Individualized 3D-printed templates for high-dose-rate interstitial multicathether brachytherapy in patients with breast cancer

Purpose

High-dose-rate, multicatheter interstitial brachytherapy is technically complex and operator-dependent, requiring lengthy training and specialized skills. Furthermore, until the advent of contouring on computerized tomography (CT) images, difficulties existed in locating the target volume precisely. The present article reports the results of a study that aimed at producing and validating a 3D-printed template to aid in target volume localization for multicatheter interstitial brachytherapy in patients with breast cancer.

A Generalized Entropy Measure of Within-Host Viral Diversity for Identifying Recent HIV-1 Infections

There is a need for incidence assays that accurately estimate HIV incidence based on cross-sectional specimens. Viral diversity-based assays have shown promises but are not particularly accurate. We hypothesize that certain viral genetic regions are more predictive of recent infection than others and aim to improve assay accuracy by using classification algorithms that focus on highly informative regions (HIRs).We analyzed HIV gag sequences from a cohort in Botswana. Forty-two subjects newly infected by HIV-1 Subtype C were followed through 500 days post-seroconversion. Using sliding window analysis, we screened for genetic regions within gag that best differentiate recent versus chronic infections. We used both nonparametric and parametric approaches to evaluate the discriminatory abilities of sequence regions. Segmented Shannon Entropy measures of HIRs were aggregated to develop generalized entropy measures to improve prediction of recency. Using logistic regression as the basis for our classification algorithm, we evaluated the predictive power of these novel biomarkers and compared them with recently reported viral diversity measures using area under the curve (AUC) analysis.Change of diversity over time varied across different sequence regions within gag. We identified the top 50% of the most informative regions by both nonparametric and parametric approaches. In both cases, HIRs were in more variable regions of gag and less likely in the p24 coding region. Entropy measures based on HIRs outperformed previously reported viral-diversity-based biomarkers. These methods are better suited for population-level estimation of HIV recency.The patterns of diversification of certain regions within the gag gene are more predictive of recency of infection than others. We expect this result to apply in other HIV genetic regions as well. Focusing on these informative regions, our generalized entropy measure of viral diversity demonstrates the potential for improving accuracy when identifying recent HIV-1 infections.     

Local Tobacco Control: Application of the Essential Public Health Services Model in a County Health Department’s Efforts to Put It Out Rockland

In 2000, Rockland County, a small suburban county north of New York City, dedicated $1 million of its Master Settlement Agreement funds to a comprehensive tobacco control program, Put It Out Rockland. Developed and implemented by the county health department, this program used an essential public health services model and an ongoing financial investment, within the context of strong statewide tobacco control efforts, to lower adult smoking rates to 9.7% and to reduce both smoking among youths and exposure to secondhand smoke over the ensuing decade. By combining state funds and local dollars for a total of $6.75 cost per capita, this comprehensive effort yielded 11 000 fewer smokers and translated to a potential savings of more than $24 million for the county.     

Mechanical Properties and Durability of CNT Cement Composites

In the present paper, changes in mechanical properties of Portland cement-based mortars due to the addition of carbon nanotubes (CNT) and corrosion of embedded steel rebars in CNT cement pastes are reported. Bending strength, compression strength, porosity and density of mortars were determined and related to the CNT dosages. CNT cement paste specimens were exposed to carbonation and chloride attacks, and results on steel corrosion rate tests were related to CNT dosages. The increase in CNT content implies no significant variations of mechanical properties but higher steel corrosion intensities were observed.     

The Basic Pharmacology of Ticlopidine and Clopidogrel

This review summarises some of the key developments that have taken place in our understanding of platelet-collagen interactions within the last 18 months. Within this time, the major activatory collagen receptor glycoprotein VI (GPVI) has been sequenced and shown to reconstitute collagen responses in a megakaryocytic cell line. It is a member of the Ig superfamily of proteins, with two extracellular Ig domains, and is constitutively associated with the Fc receptor n -chain (FcR n -chain). GPVI signals through a pathway that shares many features with those of immune receptors, with critical roles for Syk and the adapters LAT and SLP-76 in the activation of PLC n 2. Significant developments have also taken place in regard to the role of the major adhesion receptor for collagen, the integrin f 2 g 1 (also known as GPIa-IIa). An f 2 g 1-selective collagen-based peptide has been developed and co-crystalisalised with the I-domain of the f 2 subunit. Polymorphisms in f 2 have been shown to cause wide variation in expression of f 2 g 1, with the f 2 allele T 807 /A 873 leading to a high level of the integrin and increased risk of stroke in young people. Activation of platelets by a wide range of agonists has been shown to increase the affinity of f 2 g 1 to intermediate or high affinity states. This has important implications for the two-site, two-state model of collagen-platelet interactions. A new model is proposed in which collagen binds initially to either f 2 g 1 or GPVI, leading to subsequent binding to the other receptor and conversion of the integrin to a high affinity state. In this model, both receptors generate intracellular signals which support platelet activation.