Meteorological parameters and cases of COVID-19 in Brazilian cities: an observational study

Meteorological parameters modulate transmission of the SARS-Cov-2 virus, the causative agent related to coronavirus disease-2019 (COVID-19) development. However, findings across the globe have been inconsistent attributed to several confounding factors. The aim of the present study was to investigate the relationship between reported meteorological parameters from July 1 to October 31, 2020, and the number of confirmed COVID-19 cases in 4 Brazilian cities: São Paulo, the largest city with the highest number of cases in Brazil, and the cities with greater number of cases in the state of Parana during the study period (Curitiba, Londrina and Maringa). The assessment of meteorological factors with confirmed COVID-19 cases included atmospheric pressure, temperature, relative humidity, wind speed, solar irradiation, sunlight, dew point temperature, and total precipitation. The 7- and 15-day moving averages of confirmed COVID-19 cases were obtained for each city. Pearson's correlation coefficients showed significant correlations between COVID-19 cases and all meteorological parameters, except for total precipitation, with the strongest correlation with maximum wind speed (0.717, <0.001) in São Paulo. Regression tree analysis demonstrated that the largest number of confirmed COVID-19 cases was associated with wind speed (between ≥0.3381 and <1.173 m/s), atmospheric pressure (<930.5mb), and solar radiation (<17.98e⁺³). Lower number of cases was observed for wind speed <0.3381 m/s and temperature <23.86°C. Our results encourage the use of meteorological information as a critical component in future risk assessment models.

Toposome: Source of antimicrobial molecules in the gonads of the sea urchin Lytechinus variegatus (Lamarck, 1816)

Sea urchins live in a challenging environment that requires rapid and efficient responses against pathogens and invaders. This response may be also important in reproductive processes once males and females release their gametes into water. In addition, the gonads are organs with dual function: reproductive organ and nutrient reserve, therefore it needs efficient protective mechanisms to preserve the nutrients as well as the reproductive cells. The aim of this study was to evaluate the presence and characterize antimicrobial molecules in the male and female gonads of the sea urchin Lytechinus variegatus. Through HPLC purification, antimicrobial activity test and mass spectrometry several antimicrobial molecules were found in the gonads of both gender. Computational in silico analyses showed that they are fragments of a glycoprotein called toposome, also known as major yolk protein (MYP) which is one of the major proteins found in the gonads. Although different functions have been reported for this protein, this is the first description of a direct antimicrobial activity in Lytechinus variegatus. The results indicate that when undergoing proteolysis the toposome generates different fragments with antimicrobial activity which may indicate the importance of a rapid defense response strategy against invading microorganisms in the gonads used by both males and females sea urchins.

Comparison of the effective dose rate to aircrew members using hybrid computational phantoms in standing and sitting postures

Aircraft crew members are occupationally exposed to considerable levels of cosmic radiation at flight altitudes. Since aircrew (pilots and passengers) are in the sitting posture for most of the time during flight, and up to now there has been no data on the effective dose rate calculated for aircrew dosimetry in flight altitude using a sitting phantom, we therefore calculated the effective dose rate using a phantom in the sitting and standing postures in order to compare the influence of the posture on the radiation protection of aircrew members. We found that although the better description of the posture in which the aircrews are exposed, the results of the effective dose rate calculated with the phantom in the sitting posture were very similar to the results of the phantom in the standing posture. In fact we observed only a 1% difference. These findings indicate the adequacy of the use of dose conversion coefficients for the phantom in the standing posture in aircrew dosimetry. We also validated our results comparing the effective dose rate obtained using the standing phantom with values reported in the literature. It was observed that the results presented in this study are in good agreement with other authors (the differences are below 30%) who have measured and calculated effective dose rates using different phantoms.

Evaluation of personal doses associated with the use of mobile X-rays in a Brazilian hospital

In Brazilian public hospitals, the number of patients needing assistance is often much greater than the capacity of the hospital. In such situations, medical procedures are performed as quickly as possible, and mobile X-ray equipment is used intensively. This equipment is used for several types of examination, in different areas of the hospital. During the examination procedure, apart from the radiology technicians involved, there are always other people in the room who are also exposed to the radiation scattered by the patient. The objective of this study was to determine the exposure, due to the use of mobile X-ray equipment, of hospital personnel, divided into two categories named 'monitored' and 'non-monitored'. Evaluation of 413 radiographies was performed, the vast majority of them being chest examinations (75 %). During the procedures, specific information was collected to allow measurement in simulated situations. Air kerma rates were measured at different distances from the mobile X-ray equipment using an ionisation chamber and an acrylic phantom with dimensions of 30×30×15 cm(3). From the results, it was possible to estimate the personal dose equivalent received by the individuals in the room during the procedure and to determine the dose maps associated with the use of the mobile X-ray equipment. The results obtained in this study were in accordance with dose limits, but some observed situations were considered critical.

Antibodies to citrullinated peptides are not associated with the rate of joint destruction in patients with a well-established diagnosis of rheumatoid arthritis

Antibodies to citrullinated peptides are highly specific for rheumatoid arthritis (RA) and represent a significant risk factor for undifferentiated polyarthritis. This prognostic ability may be related to the very diagnostic performance of these autoantibodies, since RA is a more erosive disease than other forms of arthritis. The present study evaluated an association of antibodies to citrullinated peptides and the rate of joint destruction in patients with a well-established diagnosis of RA. Seventy-one patients with RA were evaluated in 1994 and again in 2002 (functional class, joint count, Health Assessment Questionnaire score, hands X-ray). Autoantibodies (rheumatoid factor (RF), anti-perinuclear factor, anti-cyclic citrullinated peptide (CCP) antibodies) and Sharp's index were analyzed blindly. Delta Sharp was calculated as the difference in Sharp's index obtained in 1994 and 2002. During the follow-up the Health Assessment Questionnaire score increased from 0.91 +/- 0.74 to 1.39 +/- 0.72 (P < 0.001). Similarly, the number of swollen joints increased from 4.6 +/- 5.71 to 6.4 +/- 4.1 (P = 0.002). The frequency of autoantibodies and anti-CCP titer remained stable; however, serum RF concentration increased from 202.8 +/- 357.6 to 416.6 +/- 636.5 IU/mL (P = 0.003). Sharp's index increased from 56.7 +/- 62.1 to 92.4 +/- 80.9 (P < 0.001). No correlation was observed between Delta Sharp and the presence of RF, anti-perinuclear factor, and anti-CCP antibodies at baseline. Antibodies to citrullinated epitopes are specific and early markers for the diagnosis of RA but do not seem to be associated with the rate of joint destruction in patients with a well-established diagnosis of RA.