potential mechanisms of CL toxicity towards L02 cells.
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