Anastasios Ioannidis

Terms of endearment: Bacteria meet graphene nanosurfaces

Microbial multidrug resistance poses serious risks in returning the human species into the pre-antibiotic era if it remains unsolved. While conventional research approaches to combat infectious diseases have been inadequate, nanomaterials are a promising alternative for the development of sound antimicrobial countermeasures. Graphene, a two-dimensional ultra-thin nanomaterial, possesses excellent electronic and biocompatibility properties, which position it in the biotechnology forefront for diverse applications in biosensing, therapeutics, diagnostics, drug delivery and device development. Yet, several questions remain unanswered. For instance, the way these nanosurfaces interact with the microbial entities is poorly understood. The mechanistic elucidation of this interface seems critical to determine the feasibility of applications under development. Are graphene derivatives appropriate materials to design potent antimicrobial agents, vehicles or effective diagnostic microsensors? Has the partition of major microbial resistance phenotypic determinants been sufficiently investigated? Can toxicity become a limiting factor? Are we getting closer to clinical implementation? To facilitate research conducive to answer such questions, this review describes the features of the graphene-bacterial interaction. An overview on paradigms of graphene-microbial interactions is expected to shed light on the range of materials available, and identify possible applications, serving the ultimate goal to develop deeper understanding and collective conscience for the true capabilities of this nanomaterial platform.

The Telomere/Telomerase System in Chronic Inflammatory Diseases. Cause or Effect?

Telomeres are specialized nucleoprotein structures located at the end of linear chromosomes and telomerase is the enzyme responsible for telomere elongation. Telomerase activity is a key component of many cancer cells responsible for rapid cell division but it has also been found by many laboratories around the world that telomere/telomerase biology is dysfunctional in many other chronic conditions as well. These conditions are characterized by chronic inflammation, a situation mostly overlooked by physicians regarding patient treatment. Among others, these conditions include diabetes, renal failure, chronic obstructive pulmonary disease, etc. Since researchers have in many cases identified the association between telomerase and inflammation but there are still many missing links regarding this correlation, the latest findings about this phenomenon will be discussed by reviewing the literature. Our focus will be describing telomere/telomerase status in chronic diseases under the prism of inflammation, reporting molecular findings where available and proposing possible future approaches.

Extensible platform for location based services provisioning

Location based services can be considered as the most rapidly expanding field of the mobile communications sector. The proliferation of the mobile/wireless internet, the constantly increasing use of handheld, mobile devices and position tracking technologies and the emergence of mobile computing, prepared the grounds for the introduction of this new type of services with impressively large application domain and use range. Prompted by the avalanche of technology advances in the aforementioned areas in this paper we present a generic platform for delivering location based services (LBS). The platform features a modular architecture, which can be easily extended with additional functionality. The paper focuses on the technical specifications, the design and the prototype implementation of the platforms kernel, which is responsible for coordinating communication with various pluggable components in order to provide the full range of operations involved in the LBS delivery chain (i.e., from initial deployment to invocation, execution and delivery of results). Issues such as scalability, efficiency, openness, portability and security are also considered in the design of the platform.

Demo: PoLoS: integrated platform for location based services

The PoLoS platform, implemented in the context of the European Union Information Society Technologies (IST) program, focuses on the development, deployment and provision of services and consolidates several technologies (and operation schemes) of the Location Based Services world under a single framework. The demonstration aims to provide an operational overview of the PoLoS platform and highlight the benefits the platform brings in a large-scale, competitive and fast-changing environment.

Detection of bacteria bearing resistant biofilm forms, by using the universal and specific PCR is still unhelpful in the diagnosis of periprosthetic joint infections

Intraoperative conventional bacteriological cultures were compared with different polymerase chain reaction (PCR) methods in patients with total joint arthroplasties. The isolated bacteria were investigated for biofilm formation, and the biofilm forming strains, in their planktonic and biofilm forms, were further tested for their antimicrobial resistance against several clinically important antimicrobials. Forty four bone and joint samples were included and classified as infected or non-infected according to standard criteria for periprosthetic hip and knee infections. For the bacteriological diagnosis, conventional culture, two types of universal PCR and species specific PCR for three selected pathogens (Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa) were applied. Biofilm formation determination was performed by the tissue culture plate method. Antimicrobial susceptibility of the planktonic bacteria was performed by the minimal inhibitory concentration determination and, of the biofilm forms, by the minimal inhibitory concentration for bacterial regrowth from the biofilm. Twenty samples were culture positive, with S. epidermidis, S. aureus, or P. aeruginosa. All PCR methods were very ineffective in detecting only one pathogen. All isolates were biofilm positive and their biofilm forms, were highly resistant. In this study, compared to PCR, culture remains the “gold standard.” The biofilm formation by the causative bacteria and the concomitant manifold increased antimicrobial resistance may explain the clinical failure of treatment in some cases and should be considered in the future for therapeutic planning.

Using XML and related standards to support Location Based Services

Location Based Services can be considered as the most rapidly expanding field of the mobile communications sector. The proliferation of the mobile/wireless Internet, the constantly increasing use of handheld, mobile devices and positioning technologies and the emergence of mobile computing, prepared the grounds for the introduction of this new type of services with impressively large application domain and use range. The combination of position fixing mechanisms with location-dependent, georgraphical information, can offer truly customized personal communication services through the mobile phone or other type of devices. Web Services have emerged as a set of open standards and gained a lot of momentum during the recent past. Many software vendors are announcing Web Service initiatives and adoption in their products. Many organizations are involved in the refinement of Web Service standards. Moreover, XML has become the de facto standard for data interchange on the Web and its emergence is having an enormous impact on Web development. Motivated by the technology advances in the aforementioned areas in this paper we discuss the exploitation of Web Services and XML to build a generic platform for delivering Location Based Services (LBS) to the nomadic user.

Serum and peripheral blood mononuclear cells infectious burden: Correlation to inflammation and atherosclerosis in haemodialysis patients

Background:  Infectious agents may be implicated in the inflammatory atherosclerotic process. Not only specific microorganisms but also the infectious burden, defined as the number of pathogens to which a patient is exposed, has been associated with atherosclerosis. In the present study, the infectious burden, determined directly (by identification of viable pathogens in peripheral blood mononuclear cells (PBMC)) and indirectly (by serum antibodies detection) is correlated to the inflammatory and atherosclerotic status in haemodialysis (HD) patients, a population at high risk for cardiovascular disease.

Multilocus sequence typing (and phylogenetic analysis) of Campylobacter jejuni and Campylobacter coli strains isolated from clinical cases in Greece

BackgroundThe molecular epidemiology of C. jejuni and C. coli clinical strains isolated from children with gastroenteritis, was investigated using the multilocus sequence typing method (MLST). This analysis establishes for the first time in Greece and constitutes an important tool for the epidemiological surveillance and control of Campylobacter infection in our country.MethodsThe MLST genotypes were compared with those gained by other typing methods (HS-typing, PFGE and FlaA typing) and were also phylogenetically analyzed, in order to uncover genetic relationships.ResultsAmong 68 C. jejuni strains, 41 different MLST-Sequence Types (MLST-STs) were found. Fifty six strains or 34 MLST-STs could be sorted into 15 different MLST-Sequence Type Complexes (MLST-STCs), while twelve strains or seven MLST-STs did not match any of the MLST-STCs of the database. Twenty C. coli strains belonged to 14 different MLST-STs. Eleven MLST-STs were classified in the same MLST-STC (828), and three were unclassifiable. There was no significant association between the MLST-STs and the results of the other typing methods.Phylogenetic analysis revealed that some strains, classified to the species of C. jejuni, formed a separate, phylogenetically distinct group. In eight strains some alleles belonging to the taxonomic cluster of C. jejuni, were also detected in C. coli and vice versa, a phenomenon caused by the genetic mosaic encountered inside the genus Campylobacter.ConclusionsThe MLST-ST determination proved to be a very useful tool for the typing as well as the identification of Campylobacter on the species level.

Alteration in the concentrations of Interleukin-7 (IL-7), Interleukin-10 (IL-10) and Granulocyte Colony Stimulating Factor (G-CSF) in alcohol-dependent individuals without liver disease, during detoxification therapy

BACKGROUND The course of Interleukin-7 (IL-7), Interleukin-10 (IL-10) and Granulocyte Colony Stimulating Factor (G-CSF) was investigated in alcohol-dependent individuals without liver disease in order to ascertain the use of these cytokines as markers for the follow-up testing and the outcome of the detoxification treatment. METHODS Forty-eight alcohol-dependent individuals were admitted for alcohol detoxification. Blood was obtained upon admission, two weeks later and after the completion of the detoxification period (4-5 weeks). Serum IL-7, IL-10 and G-CSF were measured with a commercially available sandwich enzyme immunoassay. RESULTS IL-7 concentration was steadily high from admission up to two weeks later and then showed a fall, yet still remaining significantly higher than in the control group at the end of the detoxification treatment. IL-10 concentration was significantly low on admission, presenting a linear increase during therapy and remained insignificantly low at the end. G-CSF was significantly elevated on admission and presented a linear fall ending up in almost normal values at the end of the detoxification therapy. CONCLUSIONS The alterations in the concentration of IL-7, IL-10 and G-CSF and their trend to normalization during the detoxification therapy are indicative of the generalized immune system disorder, caused by alcohol abuse. Further studies will help in further elucidating the pathophysiology of the immune system function in alcohol abuse, while immunological parameters might serve as biological markers and diagnostic tools for the assessment of the course and the outcome of the detoxification therapy.

Serologic markers for HBV, HCV and HIV in immigrants visiting the Athens' polyclinic of 'Doctors of the World - Greece'.

G. Papadakis , N.A. Okoba , C. Nicolaou , F. Boufidou , A. Ioannidis , S. Bersimis , Doctors of the World e Greece, S. Chatzipanagiotou * Greek Delegation of Doctors of the World, Athens, Greece Department of Medical Biopathology, Eginition Hospital, Medical School, University of Athens, Athens, Greece Department of Nursing, Faculty of Human Movement and Quality of Life Sciences, University of Peloponnese, Greece Department of Statistics and Insurance Science, University of Piraeus, Piraeus, Greece