Withaferin A inhibits ferroptosis and protects against intracerebral hemorrhage.

Recent studies have indicated that suppressing oxidative stress and ferroptosis can considerably improve the prognosis of intracerebral hemorrhage (ICH). Withaferin A (WFA), a natural compound, exhibits a positive effect on a number of neurological diseases. However, the effects of WFA on oxidative stress and ferroptosis-mediated signaling pathways to ICH remain unknown. In this study, we investigated the neuroprotective effects and underlying mechanism for WFA in the regulation of ICH-induced oxidative stress and ferroptosis. We established a mouse model of ICH by injection of autologous tail artery blood into the caudate nucleus and an in vitro cell model of hemin-induced ICH. WFA was injected intracerebroventricularly at 0.1, 1 or 5 µg/kg once daily for 7 days, starting immediately after ICH operation. WFA markedly reduced brain tissue injury and iron deposition and improved neurological function in a dose-dependent manner 7 days after cerebral hemorrhage. Through in vitro experiments, cell viability test showed that WFA protected SH-SY5Y neuronal cells against hemin-induced cell injury. Enzyme-linked immunosorbent assays in vitro and in vivo showed that WFA markedly decreased the level of malondialdehyde, an oxidative stress marker, and increased the activities of anti-oxidative stress markers superoxide dismutase and glutathione peroxidase after ICH. Western blot assay, quantitative polymerase chain reaction and immunofluorescence results demonstrated that WFA activated the nuclear factor E2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling axis, promoted translocation of Nrf2 from the cytoplasm to nucleus, and increased HO-1 expression. Silencing Nrf2 with siRNA completely reversed HO-1 expression, oxidative stress and protective effects of WFA. Furthermore, WFA reduced hemin-induced ferroptosis. However, after treatment with an HO-1 inhibitor, the neuroprotective effects of WFA against hemin-induced ferroptosis were weakened. MTT test results showed that WFA combined with ferrostatin-1 reduced hemin-induced SH-SY5Y neuronal cell injury. Our findings reveal that WFA treatment alleviated ICH injury-induced ferroptosis and oxidative stress through activating the Nrf2/HO-1 pathway, which may highlight a potential role of WFA for the treatment of ICH.

Neutrophil to high-density lipoprotein cholesterol ratio predicts adverse cardiovascular outcomes in subjects with pre-diabetes: a large cohort study from China.

BACKGROUND: This study aimed to examine whether the neutrophil to high-density lipoprotein cholesterol ratio (NHR) can predict cardiovascular outcomes in normoglycemic individuals with elevated fasting glucose levels. METHODS: A total of 130,801 participants with normal blood glucose levels were enrolled in the Kailuan study. Participants were categorized according to NHR quartiles and further divided into normal glucose regulation (NGR) and pre-diabetes (pre-DM) subgroups. The follow-up endpoint was major adverse cardiovascular events (CVE), including stroke and myocardial infarction. RESULTS: Over a median of 12.53 (8.95-13.08) years of follow-up, subjects with NHR levels in the highest quartile experienced more CVE than those with NHR levels in the lowest quartile. Multivariate Cox analyses showed that continuous changes in NHR (hazard ratio, 1.21; 95% confidence interval [CI], 1.15-1.28) and the highest quartile of NHR (hazard ratio, 1.30; 95% CI, 1.21-1.39) were independent predictors of CVE (all P < 0.001). Furthermore, when participants were categorized by both NHR quartile and glucose metabolism status, the NHR level in the highest quartile plus pre-DM group was associated with a 1.60-fold (95% CI, 1.38-1.86; P < 0.001] higher risk of CVE than that in the lowest quartile plus normoglycemic group. Significantly, the addition of NHR only, presence of pre-DM only, or combination of NHR and pre-DM to the prediction algorithm, including traditional risk factors, improved the C-statistic by 0.19, 0.05, and 0.23 (all P < 0.001). CONCLUSIONS: Elevated NHR or fasting blood glucose level were independently associated with a higher risk of CVE among normoglycemic individuals. Moreover, pre-DM participants with high NHR levels tended to have worse prognosis, suggesting that NHR could provide greater risk stratification value than traditional risk factors for subjects with pre-DM.

The Potential Vector Competence and Overwintering of West Nile Virus in Vector Aedes Albopictus in China.

West Nile virus (WNV) is an arbovirus, which causes widespread zoonotic disease globally. In China, it was first isolated in Jiashi County, Kashgar Region, Xinjiang in 2011. Determining the vector competence of WNV infection has important implications for the control of disease outbreaks. Four geographical strains of Aedes Albopictus (Ae. Albopictus) in China were allowed to feed on artificial infectious blood meal with WNV to determine the infection and transmission rate. The results indicated that four strains of Ae. Albopictus mosquitoes could infect and transmit WNV to 1- to 3-day-old Leghorn chickens. The infection rates of different strains were ranged from 16.7 to 60.0% and were statistically different (χ2 = 12.81, p < 0.05). The highest infection rate was obtained from the Shanghai strain (60.0%). The transmission rates of Ae. Albopictus Shanghai, Guangzhou, Beijing, and Chengdu strains were 28.6, 15.2, 13.3, and 6.7%, respectively. Furtherly, the results reveal that Ae. Albopictus Beijing strain infected orally can transmit WNV transovarially even the eggs are induced diapausing. The study confirmed that WNV could survive in the diapause eggs of Ae. Albopictus and could be transmitted to progeny after diapause termination. This is of great significance for clarifying that the WNV maintains its natural circulation in harsh environments through inter-epidemic seasons.

Mitochondrial Ca2+ regulation in the etiology of heart failure: physiological and pathophysiological implications.

Heart failure (HF) represents one of the leading causes of cardiovascular diseases with high rates of hospitalization, morbidity and mortality worldwide. Ample evidence has consolidated a crucial role for mitochondrial injury in the progression of HF. It is well established that mitochondrial Ca2+ participates in the regulation of a wide variety of biological processes, including oxidative phosphorylation, ATP synthesis, reactive oxygen species (ROS) generation, mitochondrial dynamics and mitophagy. Nonetheless, mitochondrial Ca2+ overload stimulates mitochondrial permeability transition pore (mPTP) opening and mitochondrial swelling, resulting in mitochondrial injury, apoptosis, cardiac remodeling, and ultimately development of HF. Moreover, mitochondria possess a series of Ca2+ transport influx and efflux channels, to buffer Ca2+ in the cytoplasm. Interaction at mitochondria-associated endoplasmic reticulum membranes (MAMs) may also participate in the regulation of mitochondrial Ca2+ homeostasis and plays an essential role in the progression of HF. Here, we provide an overview of regulation of mitochondrial Ca2+ homeostasis in maintenance of cardiac function, in an effort to identify novel therapeutic strategies for the management of HF.

Susceptibility of Armigeres subalbatus Coquillett (Diptera: Culicidae) to Zika virus through oral and urine infection.

BACKGROUND: Zika virus (ZIKV) disease outbreaks have been occurring in South America since 2015, and has spread to North America. Because birth defects and cases of Guillain Barré have been associated with infection with ZIKV, this has drawn global attention. ZIKV is generally considered an Aedes-transmitted pathogen. The transmission of ZIKV through blood by Aedes mosquito bites has been recognized as the major transmission route. However, it is not clear whether there are other transmission routes that can cause viral infection in mosquitos. The aim of the present study is to describe the susceptibility of Armigeres subalbatus, which often develop in human waste lagoons, to ZIKV, through oral infection in adult mosquitoes and urine infection in larvae. METHODOLOGY/PRINCIPAL FINDINGS: Five-day-old female Ar. subalbatus ingested infectious blood meals containing ZIKV. After 4, 7, and 10 days of ingesting infectious blood meals, ZIKV could be detected in the midguts, salivary glands, ovaries, and collected saliva of mosquitoes. The ZIKV infection rate (IR) on day 10 reached 40% in salivary glands and 13% in saliva, indicating that these mosquitoes were able to transmit ZIKV. In addition, ZIKV infection was also discovered in mosquito ovaries, suggesting the possibility of vertical transmission of virus. Moreover, Ar. subalbatus transmitted ZIKV to infant mice bitten by infectious mosquitoes. In a second experiment, 1st-instar larvae of Ar. subalbatus were reared in water containing ZIKV and human urine. After pupation, pupae were placed in clean water and transferred to a mosquito cage for emergence. Although ZIKV RNA was detected in all of the larvae tested, ZIKV was not detected in the saliva of any adult Ar. subalbatus. Considering that there are more uncontrollable factors in nature than in the laboratory environment, the possibility that the virus is transmitted to adult mosquitoes via larvae is very small period. CONCLUSIONS/SIGNIFICANCE: Adult Ar. subalbatus could be infected with ZIKV and transmit ZIKV through mosquito bites. Therefore, in many rural areas in China and in undeveloped areas of other Asian countries, the management of human waste lagoons in the prevention and control of Zika disease should be considered. Corresponding adjustments and modifications should also be made in prevention and control strategies against ZIKV.

Polymorphisms in arsenic (+ 3 oxidation state) methyltransferase (AS3MT) predict the occurrence of hyperleukocytosis and arsenic metabolism in APL patients treated with As2O3.

Polymorphisms in arsenic (+ 3 oxidation state) methyltransferase (AS3MT) have been shown to be related to interindividual variations in arsenic metabolism and to influence adverse health effects in acute promyelocytic leukemia (APL) patients treated with arsenic trioxide (As2O3). The occurrence of hyperleukocytosis with As2O3 treatment seriously affects the early survival rate of APL patients, but no definite explanation for such a complication has been clearly established. To clarify the causes of this situation, AS3MT polymorphisms 14215 (rs3740390), 14458 (rs11191439), 27215 (rs11191446), and 35991 (rs10748835) and profiles of plasma arsenic metabolites were evaluated in a group of 54 newly diagnosed APL patients treated with single-agent As2O3. High-performance liquid chromatography-hydride generation-atomic fluorescence spectrometry (HPLC-HG-AFS) was used to determine the concentrations of plasma arsenic metabolites. Plasma arsenic methylation metabolism capacity was evaluated by the percentage of inorganic arsenic (iAs), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), primary methylation index (PMI, MMA/iAs), and secondary methylation index (SMI, DMA/MMA). The results showed that APL patients who developed hyperleukocytosis had a higher plasma iAs%, but a lower MMA% and PMI than those who did not develop hyperleukocytosis during As2O3 treatment. In addition, patients with the AS3MT 14215 (rs3740390) CC genotype had significantly higher plasma iAs% and incidence of hyperleukocytosis, but lower PMI than patients with the CT + TT genotype. Conversely, we did not observe statistically significant associations between the occurrence of hyperleukocytosis and AS3MT 14458 (rs11191439), 27215 (rs11191446), and 35991 (rs10748835) polymorphisms in our study subjects. These results indicated that AS3MT 14215 (rs3740390) might be used as an indicator for predicting the occurrence of hyperleukocytosis in APL patients treated with As2O3.

RNA interference of odorant receptor CquiOR114/117 affects blood-feeding behavior in Culex quinquefasciatus.

The odorant receptors (ORs) play a critical role for mosquitoes in the identification of blood-feeding hosts and other physiological processes. The OR8 subfamily in mosquitoes has been shown to be strongly involved in the detection the mammalian host associated odor, 1-octen-3-ol. CquiOR114/117 has been shown to be an orthologous OR8 in Culex quinquefasciatus Say. In this study, the expression of CquiOR114/117 in the different developmental stages of Cx. quinquefasciatus was detected by the amplification of CquiOR114/117 with real-time fluorescence quantitative polymerase chain reaction (PCR). RNA interference (RNAi) technology was used to interfere with the expression of CquiOR114/117 in females to observe the blood-feeding behavior change. The results showed that the expression level of CquiOR114/117 in the egg-to-pupa stage was significantly lower than that in the adult stage and that the expression level of the female mosquitoes peaked on the third day after emergence. The expression of CquiOR114/117 was significantly decreased in the 2-6 days after the injection of dsRNA compared with the control groups. The analysis of the blood-feeding behavior showed a significant positive correlation between CquiOR114/117 expression and the engorgement rate of the mosquitoes. CquiOR114/117 is speculated to have an effect on the blood-feeding behavior of Cx. quinquefasciatus.

[Effect of Daunorubicin on Release and Procoagulant Activity of Microparticles Derived from Acute Promyelocytic Leukemia Cells].

OBJECTIVE: To investigate the effect of daunorubicin on the number and procoagulant activity of Microparticles derived from acute promyelocytic leukemia(APL) cells. METHODS: APL cells were isolated from bone Marrow of 5 newly diagnosed APL patients, the bone marrow mononuclear cells were collected from 5 patients with iron deficiency anemia as control.APL cells were treated with different concentration of daunorubicin(0.1,0.5,1.0 and 2.0µmol/L) for 24 h. Microparticles were extracted from the cell culture medium for qualitative anaysis of the extracted microparticles.The morphologic features of the microparticles were observed by transmission electron microscopy.The number of microparticles was detected by flow cytometry.The procoagulant activity of microparticles was measured by recalcification time assays. RESULTS: Under a transmission electron microscope, theextracted microparticles took a round or oval morphology with a transparent center,and their diameters were arund 100nm, consistent with the morphological characteristics of microparticles. Compared with bone marrow mononuclear cells-derived microparticles,the counts of the bone marrow APL cells-derived microparticles significantly increased(P<0.05).Daunorubicin increased the shedding of microparticles in a dose-dependent manner(r=0.73,P<0.01).Compared with normal bone marrow mononuclear cells-derived microparticles,bone marrow APL cells-derived microparticles showed higher procoagulant activity(P<0.05).Daunorubicin treatment enhanced the prccoagulant activity of APL cells-derived microparticles which paralleled the increasing drug concentrations(r=-0.78,P<0.01). CONCLUSION: Daunorubicin can promote the release of APL cells-derived microparticles and enhance their related procoagulan activity.

[Role of Microparticles Derived from Acute Promyelocytic Leukemia Cells in Coagulopathy].

OBJECTIVE: To evaluate the role of microparticle (MP) derived from acute promyelocytic leukemia (APL) cells and tissue factor (TF) carried by the MP in hypercoagulable state, and the effect of treatment with cytotoxic chemotherapy/differentiating agents on procoagulant activity (PCA) of these MP. METHODS: Bone marrow mononuclear cells (BMMNC) were extracted from 5 APL patients and 5 sex- and age- matched patients with iron deficiency anemia as controls. The cells were cultured in vitro for 48 h, then MP-rich culture medium and MP-free culture medium were harvested and MP was further obtained from certain volume of MP-rich culture medium. Subsequently, TF expression on MP was measured by ELISA. PCA of MP-rich culture medium or MP-free culture medium was assessed with thrombin generation assay. The role of TF on MP-related PCA was evaluated using anti-human TF antibody. In addition, APL cells were treated with all-trans retinoic acid (ATRA), arsenic trioxide (ATO) or daunorubicin (DNR) for 48 h, then MP-rich culture medium were harvested and the PCA was determined. RESULTS: No TF expression was found in the MP released from bone marrow MNC in control group, whereas the obvious TF expression was found in the MP originated from BMMNC of APL. MP from both APL and control BM-MNC had obvious PCA. However, compared with the MP derived from control MNC, the MP from APL BM-MNC induced significantly higher PCA. TF played a crucial role in the PCA of APL BM-MNC derived MP, while played no role in that of MP from control MNCs. DNR-treating APL BM-MNC resulted in an increase in the PCA of MP, whereas ATO or ATRA exposure lead to exactly the opposite results. CONCLUSION: MP derived from APL BM-MNC posseses obvious PCA. TF plays a crucial role in the MP-related PCA. The PCA of MP increases after treating APL BM-MNC with chemotherapy agent DNR and decreases following exposure of APL BM-MNC to differentiating agents ATRA or ATO.

Vector competence and transovarial transmission of two Aedes aegypti strains to Zika virus.

Zika virus (ZIKV) has become a serious threat to global health since the outbreak in Brazil in 2015. Additional Chinese cases have continuously been reported since the first case of laboratory-confirmed ZIKV infection in China on 6 February 2016. Aedes aegypti is the most important vector for ZIKV. This study shows that two strains from China exhibit high levels of midgut infection and highly disseminated infection of salivary glands and ovaries. Both strains can transmit ZIKV to infant mice bitten by infectious mosquitoes. Moreover, the results provide the evidence of transovarial transmission of ZIKV in mosquitoes. The study indicates that the two Ae. aegypti strains are not only effective transmission vectors but also persistent survival hosts for ZIKV during unfavorable inter-epidemic periods. This function as a reservoir of infection has epidemiological implications that further enhance the risk of potential future outbreaks.

Identification of Differentially Expressed Genes In Deltamethrin-Resistant Culex pipiens quinquefasciatus.

Culex quinquefasciatus is one of China's major house-dwelling mosquito species and an important vector of filariasis and encephalitis. Chemical treatments represent one of the most successful approaches for comprehensive mosquito prevention and control. However, the widespread use of chemical pesticides has led to the occurrence and development of insecticide resistance. Therefore, in-depth studies of resistance to insecticides are of vital importance. In this study, we performed a gene expression analysis to investigate genes from Cx. quinquefasciatus that may confer pyrethroid resistance. We aimed to understand the mechanisms of Cx. quinquefasciatus resistance to pyrethroid insecticides and provide insights into insect resistance management. Using a resistance bioassay, we determined the deltamethrin LC50 values (lethal concentration required to kill 50% of the population) for Cx. quinquefasciatus larvae in the F21, F23, F24, F26, F27, and F30 generations. The 7 tested strains exhibited pesticide resistance that was 25.25 to 87.83 times higher than that of the SanYa strain. Moreover, the expression of the OBPjj7a (odorant-binding protein OBPjj7a), OBP28 (odorant-binding protein OBP28), and E2 (ubiquitin-conjugating enzyme) genes was positively correlated with deltamethrin resistance ( R2 = 0.836, P = 0.011; R2 = 0.788, P = 0.018; and R2 = 0.850, P = 0.009, respectively) in Cx. quinquefasciatus. The expression of 4 additional genes, H/ACA, S19, SAR2, and PGRP, was not correlated with deltamethrin resistance. In summary, this study identified 3 Cx. quinquefasciatus genes with potential involvement in deltamethrin resistance, and these results may provide a theoretical basis for the control of mosquito resistance and insights into resistance detection.

The effectiveness of a comprehensive reminder system in the secondary prevention of hypertensive ischaemic stroke: randomized controlled trial protocol.

AIM: The aim of this study was to determine whether the Comprehensive Reminder System based on the Health Belief Model improves health belief, health behaviours, medication adherence and blood pressure control as a means of decreasing the rate of stroke recurrence among hypertensive ischaemic stroke. BACKGROUND: Hypertensive patients having experienced recent ischaemic strokes are at high risk for stroke recurrence. Several trials attempted to improve secondary stroke prevention via patient education, however, patient outcomes remained poor. Long-term follow-up studies regarding secondary stroke prevention are limited. DESIGN: A multi-centre, 12-month, assessor-blinded, parallel-group, randomized controlled longitudinal trial. METHODS: Hypertensive patients having experienced an ischaemic stroke are the target population. The intervention consists of health belief education, a calendar handbook, a weekly automated short-message service and four telephone follow-up interviews. Outcomes will be assessed at baseline and at 3, 6 and 12 months following discharge. The primary outcome is blood pressure control. The secondary outcomes include health belief, health behaviours and medication adherence. The clinical endpoint is the rate of stroke recurrence. DISCUSSION: Although many efforts to improve secondary stroke prevention have been undertaken, research indicates that improvements remain possible and warranted. This research protocol based on the Health Belief Model will improve our understanding of stroke education and transitional care needed in China and with the world-wide target population.

Vector competence of Aedes albopictus and Aedes aegypti (Diptera: Culicidae) for the DEN2-FJ10 and DEN2-FJ11 strains of the dengue 2 virus in Fujian, China.

Dengue is an acute, emerging, infectious disease transmitted by Aedes mosquitoes that has become a serious global public health problem. The DEN2-FJ10 and DEN2-FJ11 strains of the dengue 2 virus were originally isolated from the serum of a patient with dengue fever in Fujian Province, China, in 1999. Our data provide the first assessment of the vector competence of Aedes mosquitoes with respect to the DEN2-FJ10 and DEN2-FJ11 strains of the dengue virus. There were significant differences in the replication rates of these two viral strains in Aedes albopictus and Aedes aegypti (P<0.05); replication of the DEN2-FJ10 strain was greater in Ae. aegypti than in Ae. albopictus 5 days post infection whereas replication of the DEN2-FJ11 was greater in Ae. albopictus than in Ae. aegypti 7 days post infection. The replicative ability of the DEN2-FJ11 strain was greater than that of the DEN2-FJ10 strain in infected Ae. albopictus. In infected Ae. aegypti, rapid proliferation of the DEN2-FJ10 strain occurred earlier than in the DEN2-FJ11 strain. There were no significant differences in the midgut and salivary gland infection rates of Ae. albopictus and Ae. aegypti with respect to either viral strain. Although the DEN2-FJ10 and DEN2-FJ11 strains differ in their virulence to neonatal rats, there was no significant difference in the ability of either Ae. albopictus or Ae. aegypti to transmit the DEN2-FJ10 and DEN2-FJ10 strains of the dengue 2 virus (P>0.05). In summary, our results indicate that Ae. albopictus and Ae. aegypti mosquitoes are moderately competent vectors of the DEN2-FJ10 and DEN2-FJ11 strains of the dengue virus and provide the first evidence of the effect of these two viral strains on the vector competence of mosquitoes in China.

Multiple-Insecticide Resistance and Classic Gene Mutations to Japanese Encephalitis Vector Culex tritaeniorhynchus from China.

Widespread resistance of insect pests to insecticides has been widely reported in China and there is consequently an urgent need to adjust pest management strategies appropriately. This requires detailed information on the extent and causes of resistance. The aim of the present study was to investigate levels of resistance to 5 insecticides among 12 strains of Culex tritaeniorhynchus, a major vector of Japanese encephalitis in China. Resistance to deltamethrin, beta-cypermethrin, permethrin, dichlorvos, and propoxur were measured using larval bioassays. The allelic frequency of knockdown resistance (kdr) and acetylcholinesterase (AChE) mutations were determined in all strains. Larval bioassay results indicated that the field strains collected from different sites were resistant to deltamethrin, beta-cypermethrin, permethrin, dichlorvos, and propoxur, with resistance ratio values ranging from 1.70- to 71.98-fold, 7.83- to 43.07-fold, 3.54- to 40.03-fold, 291.85- to 530.89-fold, and 51.32- to 108.83-fold, respectively. A polymerase chain reaction amplification of specific alleles method for individual was developed to detect genotypes of the AChE gene mutation F455W in Cx. tritaeniorhynchus. The frequency of the AChE gene mutation F455W was 100.00% in all strains, making this mutation of no value as a marker of resistance to organophosphorous and carbamate pesticides in Cx. tritaeniorhynchus in China. The kdr allele was present in all strains at frequencies of 10.00-29.55%. Regression analysis indicated a significant correlation between kdr allele frequencies and levels of resistance to deltamethrin, beta-cypermethrin, and permethrin. These results highlight the need to monitor and map insecticide resistance in Cx. tritaeniorhynchus and to adjust pesticide use to minimize the development of resistance in these mosquitoes.

Aldehyde dehydrogenase 2 inhibits inflammatory response and regulates atherosclerotic plaque.

Previous studies demonstrated that aldehyde dehydrogenase 2 (ALDH2) rs671 polymorphism, which eliminates ALDH2 activity down to 1%-6%, is a susceptibility gene for coronary disease. Here we investigated the underlying mechanisms based on our prior clinical and experimental studies. Male apoE-/- mice were transfected with GFP, ALDH2-overexpression and ALDH2-RNAi lentivirus respectively (n=20 each) after constrictive collars were placed around the right common carotid arteries. Consequently, ALDH2 gene silencing led to an increased en face plaque area, more unstable plaque with heavier accumulation of lipids, more macrophages, less smooth muscle cells and collagen, which were associated with aggravated inflammation. However, ALDH2 overexpression displayed opposing effects. We also found that ALDH2 activity decreased in atherosclerotic plaques of human and aged apoE-/- mice. Moreover, in vitro experiments with human umbilical vein endothelial cells further illustrated that, inhibition of ALDH2 activity resulted in elevating inflammatory molecules, an increase of nuclear translocation of NF-κB, and enhanced phosphorylation of NF-κB p65, AP-1 c-Jun, Jun-N terminal kinase and p38 MAPK, while ALDH2 activation could trigger contrary effects. These findings suggested that ALDH2 can influence plaque development and vulnerability, and inflammation via MAPK, NF-κB and AP-1 signaling pathways.

An Unmanned Aerial Vehicle-Mounted Cold Mist Spray of Permethrin and Tetramethylfluthrin Targeting Aedes albopictus in China.

Aedes albopictus is the primary vector of dengue fever and dengue hemorrhagic fever in China. Although there are previous studies on the application of adulticides to control this species, the application methods have either been back-pack or vehicle-mounted systems. However, many sites are too large to be effectively treated with back-pack sprayers, and the lack of roads restricts the use of vehicle-mounted sprayers. This paper provides the first study of using unmanned aerial vehicles to conduct cold mist sprays on Ae. albopictus habitats. A spray containing 4% permethrin and 1% tetramethylfluthrin was applied at an effective application rate of 9.0 mg/m(2). This method reduced Ae. albopictus populations by more than 90%. The results indicate this novel spray system is a powerful method to achieve a rapid decline of mosquito population in Ae. albopictus habitats in China.

Identification of genes involved in pyrethroid-, propoxur-, and dichlorvos- insecticides resistance in the mosquitoes, Culex pipiens complex (Diptera: Culicidae).

Culex pipiens pallens and Cx. p. quinquefasciatus are important vectors of many diseases, such as West Nile fever and lymphatic filariasis. The widespread use of insecticides to control these disease vectors and other insect pests has led to insecticide resistance becoming common in these species. In this study, high throughout Illumina sequencing was used to identify hundreds of Cx. p. pallens and Cx. p. quinquefasciatus genes that were differentially expressed in response to insecticide exposure. The identification of these genes is a vital first step for more detailed investigation of the molecular mechanisms involved in insecticide resistance in Culex mosquitoes.

Host-Seeking Behavior and Arbovirus Detection in Mosquitoes of Habahe County, Xinjiang Uigur Autonomous Region, China.

Mosquitoes in Habahe County of Xinjiang Uigur Autonomous Region in China are considered a serious nuisance problem to local residents, but little is known of their role in enzootic disease. Therefore, host-seeking behavior and virus detection in mosquitoes were investigated in this study. Adult host-seeking mosquitoes were sampled using the Centers for Disease Control and Prevention (CDC) light traps operated at three locations in June through August 2008. Nine traps were used at each location at 3 different heights (1 m, 3 m, and 5 m). Seven mosquito species from 4 genera were collected by CDC light traps in different habitats. In total, 90,055 mosquitoes were captured, of which Aedes vexans was the most abundant species, comprising 88.02% of all mosquitoes collected. The second most abundant species was Anopheles messese, which comprised about 5.86%. Other species caught were Culex modestus (2.89%), Aedes caspius (1.11%), Coquillettidia richiardii (0.61%), Ae. dorsalis (1.36%), and An. hyrcanus (0.14%). About 93.5% of Ae. vexans individuals were caught in CO2-baited CDC light traps at 1 m above the ground. The highest numbers of Cx. modestus were caught at the highest trap level, 5 m above ground. Overall, significantly more mosquitoes of all species were collected at dusk than at dawn. Based on blood-meal analyses, Ae. vexans and An. messese fed on various vertebrate hosts, whereas Cx. modestus fed on ducks only. From a total of 335 mosquito pools tested, 10 pools of Ae. vexans were found positive for alphavirus. Comparison with the gene database revealed that the alphavirus deoxyribonucleic acid fragment obtained (GenBank accession no. HM160530) was 100% homologous at the nucleotide level to chikungunya virus isolate LK (PB) chik3408, chikungunya virus isolate SGEHICHD122508, and chikungunya virus strain FD080231. The results of this study suggest that ongoing, integrated mosquito and arbovirus surveillance is necessary in this river wetland.

Relationship between insecticide resistance and kdr mutations in the dengue vector Aedes aegypti in Southern China.

BACKGROUND: Aedes aegypti is an important vector for dengue virus and thus has been targeted with pyrethroid insecticides in many areas of the world. As such, resistance has been detected to several of these insecticides, including in China, but the mechanisms of the resistance are not well understood in this country. METHODS: Using the World Health Organization larval mosquito bioassay, five field populations of Aedes aegypti from Southern China were characterized for their resistance to cypermethrin and cyhalothrin. RNA extraction with PCR amplification, cloning and sequencing of the sodium channel gene was followed by comparisons of susceptible and wild mosquito strains Additionally, genomic DNA was used for Allele-specific PCR (AS-PCR) genotyping of the sodium channel genes to detect S989P, V1016G and F1534C mutations and allow for correlation analysis of resistance expression for the different mutations. RESULTS: All wild strains expressed resistance to cypermethrin and cyhalothrin and the resistance expression between the two insecticides was highly correlated suggesting cross-resistance between these two pyrethroids. The AS-PCR technique effectively distinguished individual genotypes for all three mutations. Among the five wild strains tested, two strains carried all three mutations. Although the S989P and V1016G mutations were positively correlated to resistance expression of both pyrethroids, the F1534C mutation was negatively correlated. CONCLUSIONS: Our methodology proved highly reliable and will aid future detection of kdr mutations. The three sodium channel mutations were common in the Ae. aegypti strains sampled from Southern China. The V1016G mutation appears to be the most important kdr mutation in Ae. aegypti strains in Southern China.

Design, synthesis and biological evaluation of novel sesquiterpene mustards as potential anticancer agents.

Several novel series of sesquiterpene mustards (SMs) bearing nitrogen mustard and glutathione (GSH)-reactive α-methylene-γ-butyrolactone groups were successfully prepared for the first time and showed excellent antiproliferative activities in vitro. Among them, compounds 2e and 2g displayed the highest antiproliferative properties with IC50 values ranging from 2.5 to 8.7 µM. The selectivity of these two compounds was evaluated by SRB method against human cancer and normal hepatic cells (HepG2 and L02). The induction of apoptosis and effects on the cell cycle distribution with compounds 2e and 2g were investigated by Hoechst 33,258 staining and flow cytometry, which exhibited that they could induce selective cell apoptosis and cell cycle arrest in HepG2 and L02 cells. In addition, further investigation showed that compounds 2e and 2g could obviously inhibit the proliferation of HepG2 cells by inducing significant DNA cross-linking and depleting GSH in cell media. The good cytotoxicity and selectivity of compounds 2e and 2g pointed them as promising leads for anticancer drug design.