Human Neutrophil Defensin-1, -3, and -4 Are Elevated in Nasal Aspirates from Children with Naturally Occurring Adenovirus Infection.

Background: Adenoviruses are highly contagious pathogens which cause respiratory disease particularly in children; they may induce severe disease in infants. Human neutrophil peptides (HNPs) have been found to exhibit antiadenoviral activity. Thus, we have investigated HNPs in nasal aspirates (NAs) of children suffering from adenoviral common cold. Objective: To investigate the release of HNP-1-4 in adenovirus infection and the relationship with self-limiting upper respiratory tract infections. Methods: Nasal aspirate samples (n=14) were obtained from children (aged 6-12 years) infected with adenovirus between June 2012 and December 2015. Control samples were taken 4 weeks after infection when the children were asymptomatic. Levels of HNPs were measured using an enzyme-linked immunosorbent assay (ELISA). Results: There were increased levels of HNP-1, -3, and -4, but not HNP-2, in nasal aspirates (NAs) during adenovirus infections compared to healthy specimens (p ≤ 0.01). Moreover, there was also increase in the neutrophil count, which is a known cell source of HNPs. Conclusion: Our finding supports the involvement of HNP-1, -3, and -4 in naturally occurring cold in children infected with adenovirus. Because of their known antiviral properties, it is tempting to hypothesize that HNPs might play a protective role in adenovirus-induced respiratory disease; however, this remains to be shown.

Considerations on the measurement of practical peak voltage in diagnostic radiology.

An evaluation of the non-invasive measurement of the practical peak voltage (PPV) in the quality control of X-ray units used in diagnostic radiology was carried out. Two instruments were employed: the PTW Diavolt Universal Tester with readings in PPV and the Waveform Tester for X-rays (WATEX) prototype proposed here, which uses a PIN structure (P-type diffusion, Intrinsic region, N-type diffusion) photodiode as a sensor. The reference for the measurements was the voltage signal obtained in an oscilloscope from an invasive high voltage divider in order to verify the accuracy and precision of the measurements. The readings of the PPV in the Diavolt show a systematic error between 1% and 8%, always being less than the real value. An explanation for this difference is proposed, based on the relation between the effect of the X-rays in the film and the response of the sensor to the product of the applied voltage to the X-ray tube (peak voltage kVp), and the anode current. This explanation was confirmed using the WATEX waveform tester.