Magnetic resonance investigation into the mechanisms involved in the development of high-altitude cerebral edema

Rapid ascent to high altitude commonly results in acute mountain sickness, and on occasion potentially fatal high-altitude cerebral edema. The exact pathophysiological mechanisms behind these syndromes remain to be determined. We report a study in which 12 subjects were exposed to a FiO2 = 0.12 for 22 h and underwent serial magnetic resonance imaging sequences to enable measurement of middle cerebral artery velocity, flow and diameter, and brain parenchymal, cerebrospinal fluid and cerebral venous volumes. Ten subjects completed 22 h and most developed symptoms of acute mountain sickness (mean Lake Louise Score 5.4; p < 0.001 vs. baseline). Cerebral oxygen delivery was maintained by an increase in middle cerebral artery velocity and diameter (first 6 h). There appeared to be venocompression at the level of the small, deep cerebral veins (116 cm3 at 2 h to 97 cm3 at 22 h; p < 0.05). Brain white matter volume increased over the 22-h period (574 ml to 587 ml; p < 0.001) and correlated with cumulative Lake Louise scores at 22 h (p < 0.05). We conclude that cerebral oxygen delivery was maintained by increased arterial inflow and this preceded the development of cerebral edema. Venous outflow restriction appeared to play a contributory role in the formation of cerebral edema, a novel feature that has not been observed previously

Research Methodologies and Business Discourse Teaching

This chapter will:; ; ; Define English for specific purposes and indicate the specific ways in which it has been influential on business discourse teaching;; ; ; Discuss the most relevant approaches to genre analysis that have been used in business discourse teaching;; ; ; Explore the most relevant approaches to critical discourse analysis and organizational rhetoric for business discourse teaching;; ; ; Identify the most relevant aspects of multimodal discourse analysis for business discourse teaching;; ; ; Provide a case study that illustrates the use of one approach to business discourse teaching, showing how practitioners can incorporate it into their classroom- or consultancy-based ideas

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Frostbite : a practical approach to hospital management

Frostbite presentation to hospital is relatively infrequent, and the optimal management of the more severely injured patient requires a multidisciplinary integration of specialist care. Clinicians with an interest in wilderness medicine/freezing cold injury have the awareness of specific potential interventions but may lack the skill or experience to implement the knowledge. The on-call specialist clinician (vascular, general surgery, orthopaedic, plastic surgeon or interventional radiologist), who is likely to receive these patients, may have the skill and knowledge to administer potentially limb-saving intervention but may be unaware of the available treatment options for frostbite. Over the last 10 years, frostbite management has improved with clear guidelines and management protocols available for both the medically trained and winter sports enthusiasts. Many specialist surgeons are unaware that patients with severe frostbite injuries presenting within 24 h of the injury may be good candidates for treatment with either TPA or iloprost. In this review, we aim to give a brief overview of field frostbite care and a practical guide to the hospital management of frostbite with a stepwise approach to thrombolysis and prostacyclin administration for clinicians

Necrosis and amputation following the bite of the Bibron's stiletto snake (Atractaspis bibronii) with a concise review of current literature.

Atractaspis bibronii are highly specialised snakes found across Southern Africa. Adapted for subterranean hunting of prey, snakes of the genus demonstrate a unique biting mechanism, with an ability to deliver venom via a single fang, protruded over an almost closed mouth in a side-to-side striking pattern. It is not possible to handle these snakes safely. can be mistaken for medically insignificant snakes and often occur in remote areas that may lead to delayed or reduced presentation to suitable care facilities. We here report a case of an envenomation in remote Southern Africa to the right ring finger from a single fang with significant complication. Medical, and subsequently, surgical management of a progression from discolouration at the bite site, to spreading oedema, blistering, local necrosis and secondary infection required amputation of the digit

Characteristics and risk factors of UCS fracture subtypes in periprosthetic fractures around the hip: results from the National Periprosthetic Fracture study

Aims: Periprosthetic fractures (PPFs) following hip arthroplasty are complex injuries. This study evaluates patient demographic characteristics, management, outcomes, and risk factors associated with PPF subtypes over a decade. Methods: Using a multicentre collaborative study design, independent of registry data, we identified adults from 29 centres with PPFs around the hip between January 2010 and December 2019. Radiographs were assessed for the Unified Classification System (UCS) grade. Patient and injury characteristics, management, and outcomes were compared between UCS grades. A multinomial logistic regression was performed to estimate relative risk ratios (RRR) of variables on UCS grade. Results: A total of 1,104 patients were included. The majority were female (57.9%; n = 639), ethnically white (88.5%; n = 977), used mobility aids (67%; n = 743), and had a median age of 82 years (interquartile range (IQR) 74 to 87). A total of 77 (7%) had pain prior to the PPF. The most common UCS grade was B2 (33%; n = 368). UCS type D fractures had the longest length of stay (median 19 days (IQR 11 to 26)), highest readmission to hospital (21%; n = 9), and highest rate of discharge to step-down care (52%; n = 23). Multinomial regression suggests that uncemented femoral stems are associated with a reduced risk of UCS C (RRR 0.36 (95% confidence interval (CI) 0.2 to 0.7); p = 0.002) and increased risk of UCS A (RRR 3.3 (95% CI 1.9 to 5.7); p < 0.001), compared to UCS B fracture. Conclusion: The most common PPF type in elderly frail patients is UCS B2. Uncemented stems have a lower risk of UCS C fractures compared to cemented stems. A national PPF database is needed to further identify correlation between implants and fracture subtypes. Cite this article: Bone Jt Open 2023;4(9):659–667

An enhancer complex confers both high-level and cell-specific expression of the human type X collagen gene

AbstractType X collagen expression is restricted to hypertrophic chondrocytes in the endochondral growth plate. Transient transfection of reporter constructs containing the human collagen X promoter into primary growth plate chondrocytes identified a cis-acting positive regulatory DNA element(s) that has cell-specific enhancer properties and binds a nuclear protein expressed specifically in growth plate chondrocytes. Functional disruption of this region results in a significant reduction in the activation of reporter gene transcription. The identified enhancer is a major element controlling both high-level and cell-specific expression of type X collagen gene