Approaching tumour therapy beyond platinum drugs: status of the art and perspectives of ruthenium drug candidates

The study of metal complexes for the treatment of cancer diseases has resulted in the identification of some unique properties of ruthenium-based compounds. Among these inorganic-based agents, two of them, namely the ruthenium(III) drugs NAMI-A and KP1019 have undertaken with some success the clinical evaluations of phase I and preliminary phase II trials in patients. Here we highlight the strategies that have led to the discovery of metal-based (NAMI-A and KP1019) and of organometallic (RM175, RAPTA-T, RDC11 and DW1/2) ruthenium-based complexes, and we report their main biological/pharmacological characteristics and expectations for further development.     

Dynamic epitope expression from static cytometry data: principles and reproducibility

Background

An imprecise quantitative sense for the oscillating levels of proteins and their modifications, interactions, and translocations as a function of the cell cycle is fundamentally important for a cartoon/narrative understanding for how the cell cycle works. Mathematical modeling of the same cartoon/narrative models would be greatly enhanced by an open-ended methodology providing precise quantification of many proteins and their modifications, etc. Here we present methodology that fulfills these features.

Methodology

Multiparametric flow cytometry was performed on Molt4 cells to measure cyclins A2 and B1, phospho-S10-histone H3, DNA content, and light scatter (cell size). The resulting 5 dimensional data were analyzed as a series of bivariate plots to isolate the data as segments of an N-dimensional “worm” through the data space. Sequential, unidirectional regions of the data were used to assemble expression profiles for each parameter as a function of cell frequency.

Results

Analysis of synthesized data in which the true values where known validated the approach. Triplicate experiments demonstrated exceptional reproducibility. Comparison of three triplicate experiments stained by two methods (single cyclin or dual cyclin measurements with common DNA and phospho-histone H3 measurements) supported the feasibility of combining an unlimited number of epitopes through this methodology. The sequential degradations of cyclin A2 followed by cyclin B1 followed by de-phosphorylation of histone H3 were precisely mapped. Finally, a two phase expression rate during interphase for each cyclin was robustly identified.

Conclusions

Very precise, correlated expression profiles for important cell cycle regulating and regulated proteins and their modifications can be produced, limited only by the number of available high-quality antibodies. These profiles can be assembled into large information libraries for calibration and validation of mathematical models.     

MyD88-Dependent Signaling Influences Fibrosis and Alternative Macrophage Activation during Staphylococcus aureus Biofilm Infection

Bacterial biofilms represent a significant therapeutic challenge based on their ability to evade host immune and antibiotic-mediated clearance. Recent studies have implicated IL-1β in biofilm containment, whereas Toll-like receptors (TLRs) had no effect. This is intriguing, since both the IL-1 receptor (IL-1R) and most TLRs impinge on MyD88-dependent signaling pathways, yet the role of this key adaptor in modulating the host response to biofilm growth is unknown. Therefore, we examined the course of S. aureus catheter-associated biofilm infection in MyD88 knockout (KO) mice. MyD88 KO animals displayed significantly increased bacterial burdens on catheters and surrounding tissues during early infection, which coincided with enhanced dissemination to the heart and kidney compared to wild type (WT) mice. The expression of several proinflammatory mediators, including IL-6, IFN-γ, and CXCL1 was significantly reduced in MyD88 KO mice, primarily at the later stages of infection. Interestingly, immunofluorescence staining of biofilm-infected tissues revealed increased fibrosis in MyD88 KO mice concomitant with enhanced recruitment of alternatively activated M2 macrophages. Taken in the context of previous studies with IL-1β, TLR2, and TLR9 KO mice, the current report reveals that MyD88 signaling is a major effector pathway regulating fibrosis and macrophage polarization during biofilm formation. Together these findings represent a novel example of the divergence between TLR and MyD88 action in the context of S. aureus biofilm infection.     

An image analysis toolbox for high-throughput C. elegans assays

We present a toolbox for high-throughput screening of image-based Caenorhabditis elegans phenotypes. The image analysis algorithms measure morphological phenotypes in individual worms and are effective for a variety of assays and imaging systems. This WormToolbox is available through the open-source CellProfiler project and enables objective scoring of whole-worm high-throughput image-based assays of C. elegans for the study of diverse biological pathways that are relevant to human disease.     

A Structural Systems Biology Approach for Quantifying the Systemic Consequences of Missense Mutations in Proteins

Gauging the systemic effects of non-synonymous single nucleotide polymorphisms (nsSNPs) is an important topic in the pursuit of personalized medicine. However, it is a non-trivial task to understand how a change at the protein structure level eventually affects a cell''s behavior. This is because complex information at both the protein and pathway level has to be integrated. Given that the idea of integrating both protein and pathway dynamics to estimate the systemic impact of missense mutations in proteins remains predominantly unexplored, we investigate the practicality of such an approach by formulating mathematical models and comparing them with experimental data to study missense mutations. We present two case studies: (1) interpreting systemic perturbation for mutations within the cell cycle control mechanisms (G2 to mitosis transition) for yeast; (2) phenotypic classification of neuron-related human diseases associated with mutations within the mitogen-activated protein kinase (MAPK) pathway. We show that the application of simplified mathematical models is feasible for understanding the effects of small sequence changes on cellular behavior. Furthermore, we show that the systemic impact of missense mutations can be effectively quantified as a combination of protein stability change and pathway perturbation.     

A sensitive assay for the quantitative analysis of vinorelbine in mouse and human EDTA plasma by high-performance liquid chromatography coupled with electrospray tandem mass spectrometry

A sensitive, specific and fast high-performance liquid chromatography/tandem mass spectrometry (HPLC-MS/MS) assay for the determination of vinorelbine in mouse and human plasma is presented. A 200 microL aliquot was extracted with solid-phase extraction (SPE) using Bond-Elut C(2) cartridges. Dried extracts were reconstituted in 100 microL 1 mM ammonium acetate pH 10.5-acetonitrile-methanol (21:9:70, v/v/v) containing the internal standard vintriptol (100 ng/mL) and 10 microL volumes were injected onto the HPLC system. Separation was achieved on a 50 mm x 2.0 mm i.d. Gemini C(18) column using isocratic elution with 1 mM ammonium acetate pH 10.5-acetonitrile-methanol (21:9:70, v/v/v) at a flow rate of 0.4 mL/min. HPLC run time was only 5 min. Detection was performed using positive ion electrospray ionization followed by tandem mass spectrometry (ESI-MS/MS). The assay quantifies vinorelbine from 0.1 to 100 ng/mL using human plasma sample volumes of 200 microL. With this method vinorelbine can be measured in mouse plasma samples when these samples are diluted eight times in control human plasma. Calibration samples prepared in control human plasma can be used for the quantification of the drug. The lower limit of quantification in mouse plasma is 0.8 ng/mL. This assay is used to support preclinical and clinical pharmacologic studies with vinorelbine.     

Diagnosis of foot-and mouth disease by real time reverse transcription polymerase chain reaction under field conditions in Brazil

Background  

Indication-based data on the use of antimicrobials in animals were collected using a prospective cross-sectional survey, similarly as for surveys carried out in human medicine, but adapting the questionnaire to include veterinary-specific issues. The participating veterinarians were randomly selected from a sample population of practising veterinarians. The sampling was stratified to take into account the proportions of different types of veterinary practice in the country. All patients consulting the veterinary practice during a 1-week period were included in the study and veterinarians returned a completed questionnaire for each patient receiving antimicrobial treatment. As cattle received most of the treatments, results from the survey are given using cattle as an example species.     

Development of polymorphic microsatellite markers for the New Zealand black stilt (Himantopus novaezelandiae) and cross-amplification in the pied stilt (Himantopus himantopus leucocephalus)

Eight polymorphic microsatellite primer pairs were developed for the critically endangered New Zealand black stilt, Himantopus novaezelandiae, representing the first microsatellite markers available for birds in the family Recurvirostridae. The number of alleles ranged from two to four per locus. Observed and expected heterozygosities ranged from 0.30 to 0.80 and from 0.37 to 0.70, respectively. All eight loci were polymorphic in the related species Himantopus himantopus leucocephalus, indicating these primer pairs may be useful for additional taxa in the globally distributed genus Himantopus.