Further study on the physiological effects of an alternative spit mask.

OBJECTIVES: Spit masks are used by law enforcement officers and healthcare providers to protect themselves from the spread of communicable disease by subjects who pose a potential risk of biological exposure by spitting. Little research is available regarding the safety of these masks. However, concerns surround the ability of subjects to properly ventilate while wearing these masks as there are several anecdotal incidents of asphyxiation. A recent pilot study performed by our group showed no significant changes in ventilatory or circulatory parameters in healthy adults wearing a standard spit mask. In this study we aim to further this baseline research by testing physiological parameters in subjects wearing an alternative design of spit mask. METHODS: This prospective study evaluated the changes in respiratory and circulatory parameters in healthy adult subjects wearing a Safariland Tranzport Hood spit mask (SKU: 8320-0-2C) at rest. Baseline measurements of pulse, blood pressure, respiratory rate, oxygen saturation, and end-tidal CO2 were taken while sitting at rest. The spit mask was then placed over the subject's head and repeat measurements were taken at 5, 10, and 15 min. Measurements at 5, 10, and 15 min were compared to baseline using paired t tests with 95% confidence intervals using SPSS. RESULTS: A total of 15 subjects participated in the study. There was no significant difference between baseline and at 5, 10, and 15 min after spit mask application in heart rate (p = 0.246, p = 0.785, p = 0.502, respectively), oxygen saturation (p = 0.751, p = 0.334, p = 1.00, respectively), respiratory rate (p = 0.866, p = 0.270, p = 0.106, respectively), systolic blood pressure (p = 0.385, p = 0.481, p = 0.182, respectively), and diastolic blood pressure (p = 0.832, p = 0.516, p = 0.597, respectively). For end-tidal CO2, there was no significant difference between baseline and at 10 and 15 min (p = 0.586, p = 0.416, respectively). End-tidal CO2 was significantly increased from baseline at 5 min (p = 0.042). CONCLUSIONS: In healthy adult subjects, there were no clinically significant differences in respiratory or circulatory parameters while wearing the Safariland Tranzport Hood spit mask.

A ribonucleoprotein complex protects the interleukin-6 mRNA from degradation by distinct herpesviral endonucleases.

During lytic Kaposi's sarcoma-associated herpesvirus (KSHV) infection, the viral endonuclease SOX promotes widespread degradation of cytoplasmic messenger RNA (mRNA). However, select mRNAs escape SOX-induced cleavage and remain robustly expressed. Prominent among these is interleukin-6 (IL-6), a growth factor important for survival of KSHV infected B cells. IL-6 escape is notable because it contains a sequence within its 3' untranslated region (UTR) that can confer protection when transferred to a SOX-targeted mRNA, and thus overrides the endonuclease targeting mechanism. Here, we pursued how this protective RNA element functions to maintain mRNA stability. Using affinity purification and mass spectrometry, we identified a set of proteins that associate specifically with the protective element. Although multiple proteins contributed to the escape mechanism, depletion of nucleolin (NCL) most severely impacted protection. NCL was re-localized out of the nucleolus during lytic KSHV infection, and its presence in the cytoplasm was required for protection. After loading onto the IL-6 3' UTR, NCL differentially bound to the translation initiation factor eIF4H. Disrupting this interaction, or depleting eIF4H, reinstated SOX targeting of the RNA, suggesting that interactions between proteins bound to distant regions of the mRNA are important for escape. Finally, we found that the IL-6 3' UTR was also protected against mRNA degradation by the vhs endonuclease encoded by herpes simplex virus, despite the fact that its mechanism of mRNA targeting is distinct from SOX. These findings highlight how a multitude of RNA-protein interactions can impact endonuclease targeting, and identify new features underlying the regulation of the IL-6 mRNA.