A novel biosensor for the detection and monitoring of -d-galactosidase of faecal origin in water

A voltammetric sensor prepared by the immobilization of metallophthalocyanine complexes onto a glassy carbon electrode has been developed for the detection of β-d-galactosidase (B-GAL) of faecal origin in water. Electrooxidation of chlorophenol red, a breakdown product of the chromogenic substrate chlorophenol red β-d-galactopyranoside, was used as a measure of β-d-galactosidase activity. At metallophthalocyanine modified electrodes, in particular copper(II) phthalocyanine, a decrease in electrode fouling was observed. The sensor was sensitive to fluctuations in pH, not significantly affected by temperature variations and could detect one colony forming unit/100 mL in 15 min. Loss of 40% sensitivity was observed over a period of 30 days. A strong correlation between sensor sensitivity and colony forming units was observed. The sensor is capable of detecting viable but nonculturable bacteria, overcoming this drawback of the use of culture media for detection of coliforms

Stochastic Drift in Mitochondrial DNA Point Mutations: A Novel Perspective Ex Silico

The mitochondrial free radical theory of aging (mFRTA) implicates Reactive Oxygen Species (ROS)-induced mutations of mitochondrial DNA (mtDNA) as a major cause of aging. However, fifty years after its inception, several of its premises are intensely debated. Much of this uncertainty is due to the large range of values in the reported experimental data, for example on oxidative damage and mutational burden in mtDNA. This is in part due to limitations with available measurement technologies. Here we show that sample preparations in some assays necessitating high dilution of DNA (single molecule level) may introduce significant statistical variability. Adding to this complexity is the intrinsically stochastic nature of cellular processes, which manifests in cells from the same tissue harboring varying mutation load. In conjunction, these random elements make the determination of the underlying mutation dynamics extremely challenging. Our in silico stochastic study reveals the effect of coupling the experimental variability and the intrinsic stochasticity of aging process in some of the reported experimental data. We also show that the stochastic nature of a de novo point mutation generated during embryonic development is a major contributor of different mutation burdens in the individuals of mouse population. Analysis of simulation results leads to several new insights on the relevance of mutation stochasticity in the context of dividing tissues and the plausibility of ROS ”vicious cycle” hypothesis

Platelet monoamine oxidase activity predicts alcohol sensitivity and voluntary alcohol intake in rhesus monkeys

Platelet monoamine oxidase B (MAO-B) has been proposed to be a biological marker for the properties of monoamine systems, with low activity being associated with vulnerability for high scores on personality traits such as sensation seeking, monotony avoidance, and impulsiveness, as well as for vulnerability for alcoholism. In the present study, platelet MAO-B activity was analysed in 78 rhesus macaques, and its relation to voluntary alcohol intake and behaviours after intravenous alcohol administration was observed

Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference

The fiscal constraint to restructuring firms in transition economies

Biotechnology research and innovation depends on the ability to understand the molecular mechanisms of biological processes such as protein–protein and protein–ligand interactions. Surface plasmon resonance (SPR) spectroscopy is now well established as a quantitative technique for monitoring biomolecular interactions. In this study, we examined the recently developed quartz crystal microbalance with dissipation (QCM-D) method as an alternative to SPR spectroscopy to investigate protein–protein interactions, in particular, for chaperone–co-chaperone interactions. In mammalian cells, the Hsp70/Hsp90 organizing protein (Hop) is a co-chaperone required for the association of the molecular chaperones, heat shock protein 70 (Hsp70) and heat shock protein 90 (Hsp90). The objective of this research was to characterize qualitatively and quantitatively the interaction of Hsp70 with Hop. A truncated version of Hop consisting of only the C-terminal region and lacking the Hsp70-binding domain (GST-C-Hop) was used as a non-Hsp70- binding control. Immobilized GST-Hop was found to bind Hsp70 successfully, displaying a QCM-D response consistent with formation of a complex that became slightly more flexible as the concentration of bound Hsp70 increased. GST-C-Hop did not bind to Hsp70, thereby validating the specificity of the GST-Hop interaction with Hsp70. The kinetics of the interaction was followed at different concentrations of Hsp70, and an apparent thermodynamic dissociation constant (KD value) in the micromolar range was determined that correlated well with the value derived previously using SPR. This study represents a proof-of-principle that QCM-D can be applied to the analysis of chaperone–co-chaperone interactions. The economic and technical accessibility of QCM-D makes it a valuable tool for analyses of chaperone interactions, and protein– protein interactions in general

Treatment of enteric fever with pefloxacin for 7 days versus 5 days: a randomized clinical trial.

In this prospective study of enteric fever, 22 patients received 400 mg of pefloxacin twice daily for 5 days (group A) and 24 received 400 mg of pefloxacin twice daily for 7 days (group B). Causative microorganisms were Salmonella typhi (8 in group A, 11 in group B) and Salmonella paratyphi B (14 in group A, 13 in group B). The clinical cure and bacterial eradication rates were 96% (21 of 22) in group A and 100% in group B. In conclusion, 5-day oral administration of pefloxacin was as effective as 7-day treatment of enteric fever caused by Salmonella spp