COVID-19 in children and the effect of schools reopening on potential transmission to household members.

AIM: The effect of reopening schools on children's contribution to SARS-CoV-2 transmission, especially within households, remains controversial. This study describes the clinical presentation of a large ambulatory COVID-19 paediatric cohort and evaluates the role of children in household transmission prior to and following school reopening. METHODS: A retrospective database cohort study was conducted in a large Health Maintenance Organization in Israel. Data of all paediatric, laboratory-confirmed Coronavirus cases between 28/2/2020 and 20/6/2020 were extracted. All cases were analysed for household contacts and primary cases within each family cluster. RESULTS: A total of 1,032 cases under 18 years old (median age 12 years) were included. Of these cases, 432 (41.9%) were asymptomatic; 122 (11.8%) cases acquired the infection at school, and 45 of them were part of two school clusters; 846 children had at least one positive household contact, in 498 family clusters, and among them, 293 primary cases were identified. Only 27 (9.2%) primary cases were under 18 years of age and six (2%) were below 10. The proportion of primary cases did not change after the re-opening of educational facilities. CONCLUSION: Children, particularly under 10 years of age, are less likely to be the vector for SARS-CoV-2 infection within household settings. Opening educational facilities did not change transmission dynamics.

Conservative management of acute mastoiditis in children.

OBJECTIVE: To review the current management of acute mastoiditis with critical emphasis on the role of myringotomy. DESIGN: A retrospective chart review. SETTING: Tertiary-care, university affiliated children's hospital. PATIENTS: One hundred and forty-four consecutive children hospitalized for acute mastoiditis between the years 1991 and 2002. INTERVENTIONS: All children were treated with parenteral antibiotics (conservative management). Myringotomy was performed at the discretion of the otolaryngologist on-call. MAIN OUTCOME MEASURES: Comparing outcomes of children with or without myringotomy regarding hospital stay, complications and the need for surgical interventions. RESULTS: Myringotomy was performed in 34.6% of episodes. The children who underwent myringotomy were found to be significantly younger (22.4 compared to 28.8 months, p=0.028) and had more complications (n=17 vs. n=8, p<0.001). Complications overall occurred in 16.3% of episodes. Performing myringotomy had no significant effect on the duration of hospital stay. Children pretreated with antibiotics underwent significantly less myringotomies p=0.027. There were no significant differences between children who underwent myringotomy and those who did not with regard to WBC count, or ESR. CONCLUSIONS: These findings suggest that myringotomy may not be required in all cases of acute mastoiditis. Parenteral antibiotics is sufficient in most cases. Criteria for myringotomy may include a younger age. Conservative management resulted in good outcomes in this series.

C5a receptor oligomerization. II. Fluorescence resonance energy transfer studies of a human G protein-coupled receptor expressed in yeast.

Recent studies demonstrate that members of the superfamily of G protein-coupled receptors (GPCRs) form oligomers both in vitro and in vivo. The mechanisms by which GPCRs oligomerize and the roles of accessory proteins in this process are not well understood. We used disulfide-trapping experiments to show that C5a receptors, expressed in mammalian cells, reside in membranes as oligomers (Klco, J. M., Lassere, T. B., and Baranski, T. J. (2003) J. Biol. Chem. 278, 35345-35353). To begin to address how C5a receptors form oligomers, we now use fluorescence resonance energy transfer experiments on human C5a receptors expressed in the lower eukaryote Saccharomyces cerevisiae. C5a receptors tagged with variants of the green fluorescent protein display energy transfer in intact yeast, demonstrating that mammalian accessory proteins are not required for C5a receptor oligomerization. In both intact yeast cells and membrane preparations, agonist does not affect FRET efficiency, and little energy transfer is observed between the C5a receptor and a co-expressed yeast pheromone receptor (encoded by STE2), indicating that C5a receptor oligomerization is both receptor-specific and constitutive. FRET studies performed on fractionated membranes demonstrate similar levels of energy transfer between tagged C5a receptors in endoplasmic reticulum compared with plasma membrane, and urea washing of membranes has little effect on the extent of energy transfer. The oligomerization of C5a receptors expressed in yeast displays characteristics similar to those observed for other GPCRs studied in mammalian cells. This model system should prove useful for further studies to define mechanisms of oligomerization of mammalian GPCRs.