Profiling of cellulose content in Indian seaweed species

Cellulose contents were estimated in 12 seaweed samples belonging to different families e.g. red, brown and green, growing in Indian waters. Each cellulose sample was fractionated to yield alpha (α) and beta (β) celluloses. Characterization was done using various analytical tools and results were validated by comparison with those of the cellulose obtained from Whatman filter paper No. 4. The greatest yields of cellulose (crude), α- and β-cellulose were obtained from Gelidiella acerosa (13.65%), Chamaedoris auriculata (9.0%) and G. acerosa (3.10%). G. acerosa was also found to contain relatively high amount of α-cellulose (8.19%). The lowest cellulose contents were recorded from Kappaphycus alvarezii (2.00%) and Sarconema scinaioides (2.1%), while the latter contained the lowest α-, and β-celluloses (1.0% and 0.30%, respectively). It appears that agarophytic and alginophytic algae contain high cellulose and α-cellulose contents, while the carrageenophyte contains low cellulose. The brown algae, in general contain high cellulose as well as α- and β-celluloses.     

Diversity and zoogeography of the fairy shrimps (Branchiopoda: Anostraca) on the Indian subcontinent

The Indian subcontinent has a specific biogeographical history, but has remained understudied with respect to invertebrates like the Anostraca. In this study, we discuss the anostracan diversity and zoogeography on the subcontinent. We collected all pertinent literature and considered nineteen bioclimatic variables along with altitude and its terrestrial ecoregions. The study area was overlaid with 10,000 km² grids, and five hundred random GIS data points per grid were extracted for analysis besides the species locality data. Species richness estimators predict at least 3–4 more species to the existing list of 19 species. The beta diversity measure βsim reveals two zoogeographic “zones,” viz., a Northern (NZ) zone and the rest of the subcontinent (RS) comprising the Central (CZ) and South (SZ) zones by Unweighted Pair-Group Method using arithmetic averages clustering and Analysis of Similarity. Complementarity index shows that no fauna is shared between NZ and RS, while CZ and SZ share 50% of the species. Principal Component analysis shows that NZ and RS differ somewhat from one another climatically. NZ and RS have different ecoregions with montane and temperate grasslands commonly observed in NZ while the latter comprising tropical forests, implying differences in soil geochemistry which is crucial for anostracan distribution.     

Life-threatening acute airway obstruction in achalasia

Acute airway obstruction from mega-esophagus is an extremely rare presentation of achalasia. We present the case of an 82-year-old woman without previously diagnosed achalasia who presented with shortness of breath. Her respiratory status deteriorated rapidly, with development of stridor. Prompt nasogastric tube placement decompressed the dilated esophagus and relieved airway obstruction. This case illustrates an unusual presentation of achalasia and underscores the need for emergent life-saving esophageal decompression. Hypotheses regarding the mechanism of airway compromise as well as treatment options are reviewed.     

Stabilization of Microtubules by Taxane Diterpenoids: Insight from Docking and MD simulations

Microtubules are formed from the molecules of tubulin, whose dynamics is important for many functions in a cell, the most dramatic of which is mitosis. Taxol is known to interact within a specific site on tubulin and also believed to block cell-cycle progression during mitosis by binding to and stabilizing microtubules. Along with the tremendous potential that taxol has shown as an anticancer drug, clinical problems exist with solubility, toxicity, and development of drug resistance. The crystal structure of taxane diterpenoids, namely, 10, 13-deacetyl-abeo-baccatin-IV (I), 5-acetyl-2-deacetoxydecinnamoyl-taxinine-0.29hydrate (II), 7, 9-dideacetyltaxayuntin (III), and Taxawallin-K (IV), are very similar to the taxol molecule. Considerable attention has been given to such molecules whose archetype is taxol but do not posses long aliphatic chains, to be developed as a substitute for taxol with fewer side effects. In the present work, the molecular docking of these taxane diterpenoids has been carried out with the tubulin alpha-beta dimer (1TUB) and refined microtubule structure (1JFF) using Glide-XP, in order to assess the potential of tubulin binding of these cytotoxic agents. Results show that all the ligands dock into the classical taxol binding site of tubulin. Taxol shows the best binding capabilities. On the basis of docking energy and interactions, apart from taxol, molecule II has a better tendency of binding with 1TUB while molecule I shows better binding capability with bovine tubulin 1JFF. To validate the binding capabilities, molecular dynamics (MD) simulations of the best docked complexes of ligands with 1JFF have been carried out for 15.0 ns using DESMOND. Average RMSD variations and time line study of interactions and contacts indicate that these complexes remain stable during the course of the dynamics. However, taxol and molecule II prevail over other taxoids.

Electronic supplementary material

The online version of this article (doi:10.1007/s10867-014-9369-5) contains supplementary material, which is available to authorized users.     

The cellulose contents of Indian seaweeds

Cellulose content as well as alpha (α) and beta (β) celluloses were evaluated in 21 seaweed species belonging to different classes growing in Indian waters. The greatest yields of cellulose (crude) and β-cellulose were obtained from Caulerpa taxifolia (approx. 11.0% and 5.2%, respectively), whilst α-cellulose (approx. 8.2%) was the greatest in Padina tetrastromatica. The lowest cellulose (crude), α- and β- contents were recorded from the calcareous red alga Liagora ceranoides (approx. 0.85%, 0.62% and 0.18%, respectively). There was no variation in the yields of cellulose in the brown algae, whilst wide variations in the yields were found in the green and red algae.     

Enhanced Growth of Endothelial Precursor Cells on PCG-Matrix Facilitates Accelerated,Fibrosis-Free,Wound Healing: A Diabetic Mouse Model

Diabetes mellitus (DM)-induced endothelial progenitor cell (EPC) dysfunction causes impaired wound healing, which can be rescued by delivery of large numbers of ‘normal’ EPCs onto such wounds. The principal challenges herein are (a) the high number of EPCs required and (b) their sustained delivery onto the wounds. Most of the currently available scaffolds either serve as passive devices for cellular delivery or allow adherence and proliferation, but not both. This clearly indicates that matrices possessing both attributes are ‘the need of the day’ for efficient healing of diabetic wounds. Therefore, we developed a system that not only allows selective enrichment and expansion of EPCs, but also efficiently delivers them onto the wounds. Murine bone marrow-derived mononuclear cells (MNCs) were seeded onto a PolyCaprolactone-Gelatin (PCG) nano-fiber matrix that offers a combined advantage of strength, biocompatibility wettability; and cultured them in EGM2 to allow EPC growth. The efficacy of the PCG matrix in supporting the EPC growth and delivery was assessed by various in vitro parameters. Its efficacy in diabetic wound healing was assessed by a topical application of the PCG-EPCs onto diabetic wounds. The PCG matrix promoted a high-level attachment of EPCs and enhanced their growth, colony formation, and proliferation without compromising their viability as compared to Poly L-lactic acid (PLLA) and Vitronectin (VN), the matrix and non-matrix controls respectively. The PCG-matrix also allowed a sustained chemotactic migration of EPCs in vitro. The matrix-effected sustained delivery of EPCs onto the diabetic wounds resulted in an enhanced fibrosis-free wound healing as compared to the controls. Our data, thus, highlight the novel therapeutic potential of PCG-EPCs as a combined ‘growth and delivery system’ to achieve an accelerated fibrosis-free healing of dermal lesions, including diabetic wounds.     

Vestibules are part of the substrate path in the multidrug efflux transporter AcrB of Escherichia coli

The path of substrates in the multidrug efflux pump AcrB of Escherichia coli was examined by using labeling with a lipophilic substrate mimic, Bodipy FL maleimide. Four (out of eight) residues in the vestibule bound the dye, suggesting its role in substrate transport, whereas only one (out of nine) residue in the central cavity tested positive.