Feasibility and Acceptability of Methods to Collect Follow-Up Information From Parents 12 Months After Their Child's Emergency Admission to Pediatric Intensive Care.

OBJECTIVES: To evaluate the feasibility and acceptability of different methods of collecting follow-up data from parents 12 months after their child's emergency admission to a PICU. DESIGN: Mixed-methods explanatory sequential design. SETTING: One regional PICU transport service and three PICUs in England. PATIENTS: Children undergoing emergency transport to PICU recruited to an ongoing biomarker study whose parents consented to be contacted for follow-up 12 months after PICU admission. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Parents or guardians who consented were asked to complete three questionnaires about their child's functional status, quality of life, and behavior 12 months after PICU admission. Parents were given a choice about method of questionnaire completion: postal, online, or telephone interview and also asked for telephone feedback about the process and the reasons for their choice. Of 486 parents who consented to be contacted at 12 months, 232 were successfully contacted. Consent to receive questionnaires was obtained in 218 of 232 (94%). Of the 218 parents, 102 (47%) chose to complete questionnaires online (with 77% completion rate), 91 (42%) chose to complete postal questionnaires (48% completion rate), and 25 (11%) chose to complete questionnaires by telephone interview (44% completion rate). CONCLUSIONS: Parents expressed different preferences for follow-up questionnaire completion. Response rates varied by completion method. Understanding and catering for parental preferences is an important factor in maximizing response rates for follow-up studies in intensive care

Characterization of Complexes of Nucleoside-5′-Phosphorothioate Analogues with Zinc Ions

On the basis of the high affinity of Zn²⁺ to sulfur and imidazole, we targeted nucleotides such as GDP-β-S, ADP-β-S, and AP₃(β-S)­A, as potential biocompatible Zn²⁺-chelators. The thiophosphate moiety enhanced the stability of the Zn²⁺-nucleotide complex by about 0.7 log units. ATP-α,β-CH₂-γ-S formed the most stable Zn²⁺-complex studied here, log <i>K</i> 6.50, being ∼0.8 and ∼1.1 log units more stable than ATP-γ-S-Zn²⁺ and ATP-Zn²⁺ complexes, and was the major species, 84%, under physiological pH. Guanine nucleotides Zn²⁺ complexes were more stable by 0.3–0.4 log units than the corresponding adenine nucleotide complexes. Likewise, AP₃(β-S)­A-zinc complex was ∼0.5 log units more stable than AP₃A complex. ¹H- and ³¹P NMR monitored Zn²⁺ titration showed that Zn²⁺ coordinates with the purine nucleotide N7-nitrogen atom, the terminal phosphate, and the adjacent phosphate. In conclusion, replacement of a terminal phosphate by a thiophosphate group resulted in decrease of the acidity of the phosphate moiety by approximately one log unit, and increase of stability of Zn²⁺-complexes of the latter analogues by up to 0.7 log units. A terminal phosphorothioate contributed more to the stability of nucleotide-Zn²⁺ complexes than a bridging phosphorothioate

Nucleoside-(5′→P) Methylenebisphosphonodithioate Analogues: Synthesis and Chemical Properties

Nucleoside-(5′→P) methylenebisphosphonodithioate analogues are bioisosteres of natural nucleotides. The potential therapeutic applications of these analogues are limited by their relative instability. With a view toward improving their chemical and metabolic stability as well as their affinity toward zinc ions, we developed a novel nucleotide scaffold, nucleoside-5′-tetrathiobisphosphonate. We synthesized P1-(uridine/adenosine-5′)-methylenebisphosphonodithioate, <b>2</b> and <b>3</b>, and P1,P2-di­(uridine/adenosine-5′)-methylenebisphosphonodithioate, <b>4</b> and <b>5</b>. Using ¹H and ³¹P NMR-monitored Zn²⁺/Mg²⁺ titrations, we found that <b>5</b> coordinated Zn²⁺ by both N7 nitrogen atoms and both dithiophosphonate moieties, whereas <b>3</b> coordinated Zn²⁺ by an N7 nitrogen atom and P_β. Both <b>3</b> and <b>5</b> did not coordinate Mg²⁺ ions. ³¹P NMR-monitored kinetic studies showed that <b>3</b> was more stable at pD 1.5 than <b>5</b>, with <i>t</i>_1/2 of 44 versus 9 h, respectively, and at pD 11 both showed no degradation for at least 2 weeks. However, <b>5</b> was more stable than <b>3</b> under an air-oxidizing atmosphere, with t_1/2 of at least 3 days versus 14 h, respectively. Analogues <b>3</b> and <b>5</b> were highly stable to NPP1,3 and NTPDase1,2,3,8 hydrolysis (0–7%). However, they were found to be poor ectonucleotidase inhibitors. Although <b>3</b> and <b>5</b> did not prove to be effective inhibitors of zinc-containing NPP1/3, which is involved in the pathology of osteoarthritis and diabetes, they may be promising zinc chelators for the treatment of other health disorders involving an excess of zinc ions

Highly Efficient Biocompatible Neuroprotectants with Dual Activity as Antioxidants and P2Y Receptor Agonists

Currently, there is a need for novel, biocompatible, and effective neuroprotectants for the treatment of neurodegenerative diseases and brain injury associated with oxidative damage. Here, we developed nucleotide-based neuroprotectants acting dually as antioxidants and P2Y-R agonists. To improve the potency, selectivity, and metabolic stability of ATP/ADP, we substituted adenine C2-position by Cl and P_α/P_β position by borano group, <b>6</b>–<b>9</b>. Nucleotides <b>6</b>–<b>9</b> inhibited oxidation in cell-free systems (Fe­(II)-H₂O₂), as detected by ESR (IC₅₀ up to 175 μM), and ABTS assay (IC₅₀ up to 40 μM). They also inhibited FeSO₄-induced oxidative stress in PC12 cells (IC₅₀ of 80–200 nM). 2-Cl-ADP­(α-BH₃), <b>7a</b>, was found to be the most potent P2Y₁-R agonist currently known (EC₅₀ 7 nM) and protected primary cortical neurons from FeSO₄ insult (EC₅₀ 170 nM). In addition, it proved to be metabolically stable in human blood serum (<i>t</i>_1/2 7 vs 1.5 h for ADP). Hence, we propose <b>7a</b> as a highly promising neuroprotectant

Cohort profile of the Biomarkers of Acute Serious Illness in Children (BASIC) study: a prospective multicentre cohort study in critically ill children.

PURPOSE: Despite significant progress, challenges remain in the management of critically ill children, including early identification of infection and organ failure and robust early risk stratification to predict poor outcome. The Biomarkers of Acute Serious Illness in Children study aims to identify genetic and biological pathways underlying the development of critical illness in infections and organ failure and those leading to poor outcome (death or severe disability) in children requiring emergency intensive care. PARTICIPANTS: We recruited a prospective cohort of critically ill children undergoing emergency transport to four paediatric intensive care units (PICUs) in Southeast England between April 2014 and December 2016. FINDINGS TO DATE: During the study period, 1017 patients were recruited by the regional PICU transport team, and blood and urine samples were obtained at/around first contact with the patient by the transport team. Consent for participation in the study was deferred until after PICU admission and 674 parents/carers were consented. Further samples (blood, urine, stool and throat swabs) were collected after consent. Samples were processed and stored for genomic, transcriptomic, proteomic and metabolomic analyses. Demographic, clinical and laboratory data at first contact, during PICU stay and at discharge, were collected, as were detailed data regarding infectious or non-infectious aetiology. In addition, 115 families have completed 12-month validated follow-up questionnaires to assess quality of life and child behaviour.The first phase of sample analyses (transcriptomic profiling) is currently in progress. FUTURE PLANS: Stored samples will be analysed using genomic, proteomic and metabolic profiling. Advanced bioinformatics techniques will be used to identify biomarkers for early diagnosis of infection, identification of organ failure and risk stratification to predict poor outcome (death/severe disability). TRIAL REGISTRATION NUMBER: NCT03238040.Great Ormond St Hospital Childrens Charit

Cohort profile of the Biomarkers of Acute Serious Illness in Children (BASIC) study: a prospective multicentre cohort study in critically ill children.

PURPOSE: Despite significant progress, challenges remain in the management of critically ill children, including early identification of infection and organ failure and robust early risk stratification to predict poor outcome. The Biomarkers of Acute Serious Illness in Children study aims to identify genetic and biological pathways underlying the development of critical illness in infections and organ failure and those leading to poor outcome (death or severe disability) in children requiring emergency intensive care. PARTICIPANTS: We recruited a prospective cohort of critically ill children undergoing emergency transport to four paediatric intensive care units (PICUs) in Southeast England between April 2014 and December 2016. FINDINGS TO DATE: During the study period, 1017 patients were recruited by the regional PICU transport team, and blood and urine samples were obtained at/around first contact with the patient by the transport team. Consent for participation in the study was deferred until after PICU admission and 674 parents/carers were consented. Further samples (blood, urine, stool and throat swabs) were collected after consent. Samples were processed and stored for genomic, transcriptomic, proteomic and metabolomic analyses. Demographic, clinical and laboratory data at first contact, during PICU stay and at discharge, were collected, as were detailed data regarding infectious or non-infectious aetiology. In addition, 115 families have completed 12-month validated follow-up questionnaires to assess quality of life and child behaviour.The first phase of sample analyses (transcriptomic profiling) is currently in progress. FUTURE PLANS: Stored samples will be analysed using genomic, proteomic and metabolic profiling. Advanced bioinformatics techniques will be used to identify biomarkers for early diagnosis of infection, identification of organ failure and risk stratification to predict poor outcome (death/severe disability). TRIAL REGISTRATION NUMBER: NCT03238040.Great Ormond St Hospital Childrens Charit

Highly Potent and Selective Ectonucleotide Pyrophosphatase/Phosphodiesterase I Inhibitors Based on an Adenosine 5′-(α or γ)-Thio-(α,β- or β,γ)-methylenetriphosphate Scaffold

Aberrant nucleotide pyrophosphatase/phosphodiesterase-1 (NPP1) activity is associated with chondrocalcinosis, osteoarthritis, and type 2 diabetes. The potential of NPP1 inhibitors as therapeutic agents, and the scarceness of their structure–activity relationship, encouraged us to develop new NPP1 inhibitors. Specifically, we synthesized ATP-α-thio-β,γ-CH₂ (<b>1</b>), ATP-α-thio-β,γ-CCl₂ (<b>2</b>), ATP-α-CH₂-γ-thio (<b>3</b>), and 8-SH-ATP (<b>4</b>) and established their resistance to hydrolysis by NPP1,3 and NTPDase1,2,3,8 (<5% hydrolysis) (NTPDase = ectonucleoside triphosphate diphosphohydrolase). Analogues <b>1</b>–<b>3</b> at 100 μM inhibited thymidine 5′-monophosphate <i>p</i>-nitrophenyl ester hydrolysis by NPP1 and NPP3 by >90% and 23–43%, respectively, and only slightly affected (0–40%) hydrolysis of ATP by NTPDase1,2,3,8. Analogue <b>3</b> is the most potent NPP1 inhibitor currently known, <i>K</i>_i = 20 nM and IC₅₀ = 0.39 μM. Analogue <b>2a</b> is a selective NPP1 inhibitor with <i>K</i>_i = 685 nM and IC₅₀ = 0.57 μM. Analogues <b>1</b>–<b>3</b> were found mostly to be nonagonists of P2Y₁/P2Y₂/P2Y₁₁ receptors. Docking analogues <b>1</b>–<b>3</b> into the NPP1 model suggested that activity correlates with the number of H-bonds with binding site residues. In conclusion, we propose analogues <b>2a</b> and <b>3</b> as highly promising NPP1 inhibitors