Specific COVID-19 risk behaviors and the preventive effect of personal protective equipment among healthcare workers in Japan.

As coronavirus disease 2019 (COVID-19) outbreaks in healthcare facilities are a serious public health concern, we performed a case-control study to investigate the risk of COVID-19 infection in healthcare workers. We collected data on participants' sociodemographic characteristics, contact behaviors, installation status of personal protective equipment, and polymerase chain reaction testing results. We also collected whole blood and assessed seropositivity using the electrochemiluminescence immunoassay and microneutralization assay. In total, 161 (8.5%) of 1,899 participants were seropositive between August 3 and November 13, 2020. Physical contact (adjusted odds ratio 2.4, 95% confidence interval 1.1-5.6) and aerosol-generating procedures (1.9, 1.1-3.2) were associated with seropositivity. Using goggles (0.2, 0.1-0.5) and N95 masks (0.3, 0.1-0.8) had a preventive effect. Seroprevalence was higher in the outbreak ward (18.6%) than in the COVID-19 dedicated ward (1.4%). Results showed certain specific risk behaviors of COVID-19; proper infection prevention practices reduced these risks.

[A case of swelling of salivary gland due to drug treatment for threatened premature labor].

Ritodrine hydrochloride (luteonin), a beta-agonist with predominant effects on beta adrenoreceptors such as those of the uterus, is effective in suppressing premature uterine contractions. This medicine was used in drug treatment in the case of threatened premature labor. A 26-year-old female who complained of acute swelling of the bilateral salivary glands was consulted to our otorhinolaryngological department. The soft swelling of the bilateral parotid and submandibular glands had developed after intravenous administration of ritodrine hydrochloride for treatment of her threatened premature labor. In addition, serum amylase levels were elevated. The swelling of the salivary glands and the elevation of the serum amylase subsided following discontinuation of the ritodrine hydrochloride. In salivary glands, too, the beta-adrenoreceptors exist. Following stimulation of those receptors in those glands increased secretion of amylase occurs. Our findings suggested that beta-stimulation by ritodrine hydrochloride led to the swelling of the salivary glands and the elevation of the serum amylase. To our knowledge, in Japan, our case is the first otorhinolaryngological report of swelling of the salivary glands due to ritodrine hydrochloride. Otolaryngologist should therefore have full knowledge regarding swelling of salivary glands due to ritodrine hydrochloride.

A free radical initiator, 2,2'-azobis (2-aminopropane) dihydrochloride enhances hyperthermia-induced apoptosis in human uterine cervical cancer cell lines.

Hyperthermia-induced apoptosis and its enhancement in the presence of a temperature-dependent free radical initiator, 2,2'-azobis (2-aminopropane) dihydrochloride (AAPH) were examined in human uterine cervical cancer cell lines, CaSki and HeLa. When both cell lines were treated with hyperthermia at 44 degrees C for 60 min, minimal apoptosis was observed. When combined with nontoxic AAPH (50mM), significant enhancement of apoptosis was observed, where the initial rate of free radical formation was about twice as high than that at 37 degrees C. Augmentation of the growth delay, lipid peroxidation (LPO), activation of caspase-3 and increase in [Ca2+]i were also observed after the combined treatment. A water-soluble vitamin E, Trolox, blocked the increase in [Ca2+]i and an intracellular Ca2+ chelator, BAPTA-AM, prevented the DNA fragmentation induced by the combination. Cytochrome c release was also revealed by fluorescence microscopy. However, no significant change in mitochondrial membrane potential and expression of Bax and Bcl-2 was observed. A slight increase in Fas expression was observed only in CaSki cells after the combined treatment. These results indicate that hyperthermia and AAPH induce enhanced apoptosis and subsequent cell killing via two pathways; a pathway dependenton increase in LPO and [Ca2+]i, and a pathway associated with cytochrome c release and subsequent caspase activation without changes of mitochondrial membrane potential and Bax/Bcl-2 expression in these cell lines. Since it is known that cancer cells are generally resistant to physical and chemical stress-induced apoptosis, free radical generators like AAPH appear to be a useful thermosensitizer for hyperthermic cancer therapy.