Slow touch and ultrafast pain fibres: Revisiting peripheral nerve classification.

One hundred years ago, Erlanger and Gasser demonstrated that conduction velocity is correlated with the diameter of a peripheral nerve axon. Later, they also demonstrated that the functional role of the axon is related to its diameter: touch is signalled by large-diameter axons, whereas pain and temperature are signalled by small-diameter axons. Certain discoveries in recent decades prompt a modification of this canonical classification. Here, we review the evidence for unmyelinated (C) fibres signalling touch at a slow conduction velocity and likely contributing to affective aspects of tactile information. We also review the evidence for large-diameter Aß afferents signalling pain at ultrafast conduction velocity and likely contributing to the rapid nociceptive withdrawal reflex. These discoveries imply that conduction velocity is not as clear-cut an indication of the functional role of the axon as previously thought. We finally suggest that a future taxonomy of the peripheral afferent nervous system might be based on the combination of the axons molecular expression and electrophysiological response properties.

Performance Evaluation of a Supervised Machine Learning Pain Classification Model Developed by Neonatal Nurses.

BACKGROUND: Early-life pain is associated with adverse neurodevelopmental consequences; and current pain assessment practices are discontinuous, inconsistent, and highly dependent on nurses' availability. Furthermore, facial expressions in commonly used pain assessment tools are not associated with brain-based evidence of pain. PURPOSE: To develop and validate a machine learning (ML) model to classify pain. METHODS: In this retrospective validation study, using a human-centered design for Embedded Machine Learning Solutions approach and the Neonatal Facial Coding System (NFCS), 6 experienced neonatal intensive care unit (NICU) nurses labeled data from randomly assigned iCOPEvid (infant Classification Of Pain Expression video) sequences of 49 neonates undergoing heel lance. NFCS is the only observational pain assessment tool associated with brain-based evidence of pain. A standard 70% training and 30% testing split of the data was used to train and test several ML models. NICU nurses' interrater reliability was evaluated, and NICU nurses' area under the receiver operating characteristic curve (AUC) was compared with the ML models' AUC. RESULTS: Nurses weighted mean interrater reliability was 68% (63%-79%) for NFCS tasks, 77.7% (74%-83%) for pain intensity, and 48.6% (15%-59%) for frame and 78.4% (64%-100%) for video pain classification, with AUC of 0.68. The best performing ML model had 97.7% precision, 98% accuracy, 98.5% recall, and AUC of 0.98. IMPLICATIONS FOR PRACTICE AND RESEARCH: The pain classification ML model AUC far exceeded that of NICU nurses for identifying neonatal pain. These findings will inform the development of a continuous, unbiased, brain-based, nurse-in-the-loop Pain Recognition Automated Monitoring System (PRAMS) for neonates and infants.

Síndrome de pinzamiento isquiofemoral: a propósito de una serie de 5 casos / Ischiofemoral impingement syndrome: A five-case series report

El dolor glúteo es un motivo frecuente de consulta médica en la práctica clínica diaria. Las causas son muy variadas, pudiendo encontrar entre aquellas que forman parte de su diagnóstico diferencial el síndrome de pinzamiento isquiofemoral. Este, incluido actualmente dentro de los síndromes de glúteo profundo, es consecuencia del atrapamiento de las estructuras neuromusculares englobadas entre el trocánter menor y la tuberosidad isquiática, lo que ocasiona un cuadro de dolor en la raíz del miembro inferior, con irradiación hacia el muslo o hacia la región glútea, y mala tolerancia a la deambulación y a la sedestación. La prueba diagnóstica fundamental es la resonancia magnética de cadera, y su manejo suele ser médico inicialmente. A pesar de no ser una entidad frecuente en las consultas de reumatología, tener esta patología en mente ayuda a mejorar su pronóstico, al poder ofrecer un tratamiento adecuado y precoz.(AU)

Gluteal pain is a frequent cause of medical attention in the daily clinical practice. It can be caused by multiple pathologies, being ischiofemoral impingement syndrome among those included in its differential diagnosis. Encompassed within the deep gluteal syndromes, this entity occurs as a consequence of the entrapment of the neuromuscular structures between the lesser femoral trochanter and the ischial tuberosity, causing pain in the root of the lower limb, with irradiation towards the thigh or the gluteal region and poor tolerance to deambulation and sedestation. The magnetic resonance imaging of the hip is fundamental for its diagnosis, and its management consists on medical treatment at onset. Despite not being a frequent diagnosis in the clinical practice in rheumatology, keeping it in mind helps improving its prognosis by establishing an early and adequate treatment.(AU)

Atualização no manejo da dor musculoesquelética / Update on Musculoskeletal Pain Management

Abstract Pain is the most common complaint reported to orthopedists in the outpatient clinic, emergency room, or booth. Numerous publications report the inadequate management of both acute and chronic pain by health professionals. This updated article aims to provide information about musculoskeletal pain, its classification, evaluation, diagnosis, and the multimodal therapeutic approach for each case. For acute pain, adequate control allows for earlier rehabilitation to work and reduces the rates of pain chronification. For chronic pain, the goal is to reduce its intensity and improve the quality of life. Currently, some procedures are increasingly used and aided by imaging tests for diagnostic and therapeutic purposes.

Resumo A dor é a queixa mais comum recebida pelo ortopedista no ambulatório e/ou emergência. Inúmeras publicações relatam o manejo inadequado tanto da dor aguda quanto da dor crônica pelos profissionais da saúde. O objetivo desse artigo de atualização é trazer informações sobre a dor musculoesquelética, sua classificação, avaliação, diagnóstico e abordagem terapêutica multimodal para cada situação. Desta maneira, nas dores agudas seu controle adequado possibilita um trabalho de reabilitação mais precoce, bem como diminui os índices de cronificação da dor. Nas dores crônicas sua abordagem além da diminuição de sua intensidade, visa também melhorar a qualidade de vida. Atualmente alguns procedimentos estão sendo cada vez mais utilizados com auxílio de aparato de imagem com objetivo diagnóstico e terapêutico.

Definición del dolor / Definition of pain

El presente trabajo aborda los diferentes aspectos implicados en la definición del dolor. Por un lado, explora los antecedentes históricos del término en medicina, así como la visión del dolor como una experiencia adaptativa pero también como un reto terapéutico. Se destaca la definición del dolor de la Asociación Internacional para el Estudio del Dolor - IASP (2020). Finalmente, desde una aproximación biopsicosocial al dolor, se destacan los peligros y las debilidades del modelo biomédico en el abordaje del dolor persistente (crónico).(AU)

El impacto en la calidad de vida, la depresión y el manejo analgésico se asocian al sufrimiento en pacientes con fibromialgia. Un estudio transversal / Impact on quality of life, depression and analgesic use, are associated with suffering in fibromyalgia patients. A cross-sectional study

Introducción: La fibromialgia (FM) es un trastorno complejo que genera impacto en la salud pública. Son escasos los estudios que determinan el sufrimiento en FM, pues el abordaje se enfoca en el dolor. Objetivo: Estimar la prevalencia de sufrimiento en los pacientes con FM y su asociación con el impacto en calidad de vida, malestar emocional, soledad, eventos vitales y aspectos clínicos y sociodemográficos en una institución de salud privada de Medellín (Colombia). Método: Se realizó un estudio transversal, en una institución especializada en manejo de dolor crónico. Se evaluó el grado de sufrimiento (PRISM), nivel de dolor (EVA), impacto de la FM (FIQR), soledad (UCLA), ansiedad y depresión (HADS), eventos vitales estresantes (CSV) y las características sociodemográficas y clínicas. Se planteó un modelo explicativo con una regresión logística. Resultados: El 55,5 % IC95 (50,0-61,1) presentó sufrimiento intenso. Se obtuvo un modelo explicativo, donde el impacto en la calidad de vida, la depresión y la toma de analgésicos fueron los factores más relevantes en el sufrimiento intenso. Discusión: Los pacientes con FM manifiestan un sufrimiento importante que debe ser atendido por el personal de salud. Si bien el dolor es un elemento relevante, existen otros factores a los que debe prestarse atención, como el impacto que causa la enfermedad en la persona y la depresión asociada.(AU)

Introduction: Fibromyalgia (FM) is a complex disorder with significant impact on public health. Few studies have explored suffering in FM, since its approach focuses on pain management. Objective: To estimate the prevalence of suffering in patients with FM and its association with impact on quality of life, emotional distress, loneliness, vital stress and clinical and sociodemographic factors in a private healthcare institution in Medellín (Colombia). Method: A cross-sectional study was conducted in an institution specialized in chronic pain management. The degree of suffering (PRISM), level of pain (EVA), impact of FM (FIQR), loneliness (UCLA), anxiety and depression (HADS), stressful life events (CSV) and sociodemographic and clinical characteristics were evaluated. An explanatory model was proposed using logistic regression. Results: 55.5 % IC95 (50,0-61,1) presented intense suffering. An explanatory model was obtained, where impact, depression and analgesic intake were the most relevant factors in intense suffering.Discussion: Patients with FM manifest an important suffering that should be attended by health personnel. Although pain is a relevant element, there are other factors to which attention should be paid, such as the impact of the disease on the person and the associated depression.(AU)

Efectividad de adicionar elongación de la cápsula posterior a un programa de ejercicios en pacientes con síndrome de pinzamiento subacromial: estudio clínico aleatorizado / Effectiveness of adding posterior capsule stretching after an exercise program in patients with subacromial impingement syndrome: a randomized clinical study

Objetivo: Determinar la efectividad clínica de adicionar el ejercicio de elongación de “estiramiento acostado” a un programa de ejercicios específicos en pacientes con síndrome de pinzamiento subacromial (SPSA). Diseño: Estudio clínico aleatorizado ciego simple. Método: Se reclutaron en forma prospectiva 64 pacientes con diagnóstico clínico e imagenológico de SPSA, quienes fueron asignados a dos grupos al azar. El grupo control (n = 32) recibió un programa de ejercicios de 12 semanas, el grupo de intervención (n = 32) recibió el mismo programa más un ejercicio de elongación de la cápsula posterior. Ambos grupos fueron evaluados al inicio y al finalizar el tratamiento. La medida de resultado primaria fue la función del hombro con el cuestionario Constant-Murley, las medidas de resultado secundarias fueron la función de la extremidad superior con el cuestionario DASH y el dolor en reposo y al movimiento con la escala visual analógica (EVA).Resultados: Todos los pacientes completaron el estudio. Al finalizar el tratamiento el cuestionario Constant-Murley mostró una diferencia de 3 puntos (p = 0.864) y el cuestionario DASH una diferencia fue de 2 puntos (p = 0.941), ambas diferencias son a favor del grupo de intervención, pero no son ni clínica ni estadísticamente significativas. Para la EVA en reposo la diferencia fue de 0,2 cm (p = 0,096) y la EVA al movimiento fue de 0,4 cm (p = 0,378), en ambas la diferencia en la reducción del dolor fue mayor en el grupo control. Conclusión: A corto plazo, adicionar el ejercicio de “estiramiento acostado” no proporciona un beneficio clínico ni estadísticamente significativo con respecto a la mejora funcional o la reducción del dolor en pacientes con SPSA.(AU)

Objective: To determine the clinical effectiveness of adding the exercise of “sleep-stretch” to a specific exercise program in patients with subacromial impingement syndrome (SIS). Design: Randomized controlled trial, single-blinded. Methods: Sixty-four patients with clinical and imagenologic diagnosis of SIS were prospectively recruited, who were randomly allocated to two groups. The control group (n = 32) received a 12-week exercise program, and intervention group (n = 32) received the same program plus stretching of the posterior capsule. Both groups were assessed at baseline and at the end of the treatment. The primary outcome measure was shoulder function assessed with Constant-Murley questionnaire. Secondary outcomes measures were upper limb function assessed with the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire, and pain at rest and movement with visual analog scale (VAS). Results: All patients completed the trial. At the end of the treatment, Constant-Murley questionnaire showed a difference of 3 points (p = 0.864), and the DASH questionnaire a difference was 2 points (p = 0.941), both differences were in favor of the intervention group, but they are neither clinically or statistically significant. For the VAS at rest the difference was 0.2 cm (p = 0.096) and the VAS at movement was 0.4 cm (p = 0.378), both differences in pain reduction was greater in the control group.Conclusion: In the short term, the addition of a “sleep-stretch” exercise does not provide a clinically or statistically significant benefit with respect to functional improvement or pain reduction in patients with SIS.(AU)

Un caso de neuralgia amiotrófica tras vacunación frente a COVID-19 / A case of neuralgic amyotrophy after vaccination against COVID-19

Introducción: La neuralgia amiotrófica es un trastorno inflamatorio del plexo braquial con una fisiopatología poco conocida, posiblemente relacionada con fenómenos inmunológicos. Se caracteriza por dolor agudo e intenso, acompañado de debilidad muscular y alteración de los resultados en los estudios electromiográficos y de conducción nerviosa. Al no tener un tratamiento específico, se aborda a través de fisioterapia y el control sintomático. Caso clínico: Presentamos el caso de una mujer de 37 años, sin antecedentes relevantes, que desarrolló el cuadro tras ser vacunada contra el SARS-CoV-2. La paciente respondió de forma discreta a la fisioterapia, analgesia convencional y corticosteroides. Después de 10 meses de tratamiento, se tomó la decisión de utilizar radiofrecuencia pulsada y bloqueo eco-guiado del plexo, lo que logró mejores resultados. Un año después de la aparición del dolor, los síntomas de la paciente habían mejorado, aunque no había podido reincorporarse a su actividad profesional previa como policía. Discusión: Se han publicado muy pocos casos de neuralgia amiotrófica después de la vacunación contra el SARS-CoV-2. El diagnóstico diferencial incluye diversos trastornos musculoesqueléticos y neurológicos comunes, que pueden despistar al profesional y retrasar la identificación de esta entidad, especialmente en el contexto de campañas de vacunación masivas con gran volumen de reacciones adversas. La analgesia convencional a menudo es insuficiente para abordar los problemas de estos pacientes, por lo que se debe prever la necesidad de programar técnicas invasivas. Dada la rareza de la afección y su impacto en la vida personal y profesional del paciente, se destaca la importancia de un diagnóstico precoz y una comunicación fluida. Finalmente, se subraya el valor de la declaración de reacciones adversas como un signo de profesionalidad y un activo para establecer una relación médico-paciente constructiva.(AU)

Introduction: neuralgic amyotrophy is an inflammatory disorder of the brachial plexus with a poorly understood pathophysiology, possibly related to immunological phenomena. It is characterized by acute and intense pain, accompanied by muscle weakness and altered results in electromyographic and nerve conduction studies. Having no specific treatment, it is approached through physiotherapy and symptomatic control. Case history: we present the case of a 37-year-old woman, with no relevant history, who developed the condition after being vaccinated against SARS-CoV-2. The patient responded discreetly to physical therapy, conventional analgesia and corticosteroids. After 10 months of treatment, the decision was made to use pulsed radiofrequency and ultrasound-guided plexus block of the plexus, which achieved better results. A year after the onset of pain, the patient’s symptoms had improved, although she had not been able to return to her professional activity as a policewoman. Discussion: very few cases of neuralgic amyotrophy have been reported after SARS-CoV-2 vaccination. The differential diagnosis includes many common muskuloskeletal and neurologic disorders, which can mislead professionals and delay identification of the disease, especially in the context of massive vaccination campaigns. Conventional analgesia is often insufficient to address these patients’ complaints; thus, scheduled invasive techniques need to be considered. Given the rarity of the condition and its impact on the personal and professional life of the patient, we highlight the importance of an early diagnosis and smooth communication with the patient. Finally, we stress the value of declaring adverse reactions as a sign of professionalism and an asset in establishing a constructive doctor-patient relationship.(AU)

Cefalea persistente tras craneotomía por meningioma en cavum de Meckel: abordaje de las aferencias nociceptivas de principio a fin / Persistent headache after craniotomy for meningioma: charting of the afferent pathways for nociception: a discussion

La mayoría de las lesiones ocupantes de espacios intracraneales requieren una resolución quirúrgica a través de la exéresis de la misma. Esta intervención podría derivar en secuelas importantes como dolor, ya sea por la cicatriz o por la persistencia de residuos de la lesión, entre otros. La neuralgia del trigémino es una afección que genera gran limitación en la calidad de vida de los pacientes que la padecen. Con el estudio de esta patología ha quedado claro que comprender la convergencia trigéminocervical es fundamental para abordar de forma exitosa un plan terapéutico óptimo. Teniendo un conocimiento claro y exhaustivo de los sustratos neuroanatómicos implicados en la transmisión del dolor de la neuralgia del trigémino, exponemos un caso clínico valorado en nuestra Unidad de Dolor. Se trata de una paciente con cefalea trigeminal incapacitante para la vida diaria y resistente a múltiples opciones terapéuticas que, además, limitaba las alternativas para su control debido a la persistencia de restos tumorales a pesar del intento de resección completa durante la intervención quirúrgica. En este caso clínico, hemos considerado diversas dianas terapéuticas abordables a través de técnicas intervencionistas que cada día son más empleadas en las Unidades de Dolor. Teniendo en cuenta la vía del dolor comprometida en este caso, hemos llegado incluso hasta abordar quirúrgicamente estructuras anatómicas centrales responsables del control del dolor para mejorar la calidad de vida de la paciente.(AU)

Most intracranial space-occupying lesions require surgical resolution through excision. This intervention could lead to significant sequelae such as pain, either due to the scar or the persistence of residue from the injury, among others. Trigeminal neuralgia is a condition that generates great limitations in the quality of life of patients who suffer from it. With the study of this pathology, it has become clear that understanding the trigeminal-cervical convergence is essential to successfully approach an optimal therapeutic plan. Having a clear and exhaustive knowledge of the neuroanatomical substrates involved in the transmission of pain from trigeminal neuralgia, we present a clinical case evaluated in our Pain Unit. This is a patient with trigeminal headache that is disabling for daily life and resistant to multiple therapeutic options that, in addition, limited the alternatives for its control due to the persistence of tumor remnants despite the attempt at complete resection during surgery. In this clinical case, we have considered various therapeutic targets that can be addressed through interventional techniques that are increasingly used in Pain Units. Taking into account the pain pathway compromised in this case, we have even gone so far as to surgically address central anatomical structures responsible for pain control to improve the patient’s quality of life.(AU)

Calidad nutricional, evaluación física, sensorial y biológica en panes convencionales y libres de gluten / Nutritional quality and evaluation physic, sensory and biological of conventional and gluten-free breads

Introducción: Los panes libres de gluten disponibles en elmercado se caracterizan por un bajo volumen, una texturadesmenuzada y mayor dureza de la miga, el cual puede mejorarse con la inclusión de pseudocereales. La harina de qui-noa es una excelente fuente de proteína vegetal de alta cali-dad y tiene importantes beneficios nutricionales para la saludhumana. Objetivo: Evaluar las características nutricionales, físicas ysensoriales de panes libre de gluten y convencionales empacados en un material Coextruído Poliamida-Polietileno (COEXPA-PE) durante su almacenamiento, como parámetros bioló-gicos en ratas Holtzman. Materiales y métodos: Se desarrollaron dos formulaciones: pan libre de gluten (PLGQ) que contenía almidón depapa (AP) y harina de quinoa Pasankalla (HQ); mientras queel pan con gluten (PCG) se elaboró a base de harina de trigo(HT). Se analizaron la composición proximal, estructura alveolar, volumen específico, polifenoles totales (PFT), fibra dietaria total (FDT) y parámetros de evaluación biológica. También, se colocaron rodajas de ambos panes en COEX PA-PE, se almacenaron (25 ºC; 80% de HR) y se evaluaron (fir-meza, humedad, aw y aceptabilidad sensorial). Resultados y discusiones: Se encontraron diferencias significativas (p<0,05) entre los panes. Los PLGQ mostraron unalto contenido de FDT (18,49%), PFT (118,46 mg AGE/100g), valor biológico (VB: 84,86%), digestibilidad aparente (DA:91,85%), retención neta de proteína (NPR: 3,25), relación deeficiencia proteica (PER: 2,81), área y estructura alveolar (4,37mm2 y 85,67 número de alveolos/cm2). Asimismo, la firmezafue mayor (3,47N) en el PLGQ frente al PCG (3,18N). Finalmente, la aceptabilidad general fue mejor en PLGQ. Conclusiones: El PLGQ tuvo mejor calidad nutricional, física, sensorial y parámetros de la evaluación biológica respecto al PCG. Además, la porción de PLGQ es considerada altaen FDT.(AU)

Introduction: Commercially available gluten-free breadsare characterized by low volume, crumbly texture and in-creased crumb toughness, which can be improved with the inclusion of pseudocereals. Quinoa flour is an excellent sourceof high quality vegetable protein and has important nutritionalbenefits for human health. Aim: Evaluate the nutritional, physical and sensory charac-teristics of gluten-free and conventional breads packaged in aCoextruded Polyamide-Polyethylene (COEX PA-PE) materialduring storage, as well as the biological parameters inHoltzman rats. Materials & methods: Two formulations were developed: gluten-free bread (PLGQ) containing potato starch (AP) andPasankalla quinoa flour (HQ); while the gluten-containingbread (PCG) was made from wheat flour (HT). Proximal com-position, alveolar structure, specific volume, total polyphenols(TFP), total dietary fiber (TDF) and biological evaluation wereanalyzed. Also, slices of both breads were placed in COEX PA-PE, stored (25 ºC; 80% RH) and evaluated (firmness, mois-ture, aw and sensory acceptability). Results and discussions: Significant differences (p<0,05)were found among the breads. The PLGQ showed high FDTcontent (18,49%), PFT (118,46 mg AGE/100g), biologicalvalue (VB: 84,86%), apparent digestibility (DA: 91,85%), netprotein retention (NPR: 3,25), protein efficiency ratio (PER:2,81), alveolar area and structure (4,37 mm2 and 85,67 number of alveoli/cm2). Likewise, firmness was higher (3,47N) in PLGQ compared to PCG (3,18N). Finally, overall acceptabilitywas better in PLGQ. Conclusions: PLGQ had better nutritional quality, physical, sensory and biological evaluation parameters with respect toPCG. In addition, the PLGQ portion is considered high in FDT.(AU)

The contribution of gastric digestion of starch to the glycaemic index of breads with different composition or structure.

Breads of higher density exhibit lower glycaemic index (GI) both in vivo and in vitro, a phenomenon generally attributed to a slower intestinal starch digestion. The aim of this work was to gain a better understanding of the relationship between bread density, oral and gastric digestion, and GI. Three breads were studied: industrial-style and traditional-style French baguettes (similar composition, different densities), and whole-wheat baguette. In vitro GI predictions confirmed that, for an identical composition, higher bread density was associated with a lower GI. Subsequent oro-gastric digestions, using the dynamic system DIDGI®, showed extensive starch digestion at the gastric stage by salivary α-amylase, in line with recently published data. They further showed that higher bread density led to a lower hydrolysis rate. The concurrence of these results with those of in vivo studies, suggests a mediating role for gastric digestion in the relationship between bread density and GI, possibly via the repercussions on the starch proportion that remains to be hydrolysed in the small intestine. This study therefore adds to the scientific knowledge of the importance of salivary α-amylase to starch digestion, and draws special attention to the possible role of the gastric phase in determining the GI.

Pain-driven emergency department visits and food insecurity: a cross-sectional study linking Canadian survey and health administrative data.

BACKGROUND: As the leading cause of emergency department visits in Canada, pain disproportionately affects socioeconomically disadvantaged populations. We examine the association between household food insecurity and individuals' pain-driven emergency department visits. METHODS: We designed a cross-sectional study linking the Canadian Community Health Survey 2005-2017 to the National Ambulatory Care Reporting System 2003-2017. Food insecurity was measured using a validated questionnaire. We excluded individuals with missing food insecurity status, individuals younger than 12 years and jurisdiction-years with partial emergency department records. We assessed emergency department visits driven by pain at different sites (migraine, other headaches, chest-throat pain, abdomen-pelvis pain, dorsalgia, joint pain, limb pain, other pain) and their characteristics (frequency, cause, acuity and time of emergency department visit) in Ontario and Alberta. We adjusted for sociodemographic characteristics, lifestyle and prior non-pain-driven emergency department visits in the models. RESULTS: The sample contained 212 300 individuals aged 12 years and older. Compared with food-secure individuals, marginally, moderately and severely food-insecure people had 1.42 (95% confidence interval [CI] 1.20-1.68), 1.64 (95% CI 1.37-1.96) and 1.99 (95% CI 1.61-2.46) times higher adjusted incidence rates of pain-driven emergency department visits, respectively. The association was similar across sexes and significant among adults but not adolescents. Food insecurity was further associated with site-specific pain, with severely food-insecure individuals having significantly higher pain incidence than food-secure individuals. Severe food insecurity predicted more frequent, multicause, high-acuity and after-hours emergency department visits. INTERPRETATION: Household food insecurity status is significantly associated with pain-driven emergency department visits in the Canadian population. Policies targeting food insecurity may reduce pain and emergency department utilization.

Antinociceptive effect of N-(9,13b-dihydro-1H-dibenzo[c, f]imidazo[1,5-a]azepin-3-yl)-2-hydroxybenzamide on different pain models in mice

Abstract N-(9,13b-dihydro-1H-dibenzo[c,f]imidazo[1,5-a]azepin-3-yl)-2-hydroxybenzamide (DDIAHB) is a new drug developed through molecular modelling and rational drug design by the molecular association of epinastine and salicylic acid. The present study was designed to assess the possible antinociceptive effects of DDIAHB on different pain models in male ICR mice. DDIAHB exerted the reductions of writhing numbers and pain behavior observed during the second phase in the formalin test in a dose-dependent manner. Moreover, DDIAHB increased the latency in the hot-plate test in a dose-dependent manner. Furthermore, intragastric administration DDIAHB caused reversals of decreased pain threshold observed in both streptozotocin-induced diabetic neuropathy and vincristine-induced peripheral neuropathy models. Additionally, intragastric pretreatment with DDIAHB also caused reversal of decreased pain threshold observed in monosodium urate-induced pain model. We also characterized the possible signaling molecular mechanism of the antinociceptive effect-induced by DDIAHB in the formalin model. DDIAHB caused reductions of spinal iNOS, p-STAT3, p-ERK and p-P38 levels induced by formalin injection. Our results suggest that DDIAHB shows an antinociceptive property in various pain models. Moreover, the antinociceptive effect of DDIAHB appear to be mediated by the reductions of the expression of iNOS, p-STAT3, p-ERK and p-P38 levels in the spinal cord in the formalin-induced pain model.

The Relationship Between Neuroprotective Activity and Antigenotoxic and Acetylcholinesterase Inhibitory Effects of Glaucium corniculatum Extracts

Abstract The purpose of this study was to investigate the relationship between the acetylcholinesterase (AChE) inhibitory and antigenotoxic effect with the neuroprotective activity of Glaucium corniculatum methanol and water extracts rich in rutin and quercetin flavonoids. Neuroprotective activity in terms of cell survival and development against oxidative damage was measured by MTT assay and microscopic analysis in H2O2-induced NGF-differentiated PC12 (dPC12) cells. QRT-PCR and western blot hybridization method was employed for the determination of AChE inhibition of the extracts in the same cell model, and the genotoxic and antigenotoxic effects were identified with Comet assay with human lymphocytes. H2O2-induced vitality loss in dPC12 cells was inhibited in pre-treated cells with these plant extracts. Moreover, extracts stimulated neurite formation and prevented the oxidative stress-induced reduction in neurite growth. In general, it was determined that G. corniculatum methanol extract containing higher amounts of rutin and quercetin was more effective than water extract in terms of AChE inhibitory, antigenotoxic and also neuroprotective effect. In this study, it was shown for the first time that both AChE inhibitory and antigenotoxic effects of G. corniculatum may be effective in neuroprotection and it's protective and therapeutic effects against neurodegeneration may be related to the flavonoid content.

Alleviation of neuropathic pain by trazodone in rats

Abstract Neuropathic pain is generally characterised by an abnormal sensation (dysesthesia), an increased response to painful stimuli (hyperalgesia), and pain in response to a stimulus that does not normally provoke pain (allodynia). The present study was designed to investigate the effect of trazodone (5mg/kg and 10mg/kg) on peripheral neuropathic pain induced by partial sciatic nerve ligation in rats. Mechanical hyperalgesia, cold allodynia and thermal hyperalgesia were assessed by performing the pinprick, acetone, and hot plate tests, respectively. Biochemically, lipid peroxidation level and total calcium levels were measured. However, trazodone administration (5 and 10 mg/ kg i.p.) for 21days significantly diminished partial sciatic nerve ligation-induced neuropathic pain along with areduction in oxidative stress and calcium levels. The results of the present study suggest that trazodone is effective in attenuating partial sciatic nerve ligation-inducedpainful neuropathic states, which may be attributed to decreased oxidative stress and calcium levels.