ABSTRACT
BACKGROUND: Patients with chronic pain account for 12-20% of total emergency department (ED) and was the primary presenting concern among 37% of patients who visited the ED > 12 times per year. Despite this, emergency physicians receive little focused training managing these patients, and there is a paucity of effective referral pathways from EDs, despite strong evidence that chronic pain is best treated longitudinally in multidisciplinary clinics. This study sought to explore the practices, perspectives, and recommendations of current Canadians emergency physicians in better serving the chronic pain patient (CPP) population in the ED. METHODS: An electronic cross-sectional survey was administered to members of the Canadian Association of Emergency Physicians (CAEP), consisting of 16 multiple choice and numerical response questions. Responses were summarized descriptively as percentages and as the median and inter-quartile range (IQR) for quantitative variables. RESULTS: The study was completed by 169/1635 respondents for a response rate of 10%. The most common presentations respondents saw were neuropathic pain and centrally mediated disorders (23% each) and low back pain (19%). 86% of respondents felt that chronic pain patients did not get appropriate referrals from the ED, and 70% of respondents were unaware of where they could even refer chronic pain patients from the ED. 96% of respondents felt that their ED did not have an effective referral pathway for chronic pain patients. Rapid access clinics for common conditions, reduced pain clinic wait times, and clear ED referral pathways were the commonest recommendations by respondents. CONCLUSION: There is a clear need to increase the accessibility to outpatient pain medicine clinics for chronic pain patients presenting to the ED. ED and pain medicine providers must collaborate to establish mutually beneficial referral pathways from EDs, and to advocate for increased funding for rapid access outpatient pain clinics.
RéSUMé: CONTEXTE: Les patients souffrant de douleur chronique représentent de 12 à 20% de l'ensemble du service d'urgence (SU) et constituaient la principale préoccupation chez 37% des patients qui ont visité le SU > 12 fois par année. Malgré cela, les urgentologues reçoivent peu de formation ciblée sur la gestion de ces patients, et il y a peu de voies d'aiguillage efficaces de la part des urgences, malgré de solides preuves que la douleur chronique est mieux traitée longitudinalement dans les cliniques multidisciplinaires. Cette étude visait à explorer les pratiques, les perspectives et les recommandations des médecins d'urgence canadiens actuels pour mieux servir la population de patients souffrant de douleur chronique (RPC) à l'urgence. MéTHODES: Un sondage transversal électronique a été administré aux membres de l'Association canadienne des médecins d'urgence (ACMU), comprenant seize questions à choix multiples et réponses numériques. Les réponses ont été résumées de façon descriptive sous forme de pourcentages et de fourchette médiane et inter quartile (IQR) pour les variables quantitatives. RéSULTATS: : L'étude a été complétée par 169/1635 répondants pour un taux de réponse de 10%. Les présentations les plus courantes que les répondants ont vues étaient des douleurs neuropathiques et des troubles médiés centraux (23% chacun) et des douleurs lombaires (19%). 86% des répondants estimaient que les patients souffrant de douleur chronique n'obtenaient pas de références appropriées de la part de l'urgence, et 70% des répondants ne savaient même pas où ils pouvaient référer les patients souffrant de douleur chronique de l'urgence. 96% des répondants estimaient que leur DE n'avait pas de voie d'aiguillage efficace pour les patients souffrant de douleur chronique. Les cliniques d'accès rapide pour les affections courantes, la réduction des temps d'attente dans les cliniques de traitement de la douleur et des voies d'aiguillage claires vers le service d'urgence étaient les recommandations les plus courantes des répondants. CONCLUSION: Il est clairement nécessaire d'accroître l'accessibilité aux cliniques de traitement de la douleur ambulatoire pour les patients souffrant de douleur chronique qui se présentent à l'urgence. Les fournisseurs de soins de l'urgence et de médicaments contre la douleur doivent collaborer pour établir des voies d'aiguillage mutuellement avantageuses à partir des urgences. et plaider en faveur d'un financement accru pour des cliniques de traitement de la douleur en consultation externe à accès rapide.
Subject(s)
Chronic Pain , Physicians , Humans , Chronic Pain/therapy , Cross-Sectional Studies , Canada , Outpatients , Emergency Service, Hospital , Referral and ConsultationABSTRACT
BACKGROUND: Chronic neuropathic pain is often debilitating and can have a significant impact on sleep health and quality of life. There is limited information on the impact of cannabinoids on sleep health when treating neuropathic pain. OBJECTIVE: The objectives of this systematic review and meta-analysis were to determine the effect of cannabinoids on sleep quality, pain intensity, and patient impression of treatment efficacy in patients with neuropathic pain. EVIDENCE REVIEW: Nine available medical literature databases were searched for randomized controlled trials comparing synthetic and natural cannabinoids to placebo in patients with neuropathic pain syndromes. Data on validated tools for sleep quality, pain intensity, patients' global impression of change (PGIC), and incidence of adverse effects of cannabinoids were extracted and synthesized. FINDINGS: Of the 3491 studies screened, eight randomized controlled trials satisfied the inclusion criteria for this review. Analyses were performed using R -4.1.2. using the metafor package and are interpreted using alpha=0.05 as the threshold for statistical significance. Validated measures for sleep health were not used in most studies. Meta-analysis of data from six studies showed that cannabinoids were associated with a significant improvement in sleep quality (standardized mean difference (SMD): 0.40; 95% CI: 0.19 to -0.61, 95% prediction interval (PI): -0.12 to 0.88, p-value=0.002, I2=55.26, τ2=0.05, Q-statistic=16.72, GRADE: moderate certainty). Meta-analysis of data from eight studies showed a significant reduction in daily pain scores in the cannabinoid (CB) group (SMD: -0.55, 95% CI:-0.69 to -0.19, 95% PI: -1.51 to 0.39, p=0.003, I2=82.49, τ2=0.20, Q-statistic=47.69, GRADE: moderate certainty). However, sleep health and analgesic benefits were associated with a higher likelihood of experiencing daytime somnolence, nausea, and dizziness. CONCLUSIONS: Cannabinoids have a role in treating chronic neuropathic pain as evidenced by significant improvements in sleep quality, pain intensity, and PGIC. More research is needed to comprehensively evaluate the impact of cannabinoids on sleep health and analgesic efficacy. PROSPERO REGISTRATION NUMBER: CRD42017074255.
Subject(s)
Cannabinoids , Chronic Pain , Neuralgia , Humans , Cannabinoids/adverse effects , Chronic Pain/drug therapy , Quality of Life , Randomized Controlled Trials as Topic , Neuralgia/drug therapy , Analgesics , SleepABSTRACT
BACKGROUND: Anaphylactic reactions may present with varying levels of severity, ranging from mild multisystem involvement to severe, and sometimes fatal, anaphylaxis. The severity of anaphylaxis is variable from one reaction to the next within the same individuals. OBJECTIVE: To compare the temporal sequence of symptoms within individuals and between individuals across multiple anaphylactic reactions. METHODS: Patients were evaluated for recurrent anaphylaxis in a tertiary care allergy clinic between 2012 and 2018. At each visit, patients were asked to record the temporal sequence in which symptoms of anaphylaxis appeared. These data were recorded at each visit and retrieved through retrospective chart review. Patients with a history of ≥2 anaphylactic reactions were included; those with anaphylaxis due to multiple allergens were excluded. The Fleiss Kappa method was used to assess reproducibility of the order of appearance of specific symptoms during anaphylaxis within individual patients and between individuals with similar triggers. RESULTS: The mean patient age was 35.6 years (standard deviation = 13.9; range: 1-68 years); 113 of 149 (76%) patients were female. The mean Fleiss Kappa reproducibility score within individuals was 0.94, 5th percentile was 0.53, and 95th percentile was 1.0. The mean Kappa score between individuals was -0.03 (range, -0.14 to 0.05). Among the 16 of 149 patients who recorded reactions of varying severity grades, the mean within-patient Kappa score was 0.96. CONCLUSION: Individual patients experience reproducibly stereotypic anaphylactic reactions over time, which are unique to a given patient, irrespective of the cause of anaphylaxis, including foods, medications, mast cell disorders, and idiopathic anaphylaxis. In contrast, symptom sequences during anaphylaxis are not reproducible between individuals.
Subject(s)
Anaphylaxis , Mastocytosis , Adolescent , Adult , Aged , Allergens/therapeutic use , Anaphylaxis/diagnosis , Anaphylaxis/drug therapy , Anaphylaxis/epidemiology , Child , Child, Preschool , Epinephrine/therapeutic use , Female , Humans , Infant , Mastocytosis/drug therapy , Middle Aged , Reproducibility of Results , Retrospective Studies , Young AdultABSTRACT
Chronic pain is a debilitating condition affecting millions of people worldwide, and an improved understanding of the pathophysiology of chronic pain is urgently needed. Nociceptors are the sensory neurons that alert the nervous system to potentially harmful stimuli such as mechanical pressure or noxious thermal temperature. When an injury occurs, the nociceptive threshold for pain is reduced and an increased pain signal is produced. This process is called nociceptive sensitization. This sensitization normally subsides after the injury is healed. However, dysregulation can occur which results in sensitization that persists after the injury has healed. This process is thought to perpetuate chronic pain. The Hedgehog (Hh) signaling pathway has been previously implicated in nociceptive sensitization in response to injury in Drosophila melanogaster. Downstream of Hh signaling, the Bone Morphogenetic Protein (BMP) pathway has also been shown to be necessary for this process. Here, we describe a role for nuclear components of BMP's signaling pathway in the formation of injury-induced nociceptive sensitization. Brinker (Brk), and Schnurri (Shn) were suppressed in nociceptors using an RNA-interference (RNAi) "knockdown" approach. Knockdown of Brk resulted in hypersensitivity in the absence of injury, indicating that it normally acts to suppress nociceptive sensitivity. Animals in which transcriptional activator Shn was knocked down in nociceptors failed to develop normal allodynia after ultraviolet irradiation injury, indicating that Shn normally acts to promote hypersensitivity after injury. These results indicate that Brk-related transcription regulators play a crucial role in the formation of nociceptive sensitization and may therefore represent valuable new targets for pain-relieving medications.
Subject(s)
Drosophila melanogaster/metabolism , Nociception/physiology , Pain/metabolism , Sensory Receptor Cells/metabolism , Animals , Bone Morphogenetic Proteins/genetics , Drosophila/metabolism , Drosophila Proteins/metabolism , Gene Expression Regulation/genetics , Hedgehog Proteins/metabolism , Nociceptors/metabolism , Signal Transduction/physiology , Transcription Factors/metabolismABSTRACT
INTRODUCTION: The state of cognitive flow, colloquially known as being 'in the zone', has been linked with enhanced performance, happiness, career satisfaction and decreased burnout. However, the concept has not been adopted strongly in health care training, continuing professional development, or daily practice. A systematic review with a narrative synthesis was undertaken to map the evidence for flow in health care. METHODS: A search was conducted in MEDLINE, PsycInfo, and EMBASE in July 2019 and updated in October 2020 for manuscripts discussing flow in all health care disciplines. Articles published between 1806 and 13 October 2020 were included. Two authors independently reviewed titles and abstracts (and subsequently full texts where necessary) for inclusion. Disagreements were resolved by consensus. Data were extracted on location, manuscript type, population and context, measures, and key findings. RESULTS: A total of 4923 unique abstracts were initially retrieved, and 15 articles were included in the final review. We report on the experience, benefits and strategies to support flow in health care. Flow may benefit providers by enhancing career enjoyment, wellness and performance, while mitigating exhaustion, burnout, and stress. Although research from other domains has focused on supporting flow through individualised training, our results highlight the importance of system and environmental factors. CONCLUSIONS: Supporting professional and trainee flow in health care requires a holistic approach, including individual training and system-level interventions.
Subject(s)
Burnout, Professional , Delivery of Health Care , Cognition , HumansABSTRACT
OBJECTIVES: Population density can limit the level of care that can be provided in local facilities in Ontario, and as such, patients with severe illnesses often require interfacility transfers to access specialized care. This study aimed to identify causes of delay in interfacility transport by air ambulance in Ontario. METHODS: Causes of delay were identified by manual review of electronic patient care records (ePCRs). All emergent interfacility transfers conducted by Ornge, the sole provider of air-based medical transport in Ontario, between January 1, 2016 and December 31, 2016 were included. The ePCRs were reviewed if they met one or more of the following: (1) contained a standardized delay code; (2) contained free text including "delay", "wait", or "duty-out"; (3) were above the 75th percentile in total transport time; or (4) were above the 90th percentile in time to bedside, time at the sending hospital, or time to receiving facility. RESULTS: Our search strategy identified 1,220 ePCRs for manual review, which identified a total of 872 delays. Common delays cited included aircraft refueling (234 delays), waiting for land emergency medical service (EMS) escort (146), and staffing- or dispatch-related issues (124). Other delays included weather/environmental hazards (43); mechanical issues (36); and procedures, imaging, or stabilization (80). CONCLUSIONS: Some common causes of interfacility delay are potentially modifiable: better trip planning around refueling and improved coordination with local EMS, could reduce delays experienced during interfacility trips. To better understand causes of delay, we would benefit from improved documentation and record availability which limited the results in this study.
Subject(s)
Air Ambulances , Emergency Medical Services , Humans , Ontario , Patient Transfer , Time FactorsABSTRACT
Background: The purpose of this study was to develop a multifaceted examination to assess the competence of fellows following completion of a sports medicine fellowship. Methods: Orthopedic sports medicine fellows over 2 academic years were invited to participate in the study. Clinical skills were evaluated with objective structured clinical examinations, multiple-choice question examinations, an in-training evaluation report and a surgical logbook. Fellows' performance of 3 technical procedures was assessed both intraoperatively and on cadavers: anterior cruciate ligament reconstruction (ACLR), arthroscopic rotator cuff repair (RCR) and arthroscopic shoulder Bankart repair. Technical procedural skills were assessed using previously validated task-specific checklists and the Arthroscopic Surgical Skill Evaluation Tool (ASSET) global rating scale. Results: Over 2 years, 12 fellows were assessed. The Cronbach α for the technical assessments was greater than 0.8, and the interrater reliability for the cadaveric assessments was greater than 0.78, indicating satisfactory reliability. When assessed in the operating room, all fellows were determined to have achieved a minimal level of competence in the 3 surgical procedures, with the exception of 1 fellow who was not able achieve competence in ACLR. When their performance on cadaveric specimens was assessed, 2 of 12 (17%) fellows were not able to demonstrate a minimal level of competence in ACLR, 2 of 10 (20%) were not able to demonstrate a minimal level of competence for RCR and 3 of 10 (30%) were not able to demonstrate a minimal level of competence for Bankart repair. Conclusion: There was a disparity between fellows' performance in the operating room and their performance in the high-fidelity cadaveric setting, suggesting that technical performance in the operating room may not be the most appropriate measure for assessment of fellows' competence.
Contexte: Le but de cette étude était de concevoir un examen à plusieurs volets pour évaluer la compétence des moniteurs cliniques à la fin de leur formation en médecine sportive. Méthodes: Après leur formation de 2 ans pour devenir orthopédistes en médecine sportive, les moniteurs cliniques ont été invités à participer à l'étude. Leurs habiletés cliniques ont été évaluées au moyen d'examens cliniques objectifs structurés, de questionnaires à choix multiple, d'un rapport d'évaluation en cours de formation et d'un journal de bord chirurgical. Leur habileté à réaliser 3 techniques chirurgicales différentes a été évaluée au bloc opératoire et sur des cadavres : reconstruction du ligament croisé antérieur (RLCA), réparation arthroscopique de la coiffe des rotateurs (RACR) et intervention de Bankart sous endoscopie pour l'épaule. Les habiletés techniques ont été évaluées au moyen de listes de vérification spécifiques aux tâches validées et au moyen de l'outil d'évaluation globale ASSET (Arthroscopic Surgical Skill Evaluation). Résultats: Sur une période de 2 ans, 12 moniteurs ont été évalués. Le coefficient α de Cronbach pour les évaluations techniques a été supérieur à 0,8, et la fiabilité inter-examinateurs pour l'évaluation des interventions sur des cadavres a été supérieure à 0,78, soit une fiabilité jugée satisfaisante. Lors de l'évaluation au bloc opératoire, on a jugé que tous les moniteurs détenaient le niveau minimum de compétences pour exécuter les 3 techniques chirurgicales, à l'exception d'un seul qui n'a pas atteint le niveau de compétence pour la RLCA. À l'évaluation de leurs compétences pour les interventions sur des cadavres, 2 sur 12 (17 %) n'ont pas atteint le niveau minimum de compétence pour la RLCA, 2 sur 10 (20 %) pour la RACR et 3 sur 10 (30 %) pour l'intervention de Bankart. Conclusion: On a noté une disparité dans la compétence des moniteurs entre le bloc opératoire et le contexte cadavérique haute fidélité, ce qui donne à penser que le rendement technique au bloc opératoire pourrait ne pas être le moyen le plus approprié d'évaluer la compétence des moniteurs cliniques.
Subject(s)
Certification , Clinical Competence , Educational Measurement/methods , Fellowships and Scholarships , Orthopedic Procedures/education , Sports Medicine/education , Cadaver , Humans , Ontario , Orthopedic Procedures/standards , Prospective StudiesSubject(s)
Artificial Intelligence/trends , Emergency Medicine/trends , Emergency Service, Hospital/organization & administration , United States Food and Drug Administration/legislation & jurisprudence , Artificial Intelligence/legislation & jurisprudence , Canada/epidemiology , Deep Learning/trends , Delivery of Health Care/trends , Humans , Neural Networks, Computer , Patient-Centered Care/ethics , Triage/methods , United States/epidemiology , United States Food and Drug Administration/organization & administrationABSTRACT
Chronic neuropathic pain (NP) is debilitating and impacts sleep health and quality of life. Treatment with gabapentinoids (GBs) has been shown to reduce pain, but its effects on sleep health have not been systematically evaluated. The objective of this systematic review and meta-analysis was to assess the relationship between GB therapy dose and duration on sleep quality, daytime somnolence, and intensity of pain in patients with NP. Subgroup comparisons were planned for high- vs low-dose GBs, where 300 mg per day or more of pregabalin was used to classify high-dose therapy. Trial data were segregated by duration less than 6 weeks and 6 weeks or greater. Twenty randomized controlled trials were included. Primary outcome measures included pain-related sleep interference and incidence of daytime somnolence. Secondary outcomes included daily pain scores (numerical rating scale 0-10) and patient global impression of change. Significant improvement in sleep quality was observed after 6 weeks of GB treatment when compared with placebo (standardized mean difference 0.39, 95% confidence interval 0.32-0.46 P < 0.001). Increased daytime somnolence was observed among all GB-treated groups when compared with placebo. Treated patients were also more likely to report improvement of patient global impression of change scores. Pain scores decreased significantly in patients both after 6 weeks of treatment (P < 0.001) and in trials less than 6 weeks (P = 0.017) when compared with placebo. Our data demonstrate that GBs have a positive impact on sleep health, quality of life, and pain in patients with NP syndromes. However, these benefits come at the expense of daytime somnolence.
Subject(s)
Analgesics/therapeutic use , Chronic Pain/drug therapy , Gabapentin/therapeutic use , Neuralgia/drug therapy , Sleep/drug effects , Analgesics/pharmacology , Chronic Pain/epidemiology , Chronic Pain/psychology , Clinical Trials as Topic/methods , Gabapentin/analogs & derivatives , Gabapentin/pharmacology , Humans , Neuralgia/epidemiology , Neuralgia/psychology , Pain Measurement , Quality of Life/psychology , Sleep/physiology , Sleep Wake Disorders/drug therapy , Sleep Wake Disorders/epidemiology , Sleep Wake Disorders/psychology , Treatment OutcomeSubject(s)
Athletic Injuries/pathology , Ear Canal/pathology , Ear Diseases/diagnosis , Exostoses/diagnosis , Hearing Loss, Conductive/pathology , Seawater/adverse effects , Adult , Athletic Injuries/therapy , Cold Temperature/adverse effects , Ear Diseases/physiopathology , Ear Diseases/therapy , Exostoses/physiopathology , Exostoses/therapy , Hearing Loss, Conductive/etiology , Humans , Male , Otoscopy , Physical Examination , Recovery of Function/physiology , Suction , Treatment Outcome , Water SportsABSTRACT
Nociceptive sensitization is a common feature in chronic pain, but its basic cellular mechanisms are only partially understood. The present study used the Drosophila melanogaster model system and a candidate gene approach to identify novel components required for modulation of an injury-induced nociceptive sensitization pathway presumably downstream of Hedgehog. This study demonstrates that RNAi silencing of a member of the Bone Morphogenetic Protein (BMP) signaling pathway, Decapentaplegic (Dpp), specifically in the Class IV multidendritic nociceptive neuron, significantly attenuated ultraviolet injury-induced sensitization. Furthermore, overexpression of Dpp in Class IV neurons was sufficient to induce thermal hypersensitivity in the absence of injury. The requirement of various BMP receptors and members of the SMAD signal transduction pathway in nociceptive sensitization was also demonstrated. The effects of BMP signaling were shown to be largely specific to the sensitization pathway and not associated with changes in nociception in the absence of injury or with changes in dendritic morphology. Thus, the results demonstrate that Dpp and its pathway play a crucial and novel role in nociceptive sensitization. Because the BMP family is so strongly conserved between vertebrates and invertebrates, it seems likely that the components analyzed in this study represent potential therapeutic targets for the treatment of chronic pain in humans.SIGNIFICANCE STATEMENT This report provides a genetic analysis of primary nociceptive neuron mechanisms that promote sensitization in response to injury. Drosophila melanogaster larvae whose primary nociceptive neurons were reduced in levels of specific components of the BMP signaling pathway, were injured and then tested for nocifensive responses to a normally subnoxious stimulus. Results suggest that nociceptive neurons use the BMP2/4 ligand, along with identified receptors and intracellular transducers to transition to a sensitized state. These findings are consistent with the observation that BMP receptor hyperactivation correlates with bone abnormalities and pain sensitization in fibrodysplasia ossificans progressiva (Kitterman et al., 2012). Because nociceptive sensitization is associated with chronic pain, these findings indicate that human BMP pathway components may represent targets for novel pain-relieving drugs.
Subject(s)
Bone Morphogenetic Proteins/metabolism , Central Nervous System Sensitization/physiology , Drosophila Proteins/metabolism , Drosophila/physiology , Nociception/physiology , Nociceptors/physiology , Smad Proteins/metabolism , Animals , Pain Threshold/physiology , Signal Transduction/physiologyABSTRACT
Steroid hormones organize many aspects of development, including that of the nervous system. Steroids also play neuromodulatory and other activational roles, including regulation of sensitivity to painful stimuli in mammals. In Drosophila, ecdysteroids are the only steroid hormones, and therefore the fly represents a simplified model system in which to explore mechanisms of steroid neuromodulation of nociception. In this report, we present evidence that ecdysteroids, acting through two isoforms of their nuclear ecdysone receptor (EcR), modulate sensitivity to noxious thermal and mechanical stimuli in the fly larva. We show that EcRA and EcRB1 are expressed by third instar larvae in the primary nociceptor neurons, known as the class IV multidendritic neurons. Suppression of EcRA by RNA interference in these cells leads to hyposensitivity to noxious stimulation. Suppression of EcRB1 leads to reduction of dendritic branching and length of nociceptor neurons. We show that specific isoforms of the ecdysone receptor play critical cell autonomous roles in modulating the sensitivity of nociceptor neurons and may indicate human orthologs that represent targets for novel analgesic drugs.
Subject(s)
Dendrites/metabolism , Drosophila melanogaster/metabolism , Insect Proteins/metabolism , Nociceptors/metabolism , Receptors, Steroid/metabolism , Animals , Animals, Genetically Modified , Drosophila melanogaster/genetics , Drosophila melanogaster/physiology , Immunohistochemistry , Insect Proteins/genetics , Larva/genetics , Larva/metabolism , Motor Activity/genetics , Motor Activity/physiology , Neuronal Plasticity/genetics , Neuronal Plasticity/physiology , Protein Isoforms/genetics , Protein Isoforms/metabolism , RNA Interference , Receptors, Steroid/genetics , Stress, Mechanical , TemperatureABSTRACT
Drosophila larvae are used in many behavioral studies, yet a simple device for measuring basic parameters of larval activity has not been available. This protocol repurposes an instrument often used to measure adult activity, the TriKinetics Drosophila activity monitor (MB5 Multi-Beam Activity Monitor) to study larval activity. The instrument can monitor the movements of animals in 16 individual 8 cm glass assay tubes, using 17 infrared detection beams per tube. Logging software automatically saves data to a computer, recording parameters such as number of moves, times sensors were triggered, and animals' positions within the tubes. The data can then be analyzed to represent overall locomotion and/or position preference as well as other measurements. All data are easily accessible and compatible with basic graphing and data manipulation software. This protocol will discuss how to use the apparatus, how to operate the software and how to run a larval activity assay from start to finish.