Review of optical reporters of radiation effects in vivo: tools to quantify improvements in radiation delivery technique.

Significance: Radiation damage studies are used to optimize radiotherapy treatment techniques. Although biological indicators of damage are the best assays of effect, they are highly variable due to biological heterogeneity. The free radical radiochemistry can be assayed with optical reporters, allowing for high precision titration of techniques. Aim: We examine the optical reporters of radiochemistry to highlight those with the best potential for translational use in vivo, as surrogates for biological damage assays, to inform on mechanisms. Approach: A survey of the radical chemistry effects from reactive oxygen species (ROS) and oxygen itself was completed to link to DNA or biological damage. Optical reporters of ROS include fluorescent, phosphorescent, and bioluminescent molecules that have a variety of activation pathways, and each was reviewed for its in vivo translation potential. Results: There are molecular reporters of ROS having potential to report within living systems, including derivatives of luminol, 2'7'-dichlorofluorescein diacetate, Amplex Red, and fluorescein. None have unique specificity to singular ROS species. Macromolecular engineered reporters unique to specific ROS are emerging. The ability to directly measure oxygen via reporters, such as Oxyphor and protoporphyrin IX, is an opportunity to quantify the consumption of oxygen during ROS generation, and this translates from in vitro to in vivo use. Emerging techniques, such as ion particle beams, spatial fractionation, and ultra-high dose rate FLASH radiotherapy, provide the motivation for these studies. Conclusions: In vivo optical reporters of radiochemistry are quantitatively useful for comparing radiotherapy techniques, although their use comes at the cost of the unknown connection to the mechanisms of radiobiological damage. Still their lower measurement uncertainty, compared with biological response assay, makes them an invaluable tool. Linkage to DNA damage and biological damage is needed, and measures such as oxygen consumption serve as useful surrogate measures that translate to in vivo use.

A 30-Min Nucleic Acid Amplification Point-of-Care Test for Genital Chlamydia trachomatis Infection in Women: A Prospective, Multi-center Study of Diagnostic Accuracy.

BACKGROUND: Rapid Point-Of-Care Tests for Chlamydia trachomatis (CT) may reduce onward transmission and reproductive sexual health (RSH) sequelae by reducing turnaround times between diagnosis and treatment. The io® single module system (Atlas Genetics Ltd.) runs clinical samples through a nucleic acid amplification test (NAAT)-based CT cartridge, delivering results in 30min. METHODS: Prospective diagnostic accuracy study of the io® CT-assay in four UK Genito-Urinary Medicine (GUM)/RSH clinics on additional-to-routine self-collected vulvovaginal swabs. Samples were tested "fresh" within 10days of collection, or "frozen" at -80°C for later testing. Participant characteristics were collected to assess risk factors associated with CT infection. RESULTS: CT prevalence was 7.2% (51/709) overall. Sensitivity, specificity, positive and negative predictive values of the io® CT assay were, respectively, 96.1% (95% Confidence Interval (CI): 86.5-99.5), 97.7% (95%CI: 96.3-98.7), 76.6% (95%CI: 64.3-86.2) and 99.7% (95%CI: 98.9-100). The only risk factor associated with CT infection was being a sexual contact of an individual with CT. CONCLUSIONS: The io® CT-assay is a 30-min, fully automated, high-performing NAAT currently CE-marked for CT diagnosis in women, making it a highly promising diagnostic to enable specific treatment, initiation of partner notification and appropriately intensive health promotion at the point of care.

Changes in HIV testing rates among patients with tuberculosis in a large multiethnic city in the UK.

Screening for HIV in patients with tuberculosis (TB) is essential, as HIV/TB co-infection has an adverse prognosis. We compared HIV testing practices in 2005 and 2008/09 in the Birmingham and Solihull region of the UK and evaluated the trends before and after the implementation of the British HIV Association (BHIVA) HIV testing guidelines (2008). A total of 371 TB patients in 2005 and 407 in 2008/09 were included. Demographics across both cohorts were similar. HIV testing increased from 14% in 2005 to 43% in 2008/09. Patients aged ≥55 years and Asian patients were less likely to be tested in 2005 and those aged ≥35 years in 2008/09. An increased rate of HIV testing was seen in all patient categories in 2008/09 compared with 2005. The odds of being tested was high in black African patients (compared with white ethnicity) in both years and increased among black Africans and African Caribbeans between both time points, albeit with wide confidence intervals (CIs). No significant difference in HIV testing was found in 2008/09 before and after the publication of the BHIVA guidelines. This study underlines the importance of continued efforts to minimize the significant gaps in HIV testing rates in TB services.