The effect of dehydration, hyperchloremia and volume of fluid resuscitation on acute kidney injury in children admitted to hospital with diabetic ketoacidosis.

BACKGROUND: Acute kidney injury (AKI) is a recognized comorbidity in pediatric diabetic ketoacidosis (DKA), although the exact etiology is unclear. The unique physiology of DKA makes dehydration assessments challenging, and these patients potentially receive excessive amounts of intravenous fluids (IVF). We hypothesized that dehydration is over-estimated in pediatric DKA, leading to over-administration of IVF and hyperchloremia that worsens AKI. METHODS: Retrospective cohort of all DKA inpatients at a tertiary pediatric hospital from 2014 to 2019. A total of 145 children were included; reasons for exclusion were pre-existing kidney disease or incomplete medical records. AKI was determined by change in creatinine during admission, and comparison to a calculated baseline value. Linear regression multivariable analysis was used to identify factors associated with AKI. True dehydration was calculated from patients' change in weight, as previously validated. Fluid over-resuscitation was defined as total fluids given above the true dehydration. RESULTS: A total of 19% of patients met KDIGO serum creatinine criteria for AKI on admission. Only 2% had AKI on hospital discharge. True dehydration and high serum urea levels were associated with high serum creatinine levels on admission (p = 0.042; p < 0.001, respectively). Fluid over-resuscitation and hyperchloremia were associated with delayed kidney recovery (p < 0.001). Severity of initial AKI was associated with cerebral edema (p = 0.018). CONCLUSIONS: Dehydration was associated with initial AKI in children with DKA. Persistent AKI and delay to recovery was associated with hyperchloremia and over-resuscitation with IVF, potentially modifiable clinical variables for earlier AKI recovery and reduction in long-term morbidity. This highlights the need to re-address fluid protocols in pediatric DKA.

Ethical issues in residency education related to the COVID-19 pandemic: a narrative inquiry study.

BACKGROUND: The COVID-19 pandemic introduced new challenges to provide care and educate junior doctors (resident physicians). We sought to understand the positive and negative experiences of first-year resident physicians and describe potential ethical issues from their stories. METHOD: We used narrative inquiry (NI) methodology and applied a semistructured interview guide with questions pertaining to ethical principles and both positive and negative aspects of the pandemic. Sampling was purposive. Interviews were audio recorded and transcribed. Three members of the research team coded transcripts in duplicate to elicit themes. Discrepancies were resolved through discussion to attain consensus. A composite story with threads was constructed. RESULTS: 11 residents participated across several programmes. Three main themes emerged from the participants' stories: (1) complexities in navigating intersecting healthcare and medical education systems, (2) balancing public health and the public good versus the individual and (3) fair health systems planning/healthcare delivery. Within these themes, participants' journeys through the first wave were elicited through the threads of (1) engage us, (2) because we see the need for the duty to treat and (3) we are all in this together. DISCUSSION: Cases of the ethical issues that took place during the COVID-19 pandemic may serve as a foundation on which ethics teaching and future pandemic planning can take place. Principles of clinical ethics and their limitations, when applied to public health issues, could help in contrasting clinical ethics with public health ethics. CONCLUSION: Efforts to understand how resident physicians can navigate public health emergencies along with the ethical issues that arise could benefit both residency education and healthcare systems.

Amygdala-Prefrontal Structural Connectivity Mediates the Relationship between Prenatal Depression and Behavior in Preschool Boys.

Prenatal depression is common, underrecognized, and undertreated. It has negative consequences on child behavior and brain development, yet the relationships among prenatal depression, child behavior, and children's brain structure remain unclear. The aim of this study was to determine whether altered brain connectivity mediates relationships between prenatal maternal depressive symptoms and child behavior. This study included 54 human mother-child pairs. Mothers completed the Edinburgh Postnatal Depression Scale during the second and third trimesters of pregnancy and 3 months postpartum. Their children had diffusion MRI at age 4.1 ± 0.8 years, and children's behavior was assessed using the Child Behavior Checklist within 6 months of their MRI scan. Structural brain connectivity of the amygdala, fornix, uncinate fasciculus, and cingulum was assessed using fractional anisotropy and mean diffusivity and analyzed with maternal prenatal depressive symptoms as well as child behavior. Third trimester maternal Edinburgh Postnatal Depression Scale scores were positively associated with mean diffusivity in the amygdala-frontal tract and the cingulum, controlling for postpartum depression. Externalizing behavior had a sex interaction in the amygdala-frontal pathway; weaker connectivity (lower fractional anisotropy, higher mean diffusivity) was associated with worse behavior in boys. Amygdala-frontal connectivity mediated the relationship between third trimester depressive symptoms and child externalizing behavior in males. These findings suggest that altered brain structure is a mechanism via which prenatal depressive symptoms can impact child behavior, highlighting the importance of both recognition and intervention in prenatal depression.SIGNIFICANCE STATEMENT Understanding how prenatal maternal depression impacts child behavior is critical for appropriately treating prenatal maternal mental health problems and improving child outcomes. Here, we show white matter changes in young children exposed to maternal prenatal depressive symptoms. Children of mothers with worse depressive symptoms had weaker white matter connectivity between areas related to emotional processing. Furthermore, connectivity between the amygdala and prefrontal cortex mediated the relationship between maternal depressive symptoms and externalizing behavior in boys, showing that altered brain structure is a possible mechanism via which maternal prenatal depression impacts children's behavior. This provides important information for understanding why children of depressed mothers may be more vulnerable to depression themselves and may help shape future guidelines on maternal prenatal care.

Optically trapped bacteria pairs reveal discrete motile response to control aggregation upon cell-cell approach.

Aggregation of bacteria plays a key role in the formation of many biofilms. The critical first step is cell-cell approach, and yet the ability of bacteria to control the likelihood of aggregation during this primary phase is unknown. Here, we use optical tweezers to measure the force between isolated Bacillus subtilis cells during approach. As we move the bacteria towards each other, cell motility (bacterial swimming) initiates the generation of repulsive forces at bacterial separations of ~3 µm. Moreover, the motile response displays spatial sensitivity with greater cell-cell repulsion evident as inter-bacterial distances decrease. To examine the environmental influence on the inter-bacterial forces, we perform the experiment with bacteria suspended in Tryptic Soy Broth, NaCl solution and deionised water. Our experiments demonstrate that repulsive forces are strongest in systems that inhibit biofilm formation (Tryptic Soy Broth), while attractive forces are weak and rare, even in systems where biofilms develop (NaCl solution). These results reveal that bacteria are able to control the likelihood of aggregation during the approach phase through a discretely modulated motile response. Clearly, the force-generating motility we observe during approach promotes biofilm prevention, rather than biofilm formation.

Measuring evidence-based clinical guideline compliance in the paediatric intensive care unit.

BACKGROUND: Evidence-based clinical care guidelines improve medical treatment by reducing error, improving outcomes and possibly lowering healthcare costs. While some data exist on individual guideline compliance, no data exist on overall compliance to multiple nuanced guidelines in a paediatric intensive care setting. METHODS: Guideline compliance was observed and measured with a prospective cohort at a tertiary academic paediatric medical-surgical intensive care unit. Adherence to 19 evidence-based clinical care guidelines was evaluated in 814 patients, and reasons for non-compliance were noted along with other associated outcomes. MEASUREMENTS AND MAIN RESULTS: Overall facility compliance was unexpectedly high at 77.8% over 4512 compliance events, involving 826 admissions. Compliance varied widely between guidelines. Guidelines with the highest compliance were stress ulcer prophylaxis (97.1%) and transfusion administration such as fresh frozen plasma (97.4%) and platelets (94.8%); guidelines with the lowest compliance were ventilator-associated pneumonia prevention (28.7%) and vitamin K administration (34.8%). There was no significant change in compliance over time with observation. Guidelines with binary decision branch points or single-page decision flow diagrams had a higher average compliance of 90.6%. Poor compliance was more often observed with poor perception of guideline trustworthiness and time limitations. CONCLUSIONS: Measuring guideline compliance, though onerous, allowed for evaluation of current clinical practices and identified actionable areas for institutional improvement.

Corticosteroids to safely reduce neonatal respiratory morbidity after late preterm and term planned caesarean section birth? A randomised placebo-controlled feasibility study.

OBJECTIVES: To assess the feasibility of conducting a randomised placebo-controlled trial of corticosteroids prior to planned caesarean section from 35+0 to 39+6 weeks. DESIGN: A triple-blind, placebo-controlled, parallel, trial randomised at the participant level (1:1 ratio). Additional feasibility data obtained by questionnaires from trial participants and women who declined trial participation, and focus groups with local site researchers and clinicians. SETTING: Three obstetric units in New Zealand including tertiary and secondary care; public and private care, and research active and non-active units. PARTICIPANTS: Women undergoing a planned caesarean section from 35+0 to 39+6 weeks; local site researchers and clinicians. INTERVENTIONS: Two doses of 11.4 mg betamethasone or saline placebo. Questionnaires and focus group meetings. PRIMARY AND SECONDARY OUTCOME MEASURES: Primary outcome: trial recruitment rate of eligible women. SECONDARY OUTCOMES: trial recruitment by gestational age, site and delivery indication; proportion of babies who completed measurements of blood glucose concentrations as per protocol; overall incidence neonatal respiratory distress requiring >60 min of respiratory support; overall incidence of neonatal hypoglycaemia, and barriers and enablers to trial participation by participants, researchers and clinicians. RESULTS: The recruitment rate was 8.9% (88/987) overall and 11.2% (88/789) for those approached about the trial. Neonatal blood glucose concentrations were measured as per protocol in 87/92 (94.6%) babies. For potential participants, key enablers to participation were contributing to research, a feeling of relevance and a good understanding; key barriers were a lack of understanding and concerns over safety. For researchers and clinicians, themes representing enablers and barriers included relevance, communication and awareness, influences on women's decision-making, resource challenges and trial process practicalities. CONCLUSIONS: Some women are willing to participate in a randomised placebo-controlled trial of corticosteroids prior to a planned caesarean section birth at late preterm and term gestations. Participation in such a trial can be enhanced.

Ghrelin Receptor Signaling Is Not Required for Glucocorticoid-Induced Obesity in Male Mice.

Chronically elevated levels of glucocorticoids increase food intake, weight gain, and adiposity. Similarly, ghrelin, a gut-secreted hormone, is also associated with weight gain, adiposity, and increased feeding. Here we sought to determine if corticosterone-induced metabolic and behavioral changes require functional ghrelin receptors (GHSR). To do this, we treated male C57BL mice with chronic corticosterone (CORT) mixed in their drinking water for 28 days. Half of these mice received the GHSR antagonist JMV2959 via osmotic minipumps while treated with CORT. In a second experiment, we gave the same CORT protocol to mice with a targeted mutation to the GHSR or their wild-type littermates. As expected, CORT treatment increased food intake, weight gain, and adiposity, but contrary to expectations, mice treated with a GHSR receptor antagonist or GHSR knockout (KO) mice did not show attenuated food intake, weight gain, or adiposity in response to CORT. Similarly, the effects of CORT on the liver were the same or more pronounced in GHSR antagonist-treated and GHSR KO mice. Treatment with JMV2959 did attenuate the effects of chronic CORT on glycemic regulation as determined by the glucose tolerance test. Finally, disruption of GHSR signaling resulted in behavioral responses associated with social withdrawal, potentially due to neuroprotective effects of GHSR activation. In all, we propose that blocking GHSR signaling helps to moderate glucose concentrations when CORT levels are high, but blocking GHSR signaling does not prevent increased food intake, weight gain, or increased adiposity produced by chronic CORT.

Hungry to gamble? Ghrelin as a predictor of persistent gambling in the face of loss.

Ghrelin, a peptide hormone associated with appetite, is also linked to increased reward seeking behaviors, including food, sex, and drug seeking behaviors through the stimulation of the mesolimbic dopaminergic system. Moreover, plasma ghrelin concentrations are increased by cues that predict rewards, suggesting that cues could facilitate cravings and ultimately relapse. In this project we examined the effects of an overnight fast, a manipulation known to increase ghrelin concentrations, on gambling behaviors. We also examined if cues associated with gambling would also increase ghrelin and, if so, we examined if these increases were associated with gambling behavior. One hundred and one (37 females) participants were asked to fast overnight or after breakfast and then asked to complete food and gambling craving questionnaires. Participants were then presented with gambling cues (a casino like environment in the lab) or a control cue (a cubicle with a computer). After the cue, subjects filled gambling craving questionnaires, and were allowed to gamble. Following 25 practice spins, the slot machines were fixed so that all subsequent spins were losses, and the number of spins in spite of losses were quantified. Blood samples were collected throughout the experiment. Results showed that the gambling cues significantly increased ghrelin concentrations particularly in fasted individuals, and that ghrelin concentrations 20 min after the cue were the best predictor for gambling persistence in the face of continued loss (p < 0.05). Our results suggest that cues that predict the opportunity to gamble have an acute effect on ghrelin concentrations that is facilitated by fasting, and that ghrelin concentrations are a significant predictor of gambling persistence.

A fast 3D reconstruction system with a low-cost camera accessory.

Photometric stereo is a three dimensional (3D) imaging technique that uses multiple 2D images, obtained from a fixed camera perspective, with different illumination directions. Compared to other 3D imaging methods such as geometry modeling and 3D-scanning, it comes with a number of advantages, such as having a simple and efficient reconstruction routine. In this work, we describe a low-cost accessory to a commercial digital single-lens reflex (DSLR) camera system allowing fast reconstruction of 3D objects using photometric stereo. The accessory consists of four white LED lights fixed to the lens of a commercial DSLR camera and a USB programmable controller board to sequentially control the illumination. 3D images are derived for different objects with varying geometric complexity and results are presented, showing a typical height error of <3 mm for a 50 mm sized object.

Identification of appressorial and mycelial cell wall proteins and a survey of the membrane proteome of Phytophthora infestans.

Proteins embedded in the cell wall and plasma membrane of filamentous oomycetes and fungi provide a means by which these organisms can interact with their local environment. However, cell wall and membrane proteins have often proved difficult to isolate using conventional proteomic techniques. Here we have used liquid chromatography tandem mass spectrometry (LC-MS/MS) to facilitate rapid and sensitive quantification of the cell wall proteome. We report the use of LC-MS/MS to identify differentially regulated proteins from the cell walls of three different lifecycle stages of the oomycete plant pathogen Phytophthora infestans: non-sporulating vegetative mycelium, sporulating mycelium, and germinating cysts with appressoria. We have also used quantitative real-time RT-PCR to confirm that the transcripts corresponding to some of these proteins, namely those identified in cell walls of germinating cysts with appressoria, accumulate differentially throughout the lifecycle. These proteins may, therefore, be important for pre-infective development and early pathogenicity. Up to 31 covalently and non-covalently bound cell wall-associated proteins were identified. All of the proteins identified in germinating cysts with appressoria, and several of those from mycelial fractions, were classified as putative effector or pathogen-associated molecular pattern (PAMP) molecules, including members of the CBEL family, the elicitin family, the crinkler (CRN) family and two transglutaminases. Thus, the cell wall of P. infestans may represent an important reservoir for surface-presented, apoplastic effectors or defence activation molecules. Proteins predicted to be cell surface proteins included IPI-B like proteins, mucins, cell wall-associated enzymes and annexin family members. Additionally we identified up to 27 membrane-associated proteins from Triton X-114 phase partitioned mycelial membrane preparations, producing the first inventory of oomycete membrane-associated proteins. Four of these proteins are small Rab-type G-proteins and several are associated with secretion.