Personal protective equipment for surgeons during COVID-19 pandemic: systematic review of availability, usage and rationing.

BACKGROUND: Surgeons need guidance regarding appropriate personal protective equipment (PPE) during the COVID-19 pandemic based on scientific evidence rather than availability. The aim of this article is to inform surgeons of appropriate PPE requirements, and to discuss usage, availability, rationing and future solutions. METHODS: A systematic review was undertaken in accordance with PRISMA guidelines using MEDLINE, Embase and WHO COVID-19 databases. Newspaper and internet article sources were identified using Nexis. The search was complemented by bibliographic secondary linkage. The findings were analysed alongside guidelines from the WHO, Public Health England, the Royal College of Surgeons and specialty associations. RESULTS: Of a total 1329 articles identified, 95 studies met the inclusion criteria. Recommendations made by the WHO regarding the use of PPE in the COVID-19 pandemic have evolved alongside emerging evidence. Medical resources including PPE have been rapidly overwhelmed. There has been a global effort to overcome this by combining the most effective use of existing PPE with innovative strategies to produce more. Practical advice on all aspects of PPE is detailed in this systematic review. CONCLUSION: Although there is a need to balance limited supplies with staff and patient safety, this should not leave surgeons treating patients with inadequate PPE.

Treatment of a large congenital melanocytic nevus with dermabrasion and autologous cell suspension (ReCELL®): a case report.

Congenital melanocytic naevi (CMN) are present at birth in between 1 and 6% of all neonates. They are caused by malformations of the neuroectoderm that are comprised of melanocytes and occasionally neural elements, following dysregulated growth and arrest of melanocytes during migration from the neural crest to the skin. Most commonly they are sub-classified according to size. They are at risk of malignant transformation, but the psychological impact of prominent CMN's is arguably of greater potential concern to the parent and child. Treatment modalities to date have included complete surgical excision with defect reconstruction, as well as less invasive methods such as dermabrasion, curretage, chemical peels and laser therapy. We present an illustrated case of a healthy, term, 4 week-old male neonate with a large CMN on his face. The lesion was dermabraded, and non-cultured epithelial autograft harvested from the right post-auricular area was applied. Dressings were no longer required by the 8th post-operative day, and excellent skin pigmentation and texture was achieved by 5 months post-op.

Characterization of transiently and constitutively expressed progesterone receptors: evidence for two functional states.

Activated steroid receptors induce chromatin remodeling events in the promoters of some target genes. We previously reported that transiently expressed progesterone receptor (PR) cannot activate mouse mammary tumor virus (MMTV) promoter when it adopts the form of ordered chromatin. However, when expressed continuously, the PR acquires this ability. In this study we explored whether this gain of function occurs through alterations in nucleoprotein structure at the MMTV promoter or through changes in receptor status. We observed no major structural differences at the MMTV promoter in the presence of constitutively expressed PR and found its mechanism of activation to be very similar to that of the glucocorticoid receptor (GR). However, a systematic comparison of the functional behavior of the transiently and constitutively expressed PR elucidated significant differences. The transiently expressed PR is activated in the absence of ligand by cAMP and by components in FBS and has significantly increased sensitivity to progestins. In contrast, the constitutively expressed PR is refractory to activation by cAMP and serum and has normal sensitivity to its ligand. In addition, while the PR is localized to the nucleus in both cases, a significant fraction of the transiently expressed PR is tightly bound to the nucleus even in the absence of ligand, while the majority of constitutively expressed PR is not. These results strongly suggest that the PR undergoes processing in the cell subsequent to its initial expression and that this processing is important for various aspects of its function, including its ability to productively interact with target genes that require chromatin remodeling for activation.

ATM phosphorylation of Nijmegen breakage syndrome protein is required in a DNA damage response.

Nijmegen breakage syndrome (NBS) is characterized by extreme radiation sensitivity, chromosomal instability and cancer. The phenotypes are similar to those of ataxia telangiectasia mutated (ATM) disease, where there is a deficiency in a protein kinase that is activated by DNA damage, indicating that the Nbs and Atm proteins may participate in common pathways. Here we report that Nbs is specifically phosphorylated in response to gamma-radiation, ultraviolet light and exposure to hydroxyurea. Phosphorylation of Nbs mediated by gamma-radiation, but not that induced by hydroxyurea or ultraviolet light, was markedly reduced in ATM cells. In vivo, Nbs was phosphorylated on many serine residues, of which S343, S397 and S615 were phosphorylated by Atm in vitro. At least two of these sites were underphosphorylated in ATM cells. Inactivation of these serines by mutation partially abrogated Atm-dependent phosphorylation. Reconstituting NBS cells with a mutant form of Nbs that cannot be phosphorylated at selected, ATM-dependent serine residues led to a specific reduction in clonogenic survival after gamma-radiation. Thus, phosphorylation of Nbs by Atm is critical for certain responses of human cells to DNA damage.