Iron- and 4-hydroxy-2-alkylquinoline-containing periplasmic inclusion bodies of Pseudomonas aeruginosa: a chemical analysis

Dark aggregated particles were seen on pellets of iron-rich, mid-logarithmic phase Pseudomonas aeruginosa. Transmission electron microscopy of these cells showed inclusion bodies in periplasmic vacuoles. Aggregated particles isolated from the spent medium of these cells contained iron as indicated by atomic absorption spectroscopy and by electron paramagnetic resonance spectroscopy that revealed Fe(3+). Scanning electron microscopy/energy dispersive X-ray analysis of whole cells revealed the presence of iron-containing particles beneath the surface of the cell, indicating that the isolated aggregates were the intracellular inclusion bodies. Collectively, mass spectroscopy and nuclear magnetic resonance spectroscopy of the isolated inclusion bodies revealed the presence of 3,4-dihydroxy-2-heptylquinoline which is the Pseudomonas quinolone signaling compound (PQS) and an iron chelator; 4-hydroxy-2-heptylquinoline (pseudan VII), which is an iron chelator, antibacterial compound and precursor of PQS; 4-hydroxy-2-nonylquinoline (pseudan IX) which is an iron chelator and antibacterial compound; 4-hydroxy-2-methylquinoline (pseudan I), and 4-hydroxy-2-nonylquinoline N-oxide.     

Human bronchial epithelial cell transcriptome: gene expression changes following acute exposure to whole cigarette smoke in vitro

Cigarette smoke is a complex mixture of more than 4,000 constituents. Its effects on cell biology are poorly understood, partly because whole smoke exposure in vitro is technically challenging. To investigate the effects of smoke on cell signaling and function, a three-dimensional air-liquid interface model of tracheobronchial epithelium, grown from primary human lung epithelial cells, was exposed to air or whole mainstream cigarette smoke for 1 h in a purpose-designed chamber. Gene expression profiles were then determined at 1, 6, and 24 h postexposure using Affymetrix HGU133-2 Plus microarrays. Cells from three different donors were used in the study, and the experiment was performed in triplicate for each donor. Genes significantly regulated by smoke, compared with the air control, in all experiments were determined. Genes exhibiting differential expression were assigned to functional categories and mapped to signaling pathways. Effects were observed on many cellular processes including xenobiotic metabolism, oxidant/antioxidant balance, and DNA damage and repair. Notably, there was marked downregulation of the transforming growth factor-beta pathway, which has not been previously reported. This study provides important data on the acute effects of whole cigarette smoke on mucociliary epithelium and may be used to gain a greater understanding of smoke toxicity.     

The history of the discovery of blood circulation: unrecognized contributions of Ayurveda masters

Ayurveda, the native healthcare system of India, is a rich resource of well-documented ancient medical knowledge. Although the roots of this knowledge date back to the Vedic and post-Vedic eras, it is generally believed that a dedicated branch for healthcare was gradually established approximately between 400 BCE and 200 CE. Probably because the language of documentation of these early textbooks is in Sanskrit, a language that is not in day-to-day use among the general population even in India, many significant contributions of Ayurveda have remained unrecognized in the literature related to the history of medicine. In this communication, the discovery of blood circulation has been taken up as a case, and a few important references from the representative Ayurveda compendia that hint at a preliminary understanding of the cardiovascular system as a "closed circuit" and the heart acting as a pump have been reviewed. The central argument of this review is that these contributions from Ayurveda too must be recorded and credited when reviewing the milestones in the history of medicine, as Ayurveda can still possibly guide various streams of the current sciences, if revisited with this spirit.     

Epoxidation of cottonseed oil by aqueous hydrogen peroxide catalysed by liquid inorganic acids

The kinetics of epoxidation of cottonseed oil by peroxyacetic acid generated in situ from hydrogen peroxide and glacial acetic acid in the presence of liquid inorganic acid catalysts were studied. It was possible to obtain up to 78% relative conversion to oxirane with very less oxirane cleavage by in situ technique. The rate constants for sulphuric acid catalysed epoxidation of cottonseed oil were in the range 0.39-5.4 x 10(-6)L mol(-1)s(-1) and the activation energy was found to be 11.7 kcal mol(-1). Some thermodynamic parameters such as enthalpy, entropy, and free energy of activation were determined to be of 11.0 kcal mol(-1), -51.4 cal mol(-1)K(-1) and 28.1 kcal mol(-1), respectively. The order of effectiveness of catalysts was found to be sulphuric acid>phosphoric acid>nitric acid>hydrochloric acid. Acetic acid was found to be superior to formic acid for the in situ cottonseed oil epoxidation.     

Investigation of apoptosis in cultured cells infected with equine herpesvirus 1

Many viruses alter different stages of apoptosis of infected cells as a strategy for successful infection. Few studies have addressed mechanisms of equine herpesvirus 1 (EHV-1) strain-induced cell death. We investigated the effect of an abortigenic strain (AR8 strain) on heterologous Madin–Darby bovine kidney cells and homologous equine dermis (ED) cells cell lines. We compared morphologic and biochemical features of early and late apoptosis at different postinfection times. We investigated translocation of phosphatidylserine to the cell surface, nuclear fragmentation and changes in the cytoskeleton using flow cytometry and annexin V/propidium iodide staining, DNA laddering, terminal deoxynucleotidyl transferase UTP nick-end labeling assay and immunofluorescence staining of cytokeratin 18 cleavage. AR8 EVH-1 strain interfered with apoptosis in both cell lines, particularly during the middle stage of the replication cycle; this was more evident in ED cells. Although this antiapoptotic effect has been reported for other alpha herpesviruses, our findings may help elucidate how EHV-1 improves its infectivity during its cycle.     

DNA isolation from fresh,dry plant samples with highly acidic tissue extracts

Current DNA isolation methods are limited in their ability to obtain quality and/or quantity DNA from plants, such asEmblica officinalis, Terminalia belerica, andTerminalia chebula, which have low pH and high amounts of secondary metabolites in tissue extracts. Our modified DNA isolation method yields good-quality, high-molecular-weight DNA that is free of contaminants and colored pigments and is suitable for PCR amplification. This method is also useful for isolating DNA from dry powders.     

Phage-Displayed Libraries for the Selection of Optimal Affinity Peptides for Protein Purification Using Ni-Nitrilotriacetic Acid Chromatography

A random hexapeptide library, cloned in bacteriophage, was used to select affinity peptides using nickel-nitrilotriacetic acid (Ni-NTA) columns. The screening protocol was successful by isolating peptides sharing common features and, in most cases, common amino acid sequences were isolated (e.g. WHHHPH, AQHHHH). Ni-NTA chromatography of the fusion phage of the selected peptides exhibited a more homogeneous elution behavior (i.e. elution in one peak) than the most commonly used His₆peptide (elution in multiple peaks).     

Stent implantation through a self-expanding stent

Jailing of a side-branch is a known complication of stent implantation, and makes access to the side-branch difficult, especially if the stent is of the self-expanding type. Although plain balloon angioplasty is feasible for the jailed side-branches, the use of newer devices (a stent, Rotablation or atherectomy) has not been described. We describe a novel way of treating a side-branch jailed by a self-expanding stent by using stent implantation through the strut of a self-expanding stent.     

Effects of inhibitors of steroid biosynthesis on prostaglandin formation in rabbit ovarian follicles

Rabbit ovarian follicles were incubated without stimulation, with LH and with LH + an inhibitor or steroid biosynthesis. Formation of prostaglandins PGE and PGF and of progesterone and estradiol was measured in these incubates. It was found that aminoglutethimide phosphate (AGP) inhibited the LH stimulated biosynthesis of both prostaglandins and steroids. However U 30870 and Metyrapone, while completely inhibiting the LH stimulated biosynthesis of progesterone and estradiol respectively, had no effect on the formation of prostaglandins. Further, the inhibition of prostaglandin formation by AGP could not be reversed by exogenou steroids. It, therefore, appears that the effect of AGP on prostaglandin biosynthesis may not be related to its effect on steroid biosynthesis. However, the response of rabbit follicles to AGP is contrary to that reported for rat follicles and indicates different control mechanisms for prostaglandin formation in the follicles of the two species.