Human MECP2 gene at Q28 arm of X chromosome as a suitable target for monitoring PCR inhibition in a nested, multiplexed HIV-1 DNA detection protocol

Human MECP2 gene located at q28 arm of X chromosome was identified as target for thermal co-amplification with HIV-1 proviral DNA of infected individuals. The selected MECP2 gene-specific primers functioned at a wide range of annealing temperature, extension time and exhibited no significant interaction with pathogen specific primers. A 466 bp PCR amplicon originating from human MECP2 gene was found to be diagnostic for inhibition-free PCR reaction when co-amplified with the HIV-1 target gene in a multiplexed, nested PCR reaction. The 5' end of the MECP2 primers were engineered to position an EcoRI restriction endonuclease site to facilitate rapid cloning in various DNA vector molecules at the corresponding EcoRI sites. Cell mass of Escherichia coli (XL1Blue) harboring the recombinant plasmid when added to pleural fluid of HIV-1 infected individuals co-infected with Mycobacterium tuberculosis, generated the diagnostic 466 bp MECP2 PCR amplicon as well as the 194 bp PCR amplicon of target gene from M. tuberculosis. The experiment underlined potential of the region spanning nucleotide position 4118099 to 4118552 of human MECP2 gene (NCBI accession number NT_011726.13) as a reliable target for multiplex PCR to accommodate a wide range of thermal cycling and multiplex reaction conditions. In both cases of this study, electrophoresis-based separation of the 466 bp MECP2 fragment and the 232 bp and 194 bp HIV-1 and M. tuberculosis fragments respectively was distinct and unambiguous. The potential of this human MECP2 gene available from human genome or recombinant plasmid as a potent target to monitor PCR inhibition for a range of different PCR reactions is discussed.     

Synthesis, biological evaluation, and molecular docking of N-{3-[3-(9-methyl-9H-carbazol-3-yl)-acryloyl]-phenyl}-benzamide/amide derivatives as xanthine oxidase and tyrosinase inhibitors

Claisen-Schmidt condensation of 3-formyl-9-methylcarbazole with various amides of 3-aminoacetophenone afforded N-{3-[3-(9-methyl-9H-carbazol-3-yl)-acryloyl]-phenyl}-benzamide/amide derivatives. All compounds were investigated for their in vitro xanthine oxidase (XO), tyrosinase and melanin production inhibitory activity. Most of the target compounds had more potent XO inhibitory activity than the standard drug (IC(50)=4.3-5.6μM). Interestingly, compound 7q bearing cyclopropyl ring was found to be the most potent inhibitor of XO (IC(50)=4.3μM). Molecular modelling study gave an insight into its binding modes with XO. Compounds 7a, 7d, 7e, 7g, and 7k were found to be potent inhibitors of tyrosinase (IC(50)=14.01-17.52μM). These results suggest the possible use of these compounds for the design and development of novel XO and tyrosinase inhibitors.     

Effect of repeated in vitro sub-culturing on the virulence of Metarhizium anisopliae against Helicoverpa armigera (Lepidoptera: Noctuidae)

The effect of repeated conidial sub-culturing of Metarhizium anisopliae on its virulence against Helicoverpa armigera (Hübner) was studied. The LT₅₀ observed against third instar larvae of H. armigera for the first sub-culture was 3.4 days; it increased to 4.5 and 5.6 days for the 20th and the 40th sub-cultures, respectively. The LT₅₀ values after passage of the 40th sub-culture on H. armigera decreased to 4.4 and 3.7 days for the 40th (first in vivo) and the 40th (fifth in vivo) passages, respectively. Similarly, the LC₅₀ of M. anisopliae towards third instar larvae of H. armigera increased from the first sub-culture (0.17×10⁴) to (3.0×10⁴) for the 40th conidial transfers on potato dextrose agar and again decreased to 0.74×10⁴ and 0.23×10⁴ in the 40th (first in vivo) and the 40th (fifth in vivo) passage, respectively. Similar trends for LC₅₀ and LT₅₀ values were seen when sugarcane woolly aphid, Ceratovacuna lanigera Zehntner was used as a host. Significant variation in appressorium formation and cuticle-degrading enzyme production such as chitinase, chitin deacetylase, chitosanase and protease during subsequent sub-culturing and passage through H. armigera was observed. Though there was no effect on internal transcribed spacer (ITS) sequence pattern, interestingly, in randomly amplified polymorphic DNA (RAPD), significant differences in the band intensities and in the banding pattern for different sub-cultures of M. anisopliae were observed. As stable virulence towards the insect pest is desirable for commercialisation of a mycoinsecticide, such changes in virulence due to repeated in vitro transfer need to be monitored and minimised.     

Comparison of Metarhizium isolates for biocontrol of Helicoverpa armigera (Lepidoptera: Noctuidae) in chickpea

Metarhizium isolates from soil (53) and insect hosts (10) were evaluated for extracellular production of cuticle degrading enzyme (CDE) activities such as chitinase, chitin deacetylase (CDA), chitosanase, protease and lipase. Regression analysis demonstrated the relation of CDE activities with Helicoverpa armigera mortality. On basis of this relation, ten isolates were selected for further evaluation. Subsequently, based on LT₅₀ of the 10 isolates towards H. armigera, five isolates were selected. Out of these five isolates, three were selected on the basis of higher conidia production (60–75 g/kg rice), faster sedimentation time (ST₅₀) (2.3–2.65 h in 0.1% (w/v) Tween 80) and lower LC₅₀ (1.4–5.7×10³ conidia/mL) against H. armigera. Finally, three Metarhizium isolates were selected for the molecular fingerprinting using ITS sequencing and RAPD patterning. All three isolates, M34412, M34311 and M81123, showed comparable RAPD patterns with a 935G primer. These were further evaluated for their field performance against H. armigera in a chickpea crop. The percent efficacies with the three Metarhizium isolates were from 65 to 72%, which was comparable to the chemical insecticide, endosulfan (74%).     

Dimensional analysis for modeling oxygen transfer in rotating biological contactor

In rotating biological contactors (RBC), the oxygen mass transfer coefficient (KLa) is often inadequately predicted by the available models. Hence, dimensional analysis based empirical models were developed for predicting KLa and the component of KLa due to turbulence (KLat) using data available in the literature. The overall oxygen transfer number (OTN) and its component due to turbulence (OTNt) were defined as dimensionless groups based on KLa and KLat, respectively. They were expressed as a function of dimensionless groups, formed using disc diameter (D), area of discs (Ad), rotational speed (omega) and cross-sectional area of the tank (At). OTN was also a function of thickness of the water film on the disc (delta) and working volume of the reactor (V). Decrease in number of discs and decrease in (Ad/At) resulted in decreasing OTN but increasing OTNt. Both OTNt and OTN increased with increase in omega. The proposed empirical models will facilitate scale-up of RBCs.     

Analysis of single nucleotide polymorphisms in the promoter region of interleukin-10 by denaturing high-performance liquid chromatography.

Interleukin-10 (IL10), an anti-inflammatory cytokine, has been implicated in a variety of immune- and inflammatory-related diseases. We investigated the following SNPs: -1082, -819, -592 in the promoter region of IL10 in a normal (control) population and selected diseases: breast cancer (BrCa), systemic lupus erythematosus (SLE), and B-cell chronic lymphocytic leukemia (B-CLL) by denaturing high-performance liquid chromatography (DHPLC) and found distinct genotype and haplotype patterns. DHPLC was performed using the Transgenomic WAVE instrument, a mutational discovery tool that allows for high throughout analysis of SNPs. The principle of DHPLC is based on separation of homo- and heteroduplex formation of individual polymerase chain reaction products at specific melting temperatures and set gradients. The melting temperature selected for each SNP was based on size and sequence of the polymerase chain reaction product (for -1082, 57 degrees C; for -819, 58 degrees C; and for -592, 59.2 degrees C). Before fragment mutational analysis, all samples were denatured at 95 degrees C and slowly reannealed to allow for reassociation of different strands. Heteroduplex samples were easily distinguished from homoduplex samples. In order to identify wild type from homozygous mutant, two homoduplex polymerase chain reaction samples had to be mixed together, denatured at 95 degrees C and reannealed. The homozygous mutant, when combined with wild type, displayed a double peak on chromatogram. Once distinct chromatograms were established for each of the SNPs and the nucleotide changes confirmed by sequencing, genotype and haplotype frequencies were tabulated for the groups studied.     

High frequency plant regeneration following abnormal shoot organogenesis in the medicinal tree Hovenia dulcis

An efficient plant regeneration protocol for shoot organogenesis from Hovenia dulcis callus cultures was established. Induction of organogenic callus was achieved on Murashige and Skoog (MS) medium supplemented with 4.65 μM kinetin and 4.5 μM 2,4-dichlorophenoxyacetic acid (2,4-D). Further differentiation of organogenic callus into primordia, shoot-like structures, and plantlets was achieved on MS medium supplemented with 0.23 μM gibberellic acid (GA₃) and 0.46 μM kinetin. Numerous abnormal shoots developed upon transfer of callus to MS medium containing cytokinins, and these failed to grow further into whole plantlets. However, transfer of ‘abnormal’ shoots to a fresh MS medium lacking cytokinins resulted in growth of normal shoots. Elongated shoots subsequently were rooted in basal MS medium, and whole plantlets were established in a soil mix. Analysis of regenerated plants using random amplified polymorphic DNA (RAPD) confirmed the genetic stability of these regenerant plantlets.     

Metagenomic study of single-nucleotide polymorphism within candidate genes associated with type 2 diabetes in an Indian population

A population-based study was undertaken to evaluate linkage between single-nucleotide polymorphisms known as risk factors and type 2 diabetes in an Indian population. The study population was comprised of 40 normal glucose-tolerant individuals (21 males and 19 females) and 40 type 2 diabetes patients (21 males and 19 females). The genes and their corresponding single-nucleotide polymorphisms that we screened were VDR (rs 731236 and rs 1544410), IL-6 (rs 1800795), TCF7L2 (rs 7903146) and TNF-α (rs 1800629). The risk alleles were more frequent in the subjects with type 2 diabetes, except for the TNF-α gene, which was very infrequent in the population; the normal allele occurred at high and similar frequencies in both normal and diabetic individuals.