P2X7 receptor-mediated release of microglial prostanoids and miRNAs correlates with reversal of neuropathic hypersensitivity in rats.

BACKGROUND: P2X7 receptor antagonists have potential for treating various central nervous system (CNS) diseases, including neuropathic pain, although none have been approved for clinical use. Reasons may include insufficient understanding of P2X7 receptor signalling in pain, and the lack of a corresponding preclinical mechanistic biomarker. METHODS: Lu AF27139 is a highly selective and potent small molecule antagonist at rat, mouse and human forms of the P2X7 receptor, with excellent pharmacokinetic and CNS permeability properties. In the current experiments, we probed the utility of previously characterized and novel signalling cascades exposed to Lu AF27139 using cultured microglia combined with release assays. Subsequently, we assessed the biomarker potential of identified candidate molecules in the rat chronic constriction injury (CCI) model of neuropathic pain; study design limitations precluded their assessment in spared nerve injury (SNI) rats. RESULTS: Lu AF27139 blocked several pain-relevant pathways downstream of P2X7 receptors in vitro. At brain and spinal cord receptor occupancy levels capable of functionally blocking P2X7 receptors, it diminished neuropathic hypersensitivity in SNI rats, and less potently in CCI rats. Although tissue levels of numerous molecules previously linked to neuropathic pain and P2X7 receptor function (e.g. IL-6, IL-1ß, cathepsin-S, 2-AG) were unaffected by CCI, Lu AF27139-mediated regulation of spinal PGE2 and miRNA (e.g. rno-miR-93-5p) levels increased by CCI aligned with its ability to diminish neuropathic hypersensitivity. CONCLUSIONS: We have identified a pain-relevant P2X7 receptor-regulated mechanism in neuropathic rats, which could hold promise as a translatable biomarker and by association enhance the clinical progression of P2X7 receptor antagonists in neuropathic pain. SIGNIFICANCE: Sub-optimal translation of preclinical molecules has hindered the clinical development of novel mechanism of action analgesics. We have undertaken a comprehensive in vitro analysis of migroglial signalling mechanisms recruited upon P2X7 receptor activation, a number of which were shown to be modulated by a selective P2X7 receptor antagonist in a well characterized animal model of neuropathic pain. Subject to further confirmation in other neuropathic models, this opens up the possibility to investigate their clinical utility as potential pain biomarkers in patients.

3D Printed Hydrogel Multiassay Platforms for Robust Generation of Engineered Contractile Tissues.

We present a method for reproducible manufacture of multiassay platforms with tunable mechanical properties for muscle tissue strip analysis. The platforms result from stereolithographic 3D printing of low protein-binding poly(ethylene glycol) diacrylate (PEGDA) hydrogels. Contractile microtissues have previously been engineered by immobilizing suspended cells in a confined hydrogel matrix with embedded anchoring cantilevers to facilitate muscle tissue strip formation. The 3D shape and mechanical properties of the confinement and the embedded cantilevers are critical for the tissue robustness. High-resolution 3D printing of PEGDA hydrogels offers full design freedom to engineer cantilever stiffness, while minimizing unwanted cell attachment. We demonstrate the applicability by generating suspended muscle tissue strips from C2C12 mouse myoblasts in a compliant fibrin-based hydrogel matrix. The full design freedom allows for new platform geometries that reduce local stress in the matrix and tissue, thus, reducing the risk of tissue fracture.

Is there a reasonable excuse for not providing post-operative analgesia when using animal models of peripheral neuropathic pain for research purposes?

INTRODUCTION: The induction of neuropathic pain-like behaviors in rodents often requires surgical intervention. This engages acute nociceptive signaling events that contribute to pain and stress post-operatively that from a welfare perspective demands peri-operative analgesic treatment. However, a large number of researchers avoid providing such care based largely on anecdotal opinions that it might interfere with model pathophysiology in the longer term. OBJECTIVES: To investigate effects of various peri-operative analgesic regimens encapsulating different mechanisms and duration of action, on the development of post-operative stress/welfare and pain-like behaviors in the Spared Nerve Injury (SNI)-model of neuropathic pain. METHODS: Starting on the day of surgery, male Sprague-Dawley rats were administered either vehicle (s.c.), carprofen (5.0mg/kg, s.c.), buprenorphine (0.1mg/kg s.c. or 1.0mg/kg p.o. in Nutella®), lidocaine/bupivacaine mixture (local irrigation) or a combination of all analgesics, with coverage from a single administration, and up to 72 hours. Post-operative stress and recovery were assessed using welfare parameters, bodyweight, food-consumption, and fecal corticosterone, and hindpaw mechanical allodynia was tested for assessing development of neuropathic pain for 28 days. RESULTS: None of the analgesic regimes compromised the development of mechanical allodynia. Unexpectedly, the combined treatment with 0.1mg/kg s.c. buprenorphine and carprofen for 72 hours and local irrigation with lidocaine/bupivacaine, caused severe adverse effects with peritonitis. This was not observed when the combination included a lower dose of buprenorphine (0.05mg/kg, s.c.), or when buprenorphine was administered alone (0.1mg/kg s.c. or 1.0mg/kg p.o.) for 72 hours. An elevated rate of wound dehiscence was observed especially in the combined treatment groups, underlining the need for balanced analgesia. Repeated buprenorphine injections had positive effects on body weight the first day after surgery, but depressive effects on food intake and body weight later during the first week. CONCLUSION: Post-operative analgesia does not appear to affect established neuropathic hypersensitivity outcome in the SNI model.

Prefrontal cortex and hippocampus in behavioural flexibility and posttraumatic functional recovery: reversal learning and set-shifting in rats.

Within one experiment and one T-maze, we examined the consequences of (i) bilateral lesions of the anteromedial prefrontal cortex (PFC), (ii) bilateral transections of the fimbria-fornix (FF), or (iii) combined lesions of both PFC and FF (COMB) on rats' ability to perform reversal or set-shifting. Postoperatively, the animals were trained to perform a spatial discrimination go-right task. This was followed by (1) a spatial reversal go-left task (reversal learning), or (2) a visual pattern discrimination task (set-shift). Neither single (PFC or FF) lesion nor combined (COMB) lesions affected the animals' ability to acquire the original spatial discrimination task. Regarding the reversal learning, the performance of the PFC and the FF groups was not significantly different from that of the sham operated control animals (Sham). In contrast, animals with combined lesion of both structures were impaired on both error rate and acquisition speed relative to all other groups. Regarding the set-shifting, all lesioned groups were impaired relative to the Sham group both regarding the error rate and the acquisition speed. There was, however, no difference in the degree of impairment between the lesioned groups. We conclude that both the PFC and the hippocampus contributed to the mediation of the reversal learning and set-shifting. During functional recovery of reversal learning, these two structures exhibited a mutual dependency, whilst the functional recovery of set-shifting was mediated by a substrate outside these two structures.

Annual cross-sectional study of nurse-sensitive problems: how to keep a finger on the pulse.

A cross-sectional evaluation of nurse-sensitive problems in hospitalized patients is conducted once per year to monitor patient problems identified by nurses, whether nurses implement interventions to overcome the problems, and if the problems are solved. This article describes a systematic method of data collection and illustrates how the data can be used to improve the quality and documentation of the nursing care. The annual cross-sectional evaluation allows us to identify relevant target areas of future nursing interventions and research.

Substance use, dental hygiene, and physical activity in adult patients with single ventricle physiology.

OBJECTIVES: The study aims to describe substance use, dental hygiene, and physical activity in adult survivors with single ventricle physiology (SVP) and to compare the behaviors with matched controls, while the patients are particularly at risk for general health problems. DESIGN: The present study is part of a larger research project on long-term outcomes in adult patients with SVP. A cross-sectional, case-control study including 59 patients out of 83 eligible patients participated in the study (response rate 71%). The patients were matched to 172 healthy controls. A questionnaire was mailed to the patients. Nonresponders did not differ significantly from the included participants on age, gender, or physical function. SETTING: The study was conducted at the Heart Center of Copenhagen University Hospital or the Department of Cardiology, Aarhus University Hospital. RESULTS: In these patients, 85% report alcohol consumption (92% in controls; odds ratio [OR] = 0.91; P = 0.575); 26% admit "binge drinking" (41% in controls; OR = 0.56; P = 0.041); 20% are cigarette smokers (36% in controls; OR = 0.59; P = 0.100); 12% have used cannabis over the past year (15% in controls; OR = 0.80; P = 0.596); 20% have had no dental visits during the last year (25% in controls; OR = 1.07; P = 0.684); 46% are not flossing their teeth (32% in controls; OR = 1.32; P = 0.239); and 39% are not physically active (24% in controls; OR = 1.63; P = 0.069). CONCLUSIONS: While in general there was no significant differences in overall health behaviors between SVP patients and controls, SVP patients are less physically active and are less likely to binge drink.

Living with half a heart--experiences of young adults with single ventricle physiology: a qualitative study.

BACKGROUND AND RESEARCH OBJECTIVE: Approximately 3% of children with congenital heart disease born in Denmark have single ventricle physiology (SVP). In previous decades, these children did not survive into adulthood. However, because of new surgical techniques and improved medical care, they now have a 90% survival rate. Several studies have described the somatic status of SVP patients using clinical parameters; however, only a few studies have researched the life perspectives and coping skills in this patient group. The aim of this study was to investigate how young adults with an SVP diagnosis are coping with adulthood and the emotional experiences of daily life. SUBJECTS AND METHODS: Semistructured, qualitative interviews were held with 11 SVP respondents, selected by physical and psychological parameters identified in an earlier quantitative study. Data from the interviews were analyzed by a research group using a phenomenological methodology. RESULTS AND CONCLUSIONS: The goal for SVP patients is to gain control over their disease to live normal lives. Patients require special support from their core network to overcome physical and psychological challenges. Respondents underscored the need for friends and resource persons outside the family to help lift them out of their role as disabled cardiac patients and provide them with "normal" life experiences.

Explanatory value of the Ability Index as assessed by cardiologists and patients with congenital heart disease.

INTRODUCTION: The Ability Index was developed to classify patients with congenital heart disease into four functional classes. Functional class is typically determined by the cardiologist, based on data from a clinical interview. The validity of the Ability Index as assessed by the patient has never been scrutinized. OBJECTIVE: We tested the agreement between cardiologists and patients in assessing functional status using the Ability Index and compared the accuracy of the two assessments in explaining patient-reported outcomes (PRO). METHODS: The Ability Index Scale was completed for 57 patients, independently by cardiologists and patients. Cohen's Kappa coefficient with quadratic weighting (K(w)) was calculated. The area under the receiver operating characteristic (ROC) curve (AUC) (=C-index) was used to test the accuracy of the Ability Index in explaining PRO, as assessed by the cardiologist or the patient. RESULTS: Agreement was observed in 61.4% of the patients. The K(w) was 0.55, showing a moderate agreement; and the R(2) was 0.29, displaying a limited shared variance. The AUC for cardiologists' assessments of the Ability Index in explaining PRO was consistently lower than the AUC for patients' assessments. The appraisal of the patients was more accurate. DISCUSSION: When cardiologists and patients are assessing functional status using the Ability Index, two different constructs are measured. These assessments cannot be interchanged, but should be used complementarily. Because the assessment of the patients regarding the Ability Index is more precise in terms of explaining PRO, it could be valuable as a simple crude marker to identify patients at risk for poor functional and psychosocial outcomes.

Patient-reported outcomes in adult survivors with single-ventricle physiology.

OBJECTIVES: Data on patient-reported outcomes (PROs) in patients with single-ventricle physiology (SVP) are scarce. We sought (1) to describe the perceived health status, quality of life, symptoms of anxiety and depression, and sense of coherence in adult survivors with SVP, (2) to compare PROs across functional classes, and (3) to compare PROs between patients and controls. METHODS: A case-control study in two adult congenital heart programmes with 62 adult survivors with SVP were matched to 172 healthy controls. A wide range of PROs were measured using validated questionnaires. The treating physician classified patients according to the Ability Index. RESULTS: Patients with SVP have a good functional status. Patients in Ability Index class I consistently reported the best scores, similar to those of healthy controls. Negative associations were found between functional class and outcomes of perceived health and quality of life. For patients in Ability Index class II and III, PROs were poorer. CONCLUSIONS: PROs in patients with SVP are generally good.