The effect of food quality during growth on spatial memory consolidation in adult pigeons.

Poor environmental conditions experienced during early development can have negative long-term consequences on fitness. Animals can compensate for negative developmental effects through phenotypic plasticity by diverting resources from non-vital to vital traits such as spatial memory to enhance foraging efficiency. We tested in young feral pigeons (Columba livia) how diets of different nutritional value during development affect the capacity to retrieve food hidden in a spatially complex environment, a process we refer to as 'spatial memory'. Parents were fed with either high- or low-quality food from egg laying until young fledged, after which all young pigeons received the same high-quality diet until memory performance was tested at 6 months of age. The pigeons were trained to learn a food location out of 18 possible locations in one session, and then their memory of this location was tested 24 h later. Birds reared with the low-quality diet made fewer errors in the memory test. These results demonstrate that food quality during development has long-lasting effects on memory, with a moderate nutritional deficit improving spatial memory performance in a foraging context. It might be that under poor feeding conditions resources are redirected from non-vital to vital traits, or pigeons raised with low-quality food might be better in using environmental cues such as the position of the sun to find where food was hidden.

The absolute number of repeat operations for complex intra-abdominal sepsis is not a useful predictor of non-survival.

BACKGROUND: When multiple repeat laparotomies are required to manage intra-abdominal sepsis, questions about futility of treatment frequently arise. This study focuses specifically on patients who required two or more repeat laparotomies and describes the spectrum of disease necessitating multiple repeat laparotomies and the associated outcomes in the hope of clarifying the issue. METHOD: This study was conducted over a 20-month period (December 2012 - July 2014) at Greys Hospital in Pietermaritzburg, South Africa. All surgical patients at Greys Hospital have admission, discharge and operative data prospectively entered into a computerised electronic registry, the Hybrid Medical Electronic Registry (HEMR). The ethics approval required to maintain this registry has been obtained from the Biomedical Research Ethics Committee (BCA221/13 BREC) of the University of KwaZulu-Natal and from the Research Unit of the Department of Health. Full ethical approval for this study was granted by the University of KwaZulu-Natal Biomedical Research Ethics Committee (BE047/14). All patients aged 13 years and older who needed at least two repeat laparotomies were included in the study. This included general surgical and trauma patients. RESULTS: During the study period, 72 patients required more than one repeat laparotomy and a total of 182 repeat laparotomy operations were performed on this patient cohort. Demographics showed a male predominance, with 54 (75%) being male and 18 (25%) being female patients. The average age was 39 years. General surgical patients accounted for 60% and trauma patients for 40% of the total. The majority of patients required only two repeat laparotomy (65 %), while two patients required a total of 6 repeat laparotomy each, both with an initial diagnosis of appendicitis and both these patients survived. Temporary abdominal closure (TAC) was performed in 26 (36%) of initial laparotomies, while 33 (46%) of patients had an open abdomen at the time of discharge or death. Sixty percent required intensive care or high care unit (ICU/HCU) admission and 53 patients (74%) had a total of 71 documented morbidities. Total mortality for this study was 21%, however there was no correlation between number of procedures and mortality. CONCLUSION: The total number of procedures is associated with increased morbidity rates but not necessarily with increased mortality rates. This is important to consider when the issue of futility of treatment arises, as the absolute number of repeat laparotomies is a poor marker of futility and other factors must be considered.

The Role of Planned and On-Demand Relaparotomy in the Developing World.

INTRODUCTION/BACKGROUND: This study compares planned repeat laparotomy (PR) with on-demand repeat laparotomy (OD) in a developing world setting. MATERIALS AND METHODS: This study was conducted over a 30-month study period (December 2012-May 2015) at Greys Hospital, Pietermaritzburg, South Africa. All trauma and general surgery adult patients requiring a single relaparotomy were included in this study. Prospectively gathered data entered into an established electronic registry were retrospectively analysed. Full ethical approval for the registry and this study was granted by the University of KwaZulu-Natal Biomedical Ethics Committee. RESULTS: A total of 162 patients were included, with an average age of 36 years (standard deviation 17) and 69 % male predominance. Appendicitis and stab abdomen were the most common underlying diagnoses. PR strategy was used in 46 % and an OD approach in 54 %. Patients selected for the PR strategy had higher admission pulse rates, higher Modified Early Warning System (MEWS) scores and significantly higher rates of diffuse intra-abdominal sepsis at initial laparotomy. However, findings at relaparotomy were similar in both groups. The PR group had a much shorter time between operations, but much higher need for intensive care unit (ICU) admission. There was no difference between the groups in terms of open abdomen at discharge, length of hospital stay, morbidity or mortality. CONCLUSION: In our environment, a planned approach to relaparotomy shows no major outcome advantages over an on-demand approach. There is however increased need for ICU admission with the PR approach. This is in keeping with international literature. Of concern is the much longer time delay between index procedure and repeat operation in the OD group. Improved post-operative decision making may help address this.

Sleep and vigilance linked to melanism in wild barn owls.

Understanding the function of variation in sleep requires studies in the natural ecological conditions in which sleep evolved. Sleep has an impact on individual performance and hence may integrate the costs and benefits of investing in processes that are sensitive to sleep, such as immunity or coping with stress. Because dark and pale melanic animals differentially regulate energy homeostasis, immunity and stress hormone levels, the amount and/or organization of sleep may covary with melanin-based colour. We show here that wild, cross-fostered nestling barn owls (Tyto alba) born from mothers displaying more black spots had shorter non-REM (rapid eye movement) sleep bouts, a shorter latency until the occurrence of REM sleep after a bout of wakefulness and more wakefulness bouts. In male nestlings, the same sleep traits also correlated with their own level of spotting. Because heavily spotted male nestlings and the offspring of heavily spotted biological mothers switched sleep-wakefulness states more frequently, we propose the hypothesis that they could be also behaviourally more vigilant. Accordingly, nestlings from mothers displaying many black spots looked more often towards the nest entrance where their parents bring food and towards their sibling against whom they compete. Owlets from heavily spotted mothers might invest more in vigilance, thereby possibly increasing associated costs due to sleep fragmentation. We conclude that different strategies of the regulation of brain activity have evolved and are correlated with melanin-based coloration.

Evaluation of two minimally invasive techniques for electroencephalogram recording in wild or freely behaving animals.

Insight into the function of sleep may be gained by studying animals in the ecological context in which sleep evolved. Until recently, technological constraints prevented electroencephalogram (EEG) studies of animals sleeping in the wild. However, the recent development of a small recorder (Neurologger 2) that animals can carry on their head permitted the first recordings of sleep in nature. To facilitate sleep studies in the field and to improve the welfare of experimental animals, herein, we test the feasibility of using minimally invasive surface and subcutaneous electrodes to record the EEG in barn owls. The EEG and behaviour of four adult owls in captivity and of four chicks in a nest box in the field were recorded. We scored a 24-h period for each adult bird for wakefulness, slow-wave sleep (SWS), and rapid-eye movement (REM) sleep using 4 s epochs. Although the quality and stability of the EEG signals recorded via subcutaneous electrodes were higher when compared to surface electrodes, the owls' state was readily identifiable using either electrode type. On average, the four adult owls spent 13.28 h awake, 9.64 h in SWS, and 1.05 h in REM sleep. We demonstrate that minimally invasive methods can be used to measure EEG-defined wakefulness, SWS, and REM sleep in owls and probably other animals.

Technical success of endoscopic stenting for malignant gastric outlet obstruction.

BACKGROUND: Palliation of irresectable malignant gastric outlet obstruction (GOO) using self-expanding metal stents (SEMS) is gaining popularity with high technical success rates. The aim of this study was to review and compare GOO stenting for malignancy with other series. METHODS: A retrospective review of all patients undergoing pyloroduodenal stenting for malignant GOO at Groote Schuur Hospital, 1 March 2018-31 August 2021, evaluating demographics, technical success, pathology, and stentrelated complications was done. RESULTS: One hundred and fourteen patients, of which 38.6% were female, were included, with gastric malignancies (74.6%) being the most frequent underlying pathology. Median age was 64 years (IQR 53-70 years), with 48.2% having at least one comorbidity. The majority (96 patients; 85.7%) required only one stent. In total, 132 stent insertion attempts were undertaken. Three technical failures were experienced (one incorrect stent placement and two failed insertions), equating to a 97.4% technical success rate. Four immediate complications occurred (3.1%): two related to sedation, one incorrect stent placement and an oesophagogastric junction perforation with procedural death. Fifteen delayed complications occurred: 13 tumour in-growth blockages, one stent fracture and one case of poor radial stent expansion. Stent blockages occurred at a median of 107 days (IQR 80-275 days). Salvage stenting was 100% successful in 14 cases requiring re-stenting. CONCLUSION: Technical insertion success rates of primary and salvage duodenal stenting for malignant GOO are on par with international high-volume units. The leading pathology locally is gastric adenocarcinoma, with palliative stenting remaining a feasible and accessible option.

The incidence and management of complications following stenting of oesophageal malignancies.

BACKGROUND: Oesophageal stenting effectively palliates malignant dysphagia with reported high technical and clinical success rates approaching 90% and a low, though often problematic, complication frequency. This study aimed to benchmark success rates, the incidence and management of complications at a tertiary interventional endoscopy centre. METHODS: This single centre three-year (March 2018-March 2021) study reviewed demographics, tumour histology/ position, and early and late complications of palliative oesophageal stenting. A multivariate analysis of tumour position association with complications was performed. RESULTS: A total of 297 patients (73.4% squamous cell carcinoma) underwent 354 stent insertion attempts. Immediate technical insertion success rate was 97.5% with dysphagia improvement achieved in all successful insertions (100% clinical success rate). Three hundred and forty-six (98.6%) were fully covered stents, with 17 (4.8%) placed for tracheaoesophageal fistulae. Twenty-one (6.0%) immediate insertion-related complications occurred, including two oesophageal perforations, but no insertion-related mortalities. Late complications occurred in 73 (20.8%) with tumour overgrowth (10.1%) and stent migration (6.1%) being the most frequent. Of all 354 stents, 75.2% had no documented complications for the lifetime of that stent, while 68 complications required re-intervention, equating to a re-intervention rate of 19.4% per stent insertion. Stent migration was significantly higher in distal tumours (11.8% vs 1.8%, p < 0.001), while discomfort necessitating same-day stent removal was higher in proximal tumours starting at < 20 cm from the incisors (16.7% vs 0.5%, p < 0.001). CONCLUSION: Oesophageal stenting for malignant dysphagia is peri-procedurally safe and effective. Outcomes reported from this South African cohort compare favourably to high-volume international units.

Current practice of inguinal hernia repair at University of Cape Town affiliated hospitals: implications for training.

BACKGROUND: Various inguinal hernia repair techniques exist, without one 'single best' option. Hernia society guidelines recommend laparoscopic repair as one of its mainstays, provided surgeons are adequately trained. The current practice for hernia repair in South Africa as well as the surgical registrar exposure to laparoscopic repair training is unknown. OBJECTIVES: To quantify the current practice of inguinal hernia surgery in hospitals affiliated to the University of Cape Town (UCT) and to assess trainee exposure to laparoscopic repair. METHODS: Adult patients who underwent inguinal hernia repair during the 12-month study period, at the four UCT affiliated hospitals were included. Collected data parameters included age, gender, primary or recurrent, uni- or bilateral hernia, primary surgeon consultant or non-consultant, operative time, and open or laparoscopic technique used. RESULTS: Three hundred and seventy-seven patients were included. Eighty-eight (23.2%) repairs were performed laparoscopically, of which five (5.7%) were converted to open. Non-consultants were present at 70/88 (79.5%) cases performed laparoscopically and were the primary surgeon at only 15 (17%). Laparoscopic repair was performed for 63.6% of bilateral versus 19.5% of unilateral hernias, 39.4% of recurrent hernias and 45% of hernias in females. Two of the four hospitals in this study performed 81.8% of all laparoscopic repairs. CONCLUSIONS: Inguinal hernias in our setting are predominantly repaired by open surgery. The likelihood of laparoscopic repair varies significantly depending on which hospital the patient is referred to. Non-consultants have limited exposure to performing laparoscopic hernia repairs as the primary surgeon.

Infant burns: A single institution retrospective review.

Thermal injuries amongst infants are common and a cause of significant mortality and morbidity in South Africa. This has been attributed to the lack of an enabling environment (poverty-related lack of safe living conditions) and the cognitive and physical developmental immaturity of infants, who depend on their surroundings and adults to keep them safe. This is a retrospective observational study of 548 infant admissions over 48 months. Infant was defined as children below 13 months of age. The 548 infants constituted 23% of all paediatric burn admissions of ages 0-12 years. Three hundred and fourteen were males (57%) and 234 (42.7%) females. The infants were divided in a pre-ambulatory group of 143 (26%) infants of 0-6 months and an ambulatory group of 7 months to 12 months consisting of 457 (83.3%). The total body surface area (TBSA) ranged from 2-65%. Seventy-six percent (417 infants) occurred in the home environment. Scalds accounted for 86% (471 infants) and 6% (33 infants) were as a result of flame burns. Non-accidental injuries accounted for 1.2%. The anatomical distributions varied between the pre-ambulatory and ambulatory groups. Conservative management was done in 397 (72.4%) and 101(18.4%) infants underwent surgery. Infection was suspected in 76 (13.5%) infants with positive blood cultures in 15(20%) of the 76. ICU care was received in 46 (8.3%) infants and 15 (32.6%) of these had inhalation injuries. Of the inhalation injuries 11(23.9%) infants underwent mechanical ventilation of an average of 4.4 days. Ventilator associated pneumonia was diagnosed in 8(17%) of the ventilated children. The mortality rate was 0.36%. The surgically treated patients acquired more complications than the conservatively treated group. Special treatment considerations should be considered in this paediatric sub-group.

Did tool-use evolve with enhanced physical cognitive abilities?

The use and manufacture of tools have been considered to be cognitively demanding and thus a possible driving factor in the evolution of intelligence. In this study, we tested the hypothesis that enhanced physical cognitive abilities evolved in conjunction with the use of tools, by comparing the performance of naturally tool-using and non-tool-using species in a suite of physical and general learning tasks. We predicted that the habitually tool-using species, New Caledonian crows and Galápagos woodpecker finches, should outperform their non-tool-using relatives, the small tree finches and the carrion crows in a physical problem but not in general learning tasks. We only found a divergence in the predicted direction for corvids. That only one of our comparisons supports the predictions under this hypothesis might be attributable to different complexities of tool-use in the two tool-using species. A critical evaluation is offered of the conceptual and methodological problems inherent in comparative studies on tool-related cognitive abilities.