Synthesis and antiviral activity evaluation of novel 2-phenyl-4-(D-arabino-4'-cycloaminobutyl)triazoles: acyclonucleosides containing unnatural bases

Five 2-phenyl-4-(D-arabino-4'-cycloamino-3'-hydroxy-O-1',2'-isopropylidene-butyl)-2H-1,2,3-triazoles, acyclonucleosides containing unnatural bases have been synthesised by opening of the epoxide ring of 2-phenyl-4-(D-arabino-3',4'-epoxy-O-1',2'-isopropylidenebutyl)-2H-1,2,3-triazole with the corresponding cyclic amines in 70-85% yields. The starting arabino-epoxytriazole was prepared in five steps starting from D-glucose in an overall yield of 15%. All the five triazolylacyclonucleosides were unambiguously identified on the basis of their spectral data. The structure of one of the intermediates, that is 2-phenyl-4-(D-arabino-1',2',3',4'-tetrahydroxybutyl)-2H-1,2,3-triazole was confirmed by its X-ray crystallographic studies. These acyclonucleosides were subjected to antiviral activity evaluation in CEM-SS cell-based anti HIV assay with the lymphocytropic virus strains HIV-1(IIIB) and HIV-1(RF).     

Development of CACTA transposon derived SCAR markers and their use in population structure analysis in <Emphasis Type="Italic">Zea mays</Emphasis>

Molecular marker technologies have proven to be an important breakthrough for genetic studies, construction of linkage maps and population genetics analysis. Transposable elements (TEs) constitute major fractions of repetitive sequences in plants and offer a wide range of possible areas to be explored as molecular markers. Sequence characterized amplified region (SCAR) marker development provides us with a simple and time saving alternative approach for marker development. We employed the CACTA-TD to develop SCARs and then integrated them into linkage map and used them for population structure and genetic diversity analysis of corn inbred population. A total of 108 dominant SCAR markers were designed out of which, 32 were successfully integrated in to the linkage map of maize RIL population and the remaining were added to a physical map for references to check the distribution throughout all chromosomes. Moreover, 76 polymorphic SCARs were used for diversity analysis of corn accessions being used in Korean corn breeding program. The overall average polymorphic information content (PIC) was 0.34, expected heterozygosity was 0.324 and Shannon’s information index was 0.491 with a percentage of polymorphism of 98.67%. Further analysis by associating with desirable traits may also provide some accurate trait specific tagged SCAR markers. TE linked SCARs can provide an added level of polymorphism as well as improved discriminating ability and therefore can be useful in further breeding programs to develop high yielding germplasm.     

Electro-optical behaviour of CuFe2O4@rGO nanocomposite for nonenzymatic detection of uric acid via the electrochemical method

Uric acid (UA) is a blood and urine component obtained as a metabolic by-product of purine nucleotides. Abnormalities in UA metabolism cause crystal deposition as monosodium urate and lead to various diseases such as gout, hyperuricemia, Lesch–Nyhan syndrome, etc. Monitoring these diseases requires a rapid, sensitive, selective, and portable detection approach. Therefore, this study demonstrates the hydrothermal synthesis of CuFe₂O₄/reduced graphene oxide (rGO) nanocomposite for selective detection of UA. After the nanocomposite synthesis, characterization was performed by X-ray diffraction spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, UV–visible spectrometry, atomic force spectroscopy, scanning electron microscopy, and electrochemical analysis. Furthermore, from the electrochemical analysis using cyclic voltammetry (CV), kinetic studies were carried out by varying the scan rate to obtain the diffusion coefficient, surface concentration, and rate of charge transfer to achieve a calibration curve that indicates the quasi reversible nature of the fabricated electrode with a linear regression coefficient of oxidation (R²: 0.9992) and reduction (R²: 0.9971) peaks. Moreover, the fabricated nonenzymatic amperometric sensor to detect UA with a linearity (R²: 0.9989) of 1–400 μM was highly sensitive (2.75 × 10⁻⁴ mAμM⁻¹ cm⁻²) and had a lower limit of detection (0.01231 μM) at pH 7.5 in phosphate-buffered saline solution. Therefore, the CuFe₂O₄/rGO/ITO-based nonenzymatic sensor could detect interfering agents and spiked real bovine serum samples with higher sensitivity and selectivity for UA detection.     

DNA barcode based delineation of freshwater fishes from northern Western Ghats of India,one of the world’s biodiversity hotspots

DNA barcodes analyzed by using relevant techniques provide an imperative approach towards validation of prevailing taxa and putative species. Here, molecular methods were used for assessment of 246 barcodes belonging to 81 fish species from northern Western Ghats of India, using, Barcode gap analysis, barcode index number, automatic barcode gap discovery, Poisson tree processes and general mixed Yule-coalescent, these methods had their potential to discriminate 97.53%, 93.90% 95.06%, 93.82% and 92.59% of species respectively. But, some of them tended to estimate the inconsistent number of species leading to discrepancies between the morphological concept and inference from molecular phylogenetic reconstructions. So, we took a standard approach to recognize those methods that produced consistent results, three of five such methods were identified that revealed three hidden cryptic species complexes in Monopterus indicus, Parambassis ranga and Systomus sarana. Further, to validate these three genetically diverged species, we used diagnostic character based approach along with nine unidentified species through BLOG and WEKAs SMO classifier. Those methods were unable to identify these species, which might be due to the limited number of specimens used for the analysis. This is the first effort to generate the DNA barcode reference library of freshwater fishes from northern Western Ghats of India, one of the world’s biodiversity hotspots. These barcodes when analyzed through the defined workflow, will provide valuable measures to prove the efficiency of molecular species delimitation methods in taxonomic discrimination which aid conservation of biodiversity.     

The Effectiveness of Electronic Differential Diagnoses (DDX) Generators: A Systematic Review and Meta-Analysis

Background

Diagnostic errors are costly and they can contribute to adverse patient outcomes, including avoidable deaths. Differential diagnosis (DDX) generators are electronic tools that may facilitate the diagnostic process.

Methods and Findings

We conducted a systematic review and meta-analysis to investigate the efficacy and utility of DDX generators. We undertook a comprehensive search of the literature including 16 databases from inception to May 2015 and specialist patient safety databases. We also searched the reference lists of included studies. Article screening, selection and data extraction were independently conducted by 2 reviewers. 36 articles met the eligibility criteria and the pooled accurate diagnosis retrieval rate of DDX tools was high with high heterogeneity (pooled rate = 0.70, 95% CI = 0.63 to 0.77; I² = 97%, p<0.0001). DDX generators did not demonstrate improved diagnostic retrieval compared to clinicians but small improvements were seen in the before and after studies where clinicians had the opportunity to revisit their diagnoses following DDX generator consultation. Clinical utility data generally indicated high levels of user satisfaction and significant reductions in time taken to use for newer web-based tools. Lengthy differential lists and their low relevance were areas of concern and have the potential to increase diagnostic uncertainty. Data on the number of investigations ordered and on cost-effectiveness remain inconclusive.

Conclusions

DDX generators have the potential to improve diagnostic practice among clinicians. However, the high levels of heterogeneity, the variable quality of the reported data and the minimal benefits observed for complex cases suggest caution. Further research needs to be undertaken in routine clinical settings with greater consideration of enablers and barriers which are likely to impact on DDX use before their use in routine clinical practice can be recommended.     

Comparison of marmoset and human FSH using synthetic peptides of the β‐subunit L2 loop region and anti‐peptide antibodies

Follicle stimulating hormone (FSH) is a glycoprotein hormone required for female and male gametogenesis in vertebrates. Common marmoset (Callithrix jacchus) is a New World primate monkey, used as animal model in biomedical research. Observations like, requirement of extremely high dose of human FSH in marmosets for superovulation compared to other primates and generation of antibodies in marmoset against human FSH after repeated superovulation cycles, point towards the possibility that FSH–FSH receptor (FSHR) interaction in marmosets might be different than in the humans. In this study we attempted to understand some of these structural differences using FSH peptides and anti‐peptide antibody approach. Based on sequence alignment, in silico modeling and docking studies, L2 loop of FSH β‐subunit (L2β) was found to be different between marmoset and human. Hence, peptides corresponding to region 32–50 of marmoset and human L2β loop were synthesized, purified and characterized. The peptides displayed dissimilarity in terms of molecular mass, predicted isoelectric point, predicted charge and in the ability to inhibit hormone–receptor interaction. Polyclonal antibodies generated against both the peptides were found to exhibit specific binding for the corresponding peptide and parent FSH in ELISA and Western blotting respectively and exhibited negligible reactivity to cross‐species peptide and FSH in ELISA. The anti‐peptide antibody against marmoset FSH was also able to detect native FSH in marmoset plasma samples and pituitary sections. In summary, the L2β loop of marmoset and human FSH has distinct receptor interaction ability and immunoreactivity indicating possibility of subtle conformational and biochemical differences between the two regions which may affect the FSH–FSHR interaction in these two primates. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.     

Large scale preparation of bacteriophage lambda by tangential flow ultrafiltration for isolation of lambda DNA

A preparative procedure for purifying bacteriophage lambda from large volumes of phage lysates by recirculating tangential flow ultrafiltration is described. Lambda DNA, isolated by deproteinization of the phage, is suitable for use in molecular biology.