Local environment in yeast-based impedance biodosimeters strongly influences the measurable dose

This work investigates the feasibility of yeast-based impedance measurements for retrospective dosimetry applications. The local environment around yeast cells in a previously developed film-badge was modeled using Geant4. A greater dose response was observed when yeast cells were surrounded by an aluminum-polymer structure, which acted as a conversion layer. Bench-top experiments were conducted using a jar-based dosimeter design that directly combined a finely-ground aluminum conversion medium with yeast powder. It was shown when irradiated in the presence of aluminum grains, yeast cells yielded a higher impedance signal, thereby indicating greater radiation-induced damage. Finally, in separate irradiation experiments, lead and aluminum sheets were placed behind yeast samples and the dosimeters were irradiated to 1 Gy. A 2-fold increase in the impedance signal was shown when samples were positioned in close contact with the lead sheet compared to the aluminum sheet. In all experiments, it was shown that the local environment significantly influences radiative energy deposition in yeast cells.

A stakeholder perspective on poverty reduction through the implementation of social marketing in the context of tourism

This study aims to establish a model that identifies the role of tourism, target group, tourism stakeholders, and the marketing mix factors in the context of tourism marketing based on behavior change and exchange theory, to contribute to poverty reduction through the implementation of social marketing in the tourism context. Phenomenology and grounded theory designs were used in the research. The research findings have revealed that social marketing tools and techniques are effective methods for reducing poverty in the context of tourism and have contributed to a better understanding of the impact of tourism on poverty in terms of roles, barriers, and expectations. It was concluded that for social marketing to be successfully applied in tourism, it needs to be adapted to government policies, institutions, and the private sector. According to the results of the study, government policies should be conducive to promoting behavior change through tourism. In line with the philosophy of social marketing, it is expected that the results will focus on behavior change in the target group in the context of tourism, creating shared values for society, and developing roles for the benefit of individuals and society.

Phytochemical screening, antimicrobial activity, in vitro and in vivo antioxidant activity of Berberis lycium Royle root bark extract

Abstract Antioxidants are materials that scavenge or remove free radicals from living systems. The oxidation process ends in the production of free radicals. These free radicals are the chief birthplace of cancerous cells. Antioxidizing agents remove free radical intermediates by terminating oxidation processes by being oxidized themselves. On the other hand, infectious diseases affect the world on a large scale. To fight these diseases several synthetic compounds have been used. Plant based medications play important role in this regard. So, the current research aimed to investigate the antibacterial and antioxidant effect of Berberis lycium Royle root bark (BLR) extract. Berberis lycium Royle was used for phytochemical analysis and also as antimicrobial and antioxidant agents. The antimicrobial activity was evaluated by the agar well diffusion method. Current study revealed that BLR was rich in phytochemicals and toxic against tested pathogenic bacteria. BLR showed the highest activity against S. pyogenes (13.3±0.8 mm). The lowest antibacterial activity was reported against E. coli (0±0 mm). In case of minimum inhibitory concentration, it was observed that BLR with 10 μg/mL concentration showed the highest activity while 2.5 μg/mL of BLR showed the least inhibitory activity. The highest In vitro antioxidant activity was recorded as 65% at 100 µg/mL. In case of in vivo antioxidant activity level of CAT, GSH and SOD were decreased while that of MDA was enhanced in groups treated with CCl4 as compared to the control group. BLR extract treatment reversed all these changes significantly. Current results indicate that BLR is effective against bacterial pathogens and also has antioxidant potential.

Patient-Reported Distress and Acute Care Utilization for Cervical Cancer Patients Undergoing Concurrent Chemoradiation

PURPOSE/OBJECTIVE(S)

Although concurrent chemo-radiation (CRT) and brachytherapy (BT) is curative for locally advanced cervical cancer (LACC), it requires complex coordination of care and is associated with treatment-related toxicity. Our objective was to evaluate patient-reported symptoms and social distress in LACC patients undergoing concurrent CRT and BT to determine whether they are predictive of unplanned acute care utilization.

MATERIALS/METHODS

Patients with LACC treated with concurrent CRT and BT between 2013-2020 completed the Edmonton Symptom Assessment Scale-revised (ESAS-r; 9 cancer-related symptoms ranked 0-10) and the Social Difficulties Inventory-21 (SDI-21; 21 social issues ranked 0-3) at every visit as part of routine distress screening. Acute care utilization was defined as any unplanned visit to the radiation nursing clinic, urgent care clinic, emergency department or hospitalization within 1 year from starting treatment. A logistic regression model will be used to evaluate associations between ESAS-r and SDI-21 scores and acute care utilization.

RESULTS

Among 151 LACC patients, a total of 354 ESAS-r and SDI questionnaires were completed longitudinally. Mean age at diagnosis was 49.9 years (30-90), 44% were FIGO 2B and overall treatment time was 53.6 days (32-135). At baseline, the most prevalent moderate to severe symptoms (ESAS-r score ≥4) were well-being (50%), anxiety (44%), tiredness (43%) and pain (36%). Post-treatment, these persisted in 42%, 27%, 38%, and 26%, respectively. The most common social distress at baseline was financial (33%). Financial distress post-treatment was significantly predictive of worse well-being (OR = 5.80, p<0.06), anxiety (OR = 3.33, p<0.04) and depression (OR = 4.76, p<0.01). Use of acute care within 1 year after starting treatment occurred in 103 patients (68%) for a total of 617 visits: radiation nursing clinic 71.3%, urgent care clinic 4.4%, emergency department 8.3%, hospitalization 16%. On average there were 6.6 visits/patient (0-31), with the average number of days between treatment start and first acute care visit being 17.9 (0-74).

CONCLUSION

Cervical cancer patients undergoing concurrent CRT report prevalent financial distress and moderate to severe symptoms that persist post-treatment. Acute care utilization commonly occurred during treatment, highlighting a time when additional support is needed. Predictive modelling for distress factors resulting in acute care utilization is now underway.

Treatment Terminations during Radiation Therapy: A Ten-Year Experience

PURPOSE/OBJECTIVE(S)

Disruptionsin cancer care adversely affect clinical outcomes, particularly when a patient does not complete the prescribed course of treatment. The impact of treatment termination (TT) during radiation therapy has not been well studied. This study addresses TT in a large multi-center department of radiation oncology over a 10-year time period.

MATERIALS/METHODS

TTs of patients undergoing radiation treatment between January 2013 and December 2022 were prospectively tracked as part of departmentalquality and safety monitoring. A TT was defined as the discontinuation of therapy at any point following consent and simulation. Causes of TTs were categorized as: hospice/death, physician choice related to toxicity, physician choice unrelated to toxicity, patient choice related to toxicity, patient choice unrelated to toxicity, progression of disease, non-cancer illness, or other. The rate of TT was calculated as a percentage of all new patients who start radiation treatments. As part of our ongoing department quality and safety program, incremental changes were made to pre-treatment evaluation and scheduling processes, collectively referred to as the "No-Fly" policy. TT rates during three iterations of this policy were compared.

RESULTS

Outof 28,707 planned treatment courses, a total of 1,467 TTs were identified (5.1%). 688 (46.9%) involved patients treated with curative intent, 770 (52.5%) with palliative intent, and 9 (0.6%) for benign disease. The rate of TT decreased from 9.3% in 2013 to 3.3% in 2022. Relative to evolutions of our No-Fly policy, the overall TT rate decreased from 8.8% under No-Fly 1 (2013-2014), to 5.2% during No-Fly 2 (2015-2018), and 4.0% with No-Fly 3 (2019-2022) (ANOVA, p<0.001). The most common sites for TT were H&N (19.3%), CNS (17.9%), and Bone Metastases (17.9%). The most common cause of TT was hospice and/or death (36.5%), 69.1% of which were in patients receiving palliative treatments. Other common causes included patient choice unrelated to toxicity (35%), physician choice unrelated to toxicity (8.8%), and progression of disease (7.6%). There were 473 TTs without radiation dose given (1.6% of planned treatments, 32.3% of TTs).

CONCLUSION

Radiation TTs reflect major deviations from the original care plan. This large cohort study highlights the value of open departmental discourse about TTs, which prompted quality improvement changes that reduced TTs over time. Future studies addressing clinical outcomes can direct treatment decision-making and improve care for our patients.

Municipal solid waste generation and its compositional assessment for efficient and sustainable infrastructure planning in an intermediate city of Pakistan

It is imperative to design and operate sustainable solid waste management (SWM) systems in cities based on the results of waste amount and characterization study (WACS). In this work, WACS was conducted and results were used to design an SWM system for an intermediate city of Pakistan. The study revealed that about 110 tons of solid waste per day is generated with a per capita rate of 0.337 kg/day. Around 51.2% of mixed municipal solid waste (MSW) is organic in nature and its non-scientific disposal is resulting in higher greenhouse gas (GHG) emissions. It was also found that more than 80% of valuables are taken away by the informal sector during the transfer of MSW from the generation source to the dumping site. Ultimate analyses showed that the moisture content (MC) and carbon to nitrogen (C:N) ratio were 64.23% and 51.14%, respectively. Proximate analysis revealed that moisture and calorific values were 57 % and 3505 BTU/lb., respectively. Based on these results, a material sorting facility (MSF) was proposed, with an estimated investment cost of US $3.64 million. However, the efficiency of the existing collection system is limited to 32 % only. In order to improve the collection efficiency (>90 %), an additional investment of US $1.638 million was estimated with an operations and maintenance (O&M) cost of US $19.25 per ton. Existing non-scientific MSW disposal practices contribute 32,079.61 CO2e tons/year of GHG emissions. The proposed MSF followed by composting is estimated to reduce GHG emissions by 38% to 19,722.38 CO2e tons/year.

Hepatitis C virus associated ALT, AST, GGT, Bili T, HB, HBA1C, CREAT, PT, aPPT, AFP, CEA, CA 125, CA 19-9, iPTH biomarkers, computed tomography and HCV burden of disease during pre COVID-19 era (2018-2019) and post COVID-19 era (2020-2022) in Pakistan

The national burden of HCV has significantly mounted over the period of last few decades placing Pakistan at the worst placement of second largest burden of HCV globally. Herein for the first time from Pakistan, we examined clinical correlation of potential biomarkers with HCV. Nation-wide study was conducted on 13,348 suspected HCV patients during 2018-2022. During pre-COVID-19 era of 2018-2019, prevalence of HCV remained 30%. During 2018, among HCV positive patients, 91% of ALT, 63% of AST, 67% of GGT, 28% of Bili T, 62% of HB, 15% of HBA1C, 25% of CREAT, 15% of PT, 15% of aPTT and 64% of AFP were abnormal. During 2019, among HCV infected 74.47% of ALT, 63.54% of AST, 70.24% of GGT, 24.71% of Bili T, 8.77% of HB and 75% of AFP were raised. CT/CAT scan revealed 4.65% liver complications (mild 13.04%, moderate 30.43% and severe 56.52%). During 2020, HCV prevalence remained 25%. 65.17% of ALT, 64.20% of AST, 68.75% of GGT, 31.25% of Bili T, 20.97% of HB, 4.65% of CREAT and 73.68% of AFP levels were raised. CAT analysis revealed liver complications among 4.41% (14.81% mild, 40.74% moderate, and 44.44% sever). 85.71% of participants diabetes was out of control. During 2021, HCV prevalence remained 27.1%. ALT (73.86%), AST (50.6%), GGT (67.95%), Bili T (28.21%), HB (20%), CREAT (5.8%) and AFP (82.14%) levels were abnormal. During 2022, the levels of ALT (56.06%), AST (56.36%), GGT (56.6%), Bili T (19.23%), HB (43.48%), HBA1C (14.81), CREAT (18.92%), AFP (93.75%) were abnormal. CAT analysis revealed 7.46% liver complications (25% mild, 30.36% moderate, and 42.86% sever). During 2021-2022, 83.33% of subject's diabetes was not controlled.

Safety and efficacy of tenecteplase in patients with wake-up stroke assessed by non-contrast CT (TWIST): a multicentre, open-label, randomised controlled trial

BACKGROUND

Current evidence supports the use of intravenous thrombolysis with alteplase in patients with wake-up stroke selected with MRI or perfusion imaging and is recommended in clinical guidelines. However, access to advanced imaging techniques is often scarce. We aimed to determine whether thrombolytic treatment with intravenous tenecteplase given within 4·5 h of awakening improves functional outcome in patients with ischaemic wake-up stroke selected using non-contrast CT.

METHODS

TWIST was an investigator-initiated, multicentre, open-label, randomised controlled trial with blinded endpoint assessment, conducted at 77 hospitals in ten countries. We included patients aged 18 years or older with acute ischaemic stroke symptoms upon awakening, limb weakness, a National Institutes of Health Stroke Scale (NIHSS) score of 3 or higher or aphasia, a non-contrast CT examination of the head, and the ability to receive tenecteplase within 4·5 h of awakening. Patients were randomly assigned (1:1) to either a single intravenous bolus of tenecteplase 0·25 mg per kg of bodyweight (maximum 25 mg) or control (no thrombolysis) using a central, web-based, computer-generated randomisation schedule. Trained research personnel, who conducted telephone interviews at 90 days (follow-up), were masked to treatment allocation. Clinical assessments were performed on day 1 (at baseline) and day 7 of hospital admission (or at discharge, whichever occurred first). The primary outcome was functional outcome assessed by the modified Rankin Scale (mRS) at 90 days and analysed using ordinal logistic regression in the intention-to-treat population. This trial is registered with EudraCT (2014-000096-80), ClinicalTrials.gov (NCT03181360), and ISRCTN (10601890).

FINDINGS

From June 12, 2017, to Sept 30, 2021, 578 of the required 600 patients were enrolled (288 randomly assigned to the tenecteplase group and 290 to the control group [intention-to-treat population]). The median age of participants was 73·7 years (IQR 65·9-81·1). 332 (57%) of 578 participants were male and 246 (43%) were female. Treatment with tenecteplase was not associated with better functional outcome, according to mRS score at 90 days (adjusted OR 1·18, 95% CI 0·88-1·58; p=0·27). Mortality at 90 days did not significantly differ between treatment groups (28 [10%] patients in the tenecteplase group and 23 [8%] in the control group; adjusted HR 1·29, 95% CI 0·74-2·26; p=0·37). Symptomatic intracranial haemorrhage occurred in six (2%) patients in the tenecteplase group versus three (1%) in the control group (adjusted OR 2·17, 95% CI 0·53-8·87; p=0·28), whereas any intracranial haemorrhage occurred in 33 (11%) versus 30 (10%) patients (adjusted OR 1·14, 0·67-1·94; p=0·64).

INTERPRETATION

In patients with wake-up stroke selected with non-contrast CT, treatment with tenecteplase was not associated with better functional outcome at 90 days. The number of symptomatic haemorrhages and any intracranial haemorrhages in both treatment groups was similar to findings from previous trials of wake-up stroke patients selected using advanced imaging. Current evidence does not support treatment with tenecteplase in patients selected with non-contrast CT.

FUNDING

Norwegian Clinical Research Therapy in the Specialist Health Services Programme, the Swiss Heart Foundation, the British Heart Foundation, and the Norwegian National Association for Public Health.

Retention of phosphorus in soils receiving bunker silo effluent

The eutrophication of freshwater systems is a pervasive issue in North America and elsewhere, which has been linked to elevated phosphorus (P) loading from watersheds. Most excess P is thought to originate from non-point agricultural sources, and less attention has been given to small rural point sources, such as bunker silos on livestock farms. Sophisticated management practices are rarely used to attenuate nutrients from bunker silo effluent, leaving simple vegetated buffer strips or riparian zones to protect surface water; however, the efficacy of these systems or larger constructed treatment systems is unclear. This study compared two systems receiving bunker silo effluent, one a natural riparian system with a vegetated buffer strip that is the most common practice and the other a constructed treatment system with a forebay, slag filter, and swale. The study quantified P retention within various subsections of each system and characterized the forms of stored P to infer the potential for remobilization. Results indicate that soils receiving bunker silo effluent represent considerable stores of legacy P in the landscape (750 and 3400 kg ha^-1), the majority of which is stored in labile forms that may be vulnerable to remobilization under the waterlogged conditions that often occur in management practices and riparian zones. Some areas of the systems were able to store considerably more P than others, with the slag filter showing the greatest treatment efficacy. Spatial variability in stored P was apparent, where sections of the systems that directly received effluent retained more P than sections located farther away from bunker silos (indirect inputs). Results indicate that passive treatment systems become P saturated over time, limiting their longterm P removal efficacy. The efficacy of these systems may be improved with the inclusion of sorptive materials as a slag filter within the constructed treatment system significantly increased the life expectancy of that system. Greater understanding of both quantity and forms of P retained in systems and soils receiving bunker silo effluent will help develop management strategies that are more effective and longer-lasting for reducing excess P losses to surface water bodies.

DD-07 INCISIONAL HERNIA FOLLOWING LAPAROSCOPIC COLORECTAL LIVER METASTASIS RESECTION. FIRST COMPARATIVE STUDY

Aim

Since first laparoscopic liver surgery (LLR) in 1991, no literature to compare Incisional hernia (IH) incidence between LLR and open Resection (OLR). This is the first comparative study

Material and methods

Single centre retrospective review of Colorectal Liver Metastasis resections between 2011 till 2018. The primary end point is developing IH related to liver resection. Incidence of IH was compared between LLR and OLR. Factors including Age, Gender, Diabetes Mellitus, Steroid intake, Pre-op Creatinine and Albumin, Previous Liver resection ASA score were compared between both groups. Subcutaneous and peri-renal fat thickness measured as indicative of fat distribution. Numeric results presented in Mean±SD. SPSS 20 (IBM, Armonk, USA) used for statistical analysis. p ≤ 0.05 was considered statistically significant

Results

247 procedures with follow-up 41 ± 29 Months. IH was observed in 48 case (19.4%). Incidence was 10%, 19% at 1, 3 years respectively (Kaplan-Meier). 87 case (35%) had LLR and 160 (65%) OLR. OLR had lower pre-op Albumin (32±9 Vs 35±8 g/L, p 0.01, Mann-Whitney U), longer hospital stay (10±7 Vs 6±4 days, p 0.00, Mann-Whitney U) and more major liver resections i.e. Resection of 3 or more segments (58% Vs 29% in LLR, p 0.00, Chi2). No difference in IH Incidence in LLR (8%, 19% Vs 10%, 19%) and OLR at 1, 3 years respectively. Similarly, no difference in hernia size (53±37 mm in LLR Vs 50 ± 33 in OLR, p 0.96, Mann-Whitney U)

Conclusion

No difference in IH incidence or size between LLR and OLR.

Behavior of right atrial strain in patients with advanced idiopathic pulmonary arterial hypertension after initiation of specific combined therapy

Background

Right atrial (RA) function has emerged as an important determinant of outcome in pulmonary arterial hypertension (PAH). However, studies exploring RA function and assessing its behavior in response to specific PAH combination therapy, independent of RA size in patients with PAH is not adequately investigated.

Purpose

Assess the behavior of strain based measures of RA in response to combined PAH therapy, independent of RA size in patients with PAH.

Methods

RA peak longitudinal strain (PLS) and peak active contraction strain (PACS) were retrospectively assessed in 38 patients with advanced idiopathic pulmonary arterial hypertension (IPAH) who were referred to Aswan heart Centre and not receiving proper GDMT; at baseline and during follow-up after initiation of specific PAH combination therapy in the form of either Sildenafil/Bosentan or Sildenafil/Macitentan.

Results

Most of the patients were females with median (IR) age 34 (27–39) years. All patients presented with dyspnea WHO-FC III. At baseline, all patients were receiving only monotherapy in the form of sildenafil. Median (IR) time to echocardiographic follow-up was 11 (8–18) months. Patients presented with markedly right ventricle (RV) and RA enlargement, depressed RV systolic function, and reduced RA strain parameters compared with values previously reported in healthy controls. Among various baseline associations of the RA PLS, the strongest were with baseline RA area (rho: −0.659; p&lt;0.001) and RVEF by CMR (rho: 0.570; p&lt;0.001). At follow up; RA PLS and PACS significantly increased (16.6 vs 24 and 7.06 vs 11.42, respectively: p&lt;0.001); however, RA area did not show significant decrease. Only RV TDI & FAC showed significant improvement among different RV function parameters measured by echocardiography. During the follow up period, 11 out of 38 patients (28.9%) were hospitalized. RA PLS change was significantly lower in the hospitalized group than the non-hospitalized group (4.40 vs 10.2; p=0.014). RA PLS change was independently associated with hospitalization in the multivariate regression analysis (95% CI: −0.061 to −0.010; p=0.008).

Conclusion

Initiation of specific PAH combination therapy in undertreated patients with IPAH showed improvement in RA strain parameters despite no change in RA area during follow up.

Funding Acknowledgement

Type of funding sources: None.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

A230 THE ROLE OF THE MICROBIOTA IN NOCICEPTOR DEVELOPMENT AND PAIN SENSITIVITY

Background

Pain is the most common cause of disability in IBD. What causes inter-individual variability in chronic pain after successful treatment of inflammation remains elusive. We have shown that activation of TRPV1+ colonic nociceptors is essential for the establishment of persistent pain in DSS colitis. Nociceptor development coincides with microbial colonization, while early life dysbiosis can lead to visceral hypersensitivity in adulthood. Whether the microbiota dictates nociceptor development and pain susceptibility remains unknown. Here we test the hypothesis that the microbiota programs nociceptor specification during early development, rendering them more susceptible to sensitization later in life. We have identified the aryl hydrocarbon receptor (AHR) that senses bacterial-derived metabolites as a candidate target that orchestrates transcriptional regulation in nociceptors.

Aims

We investigated the developmental regulation of nociceptors by the microbiome and how it influences pain sensitivity. We will determine the effects of AHR activation on nociceptor lineage and function as well as the long term impact of AHR signaling on pain sensitivity.

Methods

We have developed a germ-free (GF) TRPV1-GFP reporter mouse that was used to phenotype and visualise TRPV1+ nociceptors in the absence of a microbiota. We will isolate TRPV1+ neurons by FACS to identify genes that are under the control of the microbiota and to characterise the phosphoproteome of TRPV1+ nociceptors in GF conditions. Finally, we will investigate the role of AHR signaling in nociceptors both acutely and during development.

Results

We showed a reduction in thermal pain threshold and a reduction in capsaicin test responses in GF mice. The number and size of DRG neurons was unchanged in GF mice. Examination of molecular markers for peptidergic (CGRP) and non-peptidergic (IB4) neurons did not show a difference. Finally, there was no difference in the expression of TRPV1, suggesting post-translational modification of the channel. In cultured DRG neurons, we found a decrease in capsaicin induced action potentials and a decrease in the amplitude of the capsaicin response in GF mice. Using RNAscope, we showed that TRPV1+ neurons express AHR.

Conclusions

Our results highlight the importance of bacterial composition in regulating the development of nociceptors and pain sensitivity in adulthood. Furthermore, we are the first to demonstrate the expression of AHR in sensory neurons. These findings point to a role of the microbiota in programming nociceptors during development. My work will advance our understanding of the role of commensal bacteria in regulating pain and could lead to recommendations for the treatment of neonates in early life to reduce their risk of developing chronic pain later in life.

Funding Agencies

CAG, CIHR

A52 GUT-INNERVATING TRPV1+ NEURONS DRIVE CHRONIC VISCERAL PAIN VIA MICROGLIAL P2Y12 RECEPTOR

Background

Long-lasting changes in neural pain circuits precipitate the transition from acute to chronic pain in patients living with inflammatory bowel diseases (IBDs). While significant improvement in IBD therapy has been made to reduce inflammation, a large subset of patients continues to suffer throughout quiescent phases of the disease. Peripheral and central mechanisms contribute to the transition from acute to chronic pain during active disease and clinical remission. Lower mechanical threshold and hyperexcitability of visceral afferents induce gliosis in central pain circuits, leading to persistent visceral hypersensitivity (VHS). In the spinal cord, microglia, the immune sentinels of the central nervous system, undergo activation in multiple models of VHS. Using the Dextran Sodium Sulfate (DSS) model of colitis, we found that microglial G-CSF was able to sensitize colonic nociceptors that express the pain receptor TRPV1. While TRPV1+ nociceptors have been implicated in peripheral sensitization, their contribution to central sensitization via microglia remains unknown.

Aims

Here we investigated the mechanisms of microglia activation to identify centrally acting analgesics for chronic IBD pain.

Methods

Using Designer Receptors Exclusively Activated by Designer Drugs (DREADD) expressed in TRPV1-expressing visceral neurons that sense colonic inflammation, we tested whether neuronal activity was indispensable to control microglia activation and VHS. We then investigated the neuron-microglia signaling system involved in visceral pain chronification.

Results

We found that chemogenetic inhibition of TRPV1+ visceral afferents prevents microglial activation in the spinal cord and subsequent VHS in colitis mice. In contrast, chemogenetic activation, in the absence of colitis, enhanced microglial activation associated with VHS. We identified a purinergic signaling mechanism mediated by neuronal ATP and microglial P2RY12 receptor, triggering VHS in colitis. Inhibition of P2RY12 prevented microglial reactivity and chronic VHS post-colitis.

Conclusions

Overall, these data provide novel insights into the central mechanisms of chronic visceral pain and suggest that targeting microglial P2RY12 signaling could be harnessed to relieve pain in IBD patients who are in remission.

Funding Agencies

CCC

Enhanced microbial degradation of PET and PS microplastics under natural conditions in mangrove environment

In-situ bioremediation of mangrove soil contaminated with polyethylene terephthalate (PET) and polystyrene (PS) microplastics was investigated using indigenous microbial consortium with adequate capacity to degrade the plastics. Eight (8) bacteria were isolated from plastic/microplastic-inundated mangrove soil and screened for the ability to degrade PET and PS microplastics. Optical density at 600 nm and colony forming unit counts were measured to evaluate the growth response of the microbes in the presence of PS and PET microplastics at different times of exposure. Structural and surface changes that occurred post biodegradation on the microplastics were determined through EDS and SEM analysis. The obtained results demonstrated the elongation and disappearance of peaks, suggesting that the microbial consortium could modify both types of microplastics. The overall results of the microplastic degradation showed varied degrees of weight loss after 90 experimental days, with the treated plot recorded 18% weight loss. The augmented soil was increased in the concentrations of Si S, and Fe and decreased in the concentrations of C, O, Na, Mg, Al, Cl, and K after bioremediation.

Supplementing rabbit diets with butylated hydroxyanisole affects oxidative stress, growth performance, and meat quality

Butylated hydroxyanisole (BHA) is a synthetic antioxidant analogous of vitamin E. It is used as a preservative to prevent free radical-mediated oxidation in high-fat foods, and this study's objective was to investigate the effects of BHA on oxidative stress and apoptosis in addition to delineating its efficacy as a growth-promoting feed additive. 60 weaned male rabbits (V-line) were randomly divided into four equal groups: BHA0.0 (control), BHA50, BHA100, and BHA150, administered basal diets with 0.0, 50, 100, and 150 mg BHA/kg of feed for 60 days. Animals were examined for growth performance, markers of oxidative stress and apoptosis, and meat characteristics. Compared to the control group, rabbits receiving BHA-supplemented diets exhibited increases in BW and average daily gain (P < 0.01), where BHA50 and BHA100 groups showed increased muscle content of methionine aspartic acid, serine, and glutamine (P < 0.05). These two groups also exhibited elevated catalase and superoxide dismutase activities and diminished malondialdehyde levels in the liver. Butylated hydroxyanisole upregulated fatty acid synthase gene (FASN), especially in BHA100 animals. Bcl-2-associated X/B-celllymphoma-2 (Bax/Bcl-2) ratio significantly increased in animals receiving higher doses of BHA, and the weight of the liver significantly increased following BHA treatment. Supplementing growing rabbits with lower doses of dietary BHA may promote growth performance and meat quality via maintaining the redox balance. Hence, the 50-100 mg/kg may be recommended as a safe and still effective feed additive as well as an oxidative stress attenuator.