Non-ubiquitous expression of core spliceosomal protein SmB/B' in chick and mouse embryos.

BACKGROUND: Although splicing is an integral part of the expression of many genes in our body, genetic syndromes with spliceosomal defects affect only specific tissues. To help understand the mechanism, we investigated the expression pattern of a core protein of the major spliceosome, SmB/B' (Small Nuclear Ribonucleoprotein Polypeptides B/B'), which is encoded by SNRPB. Loss-of-function mutations of SNRPB in humans cause cerebro-costo-mandibular syndrome (CCMS) characterized by rib gaps, micrognathia, cleft palate, and scoliosis. Our expression analysis focused on the affected structures as well as non-affected tissues, using chick and mouse embryos as model animals. RESULTS: Embryos at young stages (gastrula) showed ubiquitous expression of SmB/B'. However, the level and pattern of expression became tissue-specific as differentiation proceeded. The regions relating to CCMS phenotypes such as cartilages of ribs and vertebrae and palatal mesenchyme express SmB/B' in the nucleus sporadically. However, cartilages that are not affected in CCMS also showed similar expressions. Another spliceosomal gene, SNRNP200, which mutations cause retinitis pigmentosa, was also prominently expressed in cartilages in addition to the retina. CONCLUSION: The expression of SmB/B' is spatiotemporally regulated during embryogenesis despite the ubiquitous requirement of the spliceosome, however, the expression pattern is not strictly correlated with the phenotype presentation.

Apoptotic priming is defined by the dynamic exchange of Bcl-2 proteins between mitochondria and cytosol.

Apoptosis is regulated by interactions between the BH3-only and multi-domain Bcl-2 family proteins. These interactions are integrated on the outer mitochondrial membrane (OMM) where they set the threshold for apoptosis, known as mitochondrial priming. However, how mitochondrial priming is controlled at the level of single cells remains unclear. Retrotranslocation of Bcl-XL has been proposed as one mechanism, removing pro-apoptotic Bcl-2 proteins from the OMM, thus reducing priming. Contrary to this view, we now show that Bcl-XL retrotranslocation is inhibited by binding to its BH3-only partners, resulting in accumulation of these protein complexes on mitochondria. We find that Bcl-XL retrotranslocation dynamics are tightly coupled to mitochondrial priming. Quantifying these dynamics indicates the heterogeneity in priming between cells within a population and predicts how they subsequently respond to a pro-apoptotic signal.

Factors affecting decision-making in children with complex care needs: a consensus approach to develop best practice in a UK children's hospital.

BACKGROUND: Children with complex care needs are a growing proportion of the sick children seen in all healthcare settings in the UK. Complex care needs place demands on parents and professionals who often require many different healthcare teams to work together. Care can be both materially and logistically difficult to manage, causing friction with parents. These difficulties may be reduced if common best practice standards and approaches can be developed in this area. OBJECTIVE: To develop a consensus approach to the management of complexity among healthcare professionals, we used a modified Delphi process. The process consisted of a meeting of clinical leaders to develop candidate statements, followed by two survey rounds open to all professionals in a UK children's hospital to measure and establish consensus recommendations. RESULTS: Ninety-nine professionals completed both rounds of the survey, 69 statements were agreed. These pertained to seven thematic areas: standardised approaches to communicating with families; processes for interprofessional communication; processes for shared decision-making in the child's best interests; role of the multidisciplinary team; managing professional-parental disagreement and conflict; the role of clinical psychologists; and staff support. Overall, the level of consensus was high, ranging from agreement to strong agreement. CONCLUSIONS: These statements provide a consensus basis that can inform standardised approaches to the management of complexity. Such approaches may decrease friction between parents, children and healthcare professionals.

Oral morphine versus transmucosal diamorphine for breakthrough pain in children: methods and outcomes: UK (DIPPER study) consensus.

OBJECTIVES: No randomised controlled trials have been conducted for breakthrough pain in paediatric palliative care and there are currently no standardised outcome measures. The DIPPER study aims to establish the feasibility of conducting a prospective randomised controlled trial comparing oral and transmucosal administration of opioids for breakthrough pain. The aim of the current study was to achieve consensus on design aspects for a small-scale prospective study to inform a future randomised controlled trial of oral morphine, the current first-line treatment, versus transmucosal diamorphine. METHODS: The nominal group technique was used to achieve consensus on best practice for mode of administration, dose regimen and a range of suitable pain intensity outcome measures for transmucosal diamorphine in children and young people with breakthrough pain. An expert panel of ten clinicians in paediatric palliative care and three parent representatives participated. Consensus was achieved when agreement was reached and no further comments from participants were forthcoming. RESULTS: The panel favoured the buccal route of administration, with dosing according to the recommendations in the Association for Paediatric Palliative Medicine formulary (fifth Edition, 2020). The verbal Numerical Rating Scale was selected to measure pain in children 8 years old and older, the Faces Pain Scale-Revised for children between 4 and 8 years old, and Face, Legs, Activity, Cry and Consolability (FLACC)/FLACC-Revised as the observational tools. CONCLUSIONS: The nominal group technique allowed consensus to be reached for a small-scale, prospective, cohort study and provided information to inform the design of a randomised controlled trial.

XMU-MP-1 induces growth arrest in a model human mini-organ and antagonises cell cycle-dependent paclitaxel cytotoxicity.

BACKGROUND: XMU-MP-1 is an inhibitor of the Hippo pathway kinases MST1/2 and has been shown to promote the downstream activation of the pro-proliferative, pro-regenerative and anti-apoptotic transcriptional regulator YAP1. We tested whether XMU-MP-1 can activate YAP1 in a model human mini-organ, namely the hair follicle, to determine whether it can be pharmacologically exploited to promote regeneration in the hair follicle as a novel strategy to treat pathological hair loss disorders. RESULTS: XMU-MP-1 treatment inhibited MOB1 phosphorylation but did not increase active YAP1 in the hair follicle. Rather than promote proliferation, XMU-MP-1 serendipitously decreased the number of Ki-67+, EdU+ and phospho histone H3+ hair matrix keratinocytes and antagonised the cytotoxic effects of paclitaxel. CONCLUSIONS: XMU-MP-1 perturbs epithelial cell cycle progression in a model human mini-organ. This may arise as an off-target effect, especially when XMU-MP-1 has been described to strongly inhibit 21 additional kinases beyond MST1/2. Therefore, whilst these effects may be dependent on tissue context, researchers should exercise caution when interpreting the effects of XMU-MP-1, especially in tissues with actively proliferating cell populations.

Seizure management in children requiring palliative care: a review of current practice.

OBJECTIVES: Controlling seizures in children approaching death can be difficult, and there is a limited evidence base to guide best practice. We compared current practice against the guidance for seizure management produced by the Association of Paediatric Palliative Medicine (APPM). METHODS: Retrospective case note review of episodes of challenging seizure management in children receiving end-of-life care over a 10-year period (2006-2015) in the south-west region of England. RESULTS: We reviewed 19 admissions, in 18 individuals. Six (33%) had a malignancy, nine (50%) had a progressive neurodegenerative condition and three (17%) had a static neurological condition with associated epilepsy. Thirteen (72%) died in their local hospice, four (22%) at home, and one (6%) in hospital. Seventeen of 19 episodes involved the use of subcutaneous or intravenous midazolam infusion, for a mean of 11 days (range 3-27). There was a wide range of starting doses of midazolam, and 9/17 (53%) received final doses in excess of current dose recommendations. Six individuals received subcutaneous phenobarbital infusions, with four of these (67%) receiving final doses in excess of current dose recommendations. Plans for adjustments of infusion rates, maximal doses or alternative approaches should treatment fail were inconsistent or absent. In 16/18 (88%) cases seizures were successfully controlled prior to the day of the child's death. Staff found the experience of managing seizures at end of life challenging and stressful. CONCLUSIONS: Pharmacological approaches to seizure management in end-of-life care are variable, often exceeding APPM dose recommendations. Despite this, safe and effective seizure control was possible in all settings.

CDK4/6 inhibition mitigates stem cell damage in a novel model for taxane-induced alopecia.

Taxanes are a leading cause of severe and often permanent chemotherapy-induced alopecia. As the underlying pathobiology of taxane chemotherapy-induced alopecia remains poorly understood, we investigated how paclitaxel and docetaxel damage human scalp hair follicles in a clinically relevant ex vivo organ culture model. Paclitaxel and docetaxel induced massive mitotic defects and apoptosis in transit amplifying hair matrix keratinocytes and within epithelial stem/progenitor cell-rich outer root sheath compartments, including within Keratin 15+ cell populations, thus implicating direct damage to stem/progenitor cells as an explanation for the severity and permanence of taxane chemotherapy-induced alopecia. Moreover, by administering the CDK4/6 inhibitor palbociclib, we show that transit amplifying and stem/progenitor cells can be protected from paclitaxel cytotoxicity through G1 arrest, without premature catagen induction and additional hair follicle damage. Thus, the current study elucidates the pathobiology of taxane chemotherapy-induced alopecia, highlights the paramount importance of epithelial stem/progenitor cell-protective therapy in taxane-based oncotherapy, and provides preclinical proof-of-principle in a healthy human (mini-) organ that G1 arrest therapy can limit taxane-induced tissue damage.

Paediatric palliative care: not so different from adult palliative care?

This article compares and contrasts paediatric and adult palliative care, two specialties which are commonly rooted in the need to provide high-quality holistic care for life-limited patients. It explores how professionals can work together to meet the needs of young people transitioning from paediatric to adult health-care systems.