Fucoxanthin mitigates valproic acid-induced autistic behavior through modulation of the AKT/GSK-3β signaling pathway

This study aimed to investigate the effects of fucoxanthin, a natural compound found in seaweed, on various aspects of autism using a rat model induced by valproic acid (VPA). Pregnant rats were administered VPA (600 mg/kg) on gestational day 12.5, and male pups were orally administered fucoxanthin at 50, 100, or 200 mg/kg beginning on post-natal day (PND) 23-43. Behavioral assessments were conducted on PND 45-53, and on PND 54, the animals were sacrificed for further biochemical analyses (superoxide dismutase (SOD) and glutathione (GSH), nitric oxide (NO)) via UV spectroscopy. Inflammatory markers (IL-17, TNF-α, and IL-1β) were also analyzed by sandwich ELISA, and the molecular parameters were evaluated through ELISA. The results revealed that, compared with VPA, fucoxanthin improved behavior and neuronal morphology. Specifically, fucoxanthin administration was found to enhance spatial memory, reduce pain sensitivity, and improve social interaction, locomotor activity, balance, and motor coordination. Fucoxanthin also exhibited anti-inflammatory and antioxidant effects, as indicated by the restoration of SOD and GSH levels and reduced inflammatory cytokine levels. Molecular analyses revealed that fucoxanthin restored the levels of GSK-3β and AKT. Furthermore, fucoxanthin regulates neurotransmitters, which are related to increasing GABA and reducing glutamate levels in the cortex and cerebellum. The therapeutic effects were dose-dependent, with higher doses (200 mg/kg) showing greater efficacy than lower doses (100 mg/kg) in improving behavioral, biochemical, neurotransmitter, and molecular parameters. Fucoxanthin is a potential treatment for autism, but further research, including clinical trials, is necessary to determine its effectiveness in humans.

Evaluation of the impact of continuous Kangaroo Mother Care (KMC) initiated immediately after birth compared to KMC initiated after stabilization in newborns with birth weight 1.0 to < 1.8 kg on neurodevelopmental outcomes: Protocol for a follow-up study

BACKGROUND

Preterm birth or low birth weight is the single largest cause of death in newborns, however this mortality can be reduced through newborn care interventions, including Kangaroo Mother Care (KMC). Previously, a multi-country randomized controlled trial, coordinated by the World Health Organization (WHO), reported a significant survival advantage with initiation of continuous KMC immediately after birth compared with initiation of continuous KMC a few days after birth when the baby is considered clinically stable. Whether the survival advantage would lead to higher rates of neurodevelopmental morbidities, or the immediate KMC will also have a beneficial effect on cognitive development also, has not been investigated. We therefore propose to test the hypothesis that low-birth-weight infants exposed to immediate KMC will have lower rates of neurodevelopmental impairment in comparison to traditional KMC-treated infants, by prospectively following up infants already enrolled in the immediate KMC trial for the first 2 years of life, and assessing their growth and neurodevelopment.

METHODS

This prospective cohort study will enroll surviving neonates from the main WHO immediate KMC trial. The main trial as well as this follow-up study are being conducted in five low- and middle-income countries in South Asia and sub-Saharan Africa. The estimated sample size for comparison of the risk of neurodevelopmental impairment is a total of 2200 children. The primary outcome will include rates of cerebral palsy, hearing impairment, vision impairment, mental and motor development, and epilepsy and will be assessed by the age of 3 years. The analysis will be by intention to treat.

DISCUSSION

Immediate KMC can potentially reduce low-birth-weight-associated complications such as respiratory disease, hypothermia, hypoglycemia, and infection that can result in impaired neurocognitive development. Neuroprotection may also be mediated by improved physiological stabilization that may lead to better maturation of neural pathways, reduced risk of hypoxia, positive parental impact, improved sleep cycles, and improved stress responses. The present study will help in evaluating the overall impact of KMC by investigating the long-term effect on neurodevelopmental impairment in the survivors.

TRIAL REGISTRATION

Clinical Trials Registry-India CTRI/2019/11/021899. Registered on 06 November 2019. Trials registration of parent trial: ACTRN12618001880235; Clinical Trials Registry-India: CTRI/2018/08/015369.

Exercise induced muscle damage and repeated bout effect: an update for last 10 years and future perspectives

Exercise-induced muscle damage (EIMD) and repeated bout effect (RBE) are widely researched across various populations. EIMD is the muscle damage occurring after one bout of unaccustomed exercise while RBE is the attenuation of the same muscle damage in subsequent second bout. RBE seems to have significant implications for exercise prescription. Despite existence of vast literature, there is lack of clarity on the effects of EIMD and RBE in a healthy population. The purpose of this study is to review the literature on EIMD and RBE in healthy participants published during the last 10 years. The search of major databases (including Scopus, Google Scholar and PubMed) was conducted using specific keywords ‘Exercise induced muscle damage’, ‘Repeated bout effect’, ‘Healthy participants’ ‘Pre-conditioning’, ‘Eccentric exercise’. Studies published from 2011 onwards which included EIMD and RBE assessment in healthy participants were included in this review. Database searching revealed a total of 38 studies on EIMD and RBE in healthy participants. Three major themes of papers were identified that focused on EIMD and RBE along with (1) age related differences, (2) sex-based differences, and (3) response in athletes. Findings of this comprehensive review suggests that both EIMD and RBE are age, and sex specific. Delayed onset muscle soreness played a major role in both EIMD and RBE in all the population types. Female participants are less susceptible to EIMD as compared to age-matched male counterparts. Moreover, both EIMD and RBE are more elicited in middle aged and younger adults as compared to children and older adults while the magnitude of RBE turns out to be minimal in trained individuals due to persisting adaptations.

Impact of tele rehabilitation on clinical outcomes in patients recovering from COVID-19: a preliminary investigation

Pulmonary rehabilitation has proven to be an effective therapeutic intervention for people with chronic respiratory disease. Considering the highly contagious nature of coronavirus disease (COVID-19), it becomes imperative to develop a method which can effectively improve clinical disease outcomes of these patients without any physical contact. The purpose of the study was to investigate the impact of tele rehabilitation on dyspnoea, endurance and quality-of-life in patients recovering from COVID 19. Thirty-two participants (age: 42.5±13.94, height: 165.8±10.06, weight: 68.5±9.63, body mass index: 25.0±3.61) who are recovering from COVID-19 were recruited as per the eligibility criteria. They were randomly allocated into two groups, Tele rehabilitation (n=16) and Control (n=16) by lottery method. All the selected participants were assessed at baseline for perceived dyspnoea, endurance and quality-of-life. Patients in the Tele rehabilitation group received 14 sessions of rehabilitation on alternate days online via google meet over a period of 28 days. Control group received usual care during the study period. Standard statistical tests were employed to test the study hypothesis. Results suggested a significant improvement in both dyspnoea (P=0.001) and endurance (P<0.001) in response to tele rehabilitation. Domains of quality-of-life such as physical role (P=0.02), vitality (P=0.04), emotional role (P=0.03), mental health (P=0.02) and physical components score (P=0.007) also showed significant improvement with tele rehabilitation in patients recovering from COVID-19. Findings of this preliminary study concludes that tele rehabilitation may be considered a treatment of choice in patients recovering from COVID-19 for improving outcomes of dyspnoea, endurance and quality-of-life.

The development and validation of the ‘Good Life in the Community Scale’ (GLiCS): a validation study with women migrants living in high income countries

Background

To date, few assessment instruments have been developed to quantitatively measure the mental health status of migrant populations specifically. This paper describes the development and preliminary assessment of the ‘Good Life in the Community Scale’ (GLiCS). GLiCS is a wellbeing measure for migrant women in high-income settings that was coproduced with experts by experience across two phases.

Methods

The study used a mixed-methods approach and was composed of two phases. Phase I: 88 initial items generated using qualitative data collected in a previous study were reduced to 42 through consultation with expert advisory panels, based on whether each item was considered understandable and relevant Phase II: these 42 items were piloted with a sample of migrant women (N = 109). A preliminary exploratory factor analysis was conducted using Oblique rotation. Internal consistency was measured using McDonald’s ω. Convergent validity was tested by correlating the GLiCS with the Oxford Capabilities Questionnaire Mental Health (OxCAP-MH), WHO-5 wellbeing index and Objective Social Outcomes Index (SIX). Incremental validity was tested using hierarchical regression analysis to ascertain the effect on the WHO-5 wellbeing index of: age, migration status, SIX, OxCAP-MH and GLiCS. Known groups validity, the ability a measure has to discriminate between groups likely to differ on the variables of interest, was tested between the different migrant categories using a simple between subjects ANOVA.

Results

Exploratory factor analysis confirmed a 17-item (three-factor: (i) access to resources, (ii) belonging and contributing, (iii) independence) scale with high internal consistency (McDonald’s ω = 0.91). Convergent and incremental validity were also evidenced.

Conclusion

The GLiCS has demonstrable good internal consistency and construct validity, and it presents a promising wellbeing measure for better understanding the experience of migrant women.

Mechanical and thermal behavior of hybrid composite medium density fiberboard reinforced with phenol formaldehyde

The world was in demand of wood products mainly for interior design, furniture making and household utilizes and at the same time agricultural residue usage was increased for making Engineering woods. Coconut is an abundant crop in Asia and coir fiber was extracted from coconut husk, as by-products. MDF was one of the by-products produced from coir reinforced with resin. In this work, the coconut coir was used to produce hybrid MDF with basalt fiber and phenol-formaldehyde resin hybridization. The panel was prepared with different coir and basalt fiber combinations by keeping a fixed resin percentage. The coir and basalt fiber percentage ranges from 40 to 75 % and 5–40 % respectively. SEM studied the morphological characteristic of the panel whereas thermal stability of the panel was evaluated through Thermo-gravimetric Analysis. The fire resistance was observed through a flammability test. The physical properties and mechanical properties were evaluated by ASTM Standards. From the investigations, the MoR and MoE have a higher value for Panel 3 with 29.14 N/mm² and 3143 N/mm² respectively and the internal bonding strength shows of 2.1 N/mm² maximum values of mechanical properties. The result shows for panel 3 has 15 % and 18 % more strength for MoE and MoR respectively and IB also shows 35 % of increased value.

Best clinical practice guidance for conscious sedation of children undergoing dental treatment: an EAPD policy document

BACKGROUND

Due to fear and/or behaviour management problems, some children are unable to cooperate for dental treatment using local anaesthesia and psychological support alone. Sedation is required for these patients in order for dentists to be able to deliver high quality, pain-free dental care. The aim of this guideline is to evaluate the efficacy and relative efficacy of conscious sedation agents and dosages for behaviour management in paediatric dentistry and to provide guidance as to which sedative agents should be used.

METHODS

These guidelines were developed using a multi-step approach adapted from that outlined by the National Institute for Clinical Excellence (NICE (2020) Developing NICE Guidelines: the manual. https://www.nice.org.uk/process/pmg20/chapter/introduction#main-stages-of-guideline-development . Accessed 7 Oct 2020). Evidence for this guideline was provided from a pre-existing Cochrane review (Ashley et al. Cochrane Database Syst Rev 12:CD003877, 2018) supplemented by an updated search and data extraction up to May 2020.

RESULTS

Studies were from 18 different countries and had recruited 4131 participants overall with an average of 70 participants per study. Ages ranged from 0 to 16 years with an average age of 5.6 years across all included studies. A wide variety of drugs or combinations of drugs (n = 38) were used and delivered orally, intranasally, intravenously, rectally, intramuscularly, submucosally, transmucosally or by inhalation sedation. Twenty-four different outcome measures for behaviour were used. The wide range of drug combinations and outcome measures used greatly complicated description and analysis of the data.

CONCLUSION

Oral midazolam is recommended for conscious dental sedation. Midazolam delivered via other methods or nitrous oxide/oxygen sedation could be considered, but the evidence for both was very low.

Dense bone islands in pediatric patients: a case series study

Background

Dense Bone Islands (DBIs) are anatomic variants defined as radiopaque lesions consisting of hamartomatous cortical bone, often presenting as incidental radiographic findings. DBIs can also be known as idiopathic osteosclerosis, bone whorl, focal periapical osteopetrosis, bone scar and enostosis. We found a paucity of literature for management and reporting of this condition in children. For this reason, the authors describe sixteen cases of children and adolescents with dense bony islands and suggest a pathway for management.

Case series

Cases presented to the RNENT and Eastman Dental Hospital or private practice, either as chance findings or for diagnosis and treatment planning of undiagnosed radiopaque areas. The individuals were aged between 10 and 17 years; 6 boys and 10 girls. All radiographic reports described DBIs. Diagnoses were confirmed by a Dental and Maxillofacial Radiology Consultant and advised no intervention. In some cases, monitoring was advised. Caution in orthodontic tooth movement was advised for five patients.

Conclusion

DBIs are common findings that seldom require treatment; however, caution should be exercised when undertaking orthodontic movement in the area of a DBI due to a potential risk of root resorption. Accurate identification and multidisciplinary management are of utmost importance.

The role of urea in neuronal degeneration and sensitization: An in vitro model of uremic neuropathy

Background

Uremic neuropathy commonly affects patients with chronic kidney disease, with painful sensations in the feet, followed by numbness and weakness in the legs and hands. The symptoms usually resolve following kidney transplantation, but the mechanisms of uremic neuropathy and associated pain symptoms remain unknown. As blood urea levels are elevated in patients with chronic kidney disease, we examined the morphological and functional effects of clinically observed levels of urea on sensory neurons.

Methods

Rat dorsal root ganglion neurons were treated with 10 or 50 mmol/L urea for 48 h, fixed and immunostained for PGP9.5 and βIII tubulin immunofluorescence. Neurons were also immunostained for TRPV1, TRPM8 and Gap43 expression, and the capsaicin sensitivity of urea- or vehicle-treated neurons was determined.

Results

Urea-treated neurons had degenerating neurites with diminished PGP9.5 immunofluorescence, and swollen, retracted growth cones. βIII tubulin appeared clumped after urea treatment. After 48 hours urea treatment, neurite lengths were significantly reduced to 60 ± 2.6% (10 mmol/L, **P < 0.01), and to 56.2 ± 3.3% (50 mmol/L, **P < 0.01), compared with control neurons. Fewer neurons survived urea treatment, with 70.08 ± 13.3% remaining after 10 mmol/L (*P < 0.05) and 61.49 ± 7.4% after 50 mmol/L urea treatment (**P < 0.01), compared with controls. The proportion of neurons expressing TRPV1 was reduced after urea treatment, but not TRPM8 expressing neurons. In functional studies, treatment with urea resulted in dose-dependent neuronal sensitization. Capsaicin responses were significantly increased to 115.29 ± 3.4% (10 mmol/L, **P < 0.01) and 125.3 ± 4.2% (50 mmol/L, **P < 0.01), compared with controls. Sensitization due to urea was eliminated in the presence of the TRPV1 inhibitor SB705498, the mitogen-activated protein kinase kinase inhibitor PD98059, the PI3 kinase inhibitor LY294002 and the TRPM8 inhibitor N-(3-Aminopropyl)-2-[(3-methylphenyl)methoxy]-N-(2-thienylmethyl)benzamide (AMTB hydrochloride).

Conclusion

Neurite degeneration and sensitization are consistent with uremic neuropathy and provide a disease-relevant model to test new treatments.

Observed Inter annual Variability of Upwelling Characteristics during 2016 2017 A Study using Princeton Ocean Model

Oceanographic observations carried out during 2016 and 2017 onboard INS Sagardhwani in the Southeastern Arabian sea are used to study the inter-annual variability of the upwelling. In 2016, the strong upwelling signatures are noticed in the observations (SST < 27°C and strong up-slopping of isotherms) as well as in the satellite derived sea level anomaly data. Whereas in 2017 the low sea level in June (-2 cm) are weakened during the mid of July (+3 cm) along the southern track (8 °N and 9 °N). This decrease in the strength in 2017 can be attributed to two major reasons. One is the presence of an anti-cyclonic eddy along the coast (8.5 °N, 76.5 °E) weakens the upwelling processes and second is the weak northerly component of the wind compared to 2016. In addition, Lakshadweep low is less prominent and situated towards the southern side (around 7°N) of its usual region of occurrence in 2017. The inter-annual variability of upwelling during July 2016 and 2017 is investigated using the 3D ocean model Princeton Ocean Model. Experiments with model in different combinations of forcing reveals that the alongshore wind component is the major parameter influencing the upwelling characteristics during these periods.

Effect of Azimuthal Asymmetry Caused by Upwelling on 3D Ocean Acoustic Propagation

3-D underwater parabolic equation model based on implicit finite difference method has been implemented for South Eastern Arabian Sea (SEAS). The bathymetric and geo-acoustic features have been integrated in the model for a 50 km circular region in SEAS. The model can simulate the effects of azimuthal variation in oceanographic features and compute azimuthally coupled pressure due to an omni-directional source. The azimuthal variation in oceanographic conditions can be observed during an upwelling event. In the first case study, the effect of upwelling event on three-dimensional acoustic propagation has been studied by using sound speed profile data derived from INS Sagardhwani observations. The difference in Transmission loss mosaic for upslope and downslope propagation is due to bathymetry as well as upwelling. In the second case study, the effect of upwelling only, is studied by running a model corresponding to range independent sound speed profile field and range dependent bathymetry. It was observed that during this upwelling event, the transmission loss is higher at longer ranges during upslope propagation than downslope propagation. This is due to the increase in the thickness of sonic layer duct as acoustic wave propagates from shallow to deep water. The effect of azimuthal variation i

Reduced vitamin D levels in painful diabetic peripheral neuropathy

AIM

Recent studies have reported an association between low vitamin D levels and diabetic peripheral neuropathy. However, many of these did not differentiate between people with painful diabetic peripheral neuropathy and those with painless diabetic peripheral neuropathy, or assess major confounding factors including sunlight exposure and daily activity. Our study addressed these limitations and evaluated vitamin D levels in people with carefully phenotyped diabetic peripheral neuropathy and controls.

METHODS

Forty-five white Europeans with Type 2 diabetes and 14 healthy volunteers underwent clinical and neurophysiological assessments. People with Type 2 diabetes were then divided into three groups (17 with painful diabetic peripheral neuropathy, 14 with painless diabetic peripheral neuropathy and 14 with no diabetic peripheral neuropathy). All had seasonal sunlight exposure and daily activity measured, underwent a lower limb skin biopsy and had 25-hydroxyvitamin D measured during the summer months, July to September.

RESULTS

After adjusting for age, BMI, activity score and sunlight exposure, 25-hydroxyvitamin D levels (nmol/l) (se) were significantly lower in people with painful diabetic peripheral neuropathy [painful diabetic peripheral neuropathy 34.9 (5.8), healthy volunteers 62.05 (6.7), no diabetic peripheral neuropathy 49.6 (6.1), painless diabetic peripheral neuropathy 53.1 (6.2); ANCOVAP = 0.03]. Direct logistic regression was used to assess the impact of seven independent variables on painful diabetic peripheral neuropathy. Vitamin D was the only independent variable to make a statistically significant contribution to the model with an inverted odds ratio of 1.11. Lower 25-hydroxyvitamin D levels also correlated with lower cold detection thresholds (r = 0.39, P = 0.02) and subepidermal nerve fibre densities (r = 0.42, P = 0.01).

CONCLUSIONS

We have demonstrated a significant difference in 25-hydroxyvitamin D levels in well-characterized people with painful diabetic peripheral neuropathy, while accounting for the main confounding factors. This suggests a possible role for vitamin D in the pathogenesis of painful diabetic peripheral neuropathy. Further prospective and intervention trials are required to prove causality between low vitamin D levels and painful diabetic peripheral neuropathy.

Influence of Bathymetry on the Performance of Regional Scale Model

<p class="p1"><span class="Apple-converted-space"> </span>A three dimensional ocean circulation model (Princeton Ocean Model) is utilised to study the thermohaline variability of the eastern Arabian Sea associated with changes in the three input bathymetry data sets, viz. ETOPO5 (E5), Modified ETOPO5 (ME5) and ME5 further modified based on actual fine resolution data collected using Multibeam echo-sounder (MEN5). The temperature and salinity measurements made onboard INS Sagardhwani for the period July 2000 is utilised to validate the model. Simulations of temperature using Princeton Ocean Model show good improvement in the coastal region with MEN5 bathymetry data (RMS error of 0.71 °C and correlation coefficient of 0.98). The study highlights the choice of fine resolution bathymetry data in the simulation of nearshore processes, where bathymetry is very complex.</p>

Mycolactone-mediated neurite degeneration and functional effects in cultured human and rat DRG neurons: Mechanisms underlying hypoalgesia in Buruli ulcer

Background

Mycolactone is a polyketide toxin secreted by the mycobacterium Mycobacterium ulcerans, responsible for the extensive hypoalgesic skin lesions characteristic of patients with Buruli ulcer. A recent pre-clinical study proposed that mycolactone may produce analgesia via activation of the angiotensin II type 2 receptor (AT₂R). In contrast, AT₂R antagonist EMA401 has shown analgesic efficacy in animal models and clinical trials for neuropathic pain. We therefore investigated the morphological and functional effects of mycolactone in cultured human and rat dorsal root ganglia (DRG) neurons and the role of AT₂R using EMA401. Primary sensory neurons were prepared from avulsed cervical human DRG and rat DRG; 24 h after plating, neurons were incubated for 24 to 96 h with synthetic mycolactone A/B, followed by immunostaining with antibodies to PGP9.5, Gap43, β tubulin, or Mitotracker dye staining. Acute functional effects were examined by measuring capsaicin responses with calcium imaging in DRG neuronal cultures treated with mycolactone.

Results

Morphological effects: Mycolactone-treated cultures showed dramatically reduced numbers of surviving neurons and non-neuronal cells, reduced Gap43 and β tubulin expression, degenerating neurites and reduced cell body diameter, compared with controls. Dose-related reduction of neurite length was observed in mycolactone-treated cultures. Mitochondria were distributed throughout the length of neurites and soma of control neurons, but clustered in the neurites and soma of mycolactone-treated neurons. Functional effects: Mycolactone-treated human and rat DRG neurons showed dose-related inhibition of capsaicin responses, which were reversed by calcineurin inhibitor cyclosporine and phosphodiesterase inhibitor 3-isobutyl-1-Methylxanthine, indicating involvement of cAMP/ATP reduction. The morphological and functional effects of mycolactone were not altered by Angiotensin II or AT₂R antagonist EMA401.

Conclusion

Mycolactone induces toxic effects in DRG neurons, leading to impaired nociceptor function, neurite degeneration, and cell death, resembling the cutaneous hypoalgesia and nerve damage in individuals with M. Ulcerans infection.

Dynamic optimization of a copolymerization reactor using tabu search

A novel multistage dynamic optimization strategy based on meta-heuristic tabu search (TS) is proposed and evaluated through sequential and simultaneous implementation procedures by applying it to a semi-batch styrene-acrylonitrile (SAN) copolymerization reactor. The adaptive memory and responsive exploration features of TS are exploited to design the dynamic optimization strategy and compute the optimal control policies for temperature and monomer addition rate so as to achieve the desired product quality parameters expressed in terms of single and multiple objectives. The dynamic optimization results of TS sequential and TS simultaneous implementation strategies are analyzed and compared with those of a conventional optimization technique based on iterative dynamic programming (IDP). The simulation results demonstrate the usefulness of TS for optimal control of transient dynamic systems.

Rapid determination of pesticide residues in fruits and vegetables, using ultra-high-performance liquid chromatography/time-of-flight mass spectrometry

A multiresidue method, based on the sample preparation by solid-phase extraction cartridges and detection by ultra-high-performance liquid chromatography/time-of-flight mass spectrometry (UHPLC/TOF-MS), was used for the analysis of 60 pesticides in vegetable and fruit samples. Quantitation by UHPLC/TOF-MS is accomplished by measuring the accurate mass of the protonated molecules [M+H](+). The mass accuracy typically obtained is routinely better than 2ppm. The rates of recovery for pesticides studied were satisfactory, ranging from 74% to 111% with a relative standard deviation (RSD) of less than 13.2%, at concentrations below 10μgkg(-1). The method limit of quantification (MLOQ) for most compounds was below the MRLs established by the Food Safety Standard Authority of India and the European Union. The uncertainty was determined using repeatability, recovery and calibration curves data for each pesticide. The method illustrated is suitable for routine quantitative analyses of pesticides in food samples.

Post-operative pain and anxiety related to dental procedures in children

AIM

To determine post-operative pain in children following treatment in the dental chair and its relation to dental anxiety.

METHODS

A group of 125 children, aged 5 to 18 years, attending for dental treatment had their pain recorded post-operatively using the revised version of the Faces Pain Scale (FPS-R) and the Visual Analogue Scale (VAS). Baseline anxiety scores were also recorded using the Modified Child Dental Anxiety Scale (faces) (MCDASf).

RESULTS

The mean MCDASf score was 20.1. Post-operative pain was reported in 62% of children at 2 hours, 51% at 4, and 47% at 6 hours. The surgical subgroup reported the most pain (79%), whereas the conservative treatment for primary teeth group reported the least pain (37%). Anxious patients (MCDASf > = 17) were more likely to report pain than less anxious patients at 2 (p=0.02) and 6 (p=0.03) hours post-operatively.

CONCLUSION

Dental procedures are associated with post-operative pain in children. Anxious patients are more likely to report pain.

Capsaicin 8% patch for treprostinil subcutaneous infusion site pain in pulmonary hypertension patients

BACKGROUND

Treprostinil sodium improves haemodynamics and symptoms in pulmonary arterial hypertension (PAH) patients, but its subcutaneous (s.c.) administration can produce severe local site pain, and lead to discontinuation of vital treatment. Treprostinil is a prostacyclin analogue which stimulates prostacyclin receptors in skin nociceptor terminals, resulting in pain and cutaneous hypersensitivity, for which current pain remedies have limited effect. Capsaicin 8% patch relieves neuropathic pain for 3 months after a single 60 min cutaneous application; we investigated whether its pre-application can reduce s.c. trepostinil-induced pain.

METHODS

A single-centre, double-blind, randomized, placebo-controlled, crossover study was conducted to assess the safety and efficacy of a single capsaicin 8% patch pre-application for s.c. treprostinil pain in 11 PAH patients, relative to control patch with low-dose capsaicin 0.075% cream.

RESULTS

The primary efficacy endpoint, mean difference between the two treatment arms in an 11-point numerical pain rating scale from baseline to 2 weeks after patch applications, was significantly lower on the capsaicin 8% patch treatment arm [P=0.01, mean difference=-1.47 units, 95% credible interval (CI): -2. 59 to -0.38] in the patients who completed the study per protocol, although intention-to-treat analysis did not show significant difference (P=0.28). Heat pain thresholds were decreased (P=0.027, mean difference=5.43°C, 95% CI: 0.71-10.21) and laser Doppler flux increased (P=0.016, mean difference=370 units, 95% CI: 612 to 127.9) at the application site immediately after capsaicin 8% patch, confirming activity.

CONCLUSIONS

Further investigation of the efficacy of capsaicin 8% patch in this indication is warranted.

Angiotensin II type 2 receptor (AT2 R) localization and antagonist-mediated inhibition of capsaicin responses and neurite outgrowth in human and rat sensory neurons

BACKGROUND

The angiotensin II (AngII) receptor subtype 2 (AT2 R) is expressed in sensory neurons and may play a role in nociception and neuronal regeneration.

METHODS

We used immunostaining with characterized antibodies to study the localization of AT2 R in cultured human and rat dorsal root ganglion (DRG) neurons and a range of human tissues. The effects of AngII and AT2 R antagonist EMA401 on capsaicin responses in cultured human and rat (DRG) neurons were measured with calcium imaging, on neurite length and density with Gap43 immunostaining, and on cyclic adenosine monophosphate (cAMP) expression using immunofluorescence.

RESULTS

AT2 R expression was localized in small-/medium-sized cultured neurons of human and rat DRG. Treatment with the AT2 R antagonist EMA401 resulted in dose-related functional inhibition of capsaicin responses (IC50  = 10 nmol/L), which was reversed by 8-bromo-cAMP, and reduced neurite length and density; AngII treatment significantly enhanced capsaicin responses, cAMP levels and neurite outgrowth. The AT1 R antagonist losartan had no effect on capsaicin responses. AT2 R was localized in sensory neurons of human DRG, and nerve fibres in peripheral nerves, skin, urinary bladder and bowel. A majority sub-population (60%) of small-/medium-diameter neuronal cells were immunopositive in both control post-mortem and avulsion-injured human DRG; some very small neurons appeared to be intensely immunoreactive, with TRPV1 co-localization. While AT2 R levels were reduced in human limb peripheral nerve segments proximal to injury, they were preserved in painful neuromas.

CONCLUSIONS

AT2 R antagonists could be particularly useful in the treatment of chronic pain and hypersensitivity associated with abnormal nerve sprouting.

Analgesic efficacy and safety of the novel p38 MAP kinase inhibitor, losmapimod, in patients with neuropathic pain following peripheral nerve injury: a double-blind, placebo-controlled study

BACKGROUND

Inhibitors of p38 mitogen-activated protein kinase are undergoing evaluation as a novel class of anti-rheumatic drugs, by virtue of their ability to suppress the production of pro-inflammatory cytokines. Emerging data suggests that they may also attenuate peripheral or central sensitization in neuropathic pain. A double-blind, placebo-controlled study was undertaken to evaluate the analgesic efficacy of losmapimod (GW856553), a novel p38α/β inhibitor, in subjects with neuropathic pain following traumatic peripheral nerve injury.

METHODS

One hundred and sixty-eight subjects with pain of at least moderate intensity (average daily score ≥4 on an 11-point pain intensity numeric rating scale; PI-NRS) at baseline were randomized to receive oral losmapimod, 7.5 mg BID or placebo for 28 days. Efficacy and safety assessments were undertaken at weekly clinic visits.

RESULTS

The mean treatment difference for the change in average daily pain score from baseline to week 4 of treatment based on the PI-NRS was -0.22 (95% CI -0.73, 0.28) in favour of losmapimod over placebo (p = 0.39). There were no statistically significant or clinically meaningful differences between the treatment groups over the 4-week dosing period for either the primary or secondary efficacy variables. There were no unexpected safety or tolerability findings following dosing with losmapimod.

CONCLUSIONS

Losmapimod could not be differentiated from placebo in terms of a primary analgesia response in patients with pain following peripheral nerve injury. The lack of response could reflect inadequate exposure at central sites of action or differences between rodent and human with respect to the target or neuropathic pain mechanisms.

Nerve injuries sustained during warfare: part II: Outcomes

The outcomes of 261 nerve injuries in 100 patients were graded good in 173 cases (66%), fair in 70 (26.8%) and poor in 18 (6.9%) at the final review (median 28.4 months (1.3 to 64.2)). The initial grades for the 42 sutures and graft were 11 good, 14 fair and 17 poor. After subsequent revision repairs in seven, neurolyses in 11 and free vascularised fasciocutaneous flaps in 11, the final grades were 15 good, 18 fair and nine poor. Pain was relieved in 30 of 36 patients by nerve repair, revision of repair or neurolysis, and flaps when indicated. The difference in outcome between penetrating missile wounds and those caused by explosions was not statistically significant; in the latter group the onset of recovery from focal conduction block was delayed (mean 4.7 months (2.5 to 10.2) vs 3.8 months (0.6 to 6); p = 0.0001). A total of 42 patients (47 lower limbs) presented with an insensate foot. By final review (mean 27.4 months (20 to 36)) plantar sensation was good in 26 limbs (55%), fair in 16 (34%) and poor in five (11%). Nine patients returned to full military duties, 18 to restricted duties, 30 to sedentary work, and 43 were discharged from military service. Effective rehabilitation must be early, integrated and vigorous. The responsible surgeons must be firmly embedded in the process, at times exerting leadership.

Nerve injuries sustained during warfare: part I--Epidemiology

We describe 261 peripheral nerve injuries sustained in war by 100 consecutive service men and women injured in Iraq and Afghanistan. Their mean age was 26.5 years (18.1 to 42.6), the median interval between injury and first review was 4.2 months (mean 8.4 months (0.36 to 48.49)) and median follow-up was 28.4 months (mean 20.5 months (1.3 to 64.2)). The nerve lesions were predominantly focal prolonged conduction block/neurapraxia in 116 (45%), axonotmesis in 92 (35%) and neurotmesis in 53 (20%) and were evenly distributed between the upper and the lower limbs. Explosions accounted for 164 (63%): 213 (82%) nerve injuries were associated with open wounds. Two or more main nerves were injured in 70 patients. The ulnar, common peroneal and tibial nerves were most commonly injured. In 69 patients there was a vascular injury, fracture, or both at the level of the nerve lesion. Major tissue loss was present in 50 patients: amputation of at least one limb was needed in 18. A total of 36 patients continued in severe neuropathic pain. This paper outlines the methods used in the assessment of these injuries and provides information about the depth and distribution of the nerve lesions, their associated injuries and neuropathic pain syndromes.

The menthol and cold sensation receptor TRPM8 in normal human nasal mucosa and rhinitis

BACKGROUND

Menthol and cold sensation trigger symptoms and reflex responses in the upper airway, but the underlying molecular mechanisms are unknown. We have therefore studied nerve fibres expressing the menthol and cold receptor TRPM8 in normal human mucosa, and in rhinitis. TRPM8 nerve fibres were compared with those expressing other TRP receptors including TRPV1 (capsaicin and heat receptor), and TRPA1 (mechano-cold receptor).

METHODS

Immunohistology and image-analysis were used to study TRP receptors in biopsies of nasal turbinate from control subjects, patients with allergic rhinitis, and non-allergic rhinitis.

RESULTS

TRPM8-immunoreactive nerve fibres were observed in the sub-epithelium, and were profuse around blood vessels in deeper regions, where they were markedly greater in number than TRPV1+ fibers. Image analysis of TRPM8 in sub-epithelial and vascular regions showed no significant differences between control and the rhinitis patient groups. TRPA1-immunoreactivity was weak and seen rarely in nerve fibres.

CONCLUSION

We show that TRPM8 nerve fibres are abundant in nasal mucosa particularly around blood vessels, and may mediate neurovascular reflexes. TRPM8 antagonists deserve consideration for therapeutic trial in rhinitis.

Topical capsaicin for pain management: therapeutic potential and mechanisms of action of the new high-concentration capsaicin 8% patch

Topical capsaicin formulations are used for pain management. Safety and modest efficacy of low-concentration capsaicin formulations, which require repeated daily self-administration, are supported by meta-analyses of numerous studies. A high-concentration capsaicin 8% patch (Qutenza™) was recently approved in the EU and USA. A single 60-min application in patients with neuropathic pain produced effective pain relief for up to 12 weeks. Advantages of the high-concentration capsaicin patch include longer duration of effect, patient compliance, and low risk for systemic effects or drug-drug interactions. The mechanism of action of topical capsaicin has been ascribed to depletion of substance P. However, experimental and clinical studies show that depletion of substance P from nociceptors is only a correlate of capsaicin treatment and has little, if any, causative role in pain relief. Rather, topical capsaicin acts in the skin to attenuate cutaneous hypersensitivity and reduce pain by a process best described as 'defunctionalization' of nociceptor fibres. Defunctionalization is due to a number of effects that include temporary loss of membrane potential, inability to transport neurotrophic factors leading to altered phenotype, and reversible retraction of epidermal and dermal nerve fibre terminals. Peripheral neuropathic hypersensitivity is mediated by diverse mechanisms, including altered expression of the capsaicin receptor TRPV1 or other key ion channels in affected or intact adjacent peripheral nociceptive nerve fibres, aberrant re-innervation, and collateral sprouting, all of which are defunctionalized by topical capsaicin. Evidence suggests that the utility of topical capsaicin may extend beyond painful peripheral neuropathies.

Neuropathic pain following hip resurfacing due to a transneural suture

A 60-year-old man developed severe neuropathic pain and foot-drop in his left leg following resurfacing arthroplasty of the left hip. The pain was refractory to all analgesics for 16 months. At exploration, a PDS suture was found passing through the sciatic nerve at several points over 6 cm and terminating in a large knot. After release of the suture and neurolysis there was dramatic and rapid improvement of the neuropathic pain and of motor function. This case represents the human equivalent of previously described nerve ligation in an animal model of neuropathic pain. It emphasises that when neuropathic pain is present after an operation, the nerve related to the symptoms must be inspected, and that removal of a suture or irritant may lead to relief of pain, even after many months.

Behavioral analysis after sciatic nerve compression in albino rats

BACKGROUND

Walking track analysis which has been widely used to examine the recovery of gait functions in rats with sciatic nerve injury.

PURPOSE

The present study was aimed to objectively analyze and quantify the degree of functional recovery in locomotor behavior of rats after inflicting sciatic nerve crush injury.

METHODS

Wistar rats trained on various runways, viz., narrow beam, grid and staircase, were subsequently tested following sciatic nerve crush injury.

RESULTS

Locomotor ability of injured rats on runways gradually recovered to the level that was not significantly different from their corresponding preoperative level by the sixth postoperative week.

CONCLUSION

Conventional run ways can be objectively used for quantification of the level of recovery.

Effects of taurine on glutathione peroxidase, glutathione reductase and reduced glutathione levels in rats

The aim of the present study is to investigate the effects of oral administration of taurine on endogenous glutathione peroxidase (GPx) and Glutathione Reductase (GR) activities and reduced glutathione (GSH) level in normal rats. Normal saline (Group I) or 5% taurine in normal saline was administered in dose of 50 mg (Group II), 250 mg (Group III) or 500 mg kg(-1) of body weight (Group IV) through intragastric intubation for 60 days. GPx and GR enzyme activities and GSH and taurine levels were determined in liver, heart, stomach, kidney and plasma of normal Wistar rats. GPx activity showed an increase in liver, heart, stomach and plasma. GR activity increased in kidney and decreased in liver and plasma. GSH levels increased in liver, stomach and decreased in kidney. Liver showed an increase and heart, stomach and kidney a decrease in taurine level in taurine administered rats when compared to control rats. The results varied from organ to organ and the observed variations among organs might be related to their respective enzymatic, non-enzymatic antioxidant potential and its functions. From the present study it may be concluded that long term oral administration of taurine affects GPx, GR and GSH levels in normal rats.