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Healthcare waste management is a globally challenging issue with an increased prevalence of disposable, single-use materials in developed countries and a rapidly ageing population continuing to drive an increase in the use of medical resources. One manifestation of this within ophthalmology is the increasing number of intravitreal injections given for conditions such as age-related macular degeneration and diabetic macular oedema.A prospective controlled cohort study was performed over 5 weeks in 2021 during which two sites were selected to compare different approaches to sorting the waste generated by intravitreal injections. At Site A all waste associated with these injections was placed in standard hospital waste bins. Site B was the intervention arm where a real-time sorting of waste occurred. The number of injections given and waste amounts were recorded.116 and 286 injections were given at Sites A and B, respectively over the study period. Site A generated an average of 470.7 g of waste per injection compared with 175.1 g at our intervention site. This represents a 62.8% reduction (p 0.001). At Site B, where waste was sorted, a total of 50.1 kg of medical waste was generated from these injections during the study period of which 33.8 kg (67.5%) was salvageable.This is the first quantification of the medical waste associated with intravitreal injections, a burgeoning treatment for macular degeneration and diabetic retinopathy among other conditions. This study demonstrates a significant reduction in the amount of medical waste produced using an easily implementable real-world methodology.

BACKGROUND 'Fast-track' surgery protocols aim to standardize and rationalize post-operative care, with evidence of safety and efficacy in both uncomplicated and complicated childhood appendicitis. Generalization for broader adoption has been limited by variation in protocol design, including specific antibiotic choice, discharge criteria, post-operative monitoring and patient selection. METHODS A systematic review of the literature was performed to evaluate the current evidence underpinning fast-track protocols for childhood appendicitis and identify areas of consensus and controversy. RESULTS About 33 studies met the inclusion criteria, including four prospective observational studies, 20 case-control studies, seven cohort studies and two randomized controlled trials studying uncomplicated (n = 9), complicated (n = 18) and mixed cohorts (n = 6). Reduction in length of hospital stay was almost universally reported, with equivalent or improved complication rates. Key themes of protocols included antibiotic choice and duration, discharge criteria and post-operative laboratory and radiographic testing. Rationalized analgesia is an underexplored aspect of protocol design, and a standardized definition of complicated appendicitis remains elusive. CONCLUSION Standardized care of childhood appendicitis has been shown to be safe and effective in several local and international centres. Next steps include investigation of a complicated appendicitis protocol that integrates rationalized analgesia in appendicectomy recovery, and development of a consistent classification scheme for complicated disease to aid in identification of amenable cohorts.

The use of routine gastric aspiration in the assessment of feeding intolerance is widespread in neonatal practice. Our article seeks to answer the clinical question, 'In premature infants receiving feeds via nasogastric or orogastric tube [P], does routine evaluation of gastric aspirates [I] compared with selective evaluation of gastric aspirates [C] reduce the time taken to establish full feeds without complications [O]?' Articles were identified through MEDLINE and reference lists from the sources found were reviewed for additional publications. Three papers were critically appraised and National Health and Medical Research Centre grades of level of evidence have been assigned to each. We found limited evidence to either support or reject the practice of routine gastric aspiration in preterm infants. There were no increases in the rates of significant complications in studies underpowered for this outcome. The decision to perform routine or selective gastric aspiration should be determined by individual centres. A large scale randomised controlled trial would be of significant benefit in determining the value of routine gastric aspiration in preterm infants.

There is now compelling evidence that the allocation of memory to specific neurons (neuronal allocation) and synapses (synaptic allocation) in a neurocircuit is not random and that instead specific mechanisms, such as increases in neuronal excitability and synaptic tagging and capture, determine the exact sites where memories are stored. We propose an integrated view of these processes, such that neuronal allocation, synaptic tagging and capture, spine clustering and metaplasticity reflect related aspects of memory allocation mechanisms. Importantly, the properties of these mechanisms suggest a set of rules that profoundly affect how memories are stored and recalled.

The retrosplenial cortex (RSC) is part of a network of interconnected cortical, hippocampal, and thalamic structures harboring spatially modulated neurons. The RSC contains head direction cells and connects to the parahippocampal region and anterior thalamus. Manipulations of the RSC can affect spatial and contextual tasks. A considerable amount of evidence implicates the role of the RSC in spatial navigation, but it is unclear whether this structure actually encodes or stores spatial information. We used a transgenic mouse in which the expression of green fluorescent protein was under the control of the immediate early gene c-fos promoter as well as time-lapse two-photon in vivo imaging to monitor neuronal activation triggered by spatial learning in the Morris water maze. We uncovered a repetitive pattern of cell activation in the RSC consistent with the hypothesis that during spatial learning an experience-dependent memory trace is formed in this structure. In support of this hypothesis, we also report three other observations. First, temporary RSC inactivation disrupts performance in a spatial learning task. Second, we show that overexpressing the transcription factor CREB in the RSC with a viral vector, a manipulation known to enhance memory consolidation in other circuits, results in spatial memory enhancements. Third, silencing the viral CREB-expressing neurons with the allatostatin system occludes the spatial memory enhancement. Taken together, these results indicate that the retrosplenial cortex engages in the formation and storage of memory traces for spatial information.

During long-term memory formation, cellular and molecular processes reshape how individual neurons respond to specific patterns of synaptic input. It remains poorly understood how such changes impact information processing across networks of mammalian neurons. To observe how networks encode, store, and retrieve information, neuroscientists must track the dynamics of large ensembles of individual cells in behaving animals, over timescales commensurate with long-term memory. Fluorescence Ca(2+)-imaging techniques can monitor hundreds of neurons in behaving mice, opening exciting avenues for studies of learning and memory at the network level. Genetically encoded Ca(2+) indicators allow neurons to be targeted by genetic type or connectivity. Chronic animal preparations permit repeated imaging of neural Ca(2+) dynamics over multiple weeks. Together, these capabilities should enable unprecedented analyses of how ensemble neural codes evolve throughout memory processing and provide new insights into how memories are organized in the brain.

The mechanisms that determine how information is allocated to specific regions and cells in the brain are fundamentally important for memory capacity, storage and retrieval, but are poorly understood. Here, we manipulated CREB in a subset of lateral amygdala (LA) neurons with a modified Herpes Simplex Virus (HSV), and reversibly inactivated transfected neurons with the Drosophila allatostatin G-protein-coupled receptor (AlstR)/ligand system. We found that inactivation of the HSV-CREB subpopulation of neurons with allatostatin (AL) during training disrupted memory for tone conditioning, while inactivation of a similar proportion of HSV-LacZ control neurons did not. Whole-cell recordings of fluorescently tagged HSV-CREB neurons revealed that neurons with higher CREB levels are more excitable than neighboring neurons, and show larger synaptic efficacy changes following conditioning. Our findings demonstrate that CREB modulates the allocation of fear memory to specific cells in lateral amygdala, and suggest that neuronal excitability plays a key role in this process.

Although memory allocation is a subject of active research in computer science, little is known about how the brain allocates information within neural circuits. There is an extensive literature on how specific types of memory engage different parts of the brain, and how neurons in these regions process and store information. Until recently, however, the mechanisms that determine how specific cells and synapses within a neural circuit (and not their neighbors) are recruited during learning have received little attention. Recent findings suggest that memory allocation is not random, but rather specific mechanisms regulate where information is stored within a neural circuit. New methods that allow tagging, imaging, activation, and inactivation of neurons in behaving animals promise to revolutionize studies of brain circuits, including memory allocation. Results from these studies are likely to have a considerable impact on computer science, as well as on the understanding of memory and its disorders.