The main objective of this study was to develop a nondestructive reporter system for assessing the response of human cells contained within a three-dimensional (3D) tissue-engineered construct to exogenous stress. Dermal fibroblasts were transiently transfected with a reporter construct linked to nuclear factor kappaB (NF-kappaB) activation which led to expression of a nonstable form of enhanced green fluorescent protein (d2EGFP) after stimulation. This led to a temporary production of fluorescence, which could be readily detected but was not intrinsically toxic, as cells were able to metabolize the initial cycle of d2EGFP produced. This permitted the model to be used for restimulation post recovery. To investigate the performance and predictive ability of this method for assessing cellular response to stress in 3D, we used a range of compounds known to have pro-inflammatory or oxidative properties. Tumor necrosis factor-alpha (TNF-alpha) and interleukin-1-beta (IL-1beta) were selected for having a direct cytokine action; lipopolysaccharide (LPS) was selected for modeling bacterial-mediated inflammation; and hydrogen peroxide was selected as a crude method for delivering an oxidative stress. Transfected cells were stimulated with the above compounds in 3D and the synthesis of d2EGFP was detected as a measure of NF-kappaB activation. The resultant fluorescence was scored using a series of photomicrographs taken by epifluorescence microscopy. All agents activated NF-kappaB when cells were grown in 3D scaffolds but did not cause any significant reduction in cell viability as measured by a standard MTT-ESTA viability test. Parallel NF-kappaB activation and MTT measurements was also conducted in two-dimension (2D) and confirmed findings in 3D. The 3D model described using a fluorescent reporter gene is a highly sensitive and reliable method for detecting cellular stress and represents a key step in developing tissue engineering models with the potential for screening pharmaceutical and cosmetic compounds, as an alternative to existing in vitro and in vivo methods.

Compartment syndrome, a surgical emergency, is caused by an increase in pressure within a closed osseofascial space, often due to trauma. This causes a decrease in tissue perfusion and ultimately tissue necrosis and multiorgan failure if not treated in a timely fashion. Gluteal compartment syndrome is a rare variant and often caused by a period of immobilisation secondary to intoxication with alcohol or drugs or during long operations, typically in the supine position. We report on a case of gluteal compartment syndrome developing in a patient postoperatively following a long microsurgical procedure to a hand, which has not been documented before. Although rare, we highlight the clinical course and diagnostic criteria, which are essential for early identification and treatment.

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SUMMARYHigh-pressure injection (HPI) injuries are an uncommon mechanism of trauma. The clinical effects of the HPI injury depend upon a number of variables including the pressures involved, chemical toxicity, quantity of material injected and its temperature. Evidence within the literature has shown that delay in identifying and treating such injuries can lead to devastating consequences. We describe one such case of a HPI injury involving engine oil to a digit. In addition, we review the clinical course, pathophysiology and management of such injuries. BACKGROUND

Supraglottitis occurs in <4 per 100 000 population. Following a successful UK childhood immunisation programme, most cases occur in adults. Supraglottitis secondary to N meningitidis is exceptionally rare, with only seven other reported cases worldwide. Morbidity is exceptionally high; over 60 per cent of patients require airway intervention. To our knowledge, this is the first reported UK case of supraglottitis secondary to N meningitidis. This case highlights the important clinical, diagnostic and therapeutic interventions required to prevent complications associated with this potentially fatal condition.