Parkin-deficient Mice Exhibit Nigrostriatal Deficits but not Loss of Dopaminergic Neurons

Loss-of-function mutations in parkin are the major cause of early-onset familial Parkinson's disease. To investigate the pathogenic mechanism by which loss of parkin function causes Parkinson's disease, we generated a mouse model bearing a germline disruption in parkin. Parkin-/- mice are viable and exhibit grossly normal brain morphology. Quantitative in vivo microdialysis revealed an increase in extracellular dopamine concentration in the striatum of parkin-/- mice. Intracellular recordings of medium-sized striatal spiny neurons showed that greater currents are required to induce synaptic responses, suggesting a reduction in synaptic excitability in the absence of parkin. Furthermore, parkin-/- mice exhibit deficits in behavioral paradigms sensitive to dysfunction of the nigrostriatal pathway. The number of dopaminergic neurons in the substantia nigra of parkin-/- mice, however, is normal up to the age of 24 months, in contrast to the substantial loss of nigral neurons characteristic of Parkinson's disease. Steady-state levels of CDCrel-1, synphilin-1, and α-synuclein, which were identified previously as substrates of the E3 ubiquitin ligase activity of parkin, are unaltered in parkin-/- brains. Together these findings provide the first evidence for a novel role of parkin in dopamine regulation and nigrostriatal function, and a non-essential role of parkin in the survival of nigral neurons in mice

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

Improving consent in patients undergoing surgery for fractured neck of femur

Background Neck of femur fractures and their subsequent operative fixation are associated with high rates of perioperative morbidity and mortality. Consenting in this setting is suboptimal with the Montgomery court ruling changing the perspective of consent. This quality improvement project assessed the adequacy of consenting against British Orthopaedic Association-endorsed guidance and implemented a series of changes to improve the documentation of risks associated with surgery for fractured neck of femur. Methods Seventy consecutive patients who underwent any operative fixation of a neck of femur fracture were included over a 6-month period at a single centre. Patients unable to consent or without electronic notes were excluded. Consent forms were analysed and the documented potential risks or complications associated with surgery were compared to British Orthopaedic Association-endorsed guidance. A series of changes (using the plan, do study, act (PDSA) approach) was implemented to improve the adequacy of consent. Results Documentation of four out of 12 potential risks or complications was recorded in <50% of cases for patients with intracapsular fractures (n=35), and documentation of seven out of 12 potential risks or complications was recorded in <50% of cases for patients with extracapsular fractures (n=35). Re-audit following raising awareness and attaching consent guidance showed 100% documentation of potential risks or complications in patients with intracapsular and extracapsular fractures (n=70). A neck of femur fracture-specific consent form has been implemented which will hopefully lead to sustained improvement. Conclusions Consenting patients with fractured neck of femur for surgery in the authors' unit was suboptimal when compared to British Orthopaedic Association-endorsed consent guidance. This project has shown that ensuring such guidance is readily available has improved the adequacy of consent. The authors hope that introduction of a neck of femur fracture-specific consent form within their unit will lead to sustained adequate documentation of risks associated with surgery

"Adaptive response" - some underlying mechanisms and open questions

Organisms are affected by different DNA damaging agents naturally present in the environment or released as a result of human activity. Many defense mechanisms have evolved in organisms to minimize genotoxic damage. One of them is induced radioresistance or adaptive response. The adaptive response could be considered as a nonspecific phenomenon in which exposure to minimal stress could result in increased resistance to higher levels of the same or to other types of stress some hours later. A better understanding of the molecular mechanism underlying the adaptive response may lead to an improvement of cancer treatment, risk assessment and risk management strategies, radiation protection, e. g. of astronauts during long-term space flights. In this mini-review we discuss some open questions and the probable underlying mechanisms involved in adaptive response: the transcription of many genes and the activation of numerous signaling pathways that trigger cell defenses - DNA repair systems, induction of proteins synthesis, enhanced detoxification of free radicals and antioxidant production.Publisher PDFPeer reviewe