Crop production in the USA is frequently limited by a lack of pollinators

Most of the world's crops depend on pollinators, so declines in both managed and wild bees raise concerns about food security. However, the degree to which insect pollination is actually limiting current crop production is poorly understood, as is the role of wild species (as opposed to managed honeybees) in pollinating crops, particularly in intensive production areas. We established a nationwide study to assess the extent of pollinator limitation in seven crops at 131 locations situated across major crop-producing areas of the USA. We found that five out of seven crops showed evidence of pollinator limitation. Wild bees and honeybees provided comparable amounts of pollination for most crops, even in agriculturally intensive regions. We estimated the nationwide annual production value of wild pollinators to the seven crops we studied at over $1.5 billion; the value of wild bee pollination of all pollinator-dependent crops would be much greater. Our findings show that pollinator declines could translate directly into decreased yields or production for most of the crops studied, and that wild species contribute substantially to pollination of most study crops in major crop-producing regions.

THU0204 A SUBGROUP ANALYSIS OF LOW DISEASE ACTIVITY AND REMISSION FROM PHASE 3 STUDY OF FILGOTINIB IN PATIENTS WITH INADEQUATE RESPONSE TO BIOLOGIC DMARDS

Background:

Despite effective treatments, many patients (pts) with rheumatoid arthritis (RA) have inadequate responses to biologic DMARDs (bDMARD-IR), highlighting an unmet need. It is unclear whether prior bDMARD use affects efficacy of the oral, selective JAK-1 inhibitor filgotinib (FIL).

Objectives:

To explore clinical response to FIL in bDMARD-IR pts stratified by mode of action (MOA) and number of prior bDMARDs.

Methods:

The global, phase 3 FINCH-2 (NCT02873936) study treated 448 bDMARD-IR pts with active RA.1Pts were randomised 1:1:1 to once-daily FIL 200 mg, FIL 100 mg, or placebo (PBO) for 24 weeks. Efficacy was assessed by percent of pts achieving low disease activity (LDA) or remission at week (W)24 as measured by CDAI and DAS28(CRP) stratified by number and MOA of prior bDMARDs. Comparisons were not adjusted for multiplicity. Nonresponder imputation was used.

Results:

In total, 448 bDMARD-IR pts were included, 105 with prior experience with ≥3 bDMARDs (Table). At W24, pts receiving FIL were in LDA at a higher proportion vs PBO, irrespective of number of prior bDMARDs or MOA (Figure 1). For pts receiving FIL 200 vs PBO, DAS28(CRP) ≤3.2 was achieved at W24 by 52% vs 26%, 51% vs 22%, and 38% vs 9% of pts with 1, 2, or ≥3 prior bDMARDs, respectively, and 49% vs 21% and 50% vs 13% of pts exposed to TNF or IL-6 inhibitors; for all subgroups, rates were significantly higher vs PBO (Figure 1). Delta between FIL 200 mg and PBO was maintained irrespective of number or type of prior bDMARDs. At W24, pts receiving FIL achieved remission at numerically higher rates vs PBO (Figure 2). For pts receiving FIL 200 mg vs PBO, DAS28(CRP) <2.6 was achieved at W24 by 36% vs 14%, 30% vs 14%, and 22% vs 6% of pts with 1, 2, and ≥3 prior bDMARDs, respectively, and 31% vs 14% and 29% vs 9% of pts exposed to TNF or IL-6 inhibitors (Figure 2). Delta between FIL 200 mg and PBO was maintained irrespective of number or type of prior bDMARDs. Treatment-emergent adverse events across subgroups were consistent with overall study population.

Table.

Number and MOA of prior bDMARDs

FIL 200 mgn = 147FIL 100 mgn = 153PBOn = 148TotalN = 448Prior bDMARDs 173 (49.7)86 (56.2)77 (52.0)236 (52.7) 237 (25.2)33 (21.6)36 (24.3)106 (23.7) ≥337 (25.2)34 (22.2)34 (23.0)105 (23.4)LOE ≥1 bDMARD125 (85.0)129 (84.3)126 (85.1)380 (84.8)Intolerance ≥1 bDMARD36 (24.5)34 (22.2)32 (21.6)102 (22.8)Prior TNFi121 (82.3)134 (87.6)124 (83.8)379 (84.6) LOE ≥1 TNFi97 (66.0)113 (73.9)103 (69.6)313 (69.9) Intolerance ≥1 TNFi25 (17.0)24 (15.7)24 (16.2)73 (16.3)Prior non-TNFi73 (49.7)62 (40.5)75 (50.7)210 (46.9) LOE ≥1 non-TNFi52 (35.4)43 (28.1)56 (37.8)151 (33.7) Intolerance ≥1 non-TNFi13 (8.8)13 (8.5)11 (7.4)37 (8.3)Prior IL-6i34 (23.1)35 (22.9)32 (21.6)101 (22.5) LOE ≥1 IL-6i25 (17.0)22 (14.4)21 (14.2)68 (15.2) Intolerance ≥1 IL-6i5 (3.4)10 (6.5)5 (3.4)20 (4.5)

Data presented as n (%).

i, inhibitor; LOE, lack of efficacy.

Conclusion:

Treatment with FIL vs PBO led to higher rates of LDA and remission in pts with IR to IL-6 or TNF inhibition, or to 1, 2, or ≥3 prior bDMARDs, with a similar safety profile to the overall study population. A significantly higher proportion of pts overall receiving FIL 200 mg vs PBO were in LDA at W24. Improved efficacy of FIL vs PBO in pts who previously failed multiple bDMARDs indicates distinct benefits of selective JAK-1 inhibition with FIL.

References:

[1]Genovese, et al.JAMA2019;322(4):315–25.

Disclosure of Interests: :

Jacques-Eric Gottenberg Grant/research support from: BMS, Pfizer, Consultant of: BMS, Sanofi-Genzyme, UCB, Speakers bureau: Abbvie, Eli Lilly and Co., Roche, Sanofi-Genzyme, UCB, Maya H Buch Grant/research support from: Pfizer, Roche, and UCB, Consultant of: Pfizer; AbbVie; Eli Lilly; Gilead Sciences, Inc.; Merck-Serono; Sandoz; and Sanofi, Roberto Caporali Consultant of: AbbVie; Gilead Sciences, Inc.; Lilly; Merck Sharp & Dohme; Celgene; Bristol-Myers Squibb; Pfizer; UCB, Speakers bureau: Abbvie; Bristol-Myers Squibb; Celgene; Lilly; Gilead Sciences, Inc; MSD; Pfizer; Roche; UCB, Grace C. Wright Consultant of: AbbVie, Amgen, Bristol-Myers Squibb, Exagen, Eli Lilly, Myriad Autoimmune, Novartis, Pfizer, Regeneron Pharmaceuticals, Inc., Sanofi Genzyme, UCB, Speakers bureau: AbbVie, Amgen, Bristol-Myers Squibb, Exagen, Eli Lilly, Myriad Autoimmune, Novartis, Regeneron Pharmaceuticals, Inc., Sanofi Genzyme, UCB, Tsutomu Takeuchi Grant/research support from: Eisai Co., Ltd, Astellas Pharma Inc., AbbVie GK, Asahi Kasei Pharma Corporation, Nippon Kayaku Co., Ltd, Takeda Pharmaceutical Company Ltd, UCB Pharma, Shionogi & Co., Ltd., Mitsubishi-Tanabe Pharma Corp., Daiichi Sankyo Co., Ltd., Chugai Pharmaceutical Co. Ltd., Consultant of: Chugai Pharmaceutical Co Ltd, Astellas Pharma Inc., Eli Lilly Japan KK, Speakers bureau: AbbVie GK, Eisai Co., Ltd, Mitsubishi-Tanabe Pharma Corporation, Chugai Pharmaceutical Co Ltd, Bristol-Myers Squibb Company, AYUMI Pharmaceutical Corp., Eisai Co., Ltd, Daiichi Sankyo Co., Ltd., Gilead Sciences, Inc., Novartis Pharma K.K., Pfizer Japan Inc., Sanofi K.K., Dainippon Sumitomo Co., Ltd., Kenneth Kalunian Grant/research support from: Pfizer, Lupus Research Alliance, Sanford Consortium, Consultant of: Genentech, Nektar, BMS, Janssen, AstraZeneca, Biogen, Vielabio, Equillium, Eli Lilly, ILTOO, Abbvie, Amgen, Roche, Gilead, Alena Pechonkina Shareholder of: Gilead Sciences, Inc., Employee of: Gilead Sciences, Inc., Ying Guo Shareholder of: Gilead Sciences, Inc., Employee of: Gilead Sciences, Inc., Shangbang Rao Shareholder of: Gilead Sciences Inc., Employee of: Gilead Sciences Inc., YingMeei Tan Shareholder of: Gilead Sciences, Inc., Employee of: Gilead Sciences, Inc., Robin Besuyen Shareholder of: Galapagos, Employee of: Galapagos, Mark C. Genovese Grant/research support from: Abbvie, Eli Lilly and Company, EMD Merck Serono, Galapagos, Genentech/Roche, Gilead Sciences, Inc., GSK, Novartis, Pfizer Inc., RPharm, Sanofi Genzyme, Consultant of: Abbvie, Eli Lilly and Company, EMD Merck Serono, Genentech/Roche, Gilead Sciences, Inc., GSK, Novartis, RPharm, Sanofi Genzyme

FRI0139 FILGOTINIB PROVIDED RAPID AND SUSTAINED RELIEF OF PAIN AND FATIGUE AND IMPROVED HEALTH-RELATED QUALITY OF LIFE IN PATIENTS WITH RHEUMATOID ARTHRITIS AND INADEQUATE RESPONSE TO BIOLOGIC DMARDS: RESULTS FROM THE FINCH 2 STUDY

Background:

EULAR guidelines recommend a treat-to-target approach focusing on reducing inflammation to prevent joint damage, physical disability, and mortality.1However, patients consider reduction in pain and fatigue, along with maintenance of physical function, and improvement in health-related quality of life (HRQoL) important areas for improvement with RA treatment.2In the FINCH 2 study, filgotinib (FIL)—a potent, selective, oral small molecule Janus kinase 1 inhibitor—in combination with conventional synthetic (cs)DMARD therapy significantly improved the signs and symptoms of rheumatoid arthritis (RA) in patients with an inadequate response to a biologic (b)DMARD compared with placebo (PBO).3In addition, patients experienced significant improvements in HAQ-DI at week (W)12 and W24 with FIL 100 mg (p <0.001, p = 0.003) or 200 mg (p <0.001 for both) compared with PBO.3

Objectives:

To evaluate the rate and magnitude of change in patient-reported outcomes (PROs) from FINCH 2 assessing pain, HRQoL, and fatigue.

Methods:

Patients in this double-blind, randomised study (NCT02873936) received FIL 200 mg, FIL 100 mg, or PBO while continuing csDMARD therapy. PROs were collected prospectively on day 1 and at the W2, W4, W8, W12, W14, W16, W20, and W24 visits for assessment of pain (VAS pain scale) and on day 1 and at W4, W12, and W24 for assessment of fatigue (FACIT-Fatigue) and HRQoL (SF-36). Changes from baseline for each PRO at each time point up to W24 were analysed longitudinally using a mixed-effects model for repeated measures. P values for the difference between each FIL arm and PBO at each time point were calculated.

Results:

Among the 448 patients randomised and treated (FIL 200 mg, n = 147; FIL 100 mg, n = 153; PBO, n = 148) 381 (85.0%) completed the study. Baseline mean (SD) VAS pain scale was 67 (21.0), SF-36 physical component summary (PCS) was 31.1 (7.89), SF-36 mental component summary (MCS) was 44.3 (11.6), and FACIT-Fatigue score was 24.4 (11.6); baseline values did not vary between treatment groups. Significantly greater improvements in VAS pain scores began at W2 and were maintained through W24 for patients who received either dose of FIL vs PBO (Fig 1A). FIL also significantly improved patients’ fatigue at W4, W12, and W24 compared with PBO for those receiving 200 mg doses, and at W4 and W12 for those receiving 100 mg doses (Fig 1B). HRQoL related to physical functioning (SF-36 PCS) was significantly enhanced at W4, W12, and W24 with both doses of FIL as compared with PBO (Fig 2A). Improvements to mental-health-related QoL (SF-36 MCS) were reported for FIL as early as W4 and maintained through W24, with statistically significant improvements at W4 and W12 for FIL 200 mg vs PBO (Fig 2B).

Conclusion:

In a patient population with refractory disease that had inadequate response to prior bDMARDs and had significant disease at baseline, FIL treatment—coadministered with csDMARD therapy—was able to provide rapid and sustained improvements in key measures of pain, HRQoL, and fatigue as reported by patients.

References:

[1]Smolen, et al.Ann Rheum Dis. 2017;76:960–77.

[2]Fautrel, et al.Rheumatol Int.2018;38:935–47.

[3]Genovese, et al.JAMA. 2019;322(4):315–25.

Disclosure of Interests:

David Walker Grant/research support from: Gilead, Consultant of: Gilead, Lilly, Pfizer, Roche, Speakers bureau: Lilly, Pfizer, Roche, Tsutomu Takeuchi Grant/research support from: AbbVie, Asahikasei Pharma Corp., Astellas Pharma, Inc., Chugai Pharmaceutical Co, Ltd., Daiichi Sankyo Co., Ltd., Eisai Co., Ltd., Mitsubishi-Tanabe Pharma Corp., Nipponkayaku Co. Ltd., Shionogi & Co., Ltd., Takeda Pharmaceutical Co., Ltd., UCB Japan, Consultant of: Astellas Pharma, Inc., Chugai Pharmaceutical Co, Ltd., Eli Lilly Japan,, Speakers bureau: Abbvie, AYUMI Pharmaceutical Corp., Bristol-Myers Squibb, Chugai Pharmaceutical Co, Ltd., Daiichi Sankyo Co., Ltd., Eisai Co., Ltd., Eli Lilly Japan, Gilead Sciences, Inc., Mitsubishi-Tanabe Pharma Corp., Novartis Pharma K.K., Pfizer Japan Inc., Sanofi K.K., Dainippon Sumitomo Co., Ltd, Beatrix Bartok Shareholder of: Gilead Sciences Inc., Employee of: Gilead Sciences Inc., Shangbang Rao Shareholder of: Gilead Sciences Inc., Employee of: Gilead Sciences Inc., I-Heng Lee Shareholder of: Gilead Sciences Inc., Employee of: Gilead Sciences Inc., Robin Besuyen Shareholder of: Galapagos, Employee of: Galapagos, Jacques-Eric Gottenberg Grant/research support from: BMS, Pfizer, Consultant of: BMS, Sanofi-Genzyme, UCB, Speakers bureau: Abbvie, Eli Lilly and Co., Roche, Sanofi-Genzyme, UCB, Mark C. Genovese Grant/research support from: Abbvie, Eli Lilly and Company, EMD Merck Serono, Galapagos, Genentech/Roche, Gilead Sciences, Inc., GSK, Novartis, Pfizer Inc., RPharm, Sanofi Genzyme, Consultant of: Abbvie, Eli Lilly and Company, EMD Merck Serono, Genentech/Roche, Gilead Sciences, Inc., GSK, Novartis, RPharm, Sanofi Genzyme

0057 Actigraphy-Based Circadian Measures and Cerebrospinal Fluid Biomarkers of Neurodegeneration in Alzheimer’s Disease with Mild Cognitive Impairment

Introduction

Although recent data implicates sleep and circadian disruption to neurodegeneration in Alzheimer’s Disease (AD), the association of objective circadian biomarkers and neurodegeneration remains understudied. We hypothesize that actigraphy-based circadian measures are associated with cerebrospinal fluid (CSF) biomarkers of neurodegeneration in those mild cognitive impairment due to AD (MCI-AD).

Methods

Eighteen patients with CSF biomarker-confirmed MCI-AD underwent actigraphy monitoring generating the following circadian measures: amplitude, F-ratio and mesor and morning collection of CSF biomarkers of neurodegeneration (Aβ42,t-tau,p-tau). Linear models were used to evaluate the association of circadian and CSF measures; logarithmic transformations were performed on neurodegenerative markers for greater normality. Analysis was performed using SAS software. A significance level of 0.05 was assumed for all tests.

Results

Eighteen MCI-AD patients who were 68± 6.2 years, 44% female, with median AHI=12 and underwent actigraphy monitoring for 8.2+/-3.2 days were included. There was no significant association of circadian measures and Aβ42 nor with mesor and neurodegeneration biomarkers. Amplitude was associated with both p-tau and t-tau, such that each 10 unit increase in amplitude resulted in a predicted increase in p-tau of 8% (95% CI:1%-15%, p=0.018) and an increase of 13% (3%-23%; p=0.01) in t-tau. F-ratio was positively associated with p-tau and t-tau; each 1000 unit increase in F-ratio resulted in a predicted 12% (4%-22%; p=0.007) increase in P-tau and 20%(6%-35%; p=0.005) increase in t-tau. Associations of these circadian measures and CSF levels of p-tau and t-tau remained statistically significant after adjustment for age and sex.

Conclusion

Among patients with symptomatic MCI stages of AD, objective measures of circadian rhythm disruption are associated with CSF-based biomarkers of neurodegeneration even after consideration of age and sex. Future investigation should clarify directionality of this association and potential utility of circadian-based interventions in the mitigation of AD progression.

Support

N/A

Neonatal outcomes following previable prelabour rupture of membranes before 23 weeks of gestation - A retrospective cohort study

OBJECTIVE

To compare outcomes of hospitalized preterm infants following previable prelabour rupture of membranes (PPROM) at≤23 weeks of gestation.

METHODS

Retrospective cohort study of preterm infants admitted for intensive care, between January 2006 and December 2016 following PPROM, was conducted. Short term clinical outcomes included severity of respiratory morbidity, length of hospital stay and mortality. Neurodevelopment in survivors was assessed using Bayley's Scales of Infant Development (3rd edition) at 24 months corrected age.

RESULTS

A total of 82 preterm infants were admitted following PPROM at < 23 weeks and were grouped as: Group 1 (n = 28) with PPROM < 20 weeks and Group 2 (n = 54) with PPROM between 20-22 + 6 weeks. Median latency following PPROM was significantly longer in Group 1 infants [69(Interquartile range (IQR): 43-74; Range (R): 25-100 vs. 29(IQR: 10-53; R: 2-72) days, p < 0.001]. Median gestation at delivery was 27.4 weeks (Group 1) vs. 25.1 weeks (Group 2). Group 1 had a significantly higher incidence of oligohydramnios [13(46.4%) vs. 8(14.8%), p = 0.002], lower Apgar scores (<7) at 5 minutes [19(67.9%) vs. 24(44.4%), p = 0.044], increased pulmonary hypoplasia [13(46.4%) vs. 5(9.3%), p < 0.001], joint contractures [3(10.7%) vs. 0, p = 0.037] and mortality [10(35.7%) vs. 7(13.0%), p = 0.016]. Neurodevelopmental outcomes at 24 months corrected age were comparable in the 36 surviving infants (9/18 vs. 27/547).

CONCLUSION

Morbidity and mortality is high in infants born after previable PPROM; specifically, in those with PPROM < 20 weeks although early childhood neurodevelopmental outcomes were comparable. Larger prospective studies focussing on long term neonatal outcomes are needed to confirm these findings.

The cost-effectiveness of progesterone in preventing miscarriages in women with early pregnancy bleeding: an economic evaluation based on the PRISM trial

OBJECTIVES

To assess the cost-effectiveness of progesterone compared with placebo in preventing pregnancy loss in women with early pregnancy vaginal bleeding.

DESIGN

Economic evaluation alongside a large multi-centre randomised placebo-controlled trial.

SETTING

Forty-eight UK NHS early pregnancy units.

POPULATION

Four thousand one hundred and fifty-three women aged 16-39 years with bleeding in early pregnancy and ultrasound evidence of an intrauterine sac.

METHODS

An incremental cost-effectiveness analysis was performed from National Health Service (NHS) and NHS and Personal Social Services perspectives. Subgroup analyses were carried out on women with one or more and three or more previous miscarriages.

MAIN OUTCOME MEASURES

Cost per additional live birth at ≥34 weeks of gestation.

RESULTS

Progesterone intervention led to an effect difference of 0.022 (95% CI -0.004 to 0.050) in the trial. The mean cost per woman in the progesterone group was £76 (95% CI -£559 to £711) more than the mean cost in the placebo group. The incremental cost-effectiveness ratio for progesterone compared with placebo was £3305 per additional live birth. For women with at least one previous miscarriage, progesterone was more effective than placebo with an effect difference of 0.055 (95% CI 0.014-0.096) and this was associated with a cost saving of £322 (95% CI -£1318 to £673).

CONCLUSIONS

The results suggest that progesterone is associated with a small positive impact and a small additional cost. Both subgroup analyses were more favourable, especially for women who had one or more previous miscarriages. Given available evidence, progesterone is likely to be a cost-effective intervention, particularly for women with previous miscarriage(s).

TWEETABLE ABSTRACT

Progesterone treatment is likely to be cost-effective in women with early pregnancy bleeding and a history of miscarriage.

Early clinical exposure through a vertical integration programme in physiology

Background

Early clinical exposure is likely to be beneficial during the preclinical year. This pilot programme aimed to define a learning framework of introducing first year medical students to early clinical exposure through a vertical integration programme in the physiology course. The intent was to enhance the understanding of theoretical concepts and practical applications of physiology. Student and faculty perceptions were evaluated.

Methods

First year MBBS students (n = 60) had bedside clinics conducted by 5 clinical departments, where the clinical context and applied physiological concepts were emphasized. Clinical sessions were synchronized with pedagogic highlights on related physiological concepts. The student's perceptions were recorded through a semi-structured questionnaire, while qualitative feedback was obtained from the faculty.

Results

All students ( 100%) reported that the programme was relevant and did not interfere with their physiology course. Most (91%) appreciated the synchronization of classroom knowledge with clinical exposures, and thought that integrated teaching helped in better understanding of practical applications of physiology (94%) with adequate discussions during the sessions (91 %). Fifty-nine (98%) students preferred integrated teaching over the isolated traditional classroom teaching. The clinicians involved also felt that the early clinical exposure was relevant. The students achieved a mean (SD) score of 13 (2.98) of 25 in the quiz consisting of multiple-choice questions that attempted to test their learning through early clinical exposures.

Conclusion

This pilot exercise showed the utility of early clinical exposure integrated into the physiology course. It will be worthwhile to replicate this exercise at other institutions and among a larger student strength.

P1460Seismocardiographic measurement of systolic time intervals in left ventricular dysfunction: validation with transthoracic echo

Background

Systolic time intervals (STI) measured using Transthoracic Echo (TTE) have been shown to be sensitive indicators of contractile performance, but TTE is limited to a hospital setting. Recent advances in technology have enabled the simultaneous measurement of Electrocardiograms (ECG) and Seismocardiograms (SCG) using wearable devices. However, the use SCG to measure STIs has not been validated in a mobile setting, or on pathological subjects.

Purpose

To test the validity of an automated algorithm for measuring STIs using a wearable device recording ECG and SCG, in subjects with varying degrees of left ventricular dysfunction.

Methods

179 Patients with suspected left ventricular dysfunction were assessed using TTE performed by a Cardiologist. Patients were simultaneously fitted with a novel wearable device worn on a chest strap, recording SCG and single-lead ECG data, while the cardiologist measured the pre-ejection period (PEP) and left ventricular ejection time (LVET) with the patient in a supine position. Of these subjects 29 (16.2%) were diagnosed with Dilated cardiomyopathy (DCM), and 109 (60.8%) had Ischemic Heart disease.

The SCG and ECG data recorded on the wearable device was then analysed using a peak-detection algorithm, which detected the Q,R,S points on the ECG, and then determined the 4 most prominent peaks in the SCG signal corresponding to each R-peak. Heart rate, patient's age, gender and SCG time intervals were then used in a DecisionTree algorithm to determine the values of PEP and LVET, which were were then compared against those determined by the cardiologist using TTE.

Results

The correlation coefficient (r2) between PEP calculated using TTE, and the values obtained from the algorithm analyzing SCG data was 0.92 while the mean error was 7.47%. The r2 between the LVET calculated using the TTE and the algorithm was 0.75, while the mean error was 8.53% (p-value<0.001 for all cases).

Results All Subjects With IHD Without IHD With DCM Without DCM Number of Subjects 178 109 69 29 149 PEP (r2) 0.92 0.89 0.94 0.88 0.91 PEP (% age error) 7.47 7.50 7.42 6.99 7.56 LVET (r2) 0.75 0.81 0.66 0.55 0.83 LVET (% age error) 8.53 6.69 11.4 20.42 6.16 DCM, Dilate Cardiomyopathy; IHD, Ischemic Heart Disease.

ECG + SCG signals for a DCM patient

Conclusion

The algorithm-derived STIs measured by SCG correlate well with those measured by TTE across most patient groups, including those with Dilated Cardiomyopathy and Ischemic Heart Disease, opening prospects for continuous remote monitoring of STIs in a mobile setting.

Acknowledgement/Funding

Fourth Frontier Technologies

P14.94 Mitochondrial DNA copy number in new onset and recurrent glioblastoma and its effect on radiation resistance and patient survival

BACKGROUND

Recent evidence shows that mitochondrial DNA (mtDNA) content is responsible for radiation resistance in various cancers, but not evaluated in glioblastoma(GBM).Hence,we studied the role of mtDNA content in GBM pathogenesis and treatment response.

MATERIAL AND METHODS

Archived FFPE tissues of newly diagnosed GBM(n=130), recurrent GBM (n=32 pairs) and non-neoplastic control brain(n=30) with available clinical details were utilized for the study. Immunohistochemistry, Sanger’s sequencing, methylation specific PCR and fluorescent in-situ hybridization were used to study IDH, ATRX and TERT promoter mutations, MGMT promoter methylation and EGFR amplification. mtDNA content was analyzed using quantitative real time PCR (relative quantification) and was calculated using the formula 2- ΔΔCTx100. Malignant glioma cell lines U87 and LN229 were used to study the difference in mtDNA content following radiation exposure.LN229 cell line was subjected to mtDNA depletion by incubation with ethidium bromide for 4 days.The parent and mtDNA depleted LN229 cell lines were then assessed for sensitivity to radiation and Temozolomide(TMZ) therapy using MTT assay.

RESULTS

mtDNA content was lower than control brain tissue(mean mtDNA content 19.6) in all cases studied,with significantly lower content in older patients(p=0.04).Lower mean mtDNA content was seen in IDH wild type, MGMT unmethylated and EGFR amplified tumors when compared to their counterparts(p=1.06).Survival analysis using Cox regression showed that lower mtDNA copy number is associated with higher risk and hence poorer prognosis(p=0.047).Paired tumor analysis was performed in 32 patients with recurrence of whom only 19 had received radiation therapy (RT).The mean mtDNA content was higher at recurrence as compared to the primary tumor in those who received RT(mean at diagnosis 20.1; mean at recurrence 49.3, p=0.02) while no significant difference was observed in those who did not receive RT. U87 and LN229 cell lines exposed to radiation (0, 2, 4 and 6Gy) showed an increase of 8% and 25% in mtDNA content, respectively, after 6Gy radiation exposure.LN229 parent cells showed a radiation dose dependent decline in cell viability(86% at 2Gy, 68% at 4Gy and 50% at 6Gy).The mtDNA depleted LN229 cells were 100% viable at 0, 2 and 4 Gy and 82% viable at 6Gy.The IC50 of TMZ in parent LN229 cells was 69.3 µM while in the mtDNA depleted cells,it was 100.8 µM. Conclusion:Our study shows that lower mtDNA content is associated with poorer survival in GBM.RT increased the mtDNA content in both patient samples and malignant glioma cell lines.mtDNA depleted LN229 lines are more radio-chemo resistant than parent LN229 lines,thus showing that lower mtDNA content leads to treatment resistance.Hence,we establish the significant role of mtDNA content in the pathogenesis and treatment resistance of GBM.

Evaluation of Smear Layer Removal Using Different Irrigation Methods In Root Canals

This study evaluated different irrigation methods in smear layer removal from the root canal walls using maleic acid (MA). Maxillary anterior teeth (N=30, n=10 per group) were decoronated, canals were enlarged with Protaper (size F4) and allocated to three groups: EndoUltra: 2.5 ml of 7% MA was irrigated for 30 s, followed by EndoUltra activation for 30 s; EndoSafe: EndoSafe irrigation system was used for 1 minute using 5 ml of 7% MA; Side-vented needle: 30 gauge needle irrigation was performed for 1 min using 5 ml of 7% MA. After SEM analysis, the inter-examiner reliability was verified using Kendall's Co-efficient and data were analyzed using Pearson Chi-Square test. No statistical significant differences were found between the two examiners (p⟩0.05). In intra-group comparison, needle and EndoSafe irrigation demonstrated significantly better smear layer removal at middle third of the root canal system (p⟨0.05) when compared to apical third. In inter-group comparison, smear layer was minimally removed with needle irrigation. In the apical third, EndoUltra group removed smear layer more effectively. Endosafe needle irrigation in combination with 7% MA removed the smear layer in the root canal at best, while the EndoUltra performed the best at the apical third of the root.