Search

Objectives: To explore whether training on the SICG-Peds© (Serious Illness Guide for Pediatrics) impacts a pediatric clinician's confidence and knowledge in participating and initiating/leading difficult conversations with families of children living with a serious illness., Methods: Over 2 years, clinicians from BC and Ontario who care for children with serious illnesses attended training workshops on the SICG-Peds©. These workshops were evaluated using pre- and post-workshop questionnaires. Participants reported confidence scores on a scale of 1 to 10., Results: In total, 134 and 140 clinicians attended the workshops in BC and Ontario, respectively. The majority of clinicians who completed the immediate post-workshop survey ( N  = 223, 94.5%), responded that the content enhanced their knowledge about pediatric serious illness conversations (SIC). Confidence scores in initiating/leading a SIC significantly increased from median 5 (interquartile range [IQR] 3-7) pre-workshop to 7 (IQR 7-9) immediately post-workshop ( P  < .0001). Confidence scores in participating as a non-leader in a SIC also significantly increased from median 7 (IQR 6-9) pre-workshop to median 8 (IQR 7-9) immediately post-workshop ( P  < .0001)., Conclusions: Overall, these workshops significantly improved participants' confidence. Effectiveness and knowledge enhancement were other areas where the majority of participants reported positive improvements. Areas for continued support were identified as more mentoring, and training for supporting the guide's use in a clinical setting., Competing Interests: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2024.)

Spatio-temporal definition of Ca 2+ signals involves the assembly of signaling complexes within the nano-architecture of contact sites between the sarco/endoplasmic reticulum (SR/ER) and the plasma membrane (PM). While the requirement of precise spatial assembly and positioning of the junctional signaling elements is well documented, the role of the nano-scale membrane architecture itself, as an ion-reflecting confinement of the signalling unit, remains as yet elusive. Utilizing the Na + /Ca 2+ Exchanger-1 / SR/ER Ca 2+ ATPase-2-mediated ER Ca 2+ refilling process as a junctional signalling paradigm, we provide here the first evidence for an indispensable cellular function of the junctional membrane architecture. Our stochastic modeling approach demonstrates that junctional ER Ca 2+ refilling operates exclusively at nano-scale membrane spacing, with a strong inverse relationship between junctional width and signaling efficiency. Our model predicts a breakdown of junctional Ca 2+ signaling with loss of reflecting membrane confinement. In addition we consider interactions between Ca 2+ and the phospholipid membrane surface, which may support interfacial Ca 2+ transport and promote receptor targeting. Alterations in the molecular and nano-scale membrane organization at organelle-PM contacts are suggested as a new concept in pathophysiology., Competing Interests: Declaration of Competing Interest We declare no conflict of interest., (Copyright © 2023. Published by Elsevier Ltd.)

To assess current practice and provide a basis for a provincial template, clinicians at a Canadian pediatric hospice reviewed the literature surrounding pediatric advance care planning (pACP) documentation, process, and implementation for children/youth. The scoping review protocol was developed in accordance with the Joanna Briggs Institute methodology for scoping reviews, and was prospectively registered on the Open Science Framework. MEDLINE, Embase, CINAHL, the Web of Science Core Collection, and Google Scholar, as well as sources of unpublished studies and grey literature, were reviewed. Sixty-four articles met the criteria. Fifteen pACP documentation forms/tools were also identified. Overall, the included articles highlighted that pACP should be a structured, collaborative and iterative process between the family and a trusted or relevant healthcare provider, encompassing medical and non-medical issues. Few articles provided insights into specific elements recommended for advance directive forms. Identified strategies for implementation included a structured, step-by-step pACP interventional tool along with ongoing training, mentorship, and defined organizational structures for the clinician. No single specific ACP tool was acknowledged as the gold standard. Use of a pACP tool, along with ongoing provider education and communication skill development, standardized/accessible documentation, and system-wide quality improvement support, were noted as integral components of pACP.

Objectives: To explore experiences of pediatric clinicians participating in a serious illness communication program (SICP) for advance care planning (ACP), examining how the SICP supports clinicians to improve their communication and the challenges of implementing new communication tools into clinical practice., Methods: A qualitative description study using individual interviews with a diverse group of pediatric clinicians who participated in 2.5-hour SICP training workshops at pediatric tertiary hospitals. Discussions were transcribed, coded, and arranged into overarching themes. Thematic analysis was conducted using interpretive description methodology., Results: Fourteen clinicians from 2 Canadian pediatric tertiary hospital settings were interviewed, including nurses (36%), physicians (36%), and social workers (29%), from the fields of neonatology (36%), palliative care (29%), oncology (21%), and other pediatric specialties (14%). Key themes included specific benefits of SICP, with subthemes of connecting with families, increased confidence in ACP discussions, providing tools to improve communication, and enhanced self-awareness and self-reflection. A second theme of perceived challenges emerged, which included subthemes of not having the conversation guide readily accessible, divergent team communication practices, and particular features of the clinical environment which limited the possibility of engaging in ACP discussions with parents., Significance of Results: A structured program to enhance serious illness communication supports clinicians to develop skills and tools to increase their confidence and comfort in conducting conversations about end-of-life issues. Addressing challenges of adopting the newly learned communication practices, by providing access to digital SICP tools and conducting SICP training for clinical teams may further support clinicians to engage in ACP.

Marfan syndrome (MFS) is a connective tissue disorder that results in aortic root widening and aneurysm if unmanaged. We have previously reported doxycycline, a nonselective matrix metalloproteinases (MMPs) inhibitor, to attenuate aortic root widening and improve aortic contractility and elasticity in MFS mice. We were also first to use multiphoton microscopy, a non-invasive and label-free imaging technique, to quantify and link the aortic ultrastructure to possible changes in the skin dermis. Here, we aimed to assess the effects of long-term doxycycline treatment on the aortic ultrastructure and skin dermis of MFS mice through immunohistochemical evaluation and quantification of elastic and collagen content and morphology using multiphoton microscopy. Our results demonstrate a rescue of aortic elastic fiber fragmentation and disorganization accompanied by a decrease in MMP-2 and MMP-9 expression within the aortic wall in doxycycline-treated MFS mice. At 12 months of age, reduced skin dermal thickness was observed in both MFS and control mice, but only dermal thinning in MFS mice was rescued by doxycycline treatment. MMP-2 and MMP-9 expression was reduced in the skin of doxycycline-treated MFS mice. A decrease in dermal thickness was found to be positively associated with increased aortic root elastin disorganization and wall thickness. Our findings confirm the beneficial effects of doxycycline on ultrastructural properties of aortic root as well as on skin elasticity and structural integrity in MFS mice.

Agonist-induced oscillations in calcium concentrations of cultured endothelial cell monolayers were studied to determine the mechanisms involved in calcium oscillation. The results showed that thapsigargin, which inhibits bradykinin-induced calcium release, did not inhibit agonist-induced oscillations of calcium. Conversely, removal of extracellular calcium or blockage of the calcium channels immediately abolished oscillations. These results indicate that calcium concentration fluctuations are regulated by calcium entry across the plasma membrane.

There are no therapeutics that directly enhance chronic endothelial nitric oxide (NO) release, which is typically associated with vascular homeostasis. In contrast, angiotensin II (AngII) receptor type 1 (AT1R) blockers (ARBs) can attenuate AngII-mediated oxidative stress, which often leads to increased endothelial NO bioavailability. Herein, we investigate the potential presence of direct, AngII/AT1R-independent ARB class effects on endothelial NO release and how this may result in enhanced aortic wall homeostasis and endothelial NO-specific transcriptome changes. Treatment of mice with four different ARBs induced sustained, long-term inhibition of vascular contractility by up to 82% at 16 weeks and 63% at 2 weeks, an effect reversed by L-NAME and absent in endothelial NO synthase (eNOS) KO mice or angiotensin converting enzyme inhibitor captopril-treated animals. In absence of AngII or in tissues with blunted AT1R expression or incubated with an AT2R blocker, telmisartan reduced vascular tone, supporting AngII/AT1R-independent pleiotropism. Finally, telmisartan was able to inhibit aging- and Marfan syndrome (MFS)-associated aortic root widening in NO-sensitive, BP-independent fashions, and correct aberrant TGF-β signaling. RNAseq analyses of aortic tissues identified early eNOS-specific transcriptome reprogramming of the aortic wall in response to telmisartan. This study suggests that ARBs are capable of major class effects on vasodilatory NO release in fashions that may not involve blockade of the AngII/AT1R pathway. Broader prophylactic use of ARBs along with identification of non-AngII/AT1R pathways activated by telmisartan should be investigated., (© 2022. The Author(s).)

Nano-junctions between the endoplasmic reticulum and cytoplasmic surfaces of the plasma membrane and other organelles shape the spatiotemporal features of biological Ca 2+ signals. Herein, we propose that 2D Ca 2+ exchange diffusion on the negatively charged phospholipid surface lining nano-junctions participates in guiding Ca 2+ from its source (channel or carrier) to its target (transport protein or enzyme). Evidence provided by in vitro Ca 2+ flux experiments using an artificial phospholipid membrane is presented in support of the above proposed concept, and results from stochastic simulations of Ca 2+ trajectories within nano-junctions are discussed in order to substantiate its possible requirements. Finally, we analyze recent literature on Ca 2+ lipid interactions, which suggests that 2D interfacial Ca 2+ diffusion may represent an important mechanism of signal transduction in biological systems characterized by high phospholipid surface to aqueous volume ratios.

Background: Aortic dilation, stiffening, and dissection are common and potentially lethal complications of Marfan syndrome (MFS) and Loeys-Dietz syndrome (LDS), which involve abnormal transforming growth factor beta (TGF-β) signalling. The relation of aortic dimensions, stiffness, and biomarker levels is unknown. The objective of this study was to measure aortic dimensions, stiffness, TGF-β and matrix metalloproteinase (MMP) levels, and endothelial function in patients with MFS, and to compare TGF-β levels in patients with MFS receiving different therapeutic regimens., Methods: This was a cohort study of 40 MFS and 4 LDS patients and 87 control participants. Aortic dimension and stiffness indexes, including pulse wave velocity (PWV), were measured using echocardiography and Doppler. Total and free TGF-β and MMP blood levels were measured using Quantikine (R&D Systems, Inc, Minneapolis, MN) and Quanterix (Billerica, MA) kits. Endothelial function was measured using brachial artery flow-mediated dilation., Results: PWV was increased in patients with MFS. There were increased MMP-2 levels in those with MFS but no increase in free or total TGF-β or MMP-9 levels compared with control participants. There was no difference in TGF-β levels between MFS patients receiving no medications, angiotensin receptor blockers, and β-blockers. PWV correlated most strongly with age. Endothelial function showed premature gradual decline in patients with MFS., Conclusions: Despite the increased PWV, monitoring aortic stiffness or TGF-β levels would not be helpful in patients with MFS. TGF-β levels were not increased and the increased MMP-2 levels suggest consideration of a different therapeutic target., (© 2021 The Authors.)

Aortic aneurysm is the most life-threatening complication in Marfan syndrome (MFS) patients. Doxycycline, a nonselective matrix metalloproteinases inhibitor, was reported to improve the contractile function and elastic fiber structure and organization in a Marfan mouse aorta using ex vivo small chamber myography. In this study, we assessed the hypothesis that a long-term treatment with doxycycline would reduce aortic root growth, improve aortic wall elasticity as measured by pulse wave velocity, and improve the ultrastructure of elastic fiber in the mouse model of MFS. In our study, longitudinal measurements of aortic root diameters using high-resolution ultrasound imaging display significantly decreased aortic root diameters and lower pulse wave velocity in doxycycline-treated Marfan mice starting at 6 months as compared to their non-treated MFS counterparts. In addition, at the ultrastructural level, our data show that long-term doxycycline treatment corrects the irregularities of elastic fibers within the aortic wall of Marfan mice to the levels similar to those observed in control subjects. Our findings underscore the key role of matrix metalloproteinases during the progression of aortic aneurysm, and provide new insights into the potential therapeutic value of doxycycline in blocking MFS-associated aortic aneurysm.

The fertility of men with neurofibromatosis 1 (NF1) is reduced. Despite this observation, gonadal function has not been examined in patients with NF1. In order to assess the role of reduced neurofibromin in the testes, we examined testicular morphology and function in an Nf1+/- mouse model. We found that although Nf1+/- male mice are able to reproduce, they have significantly fewer pups per litter than Nf1+/+ control males. Reduced fertility in Nf1+/- male mice is associated with disorganization of the seminiferous epithelium, with exfoliation of germ cells and immature spermatids into the tubule lumen. Morphometric analysis shows that these alterations are associated with decreased Leydig cell numbers and increased spermatid cell numbers. We hypothesized that hyper-activation of Ras in Nf1+/- males affects ectoplasmic specialization, a Sertoli-spermatid adherens junction involved in spermiation. Consistent with this idea, we found increased expression of phosphorylated ERK, a downstream effector of Ras that has been shown to alter ectoplasmic specialization, in Nf1+/- males in comparison to control Nf1+/+ littermates. These data demonstrate that neurofibromin haploinsufficiency impairs spermatogenesis and fertility in a mouse model of NF1., Competing Interests: The authors have declared that no competing interests exist.

Marfan syndrome (MFS) is a genetic disorder that frequently leads to aortic root dissection and aneurysm. Despite promising preclinical and pilot clinical data, a recent large-scale study using antihypertensive angiotensin II (AngII) receptor type 1 (ATR1) blocker losartan has failed to meet expectations at preventing MFS-associated aortic root dilation, casting doubts about optimal therapy. To study the deleterious role of normal ATR1 signaling in aortic root widening, we generated MFS mice lacking ATR1a expression in an attempt to preserve protective ATR2 signaling. Despite being hypotensive and resistant to AngII vasopressor effects, MFS/ATR1a-null mice showed unabated aortic root enlargement and remained fully responsive to losartan, confirming that blood pressure lowering is of minor therapeutic value in MFS and that losartan's antiremodeling properties may be ATR1 independent. Having shown that MFS causes endothelial dysfunction and that losartan can activate endothelial function in mice and patients, we found that nitric oxide synthase (NOS) inhibition renders losartan therapeutically inactive, whereas multiple transgenic and pharmacologic models of endothelial NOS activation block aortic root dilation by correcting extracellular signal-regulated kinase signaling. In vitro, losartan can increase endothelial NO release in the absence of AngII and correct MFS NO levels in vivo. Our data suggest that increased protective endothelial function, rather than ATR1 inhibition or blood pressure lowering, might be of therapeutic significance in preventing aortic root disease in MFS., (Copyright © 2018 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)

Pressure-induced decreases in arterial diameter are accompanied by membrane depolarization and Ca[sup 2+] entry via voltage-gated Ca[sup 2+] channels. Recent evidence also suggests the involvement of Ca[sup 2+] sensitization of the contractile proteins. Both PKC and Rho kinase are candidate second messengers for the mediation of the sensitization process. We investigated the signaling pathways of pressureinduced decreases in rat cerebral artery diameter in vessels that were depolarized with a 60 mM potassium-physiological salt solution (KPSS). Arteries were mounted on a pressure myograph, and pressure-induced constrictions were recorded. In some experiments simultaneous changes in intracellular Ca[sup 2+] concentration ([Ca[sup 2+]][sub i]) were recorded by using fura 2 fluorescence photometry. Pressure increases induced constriction with significant changes in [Ca[sup 2+]][sub i] at high pressures (60100 mmHg). The ratio of the change in diameter to change in [Ca[sup 2+]][sub i] was greater for pressure-induced constriction compared with constriction produced by depolarization with 60 mM KPSS, suggesting that in addition to increases in [Ca[sup 2+]][sub i], enhanced myofilament Ca[sup 2+] sensitivity occurs during pressureinduced decreases in arterial diameter. Depolarizing the membrane with 60 mM KPSS increased [Ca[sup 2+]][sub i] via a Ca[sup 2+] influx pathway insensitive to PKC inhibition. Cerebral arteries were able to maintain their diameters in the continued presence of 60 mM KPSS. Pressure-induced constriction under these conditions was not associated with further increases in Ca[sup 2+] but was abolished by selective inhibitors of PLC, PKC, and Rho kinase. We report for the first time that in rat cerebral arteries, pressure-induced decreases in arterial diameter are not only due to increases in voltage-gated Ca[sup 2+] influx but also to accompanying increases in myofilament sensitivity to Ca[sup 2+] mediated by PKC/ Rho kinase activation. [ABSTRACT FROM AUTHOR]