[Research progress on pyroptosis in liver diseases]

Pyroptosis is a newly discovered kind of cell death modality that, due to its association with innate immunity, plays a crucial role in cytolysis and inflammatory cytokine release during host defense against infection. In recent years, studies have shown that pyroptosis plays an important role in the occurrence and development of liver diseases. This article introduces and elaborates on the most recent research progress on pyroptosis in liver diseases based on the morphological features, molecular and pathophysiological mechanisms.

Unveiling the role of bZIP transcription factors CREB and CEBP in detoxification metabolism of Nilaparvata lugens (Stål)

The basic leucine zipper (bZIP) superfamily is a crucial group of xenobiotics in insects. However, little is known about the function of CAAT enhancer binding proteins (CEBP) and cAMP response element binding protein (CREB) in Nilaparvata lugens. In the present study, NlCEBP and NlCREB were cloned and identified. Quantitative polymerase real-time chain reaction (qRT-PCR) analysis showed the expression of NlCEBP and NlCREB was significantly induced after chemical insecticides exposure. Silencing of NlCEBP and NlCREB increased the susceptibility of N. lugens to insecticides, and the detoxification enzyme activities were also significantly decreased. In addition, comparative transcriptome analysis revealed that 174 genes were significantly co-down-regulated after interfering with the two transcription factors. GO analysis showed that co-down-regulated genes are mostly related to energy transport and metabolic functions indicating the potential regulatory role of NlCEBP and NlCREB in detoxification metabolism. Our research shed lights on the functional roles of transcription factors NlCEBP and NlCREB in the detoxification metabolism of N. lugens, providing a theoretical basis for pest management and comprehensive control of this pest and increasing our understanding of insect toxicology.

Impact of Lymphopenia on Definitive Treatment of Locally Advanced Cervical Cancer

PURPOSE/OBJECTIVE(S)

Pre-treatment lymphopenia prior to initiating treatment has been correlated with reduced survival in a number of different cancers. The purpose of this study is to evaluate the association between lymphopenia and survival in women with locally advanced cervical cancer (LACC) treated with primary chemoradiation (CRT).

MATERIALS/METHODS

We retrospectively reviewed patients with LACC treated at a single institution from 2005 - 2021 with available lymphocyte information. Patient and treatment characteristics were recorded including age, tumor size and stage, EBRT dose/fractionation, and brachytherapy dosimetry data. Absolute lymphocyte counts (ALC) were collected prior to initiating CRT and at 3-month intervals following CRT and graded based on severity of lymphopenia using CTCAE v 5.0. Overall survival (OS), progression free survival (PFS), and local control (LC) were calculated from the start of treatment to date of last follow-up. Kaplan-Meier survival analysis was performed to evaluate whether lymphocyte changes were associated with OS, PFS, or LC.

RESULTS

A total of 124 patients met study inclusion criteria with stage IB - IV disease (41 stage I, 41 stage II, 36 stage III, 6 stage IV) and a median follow up of 3.6 years (range 0.2-16.5 years). The median age was 49 years (range 26-77). The median EBRT dose was 45 Gy (range: 26-57.5 Gy) and 44.2% of patients received para-aortic (PA) nodal EBRT (28.8% elective and 15.4% with positive PA nodes). 5-year OS, PFS, and LC were 60.3% (95% CI 51.5-70.7), 47.5% (95% CI 39-58), and 75.5% (95% CI 67.3-82.9), respectively. Pre-treatment lymphopenia (ALC <1000 cells/mm3) was present in 11 (9%) patients. When the total cohort was divided into patients with and without pre-treatment lymphopenia, OS was statistically improved in the patients without baseline lymphopenia, with a 5-year OS of 63.2% (95% CI 53.9-73.9) versus 35.3% (95% CI 14.5-86.3) in the lymphopenia group (p = 0.034). LC also trended to being improved in the patients without lymphopenia, though this did not reach statistical significance in our small sample size of lymphopenic patients, with 5-year LC of 76.8% (95% CI 68.4-84.3) versus 67.5% (05% CI 36.6-93.8), p = 0.45.

CONCLUSION

In this single institution experience of LACC treated with definitive CRT, we found that baseline lymphopenia is associated with inferior OS. Patients with higher pre-CRT ALC may represent a population with more robust immune systems, producing more favorable tumor responses to treatment. Additional studies are warranted to investigate the evolving role of combined EBRT and systemic therapy in LACC.

Evaluation of National Conference-Associated Medical Student Research and Mentorship Award for Medical Students, Resident Mentors, and Radiation Oncologist Supervisors

PURPOSE/OBJECTIVE(S)

In 2020, the Canadian Association of Radiation Oncology (CARO) Medical Student Research and Mentorship Award (CARO MSRMA) was created to support medical students pursuing radiation oncology (RO) research and RO as a career. This study aims to evaluate the impact of three consecutive years of this award on medical students, RO resident mentors, and research supervisors.

MATERIALS/METHODS

Medical student mentees, resident mentors, and staff RO research supervisors who participated in one of three iterations of CARO MSRMA (2020-2022 inclusive) were identified. Three separate surveys were developed for these groups using best practice strategies for medical education surveys and circulated for peer-review amongst experts in oncology medical education. The surveys were sent to 52 participants: 18 medical students (Group 1), 18 RO resident mentors (Group 2), and 16 attending RO supervisors (Group 3). After anonymization, quantitative answers were analyzed using descriptive statistics and narrative responses were evaluated using a grounded theory approach.

RESULTS

Survey response rate was 92% (48/52). For Group 1, the award maintained (71%) or increased interest in pursuing an RO career (24%). Aspects of the award rated most important were: financial support to attend the CARO Annual Scientific Meeting (mean rating 4.8/5) and mentorship with an RO resident (mean rating 4.6/5). Through mentorship, 60% of students obtained valuable information about a career in RO, 60% reported helpful residency matching (CaRMS) advice, and another 60% attained insight into RO residency. For Group 2 respondents, 100% felt the program either maintained or increased their motivation to mentor students in RO. For Group 3, 100% agreed or strongly agreed that they enjoyed their role as a supervisor, would participate in the program again, and would recommend the opportunity to others. All three Groups agreed or strongly agreed that it would be useful for CARO to create a virtual network of radiation oncologists, residents, and medical students to share and access shadowing and research opportunities to encourage national RO exposure and collaboration. The first cohort of medical student awardees has CaRMS matching results, with approximately 50% matching to RO.

CONCLUSION

A national conference-associated medical student research and mentorship award has had a positive impact on all three populations involved: medical students in motivation to continue pursuing RO research and career opportunities, RO resident mentors in enhancing mentorship skills, and attending supervisors in inspiring the next generation of prospective RO colleagues. Further research is recommended to determine the impact of the award on subsequent Residency Specialty matching, and whether expansion of this award to other opportunities may be beneficial.

[Clinical features of primary sclerosing cholangitis and inflammatory bowel disease]

Objective: To explore disease characteristics of primary sclerosing cholangitis (PSC) and inflammatory bowel disease (IBD) and compare the differences between PSC with and without IBD. Methods: Study design was cross sectional. Forty-two patients with PSC who were admitted from January 2000 to January 2021 were included. We analyzed their demographic characteristics, clinical manifestations, concomitant diseases, auxiliary examination, and treatment. Results: The 42 patients were 11-74(43±18) years of age at diagnosis. The concordance rate of PSC with IBD was 33.3%, and the age at PSC with IBD diagnosis was 12-63(42±17) years. PSC patients with IBD had higher incidences of diarrhea and lower incidences of jaundice and fatigue than in those without IBD (all P<0.05). Alanine aminotransferase, total bilirubin, direct bilirubin, total bile acid and carbohydrate antigen 19-9 levels were higher in PSC patients without IBD than in those with IBD (all P<0.05). The positive rates for antinuclear antibodies and fecal occult blood were higher in PSC patients with IBD than in those without IBD (all P<0.05). Patients with PSC complicated with ulcerative colitis mainly experienced extensive colonic involvement. The proportion of 5-aminosalicylic acid and glucocorticoid application in PSC patients with IBD was significantly increased compared with that of PSC patients without IBD (P=0.025). Conclusions: The concordance rate of PSC with IBD is lower at Peking Union Medical College Hospital than in Western countries. Colonoscopy screening may benefit PSC patients with diarrhea or fecal occult blood-positive for early detection and diagnosis of IBD.

Insight into the regulation of the Nrf2 pathway in response to ascovirus infection in Spodoptera exigua

BACKGROUND

Ascoviruses are a type of entomopathogenic microorganism with high biological pest control potential and are expected to contribute to the natural control of lepidopteran pests. However, knowledge of the molecular mechanism underlying the biocidal activity of ascovirus on its host insects remains limited.

RESULTS

In this study, the relative enzyme activity of superoxide dismutase and peroxidase, as well as the expression level of Spodoptera exigua peroxidase (SePOD), were found to be significantly increased at 6 h post infection with Heliothis virescens ascovirus 3h (HvAV-3h). H₂ O₂ accumulation and enhanced expression of NADPH Oxidase (SeNOX) were also observed. In addition, Nuclear Factor erythroid 2-Related Factor 2 (SeNrf2) and muscle aponeurosis fibromatosis (SeMaf) were overexpressed following infection with HvAV-3h. Silencing of SeNrf2 decreased the expression of SePOD, whereas the mortality of SeNrf2-silenced larvae and viral genome copy number also increased. Further RNA interference of SeNOX significantly decreased expression of SeNrf2 and SePOD and therefore increased the mortality and viral genome copy number of the ascovirus-infected host.

CONCLUSION

The HvAV-3h activated Nrf2/ARE pathway of S. exigua and reactive oxygen species were found to respond to ascovirus infection by regulating alterations in antioxidant enzyme genes mediated by the host Nrf2/ARE pathway. These findings enhance our knowledge of ascovirus-host interactions and lay the foundation for the application of ascoviruses in biological pest control. © 2022 Society of Chemical Industry.

Microbiome variation correlates with the insecticide susceptibility in different geographic strains of a significant agricultural pest, Nilaparvata lugens

Microbiome-mediated insecticide resistance is an emerging phenomenon found in insect pests. However, microbiome composition can vary by host genotype and environmental factors, but how these variations may be associated with insecticide resistance phenotype remains unclear. In this study, we compared different field and laboratory strains of the brown planthopper Nilaparvata lugens in their microbiome composition, transcriptome, and insecticide resistance profiles to identify possible patterns of correlation. Our analysis reveals that the abundances of core bacterial symbionts are significantly correlated with the expression of several host detoxifying genes (especially NlCYP6ER1, a key gene previously shown involved in insecticides resistance). The expression levels of these detoxifying genes correlated with N. lugens insecticide susceptibility. Furthermore, we have identified several environmental abiotic factors, including temperature, precipitation, latitude, and longitude, as potential predictors of symbiont abundances associated with expression of key detoxifying genes, and correlated with insecticide susceptibility levels of N. lugens. These findings provide new insights into how microbiome-environment-host interactions may influence insecticide susceptibility, which will be helpful in guiding targeted microbial-based strategies for insecticide resistance management in the field.

[Analysis of respiratory syncytial virus infection in hospitalized children with acute lower respiratory tract infection in China from 2017 to 2020]

Objective: To understand the detection rate, epidemic pattern of respiratory syncytial virus (RSV) in hospitalized children with acute lower respiratory tract infection (ALRTI) in China. Methods: From June 2017 to March 2020, a prospective multi-center study on the viral aetiology among hospitalized children with ALRTI was conducted in six pediatrics hospital of North China, Northeast, Northwest, South China, Southeast, and Southwest China. A total of 2 839 hospitalized children with ALRTI were enrolled, and the respiratory specimens were collected from these cases. A multiplex real-time RT-PCR assay were employed to screen the respiratory viruses, and the molecular epidemiological and clinical characteristics of children infected with RSV were analyzed. Results: The positve rate of RSV was 18.6% (528/2 839), and the positive rate of RSV in different regions ranged from 5.5% to 44.3%. The positive rate of RSV in male was higher than that in female (20.2% vs 16.3%), and there was a significant statistically difference between two groups (χ2=6.74, P=0.009). The positive rate of RSV among children under 5 years old was higher than that among children older than 5 years old (22.3% vs 4.5%), and there was a significant statistically difference between two groups (χ2=97.98,P<0.001). The positive rate of RSV among the <6 months age group was higher than that of other age groups (all P<0.05). During January 2018 and December 2019, RSV was detected in almost all through the year, and showed peaks in winter and spring. RSV-positive cases accounted for 17.0% (46/270) among children with severe pneumonia, including 36 cases infected with RSV alone. Conclusion: RSV is an important viral pathogen in children under 5 years old with ALRTI in China. The virus can be detected almost all through the year and reached the peak in winter and spring. RSV could lead to severe pneumonia in children and caused huge threaten to children's health.

miRNA novel_268 targeting NlABCG3 is involved in nitenpyram and clothianidin resistance in Nilaparvata lugens

The brown planthopper (BPH), Nilaparvata lugens (Stål), is one of the most destructive pests that seriously threatens the high-quality and safe production of rice. However, due to the unscientific use of chemical insecticides, N. lugens has developed varying levels of resistance to insecticides, including nitenpyram and clothianidin. The ATP-binding cassette (ABC) transporter plays a nonnegligible role in phase III of the detoxification process, which may play an important role in insecticide resistance. In the present study, NlABCG3 was significantly overexpressed in both the NR and CR populations compared with susceptible populations. Silencing NlABCG3 significantly increased the susceptibility of BPH to nitenpyram and clothianidin. In addition, RNAi-mediated knockdown of three key genes in the miRNA biogenesis pathway altered the level of NlABCG3. Subsequently, the luciferase reporter assays demonstrated that novel_268 binds to the NlABCG3 coding region and downregulates its expression. Furthermore, injection of miRNA inhibitors or mimics of novel_268 significantly altered the susceptibility of N. lugens to nitenpyram and clothianidin. These results suggest that miRNA novel_268 targeting NlABCG3 is involved in nitenpyram and clothianidin resistance in N. lugens. These findings may help to enhance our knowledge of the transcriptional regulation of the ABC transporter that mediate insecticide resistance in N. lugens.

Insecticide Susceptibility and Mechanism of Spodoptera frugiperda on Different Host Plants

Spodoptera frugiperda (J. E. Smith) is a worldwide economically important crop pest. Although the individuals of S. frugiperda that invaded China have been characterized as the corn strain, they also have the ability to damage other crops in China. The physiological and behavioral responses of S. frugiperda to different host plants are poorly understood. In the present study, we investigated the host plant preference, fitness costs, and differences in detoxification gene expression and microbiome composition between two S. frugiperda strains that fed on different crop plant diets. The results showed that S. frugiperda larvae exhibited no obvious preference for corn or rice, but significant suppression of development was observed in the rice-fed strain. In addition, the corn-fed strain showed higher insecticide tolerance and detoxification enzyme activities than the rice-fed strain. Moreover, multiple detoxification genes were upregulated in the corn-fed strain, and microbiome composition variation was observed between the two strains. Together, the results suggest that population-specific plasticity is related to host plant diets in S. frugiperda. These results provide a theoretical basis for the evolution of resistance differences in S. frugiperda and are helpful for designing resistance management strategies for S. frugiperda aimed at different crops.

[Effect of China Children's Asthma Action Plan on exercise in school-age children with bronchial asthma]

Objective: To investigate the effect of China Children's Asthma Action Plan (CCAAP) on the exercise status of school-age children with asthma. Methods: We included 400 school-age asthmatic children as research objects from CCAAP asthma management platform of the Affiliated Hospital of Qingdao University during March 1, 2018 to February 28, 2021 by simple random sampling method. The questionnaires of basic information and international physical activity were applied through WeChat or face to face investigation to collect the basic information and exercise status of the object. There were 346 valid questionnaires included in the study to compare the differences in exercise status and incidence of exercise-related asthma-like symptoms between the good and poor CCAAP application groups. Results: There were 232 (67.05%) and 114 (32.95%) cases in good and poor CCAAP application group, respectively. Age, female proportion and BMI of good CCAAP application group were (8±2) years, 47.0% (109/232) and (19.79±2.32) kg/m², respectively, no statistic difference comparing to poor CCAAP application group [(8±2) years, 46.5% (53/114) and (19.87±2.43) kg/m², respectively] (all P values>0.05). In good CCAAP application group, 30.18% (70/232) achieved the standard of moderate (high) intensity exercise per day, no statistic difference comparing to poor CCAAP application group [29.82% (34/112)] (P=0.947); 31.90% (74/232) participated in high-intensity exercise per week, higher than that of poor CCAAP application group [17.54% (20/112)] (P=0.005); incidence of exercise-related asthma-like symptoms was 19.83% (46/232), lower than that of poor CCAAP application group [29.82% (34/112)] (P=0.038). Conclusion: CCAAP promotes the exercise of school-age children with asthma.

Odorant binding protein 3 is associated with nitenpyram and sulfoxaflor resistance in Nilaparvata lugens

Odorant binding protein (OBP) can interact with small-molecule compounds insecticides and thereby modulate variation in insecticide susceptibility in insects. However, the regulatory mechanism of OBP-mediated insecticide resistance in Nilaparvata lugens, a destructive rice pest in Asia, remains unclear. Here, we explored the role of NlOBP3 in the resistance of N. lugens to nitenpyram and sulfoxaflor. The results showed that NlOBP3 was overexpressed in association with nitenpyram and sulfoxaflor resistance, and NlOBP3 silencing significantly increased the mortality of N. lugens to nitenpyram and sulfoxaflor, suggesting that NlOBP3 may be associated with nitenpyram and sulfoxaflor resistance in N. lugens. OBP localization revealed that NlOBP3 was highly expressed in all nymph stages and was enriched in the antennae, legs, body wall, and fat body. RT-qPCR analyses showed that the mRNA levels of NlOBP3 were significantly affected by nitenpyram and sulfoxaflor. Additionally, molecular docking predicted that there were multiple binding sites that may played key roles in the binding of NlOBP3 with nitenpyram and sulfoxaflor. The current study identifies a previously undescribed mechanism of insecticide resistance in N. lugens, showing that NlOBP3 is likely to be involved in the evolution of nitenpyram and sulfoxaflor resistance in N. lugens.

miRNAs targeting CYP6ER1 and CarE1 are involved in nitenpyram resistance in Nilaparvata lugens

The evolution of nitenpyram resistance has been confirmed to be related to overexpression of two key metabolic enzyme genes, CYP6ER1 and CarE1, in Nilaparvata lugens, a highly destructive rice pest that causes substantial economic losses and has developed insecticide resistance. As microRNAs (miRNAs) are important post-transcriptional regulators of gene expression, whether they are involved in nitenpyram resistance is poorly understood in N. lugens. In this study, knockdown of key genes in the miRNA biogenesis pathway (Dicer1, Drosha, and Argonaute1) changed CYP6ER1 and CarE1 abundance, which confirmed the importance of miRNAs in nitenpyram resistance. Furthermore, global screening of miRNAs associated with nitenpyram resistance in N. lugens was performed, and a total of 42 known and 178 novel miRNAs were identified; of these, 57 were differentially expressed between the susceptible and resistant strains, and two (novel_85 and novel_191) were predicted to target CYP6ER1 and CarE1, respectively. Luciferase reporter assays demonstrated that novel_85 and novel_191 bind to the CYP6ER1 and CarE1 coding regions, respectively, and downregulate their expression. Moreover, modulating novel_85 and novel_191 expression by injection of miRNA inhibitors and mimics significantly altered N. lugens nitenpyram susceptibility. This is the first study to systematically screen and identify miRNAs associated with N. lugens nitenpyram resistance, and provides important information that can be used to develop new miRNA-based targets in insecticide resistance management.

Dietary chitooligosaccharide supplementation alleviates intestinal barrier damage, and oxidative and immunological stress in lipopolysaccharide-challenged laying hens

This study aimed to investigate the effects of chitooligosaccharide (COS) on intestinal barrier, antioxidant capacity, and immunity of lipopolysaccharide (LPS)-challenged laying hens. A total of 360 Hy-line Brown laying hens (80-wk-old) were randomly divided into 5 groups with 6 replicates of 12 birds. Hens were fed a corn-soybean meal basal diet supplemented with different COS levels (0; 5; 10; 15; 20 mg/kg) for 8 wk. The results showed that 15 mg/kg COS administration elevated albumen height and Haugh unit (P < 0.05), and numerically optimized productive performance (P > 0.05), therefore, the dosage of 15 mg/kg was chosen for the subsequent experiment. Thereafter, 12 birds from non-supplemented group were randomly selected and assigned into 2 groups, and birds in each group were administered (1.5 mg/kg BW, i.p.) with saline (control group) or LPS (challenge group). Another 6 hens from 15 mg/kg COS-supplemented group were selected and injected with LPS in the same way. Compared with the control group, LPS-challenged birds exhibited elevated circulating diamine oxidase activity, and reduced jejunal villus height and ratio of villus height to crypt depth, and these indices were reversed to control levels by COS (P < 0.05). Also, LPS increased malondialdehyde accumulation and reduced several antioxidant enzyme activities in the intestinal mucosa (P < 0.05). Additionally, LPS increased jejunal secretory IgA and interferon-γ (IFN-γ), and ileal secretory IgA, IgM, and interleukin-1β (IL-1β) concentrations, whereas COS reduced jejunal IFN-γ and IL-1β, and ileal IgM levels (P < 0.05). Moreover, LPS down-regulated mRNA abundance of jejunal occludin and claudin 2, and upregulated expression of jejunal nuclear factor erythroid-2 related factor 2, superoxide dismutase 1, and IFN-γ as well as ileal IL-1β (P < 0.05). Besides, COS increased jejunal occludin and ileal claudin 2, nuclear factor erythroid-2 related factor 2, and heme oxygenase-1 expression, and decreased jejunal IFN-γ and IL-1β abundance (P < 0.05). These results suggested that COS could alleviate LPS-induced intestinal barrier impairment, and oxidative and immunological stress in laying hens.

Resistance of Nilaparvata lugens (Hemiptera: Delphacidae) to triflumezopyrim: inheritance and fitness costs

BACKGROUND

Triflumezopyrim, a novel commercialized mesoionic chemical insecticide, has been confirmed as a promising insecticide for efficiently controlling the brown planthopper, Nilaparvata lugens (Stål). Here, a laboratory triflumezopyrim-resistant (TR) strain and an isogenic susceptible (TS) strain were established to characterize the inheritance and fitness costs of triflumezopyrim resistance in N. lugens.

RESULTS

After 29 generations of successive selection with triflumezopyrim, the TR strain developed a 155.23-fold higher resistance level than the TS strain. The median lethal concentration (LC₅₀ ) values from progenies (F₁ RS and F₁ SR) of reciprocal crosses between TR and TS strains suggested that triflumezopyrim resistance in N. lugens was autosomal and codominant. Chi-square analyses of self-bred and backcrossed progenies suggested that the resistance results from a polygenic effect. Compared to the TS strain, the TR strain showed a lower relative fitness (0.62) with a significantly decreased female adult period, longevity, total fecundity, egg hatchability, intrinsic rate of increase (r), finite rate of increase (λ), net reproductive rate (R₀ ), and prolonged pre-adult period and total preoviposition period (TPOP).

CONCLUSION

The inheritance mode of triflumezopyrim resistance in N. lugens was characterized as autosomal, codominant and polygenic. The resistance had a fitness cost, which may be an important factor limiting the evolution of resistance. These findings provide valuable information for optimizing resistance management strategies to delay triflumezopyrim resistance development and maintain sustainable control of N. lugens. © 2021 Society of Chemical Industry.

Age-related changes in liver metabolism and antioxidant capacity of laying hens

This study aimed to investigate the age-related changes of hepatic metabolism and antioxidant capacity of laying hens at 3 different ages. A total of 192 Hy-line Brown laying hens were assigned into 3 groups: 1) 195-day-old (D195 group); 2) 340-day-old (D340 group); 3) 525-day-old (D525 group). Each group replicated 8 times with 8 hens at the same age. Higher activity of aspartate aminotransferase and lower contents of total protein and globulin were observed in the serum of 525-day-old hens in comparison with their 195-day-old counterparts (P < 0.05). The 525-day-old hens accumulated higher contents of total cholesterol and triglyceride in the liver than 195-day-old birds. Additionally, compared with hens from D195 or D340 group, 525-day-old birds exhibited a lower circulating estradiol level (P < 0.05). For antioxidant capacity, birds in the D525 group showed a higher malondialdehyde concentration in both serum and liver as compared with D195 or D340 group (P < 0.05). The 525-day-old hens also exhibited lower glutathione peroxidase activities in both serum and liver when compared with 195-day-old birds (P < 0.05). Simultaneously, there was a decline of hepatic superoxide dismutase activity in the D525 group in comparison with D195 group (P < 0.05). Compared with 195-day-old counterparts, 340-day-old birds upregulated the mRNA abundance of nuclear factor erythroid-2 related factor 2 and glutathione peroxidase 1 in the liver (P < 0.05). In contrast, hens from D525 group showed the downregulation of hepatic nuclear factor erythroid-2 related factor 2, NAD(P)H quinone dehydrogenase 1, and superoxide dismutase 1 when compared with D340 group (P < 0.05). These results indicated that increasing age can adversely affect liver metabolism and function of laying hens.

Activator protein-1 mediated CYP6ER1 overexpression in the clothianidin resistance of Nilaparvata lugens (Stål)

BACKGROUND

Nilaparvata lugens, a destructive rice pest in Asia, has developed resistance to many insecticides, including the neonicotinoid clothianidin. CYP6ER1 plays an important role in N. lugens resistant to clothianidin, but only limited information on the transcriptional regulation of CYP6ER1 overexpression in clothianidin resistance is available.

RESULTS

In this study, the transcription factor activator protein 1 (AP-1) was found to be overexpressed in a clothianidin-resistant strain of N. lugens and several field resistant populations. RNA interference-mediated silencing of NlAP-1 significantly decreased CYP6ER1 expression and increased the susceptibility of N. lugens to clothianidin. Additionally, NlAP-1 was highly expressed in egg and adult stages, and in midguts, and NlAP-1 was upregulated and induced to a greater extent in the clothianidin-resistant strain after exposure to clothianidin. Finally, dual-luciferase reporter assays confirmed the interaction between NlAP-1 and the two predicted binding sites in the CYP6ER1 promoter.

CONCLUSION

NlAP-1 bound the -1388 to -1208-bp region of the CYP6ER1 promoter, enhancing its activity and then regulate the expression of CYP6ER1. These findings enhance our knowledge of the transcriptional regulation of the P450 genes that mediate insecticide resistance in insect pests. © 2021 Society of Chemical Industry.

Dual oxidase-dependent reactive oxygen species are involved in the regulation of UGT overexpression-mediated clothianidin resistance in the brown planthopper, Nilaparvata lugens

BACKGROUND

Uridine diphosphate-glycosyltransferases (UGTs) are phase II metabolic enzymes involved in metabolism of toxins and resistance to insecticides in insect pests. Reactive oxygen species (ROS) induced by xenobiotics are important for activation of detoxification pathways. However, relationships between ROS and UGTs involved in toxin metabolism and insecticide resistance remain unclear.

RESULTS

Here, involvement of dual oxidase (Duox)-dependent ROS in regulating UGT expression-mediated insecticide resistance in the brown planthopper (Nilaparvata lugens) was investigated. The overexpression of NlUGT386F2 contributed to the resistance of N. lugens to clothianidin. Furthermore, the ROS inhibitor (N-acetylcysteine) significantly reduced the expression of NlUGT386F2 and increased the susceptibility of N. lugens to clothianidin. Silencing the ROS producer Duox significantly increased the susceptibility of N. lugens to clothianidin through the down-regulation of NlUGT386F2 expression.

CONCLUSION

NlDuox-dependent ROS regulates NlUGT386F2 expression-mediated clothianidin resistance in brown planthopper. These observations further our understanding of the metabolism of toxins and of insecticide-resistance in insect pests.

Functional characterization of the transcription factors AhR and ARNT in Nilaparvata lugens

In the present study, the aryl hydrocarbon receptor (AhR) and aryl hydrocarbon receptor nuclear translocator (ARNT) of Nilaparvata lugens were cloned and identified. The NlAhR and NlARNT expression levels significantly increased after imidacloprid, etofenprox and isoprocarb treatments. Knockdowns of NlAhR and NlARNT increased the susceptibility of N. lugens to imidacloprid, etofenprox and isoprocarb, and the detoxification enzyme activities were also significantly decreased. In addition, NlCYP301A1, NlGSTt1 and NlCarE7 were significantly down-regulated after injections of dsNlAhR and dsNlARNT, with the NlCarE7 expression decreasing by greater than 80%. Moreover, after knocking down NlCarE7, the susceptibility of N. lugens to etofenprox and isoprocarb significantly increased. Both NlAhR and NlARNT bound the NlCarE7 promoter and significantly enhanced the transcriptional activity. Our research revealed the functional roles of transcription factors NlAhR and NlARNT in the detoxification metabolism of N. lugens. The results provide a theoretical basis for the pest management and comprehensive control of N. lugens and increase our knowledge of insect toxicology.

A comparison of intestinal integrity, digestive function, and egg quality in laying hens with different ages

Intestinal integrity, digestive enzyme activity, nutrient utilization, and egg quality of laying hens at different ages were evaluated and compared in this study. A total of 192 Hy-line Brown laying hens at 195-d-old (D195 group), 340-d-old (D340 group), and 525-d-old (D525 group) were allocated into one of 3 groups in accordance with their ages. Each group had 8 replicates of 8 birds each, and all birds were fed a maize-soybean meal basal diet for a 2-wk experiment. Compared with the D195 group, intestinal villus height and ratio of villus height to crypt depth, as well as serum D-lactate content increased in the D525 group (P < 0.05). The sucrase and maltase activities in the jejunal mucosa, amylase activity in the pancreas, and trypsin activity in the jejunal chyme of 525-d-old hens were lower than their 195-d-old counterparts (P < 0.05). In addition, there was a decline of trypsin and lipase activities in the ileal chyme of hens from D525 group in comparison with D195 or D340 group (P < 0.05). Apparent retention of dry matter and crude protein of birds in D340 and D525 group decreased when compared with the D195 group (P < 0.05). Moreover, birds in the D525 group exhibited a lower level of ether extract retention, and higher contents of several excreted amino acids than those in the D195 group (P < 0.05). Compared with the D195 group, eggs harvested from D525 group exhibited lower albumen height, eggshell strength and thickness, and a higher egg weight (P < 0.05). In conclusion, increased intestinal permeability (higher serum D-lactate content), compromised digestive function (lower digestive enzyme activities and apparent nutrient retention, and higher concentrations of excreted amino acids), and poor egg quality (lower albumen height, eggshell strength, and thickness) were observed with increasing age in the laying hens.

Using psychometric ability to improve education in ultrasound-guided regional anaesthesia: a multicentre randomised controlled trial

The learning curve for novices developing regional anaesthesia skills, such as real-time ultrasound-guided needle manipulation, may be affected by innate visuospatial ability, as this influences spatial cognition and motor co-ordination. We conducted a multinational randomised controlled trial to test if novices with low visuospatial ability would perform better at an ultrasound-guided needling task with deliberate practice training than with discovery learning. Visuospatial ability was evaluated using the mental rotations test-A. We recruited 140 medical students and randomly allocated them into low-ability control (discovery learning), low-ability intervention (received deliberate practice), high-ability control, and high-ability intervention groups. Primary outcome was the time taken to complete the needling task, and there was no significant difference between groups: median (IQR [range]) low-ability control 125 s (69-237 [43-600 s]); low-ability intervention 163 s (116-276 [44-600 s]); high-ability control 130 s (80-210 [41-384 s]); and high-ability intervention 177 s (113-285 [43-547 s]), p = 0.06. No difference was found using the global rating scale: mean (95%CI) low-ability control 53% (95%CI 46-60%); low-ability intervention 61% (95%CI 53-68%); high-ability control 63% (95%CI 56-70%); and high-ability intervention 66% (95%CI 60-72%), p = 0.05. For overall procedure pass/fail, the low-ability control group pass rate of 42% (14/33) was significantly less than the other three groups: low-ability intervention 69% (25/36); high-ability control 68% (25/37); and high-ability intervention 85% (29/34) p = 0.003. Further research is required to determine the role of visuospatial ability screening in training for ultrasound-guided needle skills.

[Evaluation of the efficacy of Chinese Children's Asthma Action Plan on the long-term management of children with asthma at home]

Objective: During the COVID-19 pandemic, the electronic "questionnaire star" was employed to investigate the general situation, medication situation and pandemic impact of children diagnosed with asthma in our hospital and enrolled in the electronic platform of the Chinese Children's Asthma Action Plan (CCAAP). The internet technology and big data were used to grasp the trend and asthma control of children who had been at home for a long time due to the pandemic, so as to facilitate the management. Methods: By random cluster sampling survey method, according to the needs and medication adherence score, the electronic "questionnaire star" was designed to conduct a survey among children (0 to 14 years old) who diagnosed with asthma and joined the CCAAP on the basis of bronchial asthma medication adherence scale. Finally, the results of electronic questionnaire survey were analyzed. Results: A total of 423 questionnaires were sent out, 422 of which were valid, with an effective response rate of 99.7%. The results of questionnaire survey showed that 296 cases were male, accounting for 70.1%, and 126 cases were female, accounting for 29.9%, with an average age of (5.4±2.6) years old. The average age of males and females was (5.3±2.6) and (5.4±2.6) years old, respectively. There were more children aged ≥5 years than children who were younger than 5 years. Additionally, 13.95% of the parents thought that the pandemic had more than moderate impact on children with asthma, and 76.12% of the children were in the green zone and had no asthma attack. The proportion of green zone inhaled drugs (79.8%) was higher than yellow zone and red zone (49.8%). After using the CCAAP platform, the dissatisfaction rate was only 1.42%. Moreover, 71.87% of the children's medical expenses decreased, and the proportion of frequent use and intermittent use of antibiotics reduced, however, the proportion of occasional use and never use of antibiotics increased significantly (all P<0.05). The average score of drug compliance was 4.56, and the more frequently the platform was used, the higher the score of medication compliance was (P<0.05). Conclusions: After using CCAAP management with the aid of internet technology, children with asthma who had been isolated at home for a long time were less affected by COVID-19, with high medication compliance, generally lower medical expenses, significantly reduced use of antibiotics, and high satisfaction. This management mode provides a new idea for internet medicine.

WWP2 Promotes Odontoblastic Differentiation by Monoubiquitinating KLF5

WW domain-containing E3 Ub-protein ligase 2 (WWP2) belongs to the homologous to E6AP C-terminus (HECT) E3 ligase family. It has been explored to regulate osteogenic differentiation, chondrogenesis, and palatogenesis. Odontoblasts are terminally differentiated mesenchymal cells, which contribute to dentin formation in tooth development. However, it remained unknown whether WWP2 participated in odontoblast differentiation. In this study, WWP2 was found to be expressed in mouse dental papilla cells (mDPCs), odontoblasts, and odontoblastic-induced mDPCs by immunohistochemistry and Western blotting. Besides, WWP2 expression was decreased in the cytoplasm but increased in the nuclei of differentiation-induced mDPCs. When Wwp2 was knocked down, the elevated expression of odontoblast marker genes (Dmp1 and Dspp) in mDPCs induced by differentiation medium was suppressed. Meanwhile, a decrease of alkaline phosphatase (ALP) activity was observed by ALP staining, and reduced formation of mineralized matrix nodules was demonstrated by Alizarin Red S staining. Overexpression of WWP2 presented opposite results to knockdown experiments, suggesting that WWP2 promoted odontoblastic differentiation of mDPCs. Further investigation found that WWP2 was coexpressed and interacted with KLF5 in the nuclei, leading to ubiquitination of KLF5. The PPPSY (PY2) motif of KLF5 was essential for its physical binding with WWP2. Also, cysteine 838 (Cys838) of WWP2 was the active site for ubiquitination of KLF5, which did not lead to proteolysis of KLF5. Then, KLF5 was confirmed to be monoubiquitinated and transactivated by WWP2, which promoted the expression of KLF5 downstream genes Dmp1 and Dspp. Deletion of the PY2 motif of KLF5 or mutation of Cys838 of WWP2 reduced the upregulation of Dmp1 and Dspp. Besides, lysine (K) residues K31, K52, K83, and K265 of KLF5 were verified to be crucial to WWP2-mediated KLF5 transactivation. Taken together, WWP2 promoted odontoblastic differentiation by monoubiquitinating KLF5.

Periodic repolarization dynamics for prediction of mortality: a systematic review and meta-analysis

Background

Prediction of death is the philosopher's stone of arrhythmology. The electrophysiology has proven to be an important tool to predict the risk of death. Periodic repolarization dynamics (PRD) is a novel electrocardiographic marker that indicates the sympathetic effect on repolarization. PRD qualifies the low-frequency oscillations of cardiac repolarization instability using high-resolution 12 channel 24-h Holter recording. Several studies showed that PRD was an independent predictor of all-cause mortality and cardiac mortality. However, the prediction value of PRD has not been established.

Purpose

To evaluate the prediction value of PRD as an approach of risk stratification that selects patients at a higher risk of death.

Methods

We conducted electronic searches of MEDLINE (PubMed), Embase, Cochrane Register of Controlled Trials (CENTRAL), Science Citation Index Expanded, WHO International Clinical Trials Registry platform (ICTRP) and ClinicalTrials.gov from inception to January 9th, 2020. We also screened for relevant abstracts from conferences including ACC Annual Scientific Sessions, ESC Congress and Annual Congress of the EHRA for the last five years (2014–2019). The primary outcome was all-cause mortality and secondary outcome was cardiac mortality. We included study with large sample size while more than one study were found based on the same originated population. We extracted data from included studies and reported pooled outcomes as hazard ratios (HRs) with 95% confidential intervals (CI) for time-to-event outcomes using DerSimonian-Laird random-effects model. We did statistical analyses using Stata version 12.0 and R version 3.6.1.

Results

5 studies including 6758 patients met all selection criteria for our meta-analysis. Follow-up period ranged from 20.4 to 75.1 months. Among 5 studies, 3 studies considered PRD as dichotomous variable and the cut-off value was 5.75 deg2, while 2 studies considered PRD as continuous variable and coefficient was expressed in standardized units (increase per standard deviation). We did subgroup analysis according to the type of variable because of heterogeneity. There was a significant higher risk of all-cause mortality in PRD ≥5.75 deg2 patients compared with PRD &lt;5.75 deg2 patients (HR 2.37, 95% CI 1.77–3.17). As for continuous variable, increased PRD was a predictor for all-cause death (HR 1.28, 95% CI 1.14–1.42) (Figure). The cardiac mortality was significantly increased in patients with PRD ≥5.75 deg2 vs PRD &lt;5.75 deg2 (HR 3.06, 95% CI 1.66–5.65). Increased PRD was associated with cardiac mortality in continuous variable subgroup (HR 1.34, 95% CI 1.21–1.48) (Figure).

Conclusion

Our findings suggest PRD is a significant predictor of all-cause mortality and cardiac mortality. PRD provides new additional electrophysiological indicator for risk stratification until further investigations are available.

Funding Acknowledgement

Type of funding source: None

Transcriptional Response of ATP-Binding Cassette (ABC) Transporters to Insecticide in the Brown Planthopper, Nilaparvata lugens (Stål)

The ATP-binding cassette (ABC) transporter superfamily is one of the largest groups of proteins and plays a non-negligible role in phase III of the detoxification process, which is highly involved in the response of insects to environmental stress (plant secondary metabolites and insecticides). In the present study, in Nilaparvata lugens, we identified 32 ABC transporters, which are grouped into eight subfamilies (ABCA–H) based on phylogenetic analysis. The temporal and spatial expression profiles suggested that the nymphal stages (1st–5th) and adult males showed similarity, which was different from eggs and adult females, and NlABCA1, NlABCA2, NlABCB6, NlABCD2, NlABCG4, NlABCG12, NlABCG15, and NlABCH1 were highly expressed in the midgut and Malpighian tubules. In addition, ABCG12, which belongs to the ABC transporter G subfamily, was significantly upregulated after exposure to sulfoxaflor, nitenpyram, clothianidin, etofenprox, chlorpyrifos, and isoprocarb. Moreover, verapamil significantly increased the sensitivity of N. lugens to nitenpyram, clothianidin, etofenprox, chlorpyrifos, and isoprocarb. These results provide a basis for further research on ABC transporters involved in detoxification in N. lugens, and for a more comprehensive understanding of the response of N. lugens to environmental stress.

[Clinical application effects of portable visual retractor in superficial temporal fascia flap harvesting]

Objective: To explore the clinical application effects of portable visual retractor in superficial temporal fascia flap harvesting. Methods: From January 2010 to June 2019, 27 patients meeting the inclusion criteria and planning to perform operation of superficial temporal fascia flap harvesting were admitted to the Department of Plastic and Reconstructive Surgery of the First Clinical Medical Center of the People's Liberation Army General Hospital. The patients were divided into traditional surgical method group [6 males and 3 females, aged (34±14) years], cold light source retractor group [6 males and 4 females, aged (35±16) years], and portable visual retractor group [7 males and 1 female, aged (30±14) years] according to way of superficial temporal fascia flap harvesting. The superficial temporal fascia flaps of patients in traditional surgical method group were resected by traditional way of resection, and the superficial temporal fascia flaps of patients in cold light source retractor group and portable visual retractor group were resected at assistance of cold light source retractor and portable visual retractor, respectively. Length of incision, operation time, intraoperative blood loss volume, postoperative drainage volume, and postoperative complication of patients in 3 groups were observed and recorded. Data were processed with Fisher's exact probability test, one-way analysis of variance, least significant difference test, Kruskal-Wallis H test, and Bonferroni correction. Results: The length of incision of patients in visual retractor group was (3.6±0.8) cm, significantly shorter than (12.6±1.6) cm in traditional surgical method group and (5.8±0.9) cm in cold light source retractor group (P<0.05). The incision length of patients in traditional surgical method group was significantly longer than that in cold light source retractor group (P<0.05). The operation time of patients in visual retractor group was 24.0 (23.3, 25.8) min, significantly shorter than 35.0 (30.5, 36.5) min in traditional surgical method group and 28.5 (26.8, 30.5) min in cold light source retractor group (H=16.5, 9.8, P<0.05). The operation time of patients in traditional surgical method group was significantly longer than that in cold light source retractor group (H=6.6, P<0.05). The intraoperative blood loss volume was (26±3) mL of patients in visual retractor group, significantly less than (34±4) mL in traditional surgical method group and (30±6) mL in cold light source retractor group (P<0.05). The intraoperative blood loss volume of patients in traditional surgical method group was significantly more than that in cold light source retractor group (P<0.05). The postoperative drainage volumes of patients in visual retractor group, cold light source retractor group, and traditional surgical method group were (33±4), (34±6), and (31±7) mL, respectively, and there were no significantly statistical differences in postoperative drainage volumes among patients in the three groups (F=0.3, P>0.05). There were no severe complications such as ischemia and necrosis of superficial temporal fascia flaps in patients of the three groups. One patient in cold light source retractor group had subcutaneous hematoma after operation, which was improved by removing stitches and hematoma. Conclusions: Superficial temporal fascia flap harvesting at the assistance of portable visual retractor has the advantages of clear visual field, simple operation, short operation time, small incision, and less intraoperative blood loss.

Chitinase-like protein YKL-40 regulates human bronchial epithelial cells proliferation, apoptosis, and migration through TGF-β1/Smads pathway

In order to study the effects of chitinase-like protein YKL-40 on proliferation, apoptosis, and migration of human bronchial epithelial cell line (BEAS-2B), and the underlying mechanisms, we cultured BEAS-2B alone or with different concentrations of YKL-40. thiazolyl blue tetrazolium bromide (MTT) assay was used to examine the cell proliferation. Annexin V-fluorescein isothiocyanate isomer (FITC)/propidium iodide staining and scratch assay were performed to test the cell apoptosis and migration. The concentrations of transforming growth factor-β1 (TGF-β1), Smad3, Smad7, alpha-smooth muscle actin (α-SMA), interleukin-4 (IL-4), IL-6, and IL-8 in the cell culture supernatant were detected by enzyme-linked immunosorbent assay. The messenger RNA and protein levels of YKL-40, TGF-β1, Smad3, Smad7, and α-SMA were detected by reverse transcription polymerase chain reaction and Western blot. BEAS-2B cells cultured with different concentrations of YKL-40 showed significantly higher cell proliferation and migration and inflammatory cytokines compared with that of control group, while the cell apoptosis was significantly lower than that of control group (p < 0.05). In addition, BEAS-2B cells cultured with YKL-40 had increased TGF-β1, Smad3, Smad7, and α-SMA levels in the supernatant, compared with that of BEAS-2B cells cultured alone (p < 0.05). Furthermore, LY364947, as TGF-β1/Smads signaling pathway inhibitor, decreased cell proliferation and migration ability and enhanced cell apoptosis of BEAS-2B cells compared with control group (p < 0.05). However, YKL-40 administration reversed the effect of LY364947 on the biological behavior of BEAS-2B cells. YKL-40 could affect the biological behaviors of BEAS-2B cells, which might be related to the TGF-β1/Smads pathway.

Inheritance and fitness costs of sulfoxaflor resistance in Nilaparvata lugens (Stål)

BACKGROUND

Sulfoxaflor has been considered as a new tool for Nilaparvata lugens control in the field. In this study, a laboratory-selected resistant strain and a susceptible strain were used to evaluate the inheritance and fitness costs of sulfoxaflor resistance in N. lugens.

RESULTS

The resistant strain (SFX-SEL) showed 123.63-fold resistance compared with the susceptible strain (SS). Progenies of reciprocal crosses (F₁ RS and F₁ SR) showed similar concentration-mortality responses (LC₅₀ ) to sulfoxaflor and also exhibited a similar degree of dominance; -0.16 for F₁ RS and -0.26 for F₁ SR. Significant differences between the observed and expected mortalities of F₂ individuals suggested that sulfoxaflor resistance is associated with multiple genes. The resistant strain had a relative fitness of 0.75 with substantially decreased female adult period, oviposition days, total fecundity, egg hatchability and female adult survival rate, and prolonged pre-adult period and total pre-oviposition period.

CONCLUSION

Sulfoxaflor resistance in N. lugens was inherited as autosomal, incompletely recessive and multigene. The development of resistance may have a significant fitness cost for the resistant population. Current research provides valuable information for researchers to establish management strategies to delay the development of sulfoxaflor resistance and control N. lugens sustainably in the field. © 2019 Society of Chemical Industry.

[Situation analysis of timing of first visit of anti-mitochondrial antibody-positive patients]

Objective: To understand the basic information of anti-mitochondrial antibody (anti-AMA)-positive patients after initial diagnosis, and to set groundwork for further exploring the clinical significance of AMA in various diseases. Methods: Demographic data and related clinical information recorded through the Information System of Peking University People's Hospital from January 2013 to December 2016 were collected. Patients whose AMA and/or AMA-M2 first- tested as positive were recorded. Complications were classified according to the International Classification of Diseases. Results: A total of 1323 AMA positive cases were discovered for the first time. Among them, 78.0% were women, and the age of initial diagnosis was 56.8 ± 16.0 years. The first three initially diagnosed departments were rheumatology and immunology (37.4%), liver Disease (15.9%) and hematology (15.9%) relevant to musculoskeletal and connective tissue diseases (45.2%), hematology and hematopoietic organs and immune diseases (30.6%) and circulatory system diseases (29.7%). There were 297 newly confirmed cases of primary biliary cholangitis (PBC); accounting for 89.2% of women, and the age of initial diagnosis was 60.1 ± 12.4 years. The top three departments of initially diagnosed as PBC were liver disease (37.7%), rheumatology (33.0%) and gastroenterology (15.2%), of which 39.7% had musculoskeletal and connective tissue diseases, 27.9% had circulatory diseases, and 24.9 % were combined with endocrine and metabolic diseases. Conclusion: Besides PBC and other autoimmune diseases, AMA and / or AMA-M2 positivity can be observed in a variety of diseases in several clinical departments, and its clinical significance remains to be further clarified.

Cross-resistance and biochemical characterization of buprofezin resistance in the white-backed planthopper, Sogatella furcifera (Horvath)

Buprofezin is a chitin synthesis inhibitor that is very effective against Homopteran pests, such as the white-backed planthopper (WBPH), S. furcifera (Horvath). In the present study, resistance selection, cross-resistance and mechanisms of buprofezin resistance were investigated in this planthopper species. However, the mechanism associated with resistance to growth regulator insecticides (IGRs) remains largely unknown. A resistant strain (Bup-R) with a resistance level (22-fold) to buprofezin was developed through continuous selection for 47 generations from a laboratory susceptible strain (Bup-S). The results showed that the Bup-R exhibited no cross-resistance to other tested insecticides. Synergism tests showed that piperonyl butoxide (PBO) (SR = 3.9-fold) and diethyl maleate (DEM) (SR = 1.8-fold) had synergistic effects on buprofezin toxicity in the resistant strain (F₄₇). Enzyme activity results revealed an approximate 5.7-fold difference in cytochrome P450 monooxygenase and a 2-fold difference in glutathione S-transferase (GST) between the resistant and susceptible strains, suggesting that the increased activity of these two enzymes is likely the main detoxification mechanism involved in resistance to buprofezin in this species. Furthermore, the mRNA expression levels of cytochrome P450 (CYP) and GST genes by quantitative real-time PCR results indicated that sixteen P450 and one GST gene were significantly overexpressed in the Bup-R strain, among which thirteen P450 genes and one GST gene were >2-fold higher than in the Bup-S strain. The present study increases our knowledge of the buprofezin resistance mechanism in S. furcifera and provides a useful reference for integrated pest management (IPM) strategies.

Emergence of a real-space symmetry axis in the magnetoresistance of the one-dimensional conductor Li0.9Mo6O17

We report on an emerging symmetry axis in the magnetoresistance of bulk single crystals of quasi-one-dimensional Li_0.9Mo₆O₁₇ below T _min = 25 K, the temperature at which the electrical resistivity experiences a minimum. Detailed angle-dependent magnetoresistance sweeps reveal that this symmetry axis is induced by the development of a negative magnetoresistance, which is suppressed only for magnetic fields oriented along the poles of the MoO₆ octahedra that form the conducting chains. We show that this unusual negative magnetoresistance is consistent with the melting of dark excitons, composed of previously omitted orbitals within the t _2g manifold that order below T _min. The unveiled symmetry axis in directional magnetic fields not only provides evidence for the crystallization of these dark excitons but also sheds new light on the long-standing mystery of the metal-insulator transition in Li_0.9Mo₆O₁₇.

Characterization of nitenpyram resistance in Nilaparvata lugens (Stål)

Nitenpyram is very effective in controlling Nilaparvata lugens (brown planthopper, BPH), and its resistance has been reported in field populations; however, the resistance mechanism remains unclear. In the present study, cross-resistance and resistance mechanisms in nitenpyram-resistant BPH were investigated. A resistant strain (NR) with a high resistance level (164.18-fold) to nitenpyram was evolved through successive selection for 42 generations from a laboratory susceptible strain (NS). The bioassay results showed that the NR exhibited cross-resistance to imidacloprid (37.46-fold), thiamethoxam (71.66-fold), clothianidin (149.17-fold), dinotefuran (98.13-fold), sulfoxaflor (47.24-fold), cycloxaprid (9.33-fold), etofenprox (10.51-fold) and isoprocarb (9.97-fold) but not to triflumezopyrim, chlorpyrifos and buprofezin. The NR showed a 3.21-fold increase in cytochrome P450 monooxygenase (P450) activity compared to that in the NS, while resistance was also synergized (4.03-fold) with the inhibitor piperonyl butoxide (PBO), suggesting a role of P450. Furthermore, the mRNA expression levels of cytochrome P450 (CYP) genes by quantitative real-time PCR results indicated that twelve P450 genes were significantly overexpressed in the NR strain, especially CYP6ER1 (203.22-fold). RNA interference (RNAi) suppression of CYP6ER1 through injection of dsCYP6ER1 led to significant susceptibility in the NR strain. The current study expands our understanding of the nitenpyram resistance mechanism in N. lugens, provides an important reference for integrated pest management (IPM), and enriches the theoretical system of insect toxicology.

Characterization of sulfoxaflor resistance in the brown planthopper, Nilaparvata lugens (Stål)

BACKGROUND

Sulfoxaflor is a new insecticide for controlling Nilaparvata lugens in the field. This study was conducted to investigate the risk of resistance development, the cross-resistance spectrum and the mechanisms of sulfoxaflor resistance in N. lugens.

RESULTS

A sulfoxaflor-resistant strain was obtained from a field population by successive selection with sulfoxaflor for 39 generations in the laboratory. Sulfoxaflor-resistant populations showed significant levels of cross-resistance to dinotefuran, nitenpyram, thiamethoxam, clothianidin, imidacloprid and cycloxaprid. However, they exhibited only minor or no cross-resistance to isoprocarb, etofenprox, chlorpyrifos, triflumezopyrim and buprofezin. Sulfoxaflor was synergized by the inhibitor piperonyl butoxide (PBO) in the sulfoxaflor-resistant strain (SFX-SEL) with 2.69-fold relative synergistic ratios compared with the unselected strain (UNSEL). Compared with UNSEL, the P450 enzyme activity of SFX-SEL was increased 3.50 times, and eight P450 genes were upregulated more than 2.0-fold in SFX-SEL. RNAi reduced the expression of CYP6ER1 (36.87-fold change) and significantly enhanced the susceptibility of SFX-SEL to sulfoxaflor.

CONCLUSION

Resistance development and cross-resistance risk of sulfoxaflor-resistance in N. lugens is evident. The enhanced detoxification of P450 enzymes caused by upregulation of several P450 genes is considered to be the metabolic resistance mechanism. These results suggest that CYP6ER1 might play an important role in sulfoxaflor resistance in N. lugens. © 2018 Society of Chemical Industry.

The influence of temperature on the toxicity of insecticides to Nilaparvata lugens (Stål)

The toxicity of insecticides is associated with a variety of factors including temperature, and global warming is bound to lead to the outbreak of pests; therefore, it is important to study the influence of temperature on insecticide toxicity and pest control. In this study, the influence of temperature on the toxicity of insecticides to Nilaparvata lugens (BPH) was determined. The results showed that the sensitivity of BPH to cycloxaprid (LC₅₀ = 42.5-0.388 mg/L), nitenpyram (LC₅₀ = 3.49-0.187 mg/L), triflumezopyrim (LC₅₀ = 0.354-0.0533 mg/L) and chlorpyrifos (LC₅₀ = 36.3-7.41 mg/L) increased significantly when the temperature changed from 18 °C to 36 °C. BPH sensitivity to etofenprox (LC₅₀ = 9.04-54.2 mg/L) was also affected by temperature. Additionally, the feeding amount and the activities of three detoxification enzymes [cytochrome P450 (P450), glutathione S-transferase (GST) and carboxylesterase (CarE)] of BPH at different temperatures were also measured. The feeding amounts were positively correlated with temperature increases while the activities of P450 and GST were significantly inhibited. The correlation analysis showed that changes in P450 activity (but not GST activity) were closely related to the sensitivity of BPH to cycloxaprid, nitenpyram, chlorpyrifos, and etofenprox according to the variation in temperatures. This study provides a theoretical basis for the rational use of chemical pesticides under the global warming trend and provides a reference for the integrated management of BPH in the field.

Overexpression of CYP6ER1 associated with clothianidin resistance in Nilaparvata lugens (Stål)

The brown planthopper, Nilaparvata lugens (Stål), is one of the most economically important rice pests in Asia and has become resistant to various kinds of insecticides, including neonicotinoid insecticides. In this study, an N. lugens clothianidin-resistant (CLR) strain and a susceptible (CLS) strain were established, and the potential resistance mechanisms of N. lugens to clothianidin were elucidated. The cross-resistance studies showed that the clothianidin-resistant strain exhibited cross-resistance to most neonicotinoid insecticides, especially nitenpyram (99.19-fold) and dinotefuran (77.68-fold), while there was no cross-resistance to chlorpyrifos (1.79-fold). The synergism assays and the activities of the detoxification enzymes were performed, and we found that a cytochrome P450 conferred the clothianidin resistance. Two P450 genes (CYP6ER1 and CYP6AY1) were found to be significantly overexpressed in the CLR strain compared with the CLS strain based on qRT-PCR. In addition, the knockdown of CYP6ER1 by RNA interference dramatically increased the toxicity of clothianidin against N. lugens. These data demonstrated that the overexpression of CYP6ER1 could contribute to clothianidin resistance in N. lugens. Our findings will help to improve the design of effective resistance management strategies to control brown planthoppers.