Melatonin augments hypothermic neuroprotection in a perinatal asphyxia model

Despite treatment with therapeutic hypothermia, almost 50% of infants with neonatal encephalopathy still have adverse outcomes. Additional treatments are required to maximize neuroprotection. Melatonin is a naturally occurring hormone involved in physiological processes that also has neuroprotective actions against hypoxic-ischaemic brain injury in animal models. The objective of this study was to assess neuroprotective effects of combining melatonin with therapeutic hypothermia after transient hypoxia-ischaemia in a piglet model of perinatal asphyxia using clinically relevant magnetic resonance spectroscopy biomarkers supported by immunohistochemistry. After a quantified global hypoxic-ischaemic insult, 17 newborn piglets were randomized to the following: (i) therapeutic hypothermia (33.5°C from 2 to 26 h after resuscitation, n = 8) and (ii) therapeutic hypothermia plus intravenous melatonin (5 mg/kg/h over 6 h started at 10 min after resuscitation and repeated at 24 h, n = 9). Cortical white matter and deep grey matter voxel proton and whole brain (31)P magnetic resonance spectroscopy were acquired before and during hypoxia-ischaemia, at 24 and 48 h after resuscitation. There was no difference in baseline variables, insult severity or any physiological or biochemical measure, including mean arterial blood pressure and inotrope use during the 48 h after hypoxia-ischaemia. Plasma levels of melatonin were 10 000 times higher in the hypothermia plus melatonin than hypothermia alone group. Melatonin-augmented hypothermia significantly reduced the hypoxic-ischaemic-induced increase in the area under the curve for proton magnetic resonance spectroscopy lactate/N-acetyl aspartate and lactate/total creatine ratios in the deep grey matter. Melatonin-augmented hypothermia increased levels of whole brain (31)P magnetic resonance spectroscopy nucleotide triphosphate/exchangeable phosphate pool. Correlating with improved cerebral energy metabolism, TUNEL-positive nuclei were reduced in the hypothermia plus melatonin group compared with hypothermia alone in the thalamus, internal capsule, putamen and caudate, and there was reduced cleaved caspase 3 in the thalamus. Although total numbers of microglia were not decreased in grey or white matter, expression of the prototypical cytotoxic microglial activation marker CD86 was decreased in the cortex at 48 h after hypoxia-ischaemia. The safety and improved neuroprotection with a combination of melatonin with cooling support phase II clinical trials in infants with moderate and severe neonatal encephalopathy.

Luminescence imaging microscopy and lifetime mapping using kinetically stable lanthanide(III) complexes

The sensitised luminescence from stable lanthanide complexes (1 and 2) bearing a phenanthridine antenna has been used to generate time-resolved images of silica particles. The millisecond order luminescent lifetime of these complexes is utilised to demonstrate time-gated imaging of the sample from a fluorescent background and to facilitate lifetime mapping over the area of the sample.

Xenon augmented hypothermia reduces early lactate/N-acetylaspartate and cell death in perinatal asphyxia

OBJECTIVE

Additional treatments for therapeutic hypothermia are required to maximize neuroprotection for perinatal asphyxial encephalopathy. We assessed neuroprotective effects of combining inhaled xenon with therapeutic hypothermia after transient cerebral hypoxia-ischemia in a piglet model of perinatal asphyxia using magnetic resonance spectroscopy (MRS) biomarkers supported by immunohistochemistry.

METHODS

Thirty-six newborn piglets were randomized (all groups n = 9), with intervention from 2 to 26 hours, to: (1) normothermia; (2) normothermia + 24 hours 50% inhaled xenon; (3) 24 hours hypothermia (33.5°C); or (4) 24 hours hypothermia (33.5°C) + 24 hours 50% inhaled xenon. Serial MRS was acquired before, during, and up to 48 hours after hypoxia-ischemia.

RESULTS

Mean arterial blood pressure was lower in all treatment groups compared with normothermia (p < 0.01) (although >40mmHg); the combined therapy group required more fluid boluses (p < 0.05) and inotropes (p < 0.001). Compared with no intervention, both hypothermia and xenon-augmented hypothermia reduced the temporal regression slope magnitudes for phosphorus-MRS inorganic phosphate/exchangeable phosphate pool (EPP) and phosphocreatine/EPP (both p < 0.05); for lactate/N-acetylaspartate (NAA), only xenon-augmented hypothermia reduced the slope (p < 0.01). Xenon-augmented hypothermia also reduced transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL)(+) nuclei and caspase 3 immunoreactive cells in parasagittal cortex and putamen and increased microglial ramification in midtemporal cortex compared with the no treatment group (p < 0.05). Compared with hypothermia, however, combination treatment did not reach statistical significance for any measure. Lactate/NAA showed a strong positive correlation with TUNEL; nucleotide triphosphate/EPP showed a strong negative correlation with microglial ramification (both p < 0.01).

INTERPRETATION

Compared with no treatment, xenon-augmented hypothermia reduced cerebral MRS abnormalities and cell death markers in some brain regions. Compared with hypothermia, xenon-augmented hypothermia did not reach statistical significance for any measure. The safety and possible improved efficacy support phase II trials.

Brain cell death is reduced with cooling by 3.5°C to 5°C but increased with cooling by 8.5°C in a piglet asphyxia model

BACKGROUND AND PURPOSE

In infants with moderate to severe neonatal encephalopathy, whole-body cooling at 33°C to 34°C for 72 hours is standard care with a number needed to treat to prevent a adverse outcome of 6 to 7. The precise brain temperature providing optimal neuroprotection is unknown.

METHODS

After a quantified global cerebral hypoxic-ischemic insult, 28 piglets aged <24 hours were randomized (each group, n=7) to (1) normothermia (38.5°C throughout) or whole-body cooling 2 to 26 hours after insult to (2) 35°C, (3) 33.5°C, or (4) 30°C. At 48 hours after hypoxia-ischemia, delayed cell death (terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling and cleaved caspase 3) and microglial ramification (ionized calcium-binding adapter molecule 1) were evaluated.

RESULTS

At 48 hours after hypoxia-ischemia, substantial cerebral injury was found in the normothermia and 30°C hypothermia groups. However, with 35°C and 33.5°C cooling, a clear reduction in delayed cell death and microglial activation was observed in most brain regions (P<0.05), with no differences between 35°C and 33.5°C cooling groups. A protective pattern was observed, with U-shaped temperature dependence in delayed cell death in periventricular white matter, caudate nucleus, putamen, hippocampus, and thalamus. A microglial activation pattern was also seen, with inverted U-shaped temperature dependence in periventricular white matter, caudate nucleus, internal capsule, and hippocampus (all P<0.05).

CONCLUSIONS

Cooling to 35°C (an absolute drop of 3.5°C as in therapeutic hypothermia protocols) or to 33.5°C provided protection in most brain regions after a cerebral hypoxic-ischemic insult in the newborn piglet. Although the relatively wide therapeutic range of a 3.5°C to 5°C drop in temperature reassured, overcooling (an 8.5°C drop) was clearly detrimental in some brain regions.

Planning and Evaluating Remote Consultation Services: A New Conceptual Framework Incorporating Complexity and Practical Ethics

Establishing and running remote consultation services is challenging politically (interest groups may gain or lose), organizationally (remote consulting requires implementation work and new roles and workflows), economically (costs and benefits are unevenly distributed across the system), technically (excellent care needs dependable links and high-quality audio and images), relationally (interpersonal interactions are altered), and clinically (patients are unique, some examinations require contact, and clinicians have deeply-held habits, dispositions and norms). Many of these challenges have an under-examined ethical dimension. In this paper, we present a novel framework, Planning and Evaluating Remote Consultation Services (PERCS), built from a literature review and ongoing research. PERCS has 7 domains-the reason for consulting, the patient, the clinical relationship, the home and family, technologies, staff, the healthcare organization, and the wider system-and considers how these domains interact and evolve over time as a complex system. It focuses attention on the organization's digital maturity and digital inclusion efforts. We have found that both during and beyond the pandemic, policymakers envisaged an efficient, safe and accessible remote consultation service delivered through state-of-the art digital technologies and implemented via rational allocation criteria and quality standards. In contrast, our empirical data reveal that strategic decisions about establishing remote consultation services, allocation decisions for appointment type (phone, video, e-, face-to-face), and clinical decisions when consulting remotely are fraught with contradictions and tensions-for example, between demand management and patient choice-leading to both large- and small-scale ethical dilemmas for managers, support staff, and clinicians. These dilemmas cannot be resolved by standard operating procedures or algorithms. Rather, they must be managed by attending to here-and-now practicalities and emergent narratives, drawing on guiding principles applied with contextual judgement. We complement the PERCS framework with a set of principles for informing its application in practice, including education of professionals and patients.

Brain mitochondrial oxidative metabolism during and after cerebral hypoxia-ischemia studied by simultaneous phosphorus magnetic-resonance and broadband near-infrared spectroscopy

BACKGROUND

Multimodal measurements combining broadband near-infrared spectroscopy (NIRS) and phosphorus magnetic resonance spectroscopy ((31)P MRS) assessed associations between changes in the oxidation state of cerebral mitochondrial cytochrome-c-oxidase (Δ[oxCCO]) and (31)P metabolite peak-area ratios during and after transient cerebral hypoxia-ischemia (HI) in the newborn piglet.

METHODS

Twenty-four piglets (aged<24 h) underwent transient HI (inspired oxygen fraction 9% and bilateral carotid artery occlusion for ~20 min). Whole-brain (31)P MRS and NIRS data were acquired every minute. Inorganic phosphate (Pi)/epp, phosphocreatine (PCr)/epp, and total nucleotide triphosphate (NTP)/epp were measured by (31)P MRS and were plotted against Δ[oxCCO] during HI and recovery (epp=exchangeable phosphate pool=Pi+PCr+2γ-NTP+β-NTP).

RESULTS

During HI Δ[oxCCO], PCr/epp and NTP/epp declined and Pi/epp increased. Significant correlations were seen between (31)P ratios and Δ[oxCCO]; during HI a threshold point was identified where the relationship between Δ[oxCCO] and both NTP/epp and Pi/epp changed significantly. Outcome at 48 h related to recovery of Δ[oxCCO] and (31)P ratios 1h post-HI (survived: 1-h NTP/epp 0.22 ± 0.02, Δ[oxCCO] -0.29 ± 0.50 μM; died: 1-h NTP/epp 0.10 ± 0.04, Δ[oxCCO] -2.41 ± 1.48 μM).

CONCLUSIONS

Both lowered Δ[oxCCO] and NTP/epp 1h post-HI indicated mitochondrial impairment. Animals dying before 48 h had slower recovery of both Δ[oxCCO] and (31)P ratios by 1 h after HI.

A highly virulent variant of HIV-1 circulating in the Netherlands

We discovered a highly virulent variant of subtype-B HIV-1 in the Netherlands. One hundred nine individuals with this variant had a 0.54 to 0.74 log₁₀ increase (i.e., a ~3.5-fold to 5.5-fold increase) in viral load compared with, and exhibited CD4 cell decline twice as fast as, 6604 individuals with other subtype-B strains. Without treatment, advanced HIV-CD4 cell counts below 350 cells per cubic millimeter, with long-term clinical consequences-is expected to be reached, on average, 9 months after diagnosis for individuals in their thirties with this variant. Age, sex, suspected mode of transmission, and place of birth for the aforementioned 109 individuals were typical for HIV-positive people in the Netherlands, which suggests that the increased virulence is attributable to the viral strain. Genetic sequence analysis suggests that this variant arose in the 1990s from de novo mutation, not recombination, with increased transmissibility and an unfamiliar molecular mechanism of virulence.

Systemic pro-inflammatory cytokine status following therapeutic hypothermia in a piglet hypoxia-ischemia model

Background

Inflammatory cytokines are implicated in the pathogenesis of perinatal hypoxia-ischemia (HI). The influence of hypothermia (HT) on cytokines after HI is unclear. Our aim was to assess in a piglet asphyxia model, under normothermic (NT) and HT conditions: (i) the evolution of serum cytokines over 48 h and (ii) cerebrospinal fluid (CSF) cytokine levels at 48 h; (iii) serum pro/anti-inflammatory cytokine profile over 48 h and (iv) relation between brain injury measured by magnetic resonance spectroscopy (MRS) and brain TUNEL positive cells with serum cytokines, serum pro/anti-inflammatory cytokines and CSF cytokines.

Methods

Newborn piglets were randomized to NT (n = 5) or HT (n = 6) lasting 2–26 h after HI. Serum samples were obtained 4–6 h before, during and at 6–12 h intervals after HI; CSF was obtained at 48 h. Concentrations of interleukin (IL)-1β, −4, −6, −8, −10 and TNF-α were measured and pro/anti-inflammatory status compared between groups. White matter and thalamic voxel lactate/N-acetyl aspartate (Lac/NAA) (a measure of both oxidative metabolism and neuronal loss) were acquired at baseline, after HI and at 24 and 36 h.

Results

Lac/NAA was reduced at 36 h with HT compared to NT (p = 0.013 basal ganglia and p = 0.033 white matter). HT showed lower serum TNF-α from baseline to 12 h (p < 0.05). Time-matched (acquired within 5 h of each other) serum cytokine and MRS showed correlations between Lac/NAA and serum IL-1β and IL-10 (all p < 0.01). The pro/anti-inflammatory ratios IL-1β/IL-10, IL-6/IL-10, IL-4/IL-10 and IL-8/IL-10 were similar in NT and HT groups until 36 h (24 h for IL-6/IL-10); after this, 36 h pro/anti-inflammatory cytokine ratios in the serum were higher in HT compared to NT (p < 0.05), indicating a pro-inflammatory cytokine surge after rewarming in the HT group. In the CSF at 48 h, IL-8 was lower in the HT group (p < 0.05). At 48 h, CSF TNF-α correlated with Lac/NAA (p = 0.02) and CSF IL-8 correlated with white matter TUNEL positive cell death (p = 0.04).

Conclusions

Following cerebral HI, there was a systemic pro-inflammatory surge after rewarming in the HT group, which is counterintuitive to the putative neuroprotective effects of HT. While serum cytokines were variable, elevations in CSF inflammatory cytokines at 48 h were associated with MRS Lac/NAA and white matter cell death.

Electronic supplementary material

The online version of this article (doi:10.1186/s12974-017-0821-x) contains supplementary material, which is available to authorized users.

Systemic effects of whole-body cooling to 35 °C, 33.5 °C, and 30 °C in a piglet model of perinatal asphyxia: implications for therapeutic hypothermia

INTRODUCTION

The precise temperature for optimal neuroprotection in infants with neonatal encephalopathy is unclear. Our aim was to assess systemic effects of whole-body cooling to 35 °C, 33.5 °C, and 30 °C in a piglet model of perinatal asphyxia.

METHODS

Twenty-eight anesthetized male piglets aged <24 h underwent hypoxia-ischemia (HI) and were randomized to normothermia or cooling to rectal temperature (Trec) 35 °C, 33.5 °C, or 30 °C during 2-26 h after insult (n = 7 in each group). HR, MABP, and Trec were recorded continuously.

RESULTS

Five animals cooled to 30 °C had fatal cardiac arrests. During 30 °C cooling, heart rate (HR) was lower vs. normothermia (P < 0.001). Although mean arterial blood pressure (MABP) did not vary between groups, more fluid boluses were needed at 30 °C than at normothermia (P < 0.02); dopamine use was higher at 30 °C than at normothermia or 35 °C (P = 0.005 and P = 0.02, respectively). Base deficit was increased at 30 °C at 12, 24, and 36 h vs. all other groups (P < 0.05), pH was acidotic at 36 h vs. normothermia (P = 0.04), and blood glucose was higher for the 30 °C group at 12 h vs. the normothermia and 35 °C groups (P < 0.05). Potassium was lower at 12 h in the 30 °C group vs. the 33.5 °C and 35 °C groups. There was no difference in cortisol level between groups.

DISCUSSION

Cooling to 30 °C led to metabolic derangement and more cardiac arrests and deaths than cooling to 33.5 °C or 35 °C. Inadvertent overcooling should be avoided.

Hypoplasia of the left ventricle: rare cause of postoperative mortality in tetralogy of Fallot

Severe left ventricular hypoplasia in tetralogy of Fallot is a rare complication. A case history of a 3 year old child who died after attempted repair of tetralogy is presented. Left ventricular end-diastolic volume was 26 ml/m2 (only 45 percent of predicted normal) after repair with normal filling pressure and no evidence of tamponade. Clinical examination, chest X-ray film, electrocardiogram and qualitative assessment of a preoperative left ventriculogram were not useful in assessing this degree of left ventricular hypoplasia; quantitative determination of left ventricular volumes is required for this purpose. When left ventricular end-diastolic volume is less than 55 percent of predicted normal, a shunt procedure may be indicated as an initial procedure with subsequent repair 1 to 2 years later, after left ventricular enlargement.

The extent of intrauterine growth restriction determines the severity of cerebral injury and neurobehavioural deficits in rodents

Background

Cerebral Palsy (CP) is the most common physical pediatric neurodevelopmental disorder and spastic diplegic injury is its most frequent subtype. CP results in substantial neuromotor and cognitive impairments that have significant socioeconomic impact. Despite this, its underlying pathophysiological mechanisms and etiology remain incompletely understood. Furthermore, there is a need for clinically relevant injury models, which a) reflect the heterogeneity of the condition and b) can be used to evaluate new translational therapies. To address these key knowledge gaps, we characterized a chronic placental insufficiency (PI) model, using bilateral uterine artery ligation (BUAL) of dams. This injury model results in intrauterine growth restriction (IUGR) in pups, and animals recapitulate the human phenotype both in terms of neurobehavioural and anatomical deficits.

Methods

Effects of BUAL were studied using luxol fast blue (LFB)/hematoxylin & eosin (H&E) staining, immunohistochemistry, quantitative Magnetic Resonance Imaging (MRI), and Catwalk neurobehavioural tests.

Results

Neuroanatomical analysis revealed regional ventricular enlargement and corpus callosum thinning in IUGR animals, which was correlated with the extent of growth restriction. Olig2 staining revealed reductions in oligodendrocyte density in white and grey matter structures, including the corpus callosum, optic chiasm, and nucleus accumbens. The caudate nucleus, along with other brain structures such as the optic chiasm, internal capsule, septofimbrial and lateral septal nuclei, exhibited reduced size in animals with IUGR. The size of the pretectal nucleus was reduced only in moderately injured animals. MAG/NF200 staining demonstrated reduced myelination and axonal counts in the corpus callosum of IUGR animals. NeuN staining revealed changes in neuronal density in the hippocampus and in the thickness of hippocampal CA2 and CA3 regions. Diffusion weighted imaging (DWI) revealed regional white and grey matter changes at 3 weeks of age. Furthermore, neurobehavioural testing demonstrated neuromotor impairments in animals with IUGR in paw intensities, swing speed, relative print positions, and phase dispersions.

Conclusions

We have characterized a rodent model of IUGR and have demonstrated that the neuroanatomical and neurobehavioural deficits mirror the severity of the IUGR injury. This model has the potential to be applied to examine the pathobiology of and potential therapeutic strategies for IUGR-related brain injury. Thus, this work has potential translational relevance for the study of CP.

Serum neuronal growth factor levels in von Recklinghausen's neurofibromatosis

A single neuronal cell biological assay was used to quantitate neuronal growth factors in 87 serum samples from 69 patients in 48 families with von Recklinghausen's neurofibromatosis, plus 16 samples from 16 comparison subjects. Mouse nerve growth factor was used as a standard for the bioassay, and results of serum assays were expressed as nerve growth factor equivalents. Antiserum to mouse nerve growth factor inhibited fractionally serum-induced neurite outgrowth, while kinetics of neurite outgrowth and maximal cellular response to serum differed from those induced by mouse nerve growth factor. The mean values (+/- SD) of neuronal growth factors for the patients were 20.5 +/- 15.7 pg/mg serum protein, while mean values for the comparison group as a whole were 22.3 +/- 15.6 pg/mg serum protein. Sex, race/ethnicity, patient age, and date of sample collection did not significantly influence serum levels among patients or comparison subjects. Three to six serial samples taken from women before pregnancy, during the course of pregnancy, during delivery, and in the postpartum period did not show significant differences from one period to another. These data suggest that human serum does contain non-nerve-growth-factor neuronal growth factors, but that levels of the factors do not contribute to the identification of patients with von Recklinghausen's neurofibromatosis.

Achieving Spread, Scale Up and Sustainability of Video Consulting Services During the COVID-19 Pandemic? Findings From a Comparative Case Study of Policy Implementation in England, Wales, Scotland and Northern Ireland

Requirements for physical distancing as a result of COVID-19 and the need to reduce the risk of infection prompted policy supporting rapid roll out of video consulting across the four nations of the UK-England, Northern Ireland, Scotland and Wales. Drawing on three studies of the accelerated implementation and uptake of video consulting across the four nations, we present a comparative and interpretive policy analysis of the spread and scale-up of video consulting during the pandemic. Data include interviews with 59 national level stakeholders, 55 health and social care staff and 30 patients, 20 national documents, responses to a UK-wide survey of NHS staff and analysis of routine activity data. Sampling ensured variations in geography, clinical context and adoption progress across the combined dataset. Comparative analysis was guided by theory on policy implementation and crisis management. The pandemic provided a "burning platform" prompting UK-wide policy supporting the use of video consulting in health care as a critical means of managing the risk of infection and a standard mode of provision. This policy push facilitated interest in video consulting across the UK. There was, however, marked variation in how this was put into practice across the four nations. Pre-existing infrastructure, policies and incentives for video consulting in Scotland, combined with a collaborative system-level approach, a program dedicated to developing video-based services and resourcing and supporting staff to deliver them enabled widespread buy-in and rapid spread. In England, Wales and Northern Ireland, pre-existing support for digital health (e.g., hardware, incentives) and virtual care, combined with reduced regulation and "light touch" procurement managed to override some (but by no means all) cultural barriers and professional resistance to implementing digital change. In Northern Ireland and Wales, limited infrastructure muted spread. In all three countries, significant effort at system level to develop, review and run video consulting programs enabled a substantial number of providers to change their practice, albeit variably across settings. Across all four nations ongoing uncertainty, potential restructuring and tightening of regulations, along with difficulties inherent in addressing inequalities in digital access, raise questions about the longer-term sustainability of changes to-date.

Pharmacokinetics of transdermal testosterone gel in hypogonadal men: application of gel at one site versus four sites: a General Clinical Research Center Study

Testosterone (T) in a hydroalcoholic gel has been developed as an effective and convenient open system for transdermal delivery of the hormone to men. Because the gel can be applied either to small or large areas of skin, it was important to assess whether the skin surface area on which the gel was applied was an important determinant of serum T levels. To answer this question, the pharmacokinetics of a transdermal 1% hydroalcoholic gel preparation of T was studied in nine hypogonadal men. The subjects applied in random order a 25-mg metered dose of T gel either four times at one site (left arm/shoulder) or at four different sites (left and right arms/shoulders and left and right abdomen) once daily (6-8 min) for 7 consecutive days. After 7 days of washout, each subject was then crossed over to the opposite regimen for another 7 days of treatment. Serum samples were collected for measurements of T, 5alpha dihydrotestosterone (DHT), and estradiol before, during (days 1, 2, 3, 5, and 7), and after (days 8, 9, 11, 13, and 15) application of T gel. Multiple blood samples were drawn on the 1st and 7th day after gel application; single samples were obtained just before the next T gel application on other days (24 h after the previous gel application). The T gel dried in less than 5 min, left no residue, and produced no skin irritation in any of the subjects. Mean serum T levels, irrespective of application at one site or four sites followed the same pattern: rising to 2- to 3- and 4- to 5-fold above baseline at 0.5 and 24 h after first application, respectively. Thereafter, serum T levels reached steady state and remained at 4- to 5-fold above baseline (at the upper limit of the normal adult range) for the duration of gel application and returned to baseline within 4 days after stopping application. The application of T gel at four sites (application skin area approximately four times that of one site) resulted in a mean area under the curve (AUC0-24h) for serum T levels on the 7th day (868 +/- 72 nmol*h/L, mean +/- SEM), which was 23% higher but not significantly different (P = 0.06) than repeated application at one site (706 +/- 59 nmol*h/L). This could be due to the limited number of subjects studied (n = 9). Mean serum DHT levels followed the same pattern as serum T, achieving steady-state levels by 2 days. The mean concentration of serum DHT on the 7th day was significantly higher after application at four sites (9.15 +/- 1.26 nmol/L, P < 0.05) than at one site (6.9 +/- 0.77 nmol/L). These serum DHT levels were at or above the normal adult male range. Serum DHT:T ratio was not significantly altered by T gel application. Serum estradiol levels followed the same pattern as serum T and showed no significant difference between the one- or four-site application. We conclude that transdermal daily application of 100 mg T gel resulted in similar steady levels of serum T. The surface area of the skin to which the gel was applied had only a modest impact on serum T and DHT levels. Mean serum levels of T and DHT was higher by 23% and 33%, respectively, despite application of the gel to four times the skin area in the four sites compared with the one site group. Because of the greater dosage flexibility provided, hydroalcoholic T gel application over multiple sites seems to be an effective and nonskin-irritating method of transdermal T delivery for hypogonadal men. Dose-ranging studies are required to determine dosage regimens for T gel application as a replacement therapy in hypogonadal men.

Patient safety in remote primary care encounters: multimethod qualitative study combining Safety I and Safety II analysis

BACKGROUND

Triage and clinical consultations increasingly occur remotely. We aimed to learn why safety incidents occur in remote encounters and how to prevent them.

SETTING AND SAMPLE

UK primary care. 95 safety incidents (complaints, settled indemnity claims and reports) involving remote interactions. Separately, 12 general practices followed 2021-2023.

METHODS

Multimethod qualitative study. We explored causes of real safety incidents retrospectively ('Safety I' analysis). In a prospective longitudinal study, we used interviews and ethnographic observation to produce individual, organisational and system-level explanations for why safety and near-miss incidents (rarely) occurred and why they did not occur more often ('Safety II' analysis). Data were analysed thematically. An interpretive synthesis of why safety incidents occur, and why they do not occur more often, was refined following member checking with safety experts and lived experience experts.

RESULTS

Safety incidents were characterised by inappropriate modality, poor rapport building, inadequate information gathering, limited clinical assessment, inappropriate pathway (eg, wrong algorithm) and inadequate attention to social circumstances. These resulted in missed, inaccurate or delayed diagnoses, underestimation of severity or urgency, delayed referral, incorrect or delayed treatment, poor safety netting and inadequate follow-up. Patients with complex pre-existing conditions, cardiac or abdominal emergencies, vague or generalised symptoms, safeguarding issues, failure to respond to previous treatment or difficulty communicating seemed especially vulnerable. General practices were facing resource constraints, understaffing and high demand. Triage and care pathways were complex, hard to navigate and involved multiple staff. In this context, patient safety often depended on individual staff taking initiative, speaking up or personalising solutions.

CONCLUSION

While safety incidents are extremely rare in remote primary care, deaths and serious harms have resulted. We offer suggestions for patient, staff and system-level mitigations.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Using Patient Perspectives to Inform Better Clinical Trial Design and Conduct: Current Trends and Future Directions

The approach to patient engagement (PE) in drug development has changed rapidly due to many factors, including the complexity of innovative drugs and the need to demonstrate outcomes of relevance to patients, the desire to show 'value add' of PE, and the pandemic-related changes to how clinical trials are run, e.g., decentralised studies. In parallel, there have been changes in technology-assisted ways of running clinical trials, capturing patient health outcomes and preferences, an increasing societal demand for diversity and inclusion, and efforts to improve clinical trial efficiency, transparency, and accountability. Organisations are beginning to monitor PE activities and outcomes more effectively to learn and inform future PE strategies. As a result, these factors are facilitating the incorporation of patients' lived experience, preferences and needs into the design and running of clinical trials more than ever before. In this paper, the authors reflect upon these last few years, the emerging trends and their drivers, and where we may expect PE in clinical research to progress in the near future.

The potential for stem cell therapies to have an impact on cerebral palsy: opportunities and limitations

Cerebral palsy (CP) is a chronic childhood disorder described by a group of motor and cognitive impairments and results in a substantial socio-economic burden to the individual, family, and healthcare system. With no effective biological interventions, therapies for CP are currently restricted to supportive and management strategies. Cellular transplantation has been suggested as a putative intervention for neural pathology, as mesenchymal and neural stem cells, as well as olfactory ensheathing glia and Schwann cells, have shown some regenerative and functional efficacy in experimental central nervous system disorders. This review describes the most common cell types investigated and delineates their purported mechanisms in vivo. Furthermore, it provides a cogent summary of both current early-phase clinical trials using neural precursor cells (NPCs) and the state of stem cell therapies for neurodegenerative conditions. Although NPCs are perhaps the most promising candidates for cell replacement therapy in the context of CP, much still remains to be understood regarding safety, efficacy, timing, dose, and route of transplantation, as well as the capacity for combinatorial strategies.

Precipitation SELEX: identification of DNA aptamers for calcium phosphate materials synthesis

DNA aptamers that enhance calcium phosphate mineral formation were identified using a novel precipitation SELEX method. The evolved DNA library was substantially enriched in G nucleotides and in predicted G-quadruplex structures, suggesting their importance in the mechanism of mineralization. This work could readily be extended to provide additional novel DNA aptamers for materials synthesis.

Protocol: Remote care as the 'new normal'? Multi-site case study in UK general practice

Background

Following a pandemic-driven shift to remote service provision, UK general practices offer telephone, video or online consultation options alongside face-to-face. This study explores practices' varied experiences over time as they seek to establish remote forms of accessing and delivering care.

Methods

This protocol is for a mixed-methods multi-site case study with co-design and national stakeholder engagement. 11 general practices were selected for diversity in geographical location, size, demographics, ethos, and digital maturity. Each practice has a researcher-in-residence whose role is to become familiar with its context and activity, follow it longitudinally for two years using interviews, public-domain documents and ethnography, and support improvement efforts. Research team members meet regularly to compare and contrast across cases. Practice staff are invited to join online learning events. Patient representatives work locally within their practice patient involvement groups as well as joining an online patient learning set or linking via a non-digital buddy system. NHS Research Ethics Approval has been granted. Governance includes a diverse independent advisory group with lay chair. We also have policy in-reach (national stakeholders sit on our advisory group) and outreach (research team members sit on national policy working groups).

Results anticipated

We expect to produce rich narratives of contingent change over time, addressing cross-cutting themes including access, triage and capacity; digital and wider inequities; quality and safety of care (e.g. continuity, long-term condition management, timely diagnosis, complex needs); workforce and staff wellbeing (including non-clinical staff, students and trainees); technologies and digital infrastructure; patient perspectives; and sustainability (e.g. carbon footprint).

Conclusion

By using case study methods focusing on depth and detail, we hope to explain why digital solutions that work well in one practice do not work at all in another. We plan to inform policy and service development through inter-sectoral network-building, stakeholder workshops and topic-focused policy briefings.

Idiopathic subglottic stenosis

A 2 1/2-year-old child was found to have subglottic stenosis with no obvious etiology. He initially responded well to dilatation, injection of triamcinolone and intermittent stenting of the airway, but four months later developed a marked, unyielding subglottic stenosis requiring tracheostomy. He had a gradual good response to dilatations and injections with triamcinolone and acquired a good subglottic lumen. However, he developed a recurrence following an episode of croup. Systemic steroids were added to the regimen leading to gradual resolution of the stenosis and successful decannulation. The embryogenesis of subglottic stenosis and the correlation with the known anatomy and histology are discussed. Subglottic stenosis may be congenital, traumatic, inflammatory, neoplastic or neurogenic. An additional group of patients has no obvious etiology and are classified as idiopathic. Treatment consists of various combinations of stents, systemic and intralesional steroids, dilatations and various operative procedures in the more refractory cases.

Understanding multi-stakeholder needs, preferences and expectations to define effective practices and processes of patient engagement in medicine development: A mixed-methods study

Background

The holistic evolution of patient engagement in medicines development requires a more detailed understanding of the needs of all involved stakeholders, and one that better accounts for the specific needs of some potentially vulnerable patient populations and key stages in medicines development.

Objective

The purpose of this convergent mixed‐methods study was to better understand the needs of different stakeholders concerning patient engagement at three key stages in medicines development: research priority setting, clinical trial design and early dialogues with Health Technology Assessment bodies and regulators.

Design

This study brought together findings from three sources: i) an online questionnaire, ii) face‐to‐face consultations with two potentially vulnerable patient populations, a workshop with Health Technology Assessment bodies, and iii) three‐step modified Delphi methodology.

Results

Overall stakeholders still need additional varied support mechanisms to undertake, sustain or measure value of patient engagement. Health Technology Assessment bodies need better rationale for patient engagement in early dialogue and tools to support its implementation. Improved awareness and understanding of the need and value that involving patients, who are often considered as potentially vulnerable, can bring is needed, as is better accommodation of their specific needs. Similarly, weighted Delphi categories were as follows: aims and objectives, and sustainability. Several additional themes were common across the three key stages in medicines development.

Conclusion

This broad‐reaching study provides the blocks needed to build a framework for patient engagement in medicines development.

Patient or Public Contribution

Patients were involved in review and interpretation of data.