Preclinical validation of occupational and environmental safety of an isolation system for noninvasive ventilation in COVID-19 and other aerosol-transmitted infections.

Background: The current SARS-CoV-2 pandemic has provoked the collapse of some health systems due to insufficient intensive care unit capacity. The use of continuous positive airway pressure (CPAP) and high-flow nasal oxygen (HFNO) therapies has been limited in consideration of the risk of occupational infection in health-care professionals. Aims: In preclinical experimental simulations, evaluate occupational and environmental safety of the newly developed isolation system for aerosol-transmitted infections (ISATI). Method: Simulations were conducted to test ISATI's capability to isolate aerosolized molecular (caffeine), and biological (SARS-CoV-2 synthetic RNA) markers. Caffeine deposition was analyzed on nitrocellulose sensor discs by proton nuclear magnetic resonance spectroscopy. Synthetic SARS-CoV-2 detection was performed by reverse transcription-polymerase chain reaction. Results: ISATI demonstrated efficacy in isolating molecular and biological markers within the enclosed environment in simulated conditions of CPAP, HFNO and mechanical ventilation therapy. Neither the molecular marker nor substantial amounts of synthetic SARS-CoV-2 RNA were detected in the surrounding environment, outside ISATI, indicating appropriate occupational safety for health-care professionals. Conclusion: Aerosolized markers were successfully contained within ISATI in all experimental simulations, offering occupational and environmental protection against the dissemination of aerosolized microparticles under CPAP or HFNO therapy conditions, which are indicated for patients with acute respiratory infections.

Efeitos do estresse de trabalho sobre parâmetros seminais de cães da raça Rottweiler / Evaluation of work stress effects on Rottweilers male dog´s fertility

O presente trabalho teve como objetivo avaliar os efeitos do estresse de trabalho sobre a fertilidade de cães machos. Foram utilizados 18 cães da raça rottweiler, férteis, com idade média de 4 anos, distribuídos aleatoriamente em dois grupos: repouso (controle) e trabalho (tratamento). O tratamento era composto por 5 fases: 1-adaptação, 2-adestramento básico, 3-adestramento militar e condicionamento, 4-acampamento, 5-repouso. Durante todo o período experimental, foram feitas duas coletas de sêmen semanais, para avaliação do ejaculado. No final de cada fase foi realizada coleta de sangue para dosagem dos níveis plasmáticos de cortisol. Os dados foram analisados pelo SAS, á =5%. Observou-se efeito negativo do estresse sobre os parâmetros motilidade (72,63 vs. 57,62, p<0,0001) e vigor espermático (3,06 vs. 2,52, p<0,0001), porcentagem de defeitos maiores(16,01 vs. 26,80, p< 0,0001) e totais (29,61 vs. 40,34, p<0,0001).Observou-se interação (p<0,0001) entre tempo e tratamento sobre a variável cortisol, indicando que o tipo de agente estressante (fase) interfere no nível plasmático de cortisol. Com base nesses resultados,é possível concluir que o estresse de trabalho interferiu de maneira negativa na fertilidade dos cães.

The present work aimed to evaluate the effect of work stress male dogs fertility. Eighteen fertile male Rottweiler dogs, mean aged 4 years old, were randomly allocate into two groups: resting (control) and working (treatment). Treatment consisted of 5 working stages: 1– adaptation, 2- basic obedience training, 3 - physical conditioning and military training, 4 – camping and 5 – resting. During the experimental period, semen was collected and evaluated twice a week.At the end of each stage, blood collections were performed in order to evaluate plasmatic levels of cortisol. Data were analyzed using the statistical software SAS (a=5%). A significant negative effect of stress was observed on sperm motility (resting=72.63 vs. working=57.62,p<0.001), progressive motility (resting=3.06 vs. working=2.52, p<0.0001), major defects (resting=16.01 vs. working=26.80,p<0.0001) and total defects (resting=29.61 vs. working=40.34,p<0.0001). Furthermore, a significant interaction (P<0.0001) was observed between treatment and working stage periods for the plasmatic levels of cortisol, suggesting that the level of stress may vary according to the type of work. Results indicated that work stress may negatively influence fertility in male dogs.