Antimicrobial and Antioxidant Property of a True Mangrove Rhizophora apiculata Bl.

Mangroves are abundant in bioactive natural substances that fight off pathogenic diseases. Different parts of R. apiculata, an abundant mangrove found in Bhitarkanika National Park, India were extracted with methanol and a mixture of solvents methanol/ethanol/chloroform (60 : 20 : 20) to evaluate their antimicrobial properties. The combination solvent extract of bark had the highest zone of inhibition (ZOI) of 18.62 mm against Pseudomonas aeruginosa and a ZOI of 17.41 mm against Streptococcus mitis. Bark extracts had the highest DPPH (43 %) and FRAP (96 %) activities. The combination solvent bark extract of R. apiculata had the highest ZOI of 20.42 mm (lowest MIC of 2.12 μg/ml) against Candida albicans and ZOI of 15.33 mm (MIC of 3.02 μg/mL) against Penicillium chrysogenum. Combination bark extracts of R. apiculata contained flavanols than methanolic extracts. The crude extract of R. apiculata bark made with a mixture of solvents containing more active ingredients could be used in novel drug formulation.     

Identification of a novel large intragenic deletion in a family with Fanconi anemia: First molecular report from India and review of literature

We report here an Indian case with Fanconi anemia (FA) presented with fever, pallor, short stature, hyperpigmentation and upper limb anomaly. Chromosome breakage analysis together with FANCD2 Western blot monoubiquitination assay confirmed the diagnosis as FA. Multiplex ligation-dependent probe amplification (MLPA) revealed a novel homozygous large intragenic deletion (exons 8–27 del) in the FANCA gene in the proband. His sib and parents were also analyzed and found to be heterozygous for the same mutation. We also reviewed the literature of FANCA large intragenic deletions found in FA patients from different countries and the mechanism involved in the formation of these deletions. To the best of our knowledge, this is the first molecular report from India on FA. The finding expands the mutation spectrum of the FANCA gene. Identification of the mutation confirms the diagnosis of FA at DNA level and helps in providing proper genetic counseling to the family.     

Binding of Escherichia coli to Functionalized Gold Nanoparticles

The molecular basis of the diversity of fimbrial lectins dictates the extent of adhesion in different types of Escherichia coli strains to mammalian cells. The mechanism of receptor binding by E. coli in eukaryotic cells differs based on the adhesin domains, patterns in the macromolecular structure and the ligand-binding groove. Current sensor technologies utilize biosensors that are based on the carbohydrate moieties that are involved in pathogen adhesion to host cells. Nanoparticles have been extensively used as carriers for pathogen detection. Gold nanoparticles (Au NPs) of 200?nm size were functionalized with two distinct glycoconjugates mannose (Mn?CAu NPs) and Neu??c(??2-3)-Gal-(??1-4)Glc?CPaa (Sg?CAu NPs) in order to investigate primary and fine sugar specificity of uropathogenic E. coli ORN178 and enterotoxigenic E. coli 13762, respectively. The UV-Vis measurement of pristine, 16-mercaptohexadecanoic acid (MHDA)/2-(2-aminoethoxy)ethanol (AEE)/sugar functionalized Au NPs showed a surface plasmon resonance band for Au. Dynamic light scattering analysis showed that the mean averages of the MHDA/AEE/Mn?CAu NP samples increased due to aggregation. The negative zeta potentials of the samples were indicative of aggregation. Fine sugar specificity was observed when Neu??c(??2-3)-Gal-(??1-4)Glc?CPaa functionalized Au NPs (Sg?CAu NPs) specifically showed binding with E. coli 13762 but not with E. coli ORN178. This specificity of E. coli strains to identify and bind to characteristic sugar moieties can be used in the development of biodiagnostic tools with Au NPs as carriers for diagnosis/treatment of human and veterinary diseases. In regards to the growing antibiotic resistance of microorganisms, gold nanoparticles can also be functionalized specifically to reverse adhesion of E. coli to host tissue and can be detected by their optical properties.     

Dynamic adoption of anergy by antigen-exhausted CD4+ T cells

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Intron exon boundary junctions in human genome have in-built unique structural and energetic signals

Precise identification of correct exon–intron boundaries is a prerequisite to analyze the location and structure of genes. The existing framework for genomic signals, delineating exon and introns in a genomic segment, seems insufficient, predominantly due to poor sequence consensus as well as limitations of training on available experimental data sets. We present here a novel concept for characterizing exon–intron boundaries in genomic segments on the basis of structural and energetic properties. We analyzed boundary junctions on both sides of all the exons (3 28 368) of protein coding genes from human genome (GENCODE database) using 28 structural and three energy parameters. Study of sequence conservation at these sites shows very poor consensus. It is observed that DNA adopts a unique structural and energy state at the boundary junctions. Also, signals are somewhat different for housekeeping and tissue specific genes. Clustering of 31 parameters into four derived vectors gives some additional insights into the physical mechanisms involved in this biological process. Sites of structural and energy signals correlate well to the positions playing important roles in pre-mRNA splicing.