[Development of Molecular Probes for Spatio-temporal Analysis of in Vivo Tumor with Photoacoustic Imaging].

Photoacoustic imaging (PA imaging or PAI) has been focused on as a new technique to provide images of high spatial resolution, at depths of up to 5 cm, and the development of novel PAI probes for tumor imaging is of marked interest. Although nanomaterials such as gold nanorods have been reported as PAI probes, dyes are required to aid their ease of preparation, cost-effectiveness, and safety. However, because PAI has relatively low intrinsic sensitivity compared to optical imaging, and requires high-energy laser pulse exposure, an appropriate probe design, high tumor accumulation, and photostability are required for PAI probes. We developed some dyes and evaluated their usefulness as PAI probes. We first developed a high tumor-accumulation dye probe, IC7-1-Bu, which utilizes serum albumin as a tumor-targeting carrier to deliver an adequate PA signal at the tumor. Although IC7-1-Bu showed strong tumor targeting ability and a sufficient PA signal at the tumor in in vivo studies, IC7-1-Bu lacks photostability against multiple laser irradiations of PAI. In order to improve dye photostablity, we focused on the effect of singlet oxygen ((1)O2) generated by excited PAI probes on probe degeneration, and developed a triplet-state quencher conjugated dye probe, IC-5-T. IC-5-T reduced (1)O2 generation and improved photostability against multiple irradiations compared to IC7-1-Bu. IC-5-T also showed a sufficient PA signal at the tumor, and 1.5-fold higher photostabillity compared to IC7-1-Bu in sequential in vivo PAI studies. These results suggest that IC-5-T is a potential PAI probe for tumor imaging.

Incidencia y distribución del género Armillaria en viñedos de las cinco denominaciones de origen de vino de Galicia (noroeste de España) / Incidence and distribution of the genus Armillaria in vineyards of the five protected designation of origin wines in Galicia (Northwestern Spain)

Antecedentes: el género Armillaria, y más concretamente la especie Armillaria mellea, constituye un problema muy importante en el sector vitivinícola de Galicia, lo que ha ocasionado importantes reducciones del rendimiento de los viñedos en los últimos 15 años. Este hongo ataca al sistema radicular, causando un descenso del vigor y, finalmente, la muerte de la planta. Hasta la fecha, no se conoce ningún método químico o biológico que resulte efectivo contra el patógeno una vez que ha entrado en la planta. Objetivos: el objetivo principal del presente trabajo fue conocer la incidencia y distribución del género Armillaria mediante técnicas moleculares en las distintas zonas de cultivo de vid en Galicia, abarcando las cinco denominaciones de origen (DO) vitivinícolas gallegas (Rías Baixas, Ribeiro, Ribeira Sacra, Valdeorras y Monterrei). Métodos: se analizaron 624 muestras (483 de suelo y 141 de plantas de vid sintomáticas) mediante nested-PCR/RFLP, PCR-RFLP y análisis filogenéticos. Resultados: Armillaria mellea está ampliamente distribuida en viñedos de las cinco DO, con mayor incidencia en la DO del Ribeiro. Conclusiones: es necesario establecer medidas para reducir el avance de la podredumbre radicular causada por Armillaria mellea en las cinco DO de Galicia

Blackground: the genus Armillaria, specifically Armillaria mellea, is an important phytopathological problem in the wine sector in Galicia (NW Spain), having caused yield reductions in vineyards for the last 15 years. The fungus attacks the root system, resulting in a decrease in vigour, and eventually in the death of the plant. Up to now, there is no chemical or biological method really effective against the pathogen once it has infected the plant. Aims: the main objective of this work was to study the incidence and distribution of the genus Armillaria across the five Galician protected designation of origin (DO) wines (namely Rías Baixas, Ribeiro, Ribeira Sacra, Valdeorras and Monterrei) through the application of molecular techniques. Methods: a total of 624 samples (483 soils and 141 symptomatic vines) were analyzed by nested-PCR/RFLP, PCR-RFLP and phylogeny. Results: Armillaria mellea is widely distributed in vineyards of the five DO wines, with the highest incidence in the Ribeiro DO. Conclusions: preventive control measures against Armillaria mellea must be established in the five DO wines of Galicia, in order to reduce the advance of white root rot

Luminescent nanoparticles and their applications in the life sciences.

Nanoparticles have recently emerged as an important group of materials used in numerous disciplines within the life sciences, ranging from basic biophysical research to clinical therapeutics. Luminescent nanoparticles make excellent optical bioprobes significantly extending the capabilities of alternative fluorophores such as organic dyes and genetically engineered fluorescent proteins. Their advantages include excellent photostability, tunable and narrow spectra, controllable size, resilience to environmental conditions such as pH and temperature, combined with a large surface for anchoring targeting biomolecules. Some types of nanoparticles provide enhanced detection contrast due to their long emission lifetime and/or luminescence wavelength blue-shift (anti-Stokes) due to energy upconversion. This topical review focuses on four key types of luminescent nanoparticles whose emission is governed by different photophysics. We discuss the origin and characteristics of optical absorption and emission in these nanoparticles and give a brief account of synthesis and surface modification procedures. We also introduce some of their applications with opportunities for further development, which could be appreciated by the physics-trained readership.

Surface-attached sensors for cation and anion recognition.

The development of surface-attached sensors for cationic and anionic guests is of intense current research interest. In addition to the environmental flexibility, robustness and reusability of such devices, surface-confined sensors typically exhibit an amplified response to target analytes owing to preorganization of the receptor. Whereas redox-active cations may be sensed by studying the cyclic voltammetry of host-guest systems containing ion-selective receptors attached to an appropriate electrode, redox-inactive ionic species require the use of electrochemical impedance spectroscopy, with appropriately functionalized electrodes and redox probes. Alternatively, receptors may be constructed that incorporate an electrochemical or optical reporter group within their structure to provide a macroscopic response to the presence of an ionic guest. This critical review seeks to present an up-to-date, although necessarily selective, account of the progress in the field, and provides insights into possible future developments, including the utilization of receptor-nanoparticle conjugates and mechanically interlocked receptors.

Recent trends in molecular beacon design and applications.

A molecular beacon (MB) is a hairpin-structured oligonucleotide probe containing a photoluminescent species (PLS) and a quencher at different ends of the strand. In a recognition and detection process, the hybridization of MBs with target DNA sequences restores the strong photoluminescence, which is quenched before hybridization. Making better MBs involves reducing the background photoluminescence and increasing the brightness of the PLS, which therefore involves the development of new PLS and quenchers, as well as innovative PLS-quencher systems. Heavy-metal complexes, nanocrystals, pyrene compounds, and other materials with excellent photophysical properties have been applied as PLS of MBs. Nanoparticles, nanowires, graphene, metal films, and many other media have also been introduced to quench photoluminescence. On the basis of their high specificity, selectivity, and sensitivity, MBs are developed as a general platform for sensing, producing, and carrying molecules other than oligonucleotides.

Response to treatment series: part 2, tumor response assessment--using new and conventional criteria.

OBJECTIVE: Conventional anatomic imaging biomarkers, including World Health Organization (WHO) criteria and Response Evaluation Criteria in Solid Tumors (RECIST), although effective, have limitations. This article will discuss the conventional and newer morphologic imaging biomarkers for the assessment of tumor response to therapy. CONCLUSION: Applying established methods of assessing tumor response to therapy allows consistency in image interpretation and facilitates communication with oncologists. Because of the new methods of treatment, assessment of necrosis and volumetric information will need to be incorporated into size-based criteria.

[Personalized medicine 2011]. / Individualisierte Medizin 2011.

Molecular and cell biology have not only greatly advanced our understanding of the pathogenesis of numerous human diseases but at the same time contributed to their diagnosis, therapy and prevention. Based on modern genetic as well as epigenetic and biochemical analyses it is possible to identify on the one hand point mutations and single nucleotide polymporphisms (SNPs) as well as epigenetic modifications. On the other hand, using high throughput array technologies, it is possible to analyze thousands of genes simultaneously, resulting in an individual gene or gene expression profile (signature). These data increasingly allow to define the individual risk for a given disease and to predict the individual prognosis of a disease as well as the efficacy of therapeutic strategies (personalized medicine).

In situ ligation: a decade and a half of experience.

The in situ ligation (ISL) methodology detects apoptotic cells by the presence of characteristic DNA double-strand breaks. A labeled double-stranded probe is ligated to the double-strand breaks in situ on tissue sections. Like the popular TUNEL assay, ISL detects cells in apoptosis based on the ongoing destruction of DNA by apoptotic nucleases. In comparison to TUNEL, it is more specific for apoptosis versus other causes of DNA damage, both repairable damage and necrosis. In the decade and a half since its introduction, ISL has been used in several hundred publications. Here we review the development of the method, its current status, and its uses and limitations.

Fluorescence correlation spectroscopy: past, present, future.

In recent years fluorescence correlation spectroscopy (FCS) has become a routine method for determining diffusion coefficients, chemical rate constants, molecular concentrations, fluorescence brightness, triplet state lifetimes, and other molecular parameters. FCS measures the spatial and temporal correlation of individual molecules with themselves and so provides a bridge between classical ensemble and contemporary single-molecule measurements. It also provides information on concentration and molecular number fluctuations for nonlinear reaction systems that complement single-molecule measurements. Typically implemented on a fluorescence microscope, FCS samples femtoliter volumes and so is especially useful for characterizing small dynamic systems such as biological cells. In addition to its practical utility, however, FCS provides a window on mesoscopic systems in which fluctuations from steady states not only provide the basis for the measurement but also can have important consequences for the behavior and evolution of the system. For example, a new and potentially interesting field for FCS studies could be the study of nonequilibrium steady states, especially in living cells.

[Molecular markers in the diagnostics and therapy of urothelial cancer]. / Molekulare Marker in Diagnostik und Therapie des Urothelkarzinoms.

Many clinical decisions in the management of bladder cancer would benefit from better and reliable knowledge of individual prognosis. Marker for urothelial cancer can principally be measured in blood, urine and transurethrally resected tissue. In recent years new markers have been identified by new technologies and this opens exiting avenues. Since no single marker gives a clear Yes-or-no prognostic answer but always only a measure of probability, the use of marker systems has so far not gained widespread clinical applications. This will likely change in future.

Science to practice: the dawn of molecular US imaging for clinical cancer imaging.

Ultrasonography (US) is one of the most commonly used diagnostic modalities in clinical medicine. Gas-filled microbubbles can be used to enhance the contrast of tumors by indicating increased vascularity. Because microbubbles can be detected with high sensitivity and specificity, they fulfill an important precondition for use as a molecular imaging probe. Over the past several years, there have been an increasing number of published studies that showed that markers of angiogenesis and inflammation can be assessed reliably when microbubbles are coupled to antibodies and peptides. Recently, target-specific microbubbles have been developed that are suited for use in humans. Now the identification of the optimal clinical indications for molecular US imaging in clinics is required. In this context, advantages and limitations of US with targeted microbubbles, when compared with other imaging modalities, must be carefully considered. Because US is a transportable, cheap, real-time imaging modality, molecular US imaging may have advantages for initial tumor screening and US-guided interventions; furthermore, it may support therapy monitoring in intervals between whole-body images obtained with positron emission tomography (PET), computed tomography (CT), and magnetic resonance (MR) imaging.

[Molecular tests in modern medicine - concepts, technical aspects and future direction]. / Molekulare Früherkennung in der Medizin - Konzept, Techniken, Perspektiven.

Early diagnosis by molecular tests has increasingly catched attention after deciphering the complete human genome sequence in 2001. Meanwhile, complete genome sequencing will soon become available for each individual. Molecular testing is standard of care in certain infectious or malignant diseases. Novel biomarkers are emerging as a result of modern comprehensive procedures (transcriptomics, proteomics, metabolomics etc). However, hype and hope are particularly close in this field and responsible conduct by clinicians will ensure beneficial use of new tests.

FRET for lab-on-a-chip devices - current trends and future prospects.

This review focuses on the use of Förster Resonance Energy Transfer (FRET) to monitor intra- and intermolecular reactions occurring in microfluidic reactors. Microfluidic devices have recently been used for performing highly efficient and miniaturised biological assays for the analysis of biological entities such as cells, proteins and nucleic acids. Microfluidic assays are characterised by nanolitre to femtolitre reaction volumes, which necessitates the adoption of a sensitive optical detection scheme. FRET serves as a strong 'spectroscopic ruler' for elucidating the tertiary structure of biomolecules, as the efficiency of the non-radiative energy transfer is extremely sensitive to nanoscale changes in the separation between donor and acceptor markers attached to the biomolecule of interest. In this review, we will review the implementation of various microfluidic assays which employ FRET for diverse applications in the biomedical field, along with the advantages and disadvantages of the various approaches. The future prospects for development of microfluidic devices incorporating FRET detection will be discussed.