New approaches for imaging and therapy of solid cancer

Radionuclide therapy is a systemic treatment that aims to deliver cytotoxic radiation to cancer cells. Due to their properties, antibodies have been considered as suitable agent for the delivery of therapeutic radioisotopes, radioimmunotherapy (RIT). This article gives an overview of new approaches for imaging and therapy of solid cancer with particular attention to strategies to enhance treatment success. Examples of increased antibody uptake by targeting stromal constituent of tumor microenvironment such as fibronectin (FN) an important tumor-associated angiogenesis targeting agent, with specifically designed antibody format will be provided. Strategies oriented to identify patients most likely to benefit from RIT including identification of radiosensitivity profiles, in vivo target identification by teragnostic approach and better prediction of dosimetric estimates would be presents. Combination regimens such as with chemo-radiotherapy and immunotherapy would be also discussed as an approach to enhance RIT success.

In situ identification by fluorescently labeled oligonucleotide probes of morphologically similar, closely related ciliate species

Ciliate protozoa are important members of microbial communities in which they play specific ecological roles. The determination of single species distribution is fundamental for food web analysis, but species recognition, which is mainly based on morphological characters, is often difficult between closely related species. The use of species-specific, purposely designed, fluorescently labeled probes for in situ hybridization is here presented as an easy and fast identification method for three closely related species belonging to the widespread genus Euplotes, namely E. crassus, E. vannus, and E. minuta, that in spite of their remarkable morphological similarity have significant metabolic and ecological differences. These three species can be detected simultaneously, provided the probes employed are bound to different fluorescent dyes: in this way their relative abundance and their population dynamics in the natural environment can be evaluated. As more ciliate sequences become available in databases, species-specific probes can be designed for other ciliates, thus rendering the application of the method of more general importance. The probes used in this study may also provide a tool to prevent erroneous species identification in future studies.

Trichites of Strombidium (Ciliophora, Oligotrichida) are extrusomes

The trichites of Strombidium and related genera have been considered either as a cytoskeletal armature or as extrusomes. To demonstrate their true nature, a study was undertaken on two marine Strombidium species by ultrastructural and cytochemical analysis as well as in vivo experiments. Trichites, extending from the cortex into the cell, are rod-shaped, membrane-bounded, and have a complex structure. The following elements of the trichites, are distinguishable: an electron-transparent lumen, a laminated layer, and a compact layer. In trichites of one species, thin "rings" surround the lumen. Numerous short, curved tubules with a polysaccharide wall are present in the cytoplasm surrounding the trichites. At the cortical end, each trichite is enveloped by a "cap" of electron-dense proteinaceous material. In some cases, the cortical alveoli appear interrupted, forming a "hole" for trichite ejection. Ejection of rod-shaped structures, up to 5 times longer than resting trichites, was obtained by in vivo treatments with dextran and aminoethyldextran. Negative staining indicated that these structures were transformed trichites. As no other possible extrusive structures were observed in the cytoplasm of Strombidium, trichites were considered extrusomes.