Highly stable multi-anchored magnetic nanoparticles for optical imaging within biofilms.

Magnetic nanoparticles are the next tool in medical diagnoses and treatment in many different biomedical applications, including magnetic hyperthermia as alternative treatment for cancer and bacterial infections, as well as the disruption of biofilms. The colloidal stability of the magnetic nanoparticles in a biological environment is crucial for efficient delivery. A surface that can be easily modifiable can also improve the delivery and imaging properties of the magnetic nanoparticle by adding targeting and imaging moieties, providing a platform for additional modification. The strategy presented in this work includes multiple nitroDOPA anchors for robust binding to the surface tied to the same polymer backbone as multiple poly(ethylene oxide) chains for steric stability. This approach provides biocompatibility and enhanced stability in fetal bovine serum (FBS) and phosphate buffer saline (PBS). As a proof of concept, these polymer-particles complexes were then modified with a near infrared dye and utilized in characterizing the integration of magnetic nanoparticles in biofilms. The work presented in this manuscript describes the synthesis and characterization of a nontoxic platform for the labeling of near IR-dyes for bioimaging.

Uncertain prognosis for high-quality diagnostics: clinical challenges, economic barriers and needed reforms.

Quality healthcare, as measured by outcomes and costs, needs high-quality diagnostics whose use governs the evidence-based flow of patients from screening to treatment to outcomes monitoring. The current patent, regulatory and reimbursement environment may be inadequate to spur their development, thereby placing in jeopardy the goals of healthcare reform and the aspirations of personalized medicine. Policy actions to ensure consistent quality standards and to increase development incentives through research support, reimbursement reform, increased intellectual property protection and market-making activities may be required to obtain the well-characterized, clinically proven diagnostics that US healthcare requires.

Fit-for-purpose pharmacogenomic biomarkers in drug development: a project team case study with 'what-ifs'.

Over the past four years, the annual US FDA-DIA pharmacogenomic workshops have brought together attendees with wide-ranging expertise spanning industry, regulatory authorities and academia. This special report summarizes a breakout session using a novel, interactive case format as a way to engage participants, raise awareness and share diverse learnings via 'real life' decisions that project teams might face in developing a new medicine. This case was situated just prior to approval by a Regulatory Authority as a project team is finalizing a new medicine label. To effectively integrate new biomarkers such as pharmacogenomics into developing new medicines, this session highlighted the importance in considering medical practice implications as relevant (or not) to information or actions by a prescriber; progressing validation beyond assay to clinical; and fitting pharmacogenomics into context with other evidence often built over decades during a drug's development. All converge onto a label that must communicate evidence-based use of a new medicine that is effective and safe.

Linking pharmacogenetics-based diagnostics and drugs for personalized medicine.

Progress toward personalized medicine in the five years following the sequencing of the human genome has been slower than many expected. We focus on two potential factors that might be important in explaining this disappointing progress: the limitations of genetic prediction and the lack of appropriate economic incentives. Clinical application of DNA-based and other biomarkers is likely to succeed only on a case-by-case basis, depending on such factors as information content of the biomarker, accuracy of current assessment methods, and effectiveness of available interventions. Both strong intellectual property and value-based, flexible pricing systems will be important in making personalized medicine a reality.

Commentary: where and how could biomarkers be used in 2016?

Since the beginning of the human genome project there has been considerable speculation about how this resource and the knowledge creation it enabled would change therapeutic discovery, development, and delivery. As the project neared completion, considerable claims and predictions were made about the changes that soon would be forthcoming. Many of these early predictions failed to materialize, however, leading to further speculation about the reasons, including the role of the pharmaceutical industry in realizing the promise of "genomic medicine." During this same period, considerable strides were made in other areas of molecular biology and medicine, and in response scientific thinking naturally evolved. Researchers and regulators moved from a genotype-centric view to a view that all biomarkers are potential tools to improve drug development and therapeutic decision making. Molecular biology is now seen as encouraging more "personalized medicine"-the closer alignment of biological information (derived from molecular diagnostics) and therapy selection. Meanwhile, there are growing concerns that increasing expenditures in pharmaceutical research and development are not sustainable and not reaping sufficient gains for shareholders or society at large. Thus, there is new speculation about how biomarkers, personalized medicine, and the industry will interact and create value for patients. This overview seeks to explore the issues driving pharmaceutical productivity and the likely contribution of biomarkers in the future.

Integrating genomics technologies in health care: practice and policy challenges and opportunities.

To consider broadly the potential impacts of new genetic technologies on clinical practice, a conference was convened at the Banbury Center of the Cold Spring Harbor Laboratories. Stakeholders from all sectors (industry, academia, basic and applied research, clinical genetics, medicine, law, patient advocacy, bioethics, and policy and regulatory) were brought together to explore areas of agreement and disagreement on how best to foster these changes and to guide future deliberations. We first examined the current state of technology development and potential applications. Next, current genetic applications in medicine were reviewed with the goal of identifying lessons learned and practices that can be applied to new applications. Last, the group explored regulatory and policy environments necessary for translating new technologies and knowledge into practice. We sought to better define and facilitate the necessary interaction between research, application, and policy and regulation. This perspective provides a summary of the collective thinking that emerged and a tool to identify issues for consideration and aid future discussions.

Arabidopsis map kinase 4 negatively regulates systemic acquired resistance.

Transposon inactivation of Arabidopsis MAP kinase 4 produced the mpk4 mutant exhibiting constitutive systemic acquired resistance (SAR) including elevated salicylic acid (SA) levels, increased resistance to virulent pathogens, and constitutive pathogenesis-related gene expression shown by Northern and microarray hybridizations. MPK4 kinase activity is required to repress SAR, as an inactive MPK4 form failed to complement mpk4. Analysis of mpk4 expressing the SA hydroxylase NahG and of mpk4/npr1 double mutants indicated that SAR expression in mpk4 is dependent upon elevated SA levels but is independent of NPR1. PDF1.2 and THI2.1 gene induction by jasmonate was blocked in mpk4 expressing NahG, suggesting that MPK4 is required for jasmonic acid-responsive gene expression.

Unravelling R gene-mediated disease resistance pathways in Arabidopsis.

Abstract Molecular genetic approaches were adopted in the model crucifer, Arabidopsis thaliana, to unravel components of RPP5- and RPP1-mediated disease resistance to the oomycete pathogen, Peronospora parasitica. The products of RPP5 and three genes comprising the RPP1 complex locus belong to a major subclass of nucleotide-binding/leucine-rich repeat (NB-LRR) resistance (R) protein that has amino-terminal homology to the cytoplasmic domains of Drosophila and mammalian Toll and interleukin-1 family receptors (the so called 'TIR' domain). Similarities in the domain architecture of these proteins and animal regulators of programmed cell death have also been observed. Mutational screens revealed a number of genes that are required for RPP5-conditioned resistance. Among these are EDS1 and PAD4. Both EDS1 and PAD4 precede the function of salicylic acid-mediated plant responses. The EDS1 and PAD4 genes were cloned and found to encode proteins with similarity to the catalytic site of eukaryotic lipases, suggesting that they may function by hydrolysing a lipid-based substrate.

Functional genomics: technological challenges and opportunities.

In April, the Merck Genome Research Institute and the National Cancer Institute's Cancer Genome Anatomy Project, both supporters of functional genomics technology development and research, brought together a group of 27 scientists working at the forefront of this new field. Here we report on the presentations, discussions, and outcomes from this highly interactive and stimulating meeting held at the Banbury Center.

Service integration: something old and something new.

The authors trace the definition and challenges of "service integration," variously known over time as "collaboration," "coordination," "human services integration," and "one-stop shopping." While the common use of service integration terminology currently may seem to indicate a consensus in favor of a broad systemic reform, motivations and expectations for service integration differ significantly among different players in the service system. The authors conclude that service integration cannot be defined by a particular service model or outcome, but instead should be conceived of as an ongoing reform process. This process, when well-designed and implemented with long-term vision, can reduce duplication, strengthen communities, and improve client outcomes.

Understanding socially inhibited behaviors in managers.

The authors' purpose in this study is to define and highlight socially inhibited behaviors among managers, explore the implications of these behaviors for the workplace, identify ways to assist inordinately shy managers, and help staff to understand and relate more effectively when subjected to an inhibited manager. The authors search for the origins of shyness, surveying the various perspectives in personality theory and within the concept of situational causality.

Selective damage to the active X chromosome by camptothecin and amsacrine as determined by an allele-specific alkaline unwinding assay.

Previous studies with MCF-7 cells demonstrated that several agents induce greater strand breakage in active genes than in nontranscribed centromeric regions. To better assess the effects of gene activity and inactivity, an allele-specific DNA strand break assay was developed, which allowed direct comparison of damage at a specific genetic locus on the active and inactive X chromosomes. The ZP lymphoblastoid cell line is heterozygous at the glucose-6-phosphate dehydrogenase (G6PD) locus, and the unexpressed (A) allele on the inactive X chromosome contains a FokI restriction site that is lacking in the expressed (B) allele on the active X. ZP cells were treated with camptothecin or amsacrine, and subjected to alkaline-induced DNA unwinding. Following detergent lysis and digestion of single-stranded DNA with S1 nuclease, the remaining double-stranded DNA was isolated and subjected to polymerase chain reaction (PCR) with primers that flank the polymorphic FokI site, with [alpha-32P]dCTP being added in the last PCR cycle. The resulting labeled PCR product was cleaved with FokI to assess the A/B allele ratio in the double-stranded DNA fraction. Treatment with camptothecin and amsacrine increased the apparent A/B ratio by factors of 2-3 and 1.5-2 respectively, indicating that the active B allele is preferentially damaged by these agents.

Single base-pair deletions induced by bleomycin at potential double-strand cleavage sites in the aprt gene of stationary phase Chinese hamster ovary D422 cells.

One possible mechanism for the generation of deletion mutations is inaccurate repair of DNA double-strand breaks. In an attempt to detect such aberrant repair events in intact cells, confluent stationary phase cultures of chinese hamster ovary D422 cells, which are hemizygous for aprt, were treated for two days with low concentrations of bleomycin, and aprt mutant clones were selected and analyzed by polymerase chain reaction and DNA sequencing. Bleomycin was quite mutagenic in stationary phase cells, increasing the mutant frequency by five to 40-fold at 5 to 50% survival. While spontaneous mutations generated under these conditions were predominantly base substitutions, the majority of the bleomycin-induced mutations were very small deletions, with lesser numbers of large deletions/rearrangements and base substitutions. Although the small deletions tended to be clustered in several short segments of the gene, nucleosome positioning studies indicated that there was no consistent phasing of nucleosomes in aprt, suggesting that the clustering was due to sequence specificity rather than chromatin structure. About half of the bleomycin-induced mutations were single-base-pair (-1) deletions, and the majority of these involved deletion of one C in a G-Cn sequence (n > or = 2). At such sites, bleomycin is known to induce double-strand breaks by fragmentation of deoxyribose moieties at the same sequence position in both strands, resulting in a blunt-ended double-strand break with 5'-phosphate and 3'-phosphoglycolate termini. Thus, this sequence specificity is consistent with a model in which bleomycin-induced -1 deletions are generated by a double-strand break rejoining process involving removal of phosphoglycolate moieties from both 3' ends, followed by blunt-end ligation. The results support the view that repair of free radical-mediated double-strand breaks in mammalian cells in G1/G0 phase can be effected by such simple end-joining mechanisms, without the need for homologous recombination.

Common fragile site expression in lymphocytes from an individual mosaic for trisomy 8.

During the course of a survey of fragile site expression in lymphocytes from twins one member of a dizygotic pair was found to be mosaic for trisomy 8. One hundred fifty metaphases from this individual were analyzed (100 treated with aphidicolin and 50 untreated); 43% were 46,XY and 57% 46,XY,+8. No differences were observed between the treated and control cultures in either the proportions of normal and trisomic metaphases or the overall or specific fragile site expression in the normal and trisomic cells.