Gene flow in malaria vector Anopheles stephensi (Diptera: Culicidae) across the Aravalli Hills in North-west India

The population structure of An. stephensi in North-west India was studied to assess the impact of the Aravalli Hills, as a barrier to gene flow using microsatellite markers. Large and significant genetic differentiation was found along the sides of, as well as across, the Aravalli Hills as the mean F_ST and R_ST on west vs. east of the Aravalli Hills were 0.213, 0.112 and 0.179, 0.056, respectively. Similarly, across the hills, mean values of F_ST and R_ST were 0.100 and 0.094, respectively. Genetic diversity on both sides did not vary significantly. The F_ST values were more sensitive than R_ST values, indicating that genetic drift might have caused genetic differentiation between populations. A positive correlation (r = 0.0149 and 0.157, respective to F_ST and R_ST) was found between genetic differentiations and geographic distances irrespective of the hills. Low level of gene flow was found along both sides (Nm = 0.92 and 0.14; west vs. east of Aravalli Hills, respectively) as compared to across the Aravalli Hills (Nm = 2.25). It was found that the Aravalli Hills are not working as an effective barrier to gene flow for An. Stephensi, maybe because of the low average height and discontinuous hills, however, the distance is playing a major role for differentiation between populations due to active mode of dispersal of An. stephensi mosquitoes which have a short flight range. All this information should help draw the strategies for genetic control of mosquitoes using transgenic mosquitoes.     

Identification of low molecular weight pyroglutamate A{beta} oligomers in Alzheimer disease: a novel tool for therapy and diagnosis

N-terminally truncated Aβ peptides starting with pyroglutamate (AβpE3) represent a major fraction of all Aβ peptides in the brain of Alzheimer disease (AD) patients. AβpE3 has a higher aggregation propensity and stability and shows increased toxicity compared with full-length Aβ. In the present work, we generated a novel monoclonal antibody (9D5) that selectively recognizes oligomeric assemblies of AβpE3 and studied the potential involvement of oligomeric AβpE3 in vivo using transgenic mouse models as well as human brains from sporadic and familial AD cases. 9D5 showed an unusual staining pattern with almost nondetectable plaques in sporadic AD patients and non-demented controls. Interestingly, in sporadic and familial AD cases prominent intraneuronal and blood vessel staining was observed. Using a novel sandwich ELISA significantly decreased levels of oligomers in plasma samples from patients with AD compared with healthy controls were identified. Moreover, passive immunization of 5XFAD mice with 9D5 significantly reduced overall Aβ plaque load and AβpE3 levels, and normalized behavioral deficits. These data indicate that 9D5 is a therapeutically and diagnostically effective monoclonal antibody targeting low molecular weight AβpE3 oligomers.     

The Influence of Nanocrystal Aggregates on Photovoltaic Performance in Nanocrystal–Polymer Bulk Heterojunction Solar Cells

CdSe nanocrystals (NCs) can be used as an electron acceptor in solar cells, employing organic ligands to passivate their surface and make them processable from solution. The nature and abundance of impurities present after NC ligand exchange from oleic acid to n‐butylamine are identified. A further purification step using hexane as a selective solvent is described, which excludes NC aggregates from solution. The influence of NC aggregates on photovoltaic device performance is studied in a CdSe:poly[2‐methoxy‐5‐(3′,7′‐dimethyloctyloxy)‐1,4‐phenylene vinylene] (MDMO‐PPV) bulk heterojunction solar cell. The exclusion of NC aggregates leads to a four‐fold increase in device power conversion efficiency (PCE) in optimized devices. A superior blend morphology leading to improved charge generation and a better NC percolation network is identified as the main causes of this increased solar cell performance.     

Insect Barcode Information System

Insect Barcode Information System called as Insect Barcode Informática (IBIn) is an online database resource developed by the National Bureau of Agriculturally Important Insects, Bangalore. This database provides acquisition, storage, analysis and publication of DNA barcode records of agriculturally important insects, for researchers specifically in India and other countries. It bridges a gap in bioinformatics by integrating molecular, morphological and distribution details of agriculturally important insects. IBIn was developed using PHP/My SQL by using relational database management concept. This database is based on the client– server architecture, where many clients can access data simultaneously. IBIn is freely available on-line and is user-friendly. IBIn allows the registered users to input new information, search and view information related to DNA barcode of agriculturally important insects.This paper provides a current status of insect barcode in India and brief introduction about the database IBIn.

Availability

http://www.nabg-nbaii.res.in/barcode     

Impact of UV and Peracetic Acid Disinfection on the Prevalence of Virulence and Antimicrobial Resistance Genes in Uropathogenic Escherichia coli in Wastewater Effluents

Wastewater discharges may increase the populations of pathogens, including Escherichia coli, and of antimicrobial-resistant strains in receiving waters. This study investigated the impact of UV and peracetic acid (PAA) disinfection on the prevalence of virulence and antimicrobial resistance genes in uropathogenic Escherichia coli (UPEC), the most abundant E. coli pathotype in municipal wastewaters. Laboratory disinfection experiments were conducted on wastewater treated by physicochemical, activated sludge, or biofiltration processes; 1,766 E. coli isolates were obtained for the evaluation. The target disinfection level was 200 CFU/100 ml, resulting in UV and PAA doses of 7 to 30 mJ/cm² and 0.9 to 2.0 mg/liter, respectively. The proportions of UPECs were reduced in all samples after disinfection, with an average reduction by UV of 55% (range, 22% to 80%) and by PAA of 52% (range, 11% to 100%). Analysis of urovirulence genes revealed that the decline in the UPEC populations was not associated with any particular virulence factor. A positive association was found between the occurrence of urovirulence and antimicrobial resistance genes (ARGs). However, the changes in the prevalence of ARGs in potential UPECs were different following disinfection, i.e., UV appears to have had no effect, while PAA significantly reduced the ARG levels. Thus, this study showed that both UV and PAA disinfections reduced the proportion of UPECs and that PAA disinfection also reduced the proportion of antimicrobial resistance gene-carrying UPEC pathotypes in municipal wastewaters.     

Evidence of Experimental Vertical Transmission of Emerging Novel ECSA Genotype of Chikungunya Virus in Aedes aegypti

Background

Chikungunya virus (CHIKV) has emerged as one of the most important arboviruses of public health significance in the past decade. The virus is mainly maintained through human-mosquito-human cycle. Other routes of transmission and the mechanism of maintenance of the virus in nature are not clearly known. Vertical transmission may be a mechanism of sustaining the virus during inter-epidemic periods. Laboratory experiments were conducted to determine whether Aedes aegypti, a principal vector, is capable of vertically transmitting CHIKV or not.

Methodology/Principal Findings

Female Ae. aegypti were orally infected with a novel ECSA genotype of CHIKV in the 2^nd gonotrophic cycle. On day 10 post infection, a non-infectious blood meal was provided to obtain another cycle of eggs. Larvae and adults developed from the eggs obtained following both infectious and non-infectious blood meal were tested for the presence of CHIKV specific RNA through real time RT-PCR. The results revealed that the larvae and adults developed from eggs derived from the infectious blood meal (2^nd gonotrophic cycle) were negative for CHIKV RNA. However, the larvae and adults developed after subsequent non-infectious blood meal (3^rd gonotrophic cycle) were positive with minimum filial infection rates of 28.2 (1∶35.5) and 20.2 (1∶49.5) respectively.

Conclusion/Significance

This study is the first to confirm experimental vertical transmission of emerging novel ECSA genotype of CHIKV in Ae. aegypti from India, indicating the possibilities of occurrence of this phenomenon in nature. This evidence may have important consequence for survival of CHIKV during adverse climatic conditions and inter-epidemic periods.     

Nuclear S100A7 Is Associated with Poor Prognosis in Head and Neck Cancer

Background

Tissue proteomic analysis of head and neck squamous cell carcinoma (HNSCC) and normal oral mucosa using iTRAQ (isobaric tag for relative and absolute quantitation) labeling and liquid chromatography-mass spectrometry, led to the identification of a panel of biomarkers including S100A7. In the multi-step process of head and neck tumorigenesis, the presence of dysplastic areas in the epithelium is proposed to be associated with a likely progression to cancer; however there are no established biomarkers to predict their potential of malignant transformation. This study aimed to determine the clinical significance of S100A7 overexpression in HNSCC.

Methodology

Immunohistochemical analysis of S100A7 expression in HNSCC (100 cases), oral lesions (166 cases) and 100 histologically normal tissues was carried out and correlated with clinicopathological parameters and disease prognosis over 7 years for HNSCC patients. Overexpression of S100A7 protein was significant in oral lesions (squamous cell hyperplasia/dysplasia) and sustained in HNSCC in comparison with oral normal mucosa (p_trend<0.001). Significant increase in nuclear S100A7 was observed in HNSCC as compared to dysplastic lesions (p = 0.005) and associated with well differentiated squamous cell carcinoma (p = 0.031). Notably, nuclear accumulation of S100A7 also emerged as an independent predictor of reduced disease free survival (p = 0.006, Hazard ratio (HR = 7.6), 95% CI = 1.3−5.1) in multivariate analysis underscoring its relevance as a poor prognosticator of HNSCC patients.

Conclusions

Our study demonstrated nuclear accumulation of S100A7 may serve as predictor of poor prognosis in HNSCC patients. Further, increased nuclear accumulation of S100A7 in HNSCC as compared to dysplastic lesions warrants a large-scale longitudinal study of patients with dysplasia to evaluate its potential as a determinant of increased risk of transformation of oral premalignant lesions.