The effect of household corrosive substances on latent fingermark development in the context of deliberate corrosive substance attacks.

Corrosive substance attacks (CSA) are a prevalent issue in the UK with 525 offenses involving a corrosive substance reported to the police in the year ending March 2022. Easy availability, low cost, and concealability in public are common reasons for choosing a corrosive substance as a weapon. The Metropolitan Police revealed that 68% of 1849 CSA cases resulted in no suspect identified or evidential difficulties. There is limited research into the effect of corrosive substances on latent fingermarks. This study aimed to determine the potential for fingermarks to be recovered from surfaces exposed to a household corrosive substance within the context of a deliberate CSA. Natural and sebaceous-loaded fingermarks were exposed to Domestos bleach, Harpic limescale remover (hydrochloric acid-based) and lemon juice. Harpic limescale remover had the most detrimental effect, with only 7.1% of fingermarks (n = 378) exposed being identifiable (defined as sufficient clear ridge detail for identification) after enhancement, followed by bleach with only 10.3% of fingermarks (n = 378) identifiable. Lemon juice had the least detrimental effect on fingermarks, with 40.5% fingermarks (n = 378) identifiable compared to 53.4% for the controls (not exposed to any substance; n = 378). Throughout the study, fewer natural fingermarks were identifiable after exposure to corrosive substances compared to sebaceous fingermarks which was as expected. Overall, this study demonstrated that there is potential to recover latent fingermarks, depending on their composition, following exposure to a household corrosive substance. This area warrants further research to establish best practice to maximize the potential to recover identifiable fingermarks.

Interplay of adherens junctions and matrix proteolysis determines the invasive pattern and growth of squamous cell carcinoma.

Cancers, such as squamous cell carcinoma, frequently invade as multicellular units. However, these invading units can be organised in a variety of ways, ranging from thin discontinuous strands to thick 'pushing' collectives. Here we employ an integrated experimental and computational approach to identify the factors that determine the mode of collective cancer cell invasion. We find that matrix proteolysis is linked to the formation of wide strands but has little effect on the maximum extent of invasion. Cell-cell junctions also favour wide strands, but our analysis also reveals a requirement for cell-cell junctions for efficient invasion in response to uniform directional cues. Unexpectedly, the ability to generate wide invasive strands is coupled to the ability to grow effectively when surrounded by extracellular matrix in three-dimensional assays. Combinatorial perturbation of both matrix proteolysis and cell-cell adhesion demonstrates that the most aggressive cancer behaviour, both in terms of invasion and growth, is achieved at high levels of cell-cell adhesion and high levels of proteolysis. Contrary to expectation, cells with canonical mesenchymal traits - no cell-cell junctions and high proteolysis - exhibit reduced growth and lymph node metastasis. Thus, we conclude that the ability of squamous cell carcinoma cells to invade effectively is also linked to their ability to generate space for proliferation in confined contexts. These data provide an explanation for the apparent advantage of retaining cell-cell junctions in squamous cell carcinomas.

Safety of Percutaneous Dilatational Tracheostomy During Veno-Venous Extracorporeal Membrane Oxygenation Support in Adults With Severe Respiratory Failure.

OBJECTIVES: To investigate the safety of percutaneous dilatational tracheostomy in severe respiratory failure patients during veno-venous extracorporeal membrane oxygenation support. DESIGN: A single-center, retrospective, observational cohort study. SETTING: Tertiary referral severe respiratory failure center, university teaching hospital. PATIENTS: Severe respiratory failure patients consecutively admitted and supported with veno-venous extracorporeal membrane oxygenation between January 2010 and December 2015. INTERVENTION: A bronchoscopy-guided percutaneous dilatational tracheostomy was performed in all cases. MEASUREMENTS AND MAIN RESULTS: Sixty-five veno-venous extracorporeal membrane oxygenation patients (median [interquartile range] age, 47 yr [interquartile range, 35-59 yr]; 39 males; Acute Physiology and Chronic Health Evaluation-II score, 18 [interquartile range, 17-22] Sequential Organ Failure Assessment score, 10 [interquartile range, 7-16]) underwent percutaneous dilatational tracheostomy. Ten patients (15%) developed one or more major complications. Of these, seven (11%) had major bleeding, and three of these also required circuit change due to extracorporeal membrane oxygenation circuit dysfunction. Two more patients (3.1%) presented with isolated extracorporeal membrane oxygenation circuit dysfunction requiring circuit change, and one developed bilateral pneumothoraces (1.5%) requiring intercostal drain insertion. Patients who developed complications had significantly lower extracorporeal membrane oxygenation postoxygenator PO2 prior to percutaneous dilatational tracheostomy (45.8 kPa [interquartile range, 36.9-56.5 kPa] vs 57.9 kPa [interquartile range, 45.1-64.2 kPa]; p = 0.019]. On multivariate analysis, including demographic, clinical, biochemical, hematologic variables, and extracorporeal membrane oxygenation circuit functional variables, extracorporeal membrane oxygenation postoxygenator PO2 was the only independent variable associated with major complications following percutaneous dilatational tracheostomy (beta = -0.09; odds ratio, 0.9; 95% CI, 0.84-0.99; p = 0.03). CONCLUSIONS: Percutaneous dilatational tracheostomy is associated with a considerable complication rate in veno-venous extracorporeal membrane oxygenation patients. Preprocedure circuit performance as indicated by extracorporeal membrane oxygenation postoxygenator PO2 is an independent predictor of major complications following percutaneous dilatational tracheostomy.