Measuring Image Resolution in Ultrasound Localization Microscopy

The resolution of an imaging system is usually determined by the width of its point spread function and is measured using the Rayleigh criterion. For most system, it is in the order of the imaging wavelength. However, super resolution techniques such as localization microscopy in optical and ultrasound imaging can resolve features an order of magnitude finer than the wavelength. The classical description of spatial resolution no longer applies and new methods need to be developed. In optical localization microscopy, the Fourier Ring Correlation has showed to be an effective and practical way to estimate spatial resolution for Single Molecule Localization Microscopy data. In this work, we wish to investigate how this tool can provide a direct and universal estimation of spatial resolution in Ultrasound Localization Microscopy. Moreover, we discuss the concept of spatial sampling in Ultrasound Localization Microscopy and demonstrate how the Nyquist criterion for sampling drives the spatial/temporal resolution tradeoff. We measured spatial resolution on five different datasets over rodent's brain, kidney and tumor finding values between [Formula: see text] and [Formula: see text] for precision of localization between [Formula: see text] and [Formula: see text]. Eventually, we discuss from those in vivo datasets how spatial resolution in Ultrasound Localization Microscopy depends on both the localization precision and the total number of detected microbubbles. This study aims to offer a practical and theoretical framework for image resolution in Ultrasound Localization Microscopy.

Safety profile of the 9-valent human papillomavirus vaccine: assessment in prior quadrivalent HPV vaccine recipients and in men 16 to 26 years of age

A 9-valent HPV (9vHPV) vaccine has been developed to protect against HPV type 6/11/16/18/31/33/45/52/58-related infection and disease. Previous safety analyses from 7 clinical trials conducted in 9vHPV vaccine recipients 9–26 years of age, including comparisons of 9vHPV and quadrivalent HPV (qHPV) vaccines in girls and women 16–26 years of age, showed that the 9vHPV vaccine was generally well tolerated. Additional safety analyses were conducted to include the results of new clinical studies. The safety profile of the 9vHPV vaccine in prior qHPV vaccine recipients (n = 3756 from 1 randomized controlled trial and 2 open-label extension studies) and young men (n = 248 9vHPV and n = 248 qHPV vaccine recipients from 1 randomized controlled trial) was evaluated. Vaccine was administered as a 3-dose regimen (at Day 1 and Months 2 and 6), and adverse events (AEs) were monitored. The most common AEs were injection-site events (91.1% and 79.0% in prior qHPV vaccine recipients and young men, respectively), the majority of which were mild. Discontinuations due to an AE were rare (0.2% and 0.0% among prior qHPV vaccine recipients and young men, respectively). In young men, the AE profile of the 9vHPV vaccine was generally similar to that of the qHPV vaccine. Overall, the 9vHPV vaccine was generally well tolerated in prior qHPV vaccine recipients and in young men, with an AE profile generally consistent with that previously reported with the broader clinical program.

[Clinical relevance of nucleic acid detection of human papillomaviruses (HPV) in cells from smears of the cervix uteri]

Cervical smears from 516 women were investigated cytologically and for the presence of papilloma virus (HPV) type 16/18 DNA sequences. From the cytologically normal smears (Pap I, II, IIw) 57/424 (13%) 16/18 were found HPV positive and from the pathological ones (Pap III, IIID, IVa, IVb, V), 30/92 (33%). The age prevalence of the HPV infection--provided a cytologically normal smear--appears compatible with the period of sexual activity, but persistence of the HPV infection has to be considered as a complicating factor. Our investigations on successive smears nevertheless permit the hypothesis that an HPV infection may disappear. The use of biotin-labeled nucleic acid probes yields results at least as reliable as those obtained with radioactive probes. The test for HPV positivity appears at present to be of limited diagnostic and prognostic benefit, particularly for the individual case. Investigations on fundamental oncogenic mechanisms are a different matter.

Use of biotinylated DNA probes in screening cells obtained from cervical swabs for human papillomavirus DNA sequences

A nonradioactive DNA-detection procedure using biotinylated DNA probes in the screening of cells from cervical swabs for DNA sequences homologous to human papillomavirus (HPV) DNA was tested. This alternative DNA-detection method yielded results comparable to those obtained with radioisotope-labeled DNA probes in 32 cases tested. This procedure obviates the special precautions required for radioisotope materials. Accordingly, this technique can be made available to many laboratories, and conclusive evidence as to the relation of HPV infection to cervical cancer may thus be accumulated.