AP-1/C-FOS and AP-1/FRA2 differentially regulate early and late adipogenic differentiation of mesenchymal stem cells

Obesity is defined as an abnormal accumulation of adipose tissue in the body and is a major global health problem due to increased morbidity and mortality. Adipose tissue is made up of adipocytes, which are fat-storing cells, and the differentiation of these fat cells is known as adipogenesis. Several transcription factors (TFs) such as CEBPβ, CEBPα, PPARγ, GATA, and KLF have been reported to play a key role in adipogenesis. In this study, we report one more TF AP-1, which is found to be involved in adipogenesis. Human mesenchymal stem cells  were differentiated into adipocytes, and the expression pattern of different subunits of AP-1 was examined during adipogenesis. It was observed that C-FOS was predominantly expressed at an early stage (Day 2), whereas FRA2 expression peaked at later stages (Days 6 and 8) of adipogenesis. Chromatin immunoprecipitation-sequencing analysis revealed that C-FOS binds mainly to the promoters of WNT1, miR-30a, and ANAPC7 and regulates their expression during mitotic clonal expansion. In contrast, FRA2 binds to the promoters of CIDEA, NOTCH1, ARAF, and MYLK, regulating their expression and lipid metabolism. Data obtained clearly indicate that the differential expression of C-FOS and FRA2 is crucial for different stages of adipogenesis. This also raises the possibility of considering AP-1 as a therapeutic target for treating obesity and related disorders.

Andrographolide and pterostilbene inhibit adipocyte differentiation by downregulating PPARγ through different regulators

Adipogenesis involves commitment of stem cells and their differentiation into mature adipocytes. It is tightly regulated by hormones, nutrients and adipokines. Many natural compounds are being tested for their anti-adipogenic activity which can be attributed to apoptosis induction in adipocytes, blocking adipocyte differentiation, or inhibiting intracellular triglyceride synthesis and accumulation. In this study, we have determined molecular mechanism of two phytocompounds: andrographolide (AN) and pterostilbene (PT) during differentiation of the human MSCs into adipocyte. Interestingly, AN upregulates miR27a, whereas, PT upregulated SIRT1 which inhibits the expression of PPARγ. Thus, our results clearly demonstrate that both AN and PT inhibited adipogenesis by blocking a surge of reactive oxygen species (ROS) during differentiation and inhibiting expression of crucial transcription factors like SREBP1c and PPARγ.

Efficacy of Radial Endobronchial Ultrasound (R-EBUS) guided transbronchial cryobiopsy for peripheral pulmonary lesions (PPL...s): A systematic review and meta-analysis

BACKGROUND

Transbronchial lung cryobiopsy (TBLC) is frequently described for the diagnosis of diffuse parenchymal lung diseases (DPLD). A few studies have reported transbronchial cryobiopsy for the diagnosis of peripheral pulmonary lesions (PPL...s). We aimed to study the utility and safety of transbronchial cryobiopsy for the diagnosis of PPL...s.

METHODS

We performed a systematic search of the PubMed and Embase databases to extract the relevant studies. We then performed a meta-analysis to calculate the diagnostic yields of transbronchial cryobiopsy and bronchoscopic forceps biopsy.

RESULTS

Following a systematic search, we identified nine relevant studies (300 patients undergoing cryobiopsy). All used Radial Endobronchial Ultrasound (R-EBUS) for PPL localization. The pooled diagnostic yield of transbronchial cryobiopsy was 77% (95% CI, 71%...84%) (I^2=38.72%, p=0.11). The diagnostic yield of forceps biopsy was 72% (95% CI, 60%...83%) (I^2=78.56%, p<0.01). The diagnostic yield of cryobiopsy and forceps biopsy was similar (RR 1.05, 95% CI 0.96...1.15), with a 5% risk difference for diagnostic yield (95% CI, ...6% to 15%). There was significant heterogeneity (I^2=57.2%, p=0.017), and no significant publication bias. One severe bleeding and three pneumothoraxes requiring intercostal drain (ICD) placement (major complication rate 4/122, 1.8%) were reported with transbronchial cryobiopsy.

CONCLUSIONS

R-EBUS guided transbronchial cryobiopsy is a safe and efficacious modality. The diagnostic yields of TBLC and forceps biopsy are similar. More extensive multicentre randomized trials are required for the further evaluation and standardization of transbronchial cryobiopsy for PPL...s.

Absence of atrial fibrillation in the blanking period following cryoballoon pulmonary vein isolation – does it always portend a good prognosis?

Background

Cryoballoon (CB) pulmonary vein isolation (PVI) is an accepted method for ablation in patients with paroxysmal and persistent atrial fibrillation (PAF, PeAF). Freedom from AF in the blanking period (BP), conventionally defined as the first 3-months post-PVI, has been associated with the best long-term outcomes. However, the influence of antiarrhythmic drugs (AADs) during the BP on long-term outcomes is not well understood.

Objective

To compare long-term outcomes between patients who were and were not on an AAD prior to ablation and remained free from AF during the 3-month BP post CB PVI.

Methods

We enrolled consecutive AF patients undergoing CB PVI; all pts had an implantable loop recorder (ILR). No patient had any AF in the first 90 days post CB PVI. We divided the patients into three groups: (1) never had exposure to an AAD; (2) were intolerant to/failed AAD and thus were not taking an AAD at time of ablation; and (3) were on AAD at time of ablation. In the latter group, every effort was made to stop the AAD before the end of the BP.

Results

The cohort included 96 pts (66±10 years; 60 [63%] male; 55 [57%] PAF; CHA2DS2-VASc 2.5±1.4). There were 23 (24%) patients in group 1, 13 (14%) patients in group 2, and 60 (63%) pts in group 3. Patients in group 3 were more likely to have PeAF; AADs were stopped at a median of 36 days IQR (27, 91) in this group. Patients were followed for 1-year during which time 28 (29%) patients had recurrent AF (despite having no AF during the BP). The best outcome was seen in patients who never used an AAD; the worst outcome was seen in patients who were on an AAD at time of ablation (Figure 1).

Conclusion

Our data show that absence of AF during a 3-month post CB PVI BP alone does not guarantee good-long term outcome, unless the patient was never treated with an AAD. In contrast, in patients ablated while taking an AAD, recurrent AF was observed in 37% even though they were completely AF-free during the BP.

Funding Acknowledgement

Type of funding sources: None.

Recurrence of atrial fibrillation following pulmonary vein isolation: impact of body mass index on one- and three-year outcomes

Background

Cryoballoon (CB) pulmonary vein isolation (PVI) is an accepted method for ablation in patients with paroxysmal and persistent atrial fibrillation (PAF, PeAF). However, there are a paucity of data about the impact of body mass index (BMI) on one-year and longer-term outcomes following ablation.

Objective

To objectively understand the impact of BMI on outcomes following CB PVI.

Methods

We enrolled consecutive AF patients undergoing CB PVI; all patients had an implantable loop recorder (ILR), which transmitted data wirelessly daily. We assessed AF recurrences after excluding an initial 3-month post-ablation blanking period.

Results

The cohort included 222 pts (66±9 years; 143 [64%] male; 120 [54%] PAF; CHA2DS2-VASc 2.6±1.6). The mean BMI was 30±5. Patients were followed for 763±347 days, during which time 50% and 68% had recurrent AF 1- and 3-years post ablation. We divided the cohort based on the mean BMI into 2 groups: BMI &lt;30 and BMI &gt;30. Heavier patients were younger and more likely to have PeAF. Over 1-year of follow-up, patients with a BMI &lt;30 had similar likelihood of being free of AF to patients with a BMI &gt;30 (46% vs, 56%, p=0.0.097, Figure 1, left). However, as patients were followed for 3-years, freedom from AF was significantly higher in patients with a BMI &lt;30 (59% vs. 81% in BMI &gt;30, p=0.002, Figure 1, right).

Conclusions

Our data show that although patients had similar outcomes 1-year post-ablation, during longer-term follow-up patients with a BMI &gt;30 had a much worse outcome. Our study uniquely offers objective (using an ILR) assessment of the impact of BMI on long-term outcomes following CB PVI (homogenous ablation strategy). These data highlight the need to identify strategies to improve outcomes in obese patients.

Funding Acknowledgement

Type of funding sources: None.

Superconducting-qubit readout via low-backaction electro-optic transduction

Entangling microwave-frequency superconducting quantum processors through optical light at ambient temperature would enable means of secure communication and distributed quantum information processing¹. However, transducing quantum signals between these disparate regimes of the electro-magnetic spectrum remains an outstanding goal^2-9, and interfacing superconducting qubits, which are constrained to operate at millikelvin temperatures, with electro-optic transducers presents considerable challenges owing to the deleterious effects of optical photons on superconductors^9,10. Moreover, many remote entanglement protocols^11-14 require multiple qubit gates both preceding and following the upconversion of the quantum state, and thus an ideal transducer should impart minimal backaction¹⁵ on the qubit. Here we demonstrate readout of a superconducting transmon qubit through a low-backaction electro-optomechanical transducer. The modular nature of the transducer and circuit quantum electrodynamics system used in this work enable complete isolation of the qubit from optical photons, and the backaction on the qubit from the transducer is less than that imparted by thermal radiation from the environment. Moderate improvements in the transducer bandwidth and the added noise will enable us to leverage the full suite of tools available in circuit quantum electrodynamics to demonstrate transduction of non-classical signals from a superconducting qubit to the optical domain.

The impact of atrial fibrillation burden early post cryoballoon pulmonary vein isolation on long-term freedom from recurrent atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Background

Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. A three-month blanking period (BP) is commonly used in clinical trials and practice. Early recurrence of AF portends worse ablation long-term outcome; however, the utility of using AF burden (AFB) early post cryoballoon (CB) PVI to predict long-term outcome is unknown.

Purpose

To determine, using ECG data acquired by an implantable loop recorder (ILR), the relationship between post-ablation AFB and long-term freedom from AF.

Methods

We enrolled consecutive patients with AF who had CB PVI and an ILR. We determined the monthly AFB for the first 3 months post CB PVI and assessed the relationship between AFB and 1-year freedom from AF. We defined 4 distinct AFB groups: (1) 0%, (2) &gt; 0-0.1%, (3) &gt; 0.1-0.5%, and (4) &gt; 0.5%.

Results

There were 210 patients (66 ± 9 years; 138 [66%] male; 116 [55%] paroxysmal AF; CHA2DS2-VASc 2.5 ± 1.6). Following a 3-month BP, 101 (48%) patients had a recurrence of AF at 160 ± 86 days post-ablation. An AFB of &gt; 0% over the first 3 months predicted AF recurrence (p &lt; 0.0001, Figure 1). Patients with &gt; 0.5% AF burden after 1st month and any AF after 2nd month post CB PVI have a very high long-term AF recurrence rate (Figure 2).

Conclusion

The best long term outcome post CB PVI is seen in pts who have no AF in the first 3 months post ablation. An AFB &gt;0.5% after the first month and any AF after the second month portend ablation failure. These data define a clinical utility of using AFB to risk stratify patients post CB PVI.

Yearly incidence and pattern of very late recurrence of atrial fibrillation as detected by continuous electrocardiographic monitoring using an implantable loop recorder

Funding Acknowledgements

Type of funding sources: None.

Background

A very late recurrence (VLR) of atrial fibrillation (AF) is considered present when patients have their first recurrence of AF &gt; 12 months post-ablation. Little is known about the yearly rates and patterns of VLR AF recurrence.

Objective

To assess the yearly incidence and pattern of VLR in pts with AF who underwent cryoballoon (CB) pulmonary vein isolation (PVI).

Methods

We prospectively enrolled consecutive patients with AF who underwent CB PVI and had an implantable loop recorder (ILR) inserted up to 3 months post-ablation. Patients were followed for recurrent AF (excluding a 3-month post-ablation blanking period).

Results

Our cohort included 222 patients (66 ± 9 years; 143 [64%] male; 120 [54%] paroxysmal AF; CHA2DS2-VASc 2.6 ± 1.6). At 1-year, 111 (50%) patients remained free of AF. Two-year follow-up was available in 95 of these patients; 62 (65%) remained in sinus. Three-year follow-up was available in 42 of these patients; 36 (86%) remained in sinus (Figure). Of the 39 patients who developed AF after initially being free of AF for at least 1-year post ablation, 24 (62%) patients had either a frequent or persistent pattern of AF.

Conclusions

Our data show that the greatest likelihood of failure following a CB PVI occurs in the first year of ablation. The rate of failure becomes lower year by year. These data suggest that long term outcome may be driven more by the initial ablation as opposed to progressive evolution of the patient’s substrate

Risk factors of mortality after secondary procedures during the world-wide randomized antibiotic envelope infection prevention trial (WRAP-IT)

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Medtronic

Background

Previous analysis of WRAP-IT (World-wide Randomized Antibiotic Envelope Infection Prevention trial) data identified both patient and procedural characteristics as risk factors for cardiac implantable electronic device (CIED) infection. In the current analysis, we sought to similarly use prospectively collected WRAP-IT data to assess risk factors of all-cause mortality. Understanding if mortality risk can be modified and identifying baseline characteristics associated with high risk can help guide physician decision making.

Purpose

To identify modifiable and non-modifiable risk factors for 1-year all-cause mortality after a secondary (replacement, revision, or upgrade) CIED procedure.

Methods

This analysis included 5,461 secondary procedure patients from the WRAP-IT study. Included as candidate factors were patient and procedural characteristics. Patients with more than one year follow-up were censored at one year. A multivariate Cox Proportional Hazards model was reached by stepwise selection to minimize Akaike Information Criterion.

Results

The overall one-year mortality rate was 5.2% after secondary procedures. Of the 26 patient and 18 procedural characteristics analyzed, the following variables best predicted risk of a 1-year all-cause mortality: age, NYHA class, renal dysfunction, anticoagulant use, ischemic cardiomyopathy, diabetes, BMI, procedure time, myocardial infarction, valve surgery, and hypertrophic cardiomyopathy (Table).

Conclusion

In WRAP-IT patients undergoing secondary procedures, the only procedure characteristics that had any association with all-cause 1-year mortality risk was procedure time suggesting that most of the risk factors of mortality are non-modifiable. Baseline patient characteristics and co-morbidities were the principal risk factors of all-cause 1-year mortality. Specifically, increasing age, NYHA class, and a history of renal dysfunction were strongly associated with mortality.

Is there clinical utility to replacement of an implantable loop recorder in patients who have previously undergone cryoballoon pulmonary vein isolation?

Funding Acknowledgements

Type of funding sources: None.

Background

Implantable loop recorders (ILRs) are used for long-term ECG monitoring following catheter ablation in patients (pts) with atrial fibrillation (AF) to guide clinical management. However, little is known about what do when the ILR reaches end of service (EOS).

Purpose

To identify pts who underwent replacement of their ILR and determine the diagnostic yield and clinical utility of the replacement device.

Methods

We enrolled 222 consecutive pts with AF who underwent cryoballoon pulmonary vein isolation (CB PVI) and had an ILR. We identified pts who subsequently underwent ILR replacement. The diagnostic and clinical utility of the newly replaced ILR was determined.

Results

The cohort included 56 pts (64 + 9 years; 35 [63%] male; 27 [48%] PAF; CHA2DS2-VASc 2.3 ± 1.5) in whom the initial ILR reached EOS. They were followed for 3.7 ± 2.1 years. Recurrent AF was observed in 41 (73%) of these pts; this triggered an intervention in 17 (41%) pts (Figure). Of the other 15 (27%) pts without any documented AF, anticoagulation was withheld in 13 [87%] pts. Following ILR replacement, 33 (80%) of the 41 pts had more AF (n=11 [33%] required an intervention) and 5 additional pts had AF for the first time.

Conclusions

Our data show that after CB PVI, ILRs help guide decisions regarding rhythm management and oral anticoagulation. When the initial ILR was replaced by a second ILR, AF was detected (often for the first time) in some patients; the findings were used to guide clinical decision making in the entire cohort. Thus, at this time, it remains undefined when ECG monitoring of these pts can be stopped because it is no longer clinical meaningful.

Defining the optimal blanking period duration after cryoballoon pulmonary vein isolation in patients with atrial fibrillation who have never been treated with an antiarrhythmic drug

Background

Cryoballoon (CB) pulmonary vein isolation (PVI) is an approved method for ablation in patients with paroxysmal (PAF) or persistent (PeAF) atrial fibrillation (AF). Although the first 90 days post-ablation are considered within the blanking period (BP), the optimal duration of the BP remains undefined.

Purpose

To objectively define the BP duration in pts undergoing CB PVI by evaluating a cohort never treated with an antiarrhythmic drug (AAD).

Methods

We enrolled consecutive pts with either PAF or PeAF who underwent initial CB PVI; all pts had an implantable loop recorder (ILR) for long-term ECG monitoring. No pt received an AAD either before or after ablation. We determined the time to last AF episode within the first 90 days of ablation. We then correlated this to the likelihood a patient had recurrent AF between 91 and 365 days of ablation.

Results

There were 45 pts (67±8 years; 26 [58%] male; 40 [89%] PAF; CHA2DS2-VASc 2.6±1.3). We defined 4 distinct groups post ablation based on whether or not they had AF in the BP: (1) no AF days 0–90 (n=19 [42%]), (2) last AF days 0–30 (n=11 [24%]), (3) last AF days 31–60 (n=3 [7%]), and (4) last AF days 61–90 (n=12 [27%]). After the 90-day BP, 15 (33%) pts had AF recurrence. Pts with no AF and those with AF only within 30 days of ablation had similar long-term outcome; however, recurrent AF more than 32 days after ablation predicted long-term ablation failure (Figure).

Conclusion

The post CB PVI blanking period is just a month. AF recurrences beyond a month in patients not on an AAD are associated with AF recurrence in the majority of pts.

Funding Acknowledgement

Type of funding sources: None. Blanking Group by AF Recurrence

Cloning and characterization of Thioredoxin 1 from the Cnidarian Hydra

Thioredoxins, small disulphide-containing redox proteins, play an important role in the regulation of cellular thiol redox balance through their disulfide reductase activity. In this study, we have identified, cloned, purified and characterized thioredoxin 1 (HvTrx1) from the Cnidarian Hydra vulgaris Ind-Pune. Bioinformatics analysis revealed that HvTrx1 contains an evolutionarily conserved catalytic active site CGPC and shows a closer phylogenetic relationship with vertebrate Trx1. Optimum pH and temperature for enzyme activity of purified HvTrx1 was found to be pH 7.0 and 25 °C respectively. Enzyme activity decreased significantly at acidic or alkaline pH as well as at higher temperatures. HvTrx1 was found to be expressed ubiquitously in whole mount in situ hybridization. Treatment of Hydra with hydrogen peroxide (H2O2), a highly reactive oxidizing agent, led to a significant increase in gene expression and enzyme activity of Trx1. Further experiments using PX12, an inhibitor of Trx1, indicated that Trx1 plays an important role in regeneration in Hydra. Finally, by using growth assay in E. coli and wound healing assay in human colon cancer cells, we demonstrate that HvTrx1 is functionally active in both prokaryotic and eukaryotic heterologous systems.

Is the optimal blanking period duration after cryoballoon pulmonary vein isolation impacted by use of antiarrhythmic drugs?

Funding Acknowledgements

Type of funding sources: None.

Background

Cryoballoon pulmonary vein isolation (CB) is an accepted method for ablation in patients with atrial fibrillation (AF). A three-month blanking period (BP) is commonly used in clinical trials and practice. However, when the optimal BP duration differs in patients (pts) on or off an antiarrhythmic drug (AAD) at time of ablation remains undefined.

Objective

To compare the BP duration in pts undergoing CB while either taking or not taking an AAD.

Methods

We enrolled consecutive pts with AF who had CB PVI while on an AAD. All pts had an implantable loop recorder (ILR). We prospectively followed all pts and determined the time to last AF episode during the 90-day post-PVI BP. This was then correlated with likelihood of having an AF recurrence between 3-12 months post-PVI.

Results

The cohort included 164 pts (66 ± 9 years; 97 [60%] male; 90 [55%] PAF; CHA2DS2-VASc 2.7 ± 1.7). Ablation was performed with 92 (56%) pts taking an AAD, which was stopped at a median of 80 [36, 105] days post-PVI. We defined 4 distinct groups: (1) no AF in 90-day BP (n = 75 [46%]); (2) last AF within 30 days of PVI (n = 32 [20%]); (3) last AF within 60 days of PVI (n = 17 [10%]); and (4) last AF within 90 days of PVI (n = 40 [24%]). Following the 90-day BP, 81 (49%) pts had a recurrence of AF. Long-term freedom from recurrent AF was similar in pts who did and did not use an AAD, irrespective of BP duration (Figure).

Conclusion

Our data suggest that the optimal BP duration in AF patients undergoing CB PVI while taking an AAD is 30 days. An AF recurrence after 30 days is associated with a very high likelihood of recurrent AF during longer-term follow-up, irrespective of whether an AAD is being used or not. Abstract Figure.

Defining the blanking period duration after cryoballoon pulmonary vein isolation in patients taking an antiarrhythmic drug

Funding Acknowledgements

Type of funding sources: None.

Background

Cryoballoon pulmonary vein isolation (CB) is an accepted method for ablation in patients with atrial fibrillation (AF). A three-month blanking period (BP) is commonly used in clinical trials and practice. However, the actual BP duration in patients (pts) on an antiarrhythmic drug (AAD) at time of ablation remains undefined.

Objective

To objectively define the BP duration in pts undergoing CB while taking an AAD.

Methods

We enrolled consecutive pts with AF who had CB PVI while on an AAD. All pts had an implantable loop recorder (ILR). We prospectively followed all pts and determined the time to last AF episode during the 90-day post-PVI BP. This was then correlated with likelihood of having an AF recurrence between 3-12 months post-PVI.

Results

The cohort included 92 pts (66 ± 10 years; 62 [67%] male; 33 [36%] PAF; CHA2DS2-VASc 2.6 ± 1.7). AADs used included dofetilide (42), dronedarone (14), amiodarone (25), sotalol and propafenone (3 each), and flecainide (5). The AAD was stopped at a median of 80 [36, 105] days post-PVI.  We defined 4 distinct groups: (1) no AF in 90-day BP (n = 45 [49%]); (2) last AF within 30 days of PVI (n = 17 [18%]); (3) last AF within 60 days of PVI (n = 13 [15%]); and (4) last AF within 90 days of PVI (n = 17 [18%]). Following the 90-day BP, 47 (51%) pts had a recurrence of AF. Once recurrent AF was observed &gt; 30 days post-ablation, patients had high likelihood of having a long term AF recurrence (p = 0.037, Figure).

Conclusion

Our data suggest that the optimal BP duration in AF patients undergoing CB PVI while taking an AAD is 30 days. An AF recurrence after 30 days is associated with a very high likelihood of recurrent AF during longer-term follow-up. Abstract Figure.

A study on the effects of stress and hopelessness in isolated COVID-19 patients in relation to severity of infection

Introduction

In India, Coronavirus pandemic started in the month of march 2020 and is growing day by day. In view of India being one of the most populous countries, it is hard to follow social distancing and abide by the lockdown rules. Therefore, as of December 2020, total number of covid-19 cases has crossed the 10 million. But the recovery rate in India is high, so the fear due to Covid-19 has decreased in intensity.

Objectives

To assess level of perceived stress in isolated covid-19 patients To assess level of hopelessness in isolated covid-19 patients

Methods

30 Patients of diagnosed Covid-19 positive,who were isolated in covid care setting in Uttar Pradesh(India),above 18yrs of age,of both sexes and willing to participate in the study were included, their socio-demographic data collected. Beck’s hopelessness scale and Perceived stress scale were administered. Infection severity upto moderate was selected and ICU patients were excluded. Results were analysed using SPSS software.

Results

It was observed that level of hopelessness increased with increasing age and increasing severity of covid-19.Level of perceived stress also increased with increasing age and increasing covid severity. There was no relation seen between hopelessness level and perceived stress level and no difference was seen in the levels of hopelessness and perceived stress between the two sexes.

Conclusions

Levels of hopelessness and stress increased with increasing age and increasing severity of covid-19.No relation seen between hopelessness level and perceived stress level and no difference was seen in the levels of hopelessness and perceived stress between the two sexes.

Disclosure

No significant relationships.

COVID-19 lockdown: a rare opportunity to establish baseline pollution level of air pollutants in a megacity, India

This paper analyses air quality data from megacity Delhi, India, during different periods related to the COVID-19, including pre-lockdown, lockdown and unlocked (post-lockdown) (2018-2020) to determine what baseline levels of air pollutants might be and the level of impact that could be anticipated under the COVID-19 lockdown emission scenario. The results show that air quality improved significantly during the lockdown phases, with the most significant changes occurring in the transportation and industrially dominated areas. A pronounced decline in PM_{2.5 and} PM₁₀ up to 63% and 58%, respectively, was observed during the lockdown compared to the pre-lockdown period in 2020. When compared to 2018 and 2019, they were lower by up to 51% and 61%, respectively, dropping by 56% during unlock. Some pollutants (NOx and CO) dropped significantly during lockdown, while SO₂ and O₃ declined only slightly. Moreover, when compared between the different phases of lockdown, the maximum decline for most of the pollutants and air quality index occurred during the lockdown phase 1; thus, this period was used to report the COVID-19 baseline threshold values (CBT; threshold value is the upper limit of baseline variation). Of the various statistical methods used median + 2 median absolute deviation (mMAD) was most suitable, indicating CBT values of 143 and 75 ug/m³ for PM₁₀ and PM_2.5, respectively. This results although preliminary, but it gives a positive indication that temporary lockdown can be considered as a boon to mitigate the damage we have done to the environment. Also, this baseline levels can be helpful as a first line of information to set future target limits or to develop effiective management policies for achieving better air quality in urban centres like Delhi.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13762-021-03142-3.

Practical consensus recommendations on fertility preservation in patients with breast cancer

Young women diagnosed with cancer today have a greater chance of long-term survival than ever before. Successful survivorship for this group of patients includes maintaining a high quality of life after a cancer diagnosis and treatment; however, lifesaving treatments such as chemotherapy, radiation, and surgery can impact survivors by impairing reproductive and endocrine health. Expert oncologists along with reproductive medicine specialists discuss fertility preservation options in this chapter since fertility preservation is becoming a priority for young women with breast cancer. This expert group used data from published literature, practical experience and opinion of a large group of academic oncologists to arrive at these practical consensus recommendations for the benefit of community oncologists.

Low-temperature electrocautery reduces lead-related complications: insights from the WRAP-IT study

Background

Patients with an existing cardiovascular implantable electronic device (CIED) often require a generator replacement or system upgrade/revision, during which some degree of dissection is usually necessary to free the existing lead(s). Commonly used techniques include blunt dissection, standard surgical electrocautery, or newer forms of electrocautery such as the low-temperature electrosurgical device (PlasmaBlade Soft Tissue Dissection Device) designed to minimize inadvertent thermal injury to leads.

Objective

Determine whether the dissection technique impacts the likelihood of developing a lead-related complication.

Methods

The WRAP-IT trial enrolled patients undergoing CIED replacement, upgrade, revision or de novo CRT-D implant. This analysis excluded patients undergoing a de novo procedure. All adverse events were adjudicated by an independent physician committee. Data were analyzed using Cox proportional hazard regression modeling, controlling for capsulectomies and lead dissections.

Results

5639 patients (mean [±SD] age: 70.6±12.7 years; 28.8% female) underwent a replacement/upgrade/revision. Electrocautery was used in 5203 (92.3%) patients and among these, low-temperature electrocautery was used in 1866 (35.9%) patients. Compared to standard electrocautery, low-temperature electrocautery was used more often when leads were dissected or mobilized (P&lt;0.001) or when a partial or complete capsulectomy was performed (P&lt;0.001). Use of low-temperature electrocautery was associated with a 31% reduction in lead-related complications (HR: 0.69, 95% CI: 0.49–0.98, P=0.037) (Figure).

Conclusion

The low-temperature electrosurgical device (PlasmaBlade) uses precise pulses of radiofrequency energy to dissect tissue with only minimal thermal damage. In this large cohort of replacement, revision, and upgrade procedures, use of low-temperature electrocautery led to significantly fewer lead-related complications.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Medtronic

Hardware challenges with an anticoagulation strategy guided by detection of atrial fibrillation by an implantable loop recorder

Background

A “pill-in-the-pocket” anticoagulation strategy, guided by ECG data from an implantable loop recorder (ILR), has been advocated as a clinical strategy. However, a fundamental requirement is the ability to reliably obtain daily ECG data from patients.

Objective

To determine the reliability of daily ECG data transfer from ILRs.

Methods

We evaluated patients implanted with an ILR in whom we sought to withhold oral anticoagulation (OAC) unless atrial fibrillation (AF) was detected. The ILR transmits data nightly to a bedside monitor. Once received, the data are sent to a central server. Over the course of a month, we tracked for each patient whether ECG data were received by the server.

Results

The study included 170 AF patients with an ILR where we planned to withhold OAC unless AF was documented. Daily ECG data were automatically transmitted and retrievable in only 36 (21%) patients. Two (1%) pts had not a single day of connectivity, 6 (4%) pts were connected &lt;7 days, and 16 (9%) pts were connected &lt;14 days. Wireless connectivity was lost for &gt;48 hours in 89 (52%) patients (Figure). Most patients experienced multiple reasons for data transmission failure within the month.

Conclusions

To determine whether an ILR guided OAC strategy is feasible, reliable daily transmission of ECG data is a fundamental prerequisite. Current technology facilitated daily ECG data transfer in only 1/5 of patients. In the remaining, there was either extended loss of connectivity or no connectivity at all. A “pill-in-the-pocket” anticoagulation approach is currently difficult given existing hardware limitations.

Funding Acknowledgement

Type of funding source: None

miR-3666 inhibits development of hepatic steatosis by negatively regulating PPARγ

AIMS

PPARγ is a crucial transcription factor involved in development of hepatic steatosis, an early stage of NAFLD. PPARγ is tightly regulated through various positive and negative regulators including miRNAs. In this study, we report for the first time miR-3666 as a negative regulator of PPARγ and its involvement in development of hepatic steatosis.

METHODS

Binding of miR-3666 to regulate PPARγ was checked by luciferase assay and was confirmed by mutating PPARγ 3'UTR. Regulation of PPARγ was determined by overexpression of miR-3666 in HepG2 cells. Hepatic steatotic state in HepG2 cells was developed by exposure to excess palmitic acid and expression of PPARγ, miR-3666 and some PPARγ target and non-target genes was checked. Involvement of mir-3666 by regulating PPARγ in hepatic steatosis was also examined in liver of HFD fed mice.

RESULTS

On overexpression of miR-3666, PPARγ expression decreased significantly in a dose-dependent manner in HepG2 cells. Binding of miR-3666 to PPARγ was confirmed as the luciferase activity using pMIR-REPORT with PPARγ 3'UTR decreased in PA treated HepG2 cells overexpressing miR-3666 and remained unchanged when PPARγ 3'UTR was mutated. In PA treated HepG2 cells during development of hepatic steatosis PPARγ was significantly up-regulated concomitant with down-regulation of miR-3666. Overexpression of miR-3666 in these cells decreased the extent of hepatic steatosis. Significant up-regulation of PPARγ and down-regulation of miR-3666 was also observed in liver of HFD fed mice indicating that miR-3666 regulates PPARγ in vivo.

CONCLUSIONS

miR-3666 negatively regulates PPARγ by binding to its 3'UTR during development of hepatic steatosis.

1261Geographical variations in the incidence of CIED infection and infection prevention strategies: Update from the global WRAP-IT study

Funding Acknowledgements

Medtronic, Inc.

Introduction

Cardiac Implantable Electronic Device (CIED) infections lead to significant morbidity, mortality, and use of health care resources. There is variation in infection prevention strategies among centers, and it is not clear whether there is also variation in infection rates across different geographies. Recently, WRAP-IT, the largest global randomized trial to evaluate an infection reduction strategy, randomized 6,983 patients to receive an antibacterial envelope (treatment) vs. no envelope (control). The results demonstrated a significant reduction in major CIED infection with the TYRX antibiotic envelope (12-mo infection rate for envelope vs. control 0.7% and 1.2%, respectively; HR, 0.60; 95% [CI], 0.36 to 0.98; P = 0.04).  The purpose of this analysis is to assess geographical variations in patient characteristics, procedural routines, and infection rates.

Methods

The WRAP-IT study enrolled patients undergoing a CIED pocket revision, generator replacement, or system upgrade or an initial implantation of a cardiac resynchronization therapy defibrillator and randomized them to receive the envelope or not, in addition to mandated pre-procedure intravenous antibiotic prophylaxis. To assess geographical variations in infection rates, the control group (per protocol) baseline demographics and procedural characteristics were identified. Major infection was defined as CIED infections resulting in system extraction or revision, long-term antibiotic therapy with infection recurrence, or death.

Results

A total of 3429 control patients were evaluated and followed for a mean of 20.9 ± 8.3 months; 2530 patients from 123 centers in North America, 777 patients from 46 centers in Europe, and 122 patients from 11 centers in Asia/South America. The 24-month Kaplan-Meier major infection rates were 1.2% in North America (30 pts), 2.5% in Europe (16 pts), and 4.3% Asia/South America (5 pts) (see Figure). These geographical variations in the incidence of major CIED infections were significant (overall P = 0.008, univariate). There were differences in baseline patient characteristics, including age, sex, medication use, NYHA Class, and number of previous devices across geographies. Differences also included procedural characteristics, such as device type, use of pocket wash, skin preparation, pre-operative antibiotic drug use, and procedure time.

Conclusion

Major CIED infection rates vary significantly across geographies. The effect of patient demographics and procedural characteristics on these findings will be assessed and presented at EHRA. Insights into geographical variability of CIED infections is important to mitigate infection risk, reduce morbidity and cost.

Abstract Figure. Major CIED Infection Rate by Geography

Mapping of scaffold/matrix attachment regions in human genome: a data mining exercise

Scaffold/matrix attachment regions (S/MARs) are DNA elements that serve to compartmentalize the chromatin into structural and functional domains. These elements are involved in control of gene expression which governs the phenotype and also plays role in disease biology. Therefore, genome-wide understanding of these elements holds great therapeutic promise. Several attempts have been made toward identification of S/MARs in genomes of various organisms including human. However, a comprehensive genome-wide map of human S/MARs is yet not available. Toward this objective, ChIP-Seq data of 14 S/MAR binding proteins were analyzed and the binding site coordinates of these proteins were used to prepare a non-redundant S/MAR dataset of human genome. Along with co-ordinate (location) details of S/MARs, the dataset also revealed details of S/MAR features, namely, length, inter-SMAR length (the chromatin loop size), nucleotide repeats, motif abundance, chromosomal distribution and genomic context. S/MARs identified in present study and their subsequent analysis also suggests that these elements act as hotspots for integration of retroviruses. Therefore, these data will help toward better understanding of genome functioning and designing effective anti-viral therapeutics. In order to facilitate user friendly browsing and retrieval of the data obtained in present study, a web interface, MARome (http://bioinfo.net.in/MARome), has been developed.

The effect of an intraorifice barrier and base under coronal restorations on the healing of apical periodontitis: a randomized controlled trial

AIM

To evaluate the effect of intraorifice barriers and bases on the healing of apical periodontitis following root canal treatment in mandibular molars.

METHODOLOGY

A total of 120 permanent mandibular molars with necrotic pulps and periapical radiolucencies (PAI score ≥ 3) were recruited. Root canal treatment was performed in all teeth using a standard protocol, following which they were randomly allocated to one of the three treatment groups: intraorifice barrier group: coronal 3-mm gutta-percha was removed and replaced with glass-ionomer cement (GIC) barrier. The floor of the pulp chamber was then sealed with 2-mm-thick GIC base followed by final composite resin restoration; base group: received 2-mm-thick GIC base before placement of composite resin restoration; and control group: had pulp chamber entirely filled with composite resin only. Follow-up was done at 3, 6, 9 and 12 months. Combination of clinical and radiographic parameters were used to assess treatment outcome. The data were analysed using Kruskal-Wallis, chi-square and Wilcoxon signed-rank tests and logistic regression analysis.

RESULTS

At the end of 12 months, the base group had the most favourable healing (97.1%), whilst the control group had the least favourable healing (83.8%). The intraorifice barrier group had healing of 92.1%. However, there was no significant difference in healing between groups at the end of the follow-up period (P > 0.05). Additional subgroup analysis revealed a nonsignificant effect of periodontal status and root filling level on periapical healing.

CONCLUSION

The use of an additional barrier under permanent restorations did not significantly improve the outcome of primary root canal treatment in posterior teeth after 12 months. However, its influence in the long term requires further evaluation.

P577Early experience with the first pacemakers to directly connect with smart devices for remote monitoring

Background

Remote monitoring is associated with improved patient outcomes; however, adoption and adherence to remote monitoring via home-based consoles remains suboptimal. BlueSync technology in new generation pacemaker and CRT-P models enables the implanted device to communicate directly with patient-owned, Bluetooth-equipped smartphones/tablets and an app (MyCareLink Heart). The app can automatically retrieve information from the cardiac device and transmit the data to the remote network, eliminating the need for traditional remote monitoring consoles.

Objectives

To characterize the communication process between implanted pacemakers and smart device remote monitoring apps by assessing the success of prescheduled remote transmissions in the first month of follow-up. Additionally, to assess the feedback of both patients and clinicians about the process of device pairing.

Methods

Enrollment in the BlueSync Field Evaluation began in April 2018 and was completed November 2018. Follow-up is ongoing. Prior to enrollment in the evaluation, patients completed the device pairing process with the app using their own compatible smartphone or tablet. Patient and clinician questionnaires were completed at the time of the device pairing process. After enrollment, successful completion of scheduled transmissions occurring in the first month were analyzed.

Results

Preliminary data includes 241 enrolled patients with mean age of 64.7±15.5 yrs (min 20, max 90 yrs), who completed device pairing between their implanted device and their smart device app. Of enrolled patients, 79% felt that the device paring was easy to do, 85% were satisfied with the amount of time it took to complete it, and 93% felt that they would be comfortable using the app. Clinicians reported that 67% of the device pairings took less than 20 minutes and 78% felt patients would be able to use the app independently. At the time of analysis 174 patients had at least one scheduled transmission within the first month, and collectively had a total of 322 scheduled transmissions. Out of these, 309 (96%, 95% CI: 93%-98%) were successfully completed.

MyCareLink Heart App

Conclusions

Initial experience with the world's first app based remote monitoring system for Bluetooth enabled pacemakers demonstrated success to scheduled transmissions in the first month across a wide range of patient ages. Patients and clinicians reported high satisfaction with this novel technology.

Acknowledgement/Funding

Medtronic PLC

P1913Implantable Loop Recorder Detected Pattern of Atrial Fibrillation Recurrence Following Cryoballoon Pulmonary Vein Isolation in Patients with Persistent Atrial Fibrillation

Background

Cryoballoon (CB) pulmonary vein isolation (PVI) is increasingly being used in patients (pts) with persistent atrial fibrillation (AF). However, there are limited data about the pattern of atrial fibrillation (AF) recurrence in these pts.

Objective

To assess, using an implantable loop recorder (ILR), the patterns of AF recurrence following CB PVI in pts with persistent atrial fibrillation.

Methods

We enrolled consecutive pts with persistent AF ablation undergoing their first CB ablation. Other cavotricuspid isthmus ablation when indicated, no other ablation was performed. A Reveal LINQ ILR (Medtronic) was implanted <3 months following ablation; all pts had a minimum of 1-year follow-up. The recurrence of any atrial arrhythmia was determined and adjudicated; 4 distinct AF patterns were characterized (Figure).

Results

We studied 64 pts (66±9 years; 50 [78%] male; CHA2DS2-VASc 2.6±1.9) with persistent AF; 52 (81%) pts were on an antiarrhythmic drug (AAD) peri-ablation. During 803±361 days of follow-up, 33 (52%) pts had their 1st AF recurrence 91–365 days post-ablation and another 17 (27%) pts had their 1st AF recurrence >365 days post-ablation. No AF was seen in 14 (31%) pts. Most pts (33 of 50, 66%) with AF recurrence presented with 1 of 3 distinct patterns of paroxysmal AF (Figure), which ranged from 22 min to 124 hours. In 2/3 of these pts, all AF recurrences lasted <24 hours. Only 17 (34%) pts recurred with persistent AF.

Conclusion

Following single CB PVI, most pts with persistent AF remained free of persistent AF during long-term follow-up. Most pts with recurrent AF have 1 of 3 distinct patterns with episodes commonly last <24 hours. These data suggest that CB PVI ablation may halt AF progression in pts initially presenting with persistent AF.

P3807Impact of unipolar vs bipolar left ventricular pacing using a quadripolar lead on heart failure hospitalization in patients undergoing cardiac resynchronization therapy

Background

Unipolar (uni) pacing from a bipolar left ventricular (LV) pacing lead in cardiac resynchronization therapy (CRT) patients (pts) has been associated with worse outcomes than bipolar (bi) pacing (MADIT CRT and ALTITUDE analyses). However, it is unknown whether the same is true with quadripolar LV pacing leads.

Purpose

To determine whether there is a difference in heart failure hospitalization (HFH) following CRT implantation in pts undergoing uni vs. bi LV pacing.

Methods

All pts enrolled in the NAVIGATE study were implanted with a CRT-D (RESONATE, Boston Scientific) using a quadripolar LV lead (ACUITY X4 Spiral Long, Spiral Short, or Straight). Pts were followed, and data collected on HFH and mortality. Vectors were programmed at the discretion of the implanter. Outcomes were adjusted for age, gender, NYHA class, ischemic etiology, conduction disorder pattern, EF, LV lead location, and LV lead shape.

Results

The study cohort included 2080 pts; 1781 pts had bi and 299 pts had uni LV pacing. Bi LV had higher % female, NYHA II/III, non-ischemic, LBBB, spiral shape, lateral and apical locations. During follow-up, the adjusted likelihood of HFH was significantly lower in pts undergoing bi LV pacing (HR 0.75, 0.58–0.97, p=0.027, Figure). Mortality was similar between the two groups.

Conclusions

In this large prospective study, uni LV pacing was associated with significantly greater likelihood of need for HFH during a 4-year follow-up period. These data suggest that routine programming in a bi configuration may be better for post-CRT pts. However, further study is needed to confirm causality and mechanism of this finding.

P14.69 Evaluation of electric field intensity delivered by Tumor-Treating Fields therapy to PET-defined metabolic volumes in recurrent glioblastomas

BACKGROUND

Tumor-Treating Fields (TTFields) therapy is a clinical treatment option for patients with newly-diagnosed and recurrent glioblastomas. Electric field intensities (EFIs) delivered to the tumor mass may affect treatment responses. In this study, we used the patients’ neuroimaging data to create realistic head models and evaluate: (i) the magnitude of EFIs delivered to the tumor mass; (ii) factors affecting the EFI values; and (iii) factors affecting treatment responses as assessed by amino acid PET.

MATERIAL AND METHODS

Fourteen recurrent glioblastomas in 9 patients were evaluated with α-[11C]-methyl-L-tryptophan (AMT)-PET before and up to 3 months after TTFields therapy (mean follow-up: 2.3 months). Individual MRI and CT scans were used to create patient-specific realistic head models and simulate TTFields delivery to the tumors. For each direction of treatment (antero-posterior, left-right), two 9-disk transducer arrays were simulated using disks placed according to the patients’ NovoTAL System™ based treatment plan. To generate TTFields, an alternating voltage difference (200V peak-to-peak, 200 kHz) was imposed on the outer surfaces of the disks. The simulations were performed using the Sim4Life V3.0 (ZMT-Zurich) quasi-electrostatic solver. The field intensities were normalized to simulate 2A peak-to-peak current supplied by the device. 3D EFI maps were created and fused with the pre- and post-TTFields PET images to measure EFIs delivered to the PET-defined metabolic tumor volume. Interval changes of static AMT uptake and kinetic PET variables were also evaluated.

RESULTS

The mean EFI delivered to the tumors varied between 1.34–2.43 V/cm (mean: 1.86 V/cm). Fronto-parietal tumors received higher mean EFI than temporal lobe tumors (p=0.05). Most tumors showed decreasing (n=9) or stable (n=4) AMT uptake on follow-up PET imaging after TTFields therapy. Higher EFIs delivered to the tumors (r=-0.56, p=0.04) and concomitant bevacizumab treatment (n=7, p=0.01) were associated with a greater PET response. On tracer kinetic analysis, the AMT uptake responses correlated with transport rate changes (p=0.04).

CONCLUSION

TTFields treatment of recurrent glioblastomas delivers variable EFIs to the metabolic tumor volume. Treatment responses on PET are driven by decreased amino acid transport rates, whose magnitude is associated with higher EFIs delivered to the tumor mass and also with concomitant antiangiogenic treatment in those with combined therapy. (The cost of the PET scans was supported by a grant from NovoCure Ltd., Haifa, Israel)

P14.57 Association of tryptophan metabolism and depression in patients with primary brain tumors

BACKGROUND

Patients with brain tumor have an increased risk for depressive disorder, whose underlying pathomechanism may involve dysregulated tryptophan/kynurenine metabolism. In this study, we analyzed the relation of depression to cerebral and systemic tryptophan metabolism in patients with primary brain tumors.

MATERIAL AND METHODS

Thirty-four patients with newly-diagnosed (n=19) or recurrent (n=15) primary brain tumors (25 gliomas, 8 meningiomas, 1 dysembryoplastic neuroepithelial tumor) underwent pre-treatment alpha-[11C]methyl-L-tryptophan (AMT)-PET and completed the Beck Depression Inventory-II (BDI-II) questionnaire. MRI and AMT-PET images were co-registered, and AMT K values (estimate of unidirectional tryptophan uptake, related to tryptophan metabolism) were measured in contralateral non-tumoral cortical and subcortical regions and correlated with BDI-II total and subscale (cognitive, affective, and somatic) scores. In a subset of 28 patients, plasma tryptophan metabolite levels were also measured and correlated with BDI-II scores.

RESULTS

In the whole group (n=34), 35% of the patients (n=12) had BDI-II scores indicating depression, while only a minority of them (n=5) were treated with selective serotonin reuptake inhibitors (SSRI). No difference was observed in AMT K values between gliomas vs. non-gliomas or between newly-diagnosed vs. recurrent tumors. Frontal cortical and thalamic AMT K values positively correlated with BDI-II total and somatic subscale scores (r=0.49, p=0.004 and r=0.53, p=0.001, respectively), and these correlations became stronger when patients with SSRI treatment were excluded. Levels of plasma tryptophan and its metabolites were not different between gliomas vs. non-gliomas, newly-diagnosed vs. recurrent tumor nor depressed vs. non-depressed patients. SSRI treatment showed no effect on plasma tryptophan metabolite levels. No correlation was found between depression and plasma tryptophan and its metabolite levels.

CONCLUSION

While plasma levels of tryptophan metabolites are not associated with depressive symptoms, higher tryptophan metabolism in the frontal cortex and thalamus, measured by PET, may serve as an imaging biomarker of brain tumor-associated depression and supports the role of dysregulated tryptophan/kynurenine metabolism in this condition.

P14.37 Depression in patients with primary brain tumors: Relation to clinical variables and tumor characteristics

BACKGROUND

Patients with brain tumor have an increased risk for depressive disorder, however, the association between depression and clinical or tumor-related variables remains mostly unclear. In this study, we analyzed the relation of depression to several clinical and tumor-related characteristics in patients with primary brain tumors.

MATERIAL AND METHODS

Sixty patients with newly-diagnosed (n=34) or recurrent (n=26) primary brain tumors (50 gliomas, 10 meningiomas) underwent testing with the Beck Depression Inventory-II (BDI-II). Relation of BDI-II scores to clinical and tumor-related characteristics, including age, Karnofsky Performance Status (KPS) scores, presence of antiepileptic, antidepressant, or steroid treatment, as well as tumor grade, lateralization, and lobar localization, were analyzed. In a subset of recurrent malignant glioma patients, the prognostic value of BDI-II scores on overall survival was also analyzed.

RESULTS

The mean total BDI-II score was 10±8 (range: 0–37); while 27% of patients (n=16) had BDI-II scores indicating at least mild depressive disorder (≥13), only a portion of them (17%) was on antidepressant treatment. No BDI-II difference was found between gliomas vs. meningiomas or newly-diagnosed vs. recurrent tumors; also, no association was found with any tumor-related characteristics. Antiepileptic or steroid therapy had no association with BDI-II scores, while higher BDI-II scores were observed in patients with ongoing antidepressant therapy (15±10 vs. 8±7, p=0.017). Higher BDI-II total and somatic subscale scores correlated with lower KPS scores (r=-0.32, p=0.014 and r=-0.31, p=0.017, respectively). In recurrent malignant glioma patients (n=18), higher depression scores were associated with shorter survival (hazard ratio: 3.7; 95% confidence interval: 1.0–13.6; p=0.048).

CONCLUSION

Depression affected more than ¼ of patients with primary brain tumors in this single-center cohort and was independent from most clinical and tumor-related characteristics, except KPS scores. Although most of these patients have mild depression that is often overlooked without targeted screening, higher BDI-II scores may predict shorter overall survival in recurrent malignant glioma patients. These data reinforce the importance of early recognition and treatment of depressive symptoms in patients with primary brain tumors.

P11.35 Fluorine-18-labeled PET radiotracers for imaging tryptophan uptake and metabolism in brain tumors

BACKGROUND

Abnormal metabolism of tryptophan via the serotonin and kynurenine pathways plays a key role in multiple disease processes including cancer. Upregulation of key enzymes of the kynurenine pathway (such as indoleamine 2,3-dioxygenase [IDO] and tryptophan 2,3-dioxygenase [TDO]) plays an important role in immune resistance in human brain tumors. IDO inhibitors have recently entered in human clinical trials, and their use can benefit from molecular imaging evaluating IDO activity. Imaging tryptophan uptake and metabolism in vivo can be achieved with tryptophan derivative PET radiotracers. Human studies with such tracers showed promise but have been confined to carbon-11-labeled compounds (such as alpha-[11C]methyl-L-tryptophan). Preclinical development of fluorine-18-labeled tryptophan-based radiotracers has surged only in recent years. We performed a systematic review of studies reporting on such tracers and summarized their biological characteristics and their potential for imaging key enzymes of the kynurenine pathway.

MATERIAL AND METHODS

A PubMed search using the key words “tryptophan” and “PET”/”positron emission tomography” was performed. English language original articles including data on the preparation and/or radiochemical or biological characteristics of fluorine-18-labeled tryptophan derivative radiotracers have been reviewed.

RESULTS

Nineteen original papers identified by the search included data on 15 unique fluorine-18-labeled tryptophan-derived radiotracers. Automated synthesis was reported for 1-(2-[18F]fluoroethyl)-L-tryptophan, the most extensively evaluated tracer among the 15. Biodistribution studies showed high uptake in the pancreas, and the L-type amino acid transporter was the dominant transport mechanism for most of the reported radiotracers. Multiple tracers showed accumulation in various tumor cell lines, including glioma cell lines, in vitro and in xenografts in vivo, with favorable tumor-to-background uptake ratios in comparison to clinically used fluorine-18-labeled radiotracers (such as glucose and non-tryptophan amino acid analogs). Five of the 15 tracers showed promise for imaging IDO activity, including a fluorine-18-labeled analog of alpha-[11C]methyl-L-tryptophan. Two of the 15 radiotracers were metabolized by TDO but showed rapid defluorination in vivo.

CONCLUSION

Most fluorine-18-labeled tryptophan derivative PET tracers share common transport mechanisms and biodistribution characteristics. Several of these radiotracers show promise for imaging IDO activity in vivo, and, therefore, could be leading candidates for testing and validation toward human tumor PET imaging applications.

Andrographolide enhances redox status of liver cells by regulating microRNA expression

Andrographis paniculata Nees and its principal compound andrographolide are well known for exerting beneficial effects by modulating signaling pathways in different biological systems. Our earlier studies have demonstrated the ability of andrographolide as well as andrographolide enriched extracts to activate Nrf2/HO-1 pathway through adenosine A_2a receptor. Present study investigated ability of andrographolide to regulate Nrf2 induced antioxidant defense systems by miRNAs using HepG2 cells. Andrographolide strongly induced Nrf2 which in turn modulated enzymes of glutathione and thioredoxin antioxidant systems. It also regulated crucial transcription factors viz. hepatocyte nuclear factor alpha (HNF4A) and tumor suppressor protein 53 (p53). Downregulation of HNF4A by andrographolide led to decrease in miRNAs regulating Heme oxygenase-1 (miR-377) and glutathione cysteine ligase (miR-433). Upregulation of p53 on the other hand led to increase in miRNAs regulating thioredoxin interacting protein (miR-17, miR-224) and glutathione peroxidase (miR-181a). Involvement of p53 and HNF4A in modulation of these miRNAs was confirmed by chromatin immunoprecipitation assay. Overall, the work reveals that andrographolide through modulation of p53 and HNF4A, regulates miRNAs leading to upregulation of HO-1, glutathione and thioredoxin systems. Andrographolide thus, can play a beneficial role in modulating antioxidant defense in oxidative stress induced diseases such as diabetes, ageing etc.

Enablers and Barriers of Follow-Up Care: An Experience From an HPV DNA Detection–Based Cervical Cancer Screening Program in Rural India

Background: Success of a cervical cancer screening program is intrinsically linked with appropriate management of women detected positive on screening tests. While routine screening can be done in any setting, the follow-up care of screen positive women is linked with settings that are equipped with diagnostic and treatment facilities, and trained medical providers. In low resource settings, the major obstacles to deliver follow-up care are lack of adequate healthcare infrastructure and trained service providers at district or subdistrict levels. Aim: To assess feasibility of implementing community based interventions to increase uptake of follow-up care of screen positive women in a HPV detection based screening program conducted by Chittaranjan National Cancer Institute (CNCI), Kolkata. Strategy: A network of key stakeholders including government authorities and civil society organizations was developed to deliver continuum of care at the doorsteps of screen positive women. The infrastructure of government's primary health care delivery system was used to set up temporary clinics at district and subdistrict levels. The clinics were organized on prescheduled dates and times that were convenient to the women. Community health workers (CHWs) were trained in community mobilization strategies to increase uptake of follow-up services. All instruments, equipment and consumables required for providing follow-up services were carried to the clinics in a vehicle. Program: The CHWs played a key role in counseling and recalling the screen positive women. The temporary clinics were arranged in the government primary health centers. A team of trained doctors and paramedics provided the diagnostic and treatment services. Colposcopy was performed on all screen positive women using portable colposcopes and guided biopsies were taken as indicated. Women who were eligible for ablative treatment were counseled and treated in the same sitting. All women were advised yearly follow-up. Outcomes: A total of 43,325 women were screened by HC2 test during July 2010 to March 2015, and 2045 (4.7%) women were detected to be high-risk HPV positive. Compliance to first recall was good with 78.6% (1608/2045) of women undergoing diagnostic evaluation at field clinics. But overall compliance to at least one follow-up visit after 1 year was poor (23.2%). Follow-up compliance rate was higher in women who were diagnosed with CIN1 as compared with those with normal diagnosis ( P < 0.001). What was learned: Diagnostic and treatment services could be effectively organized in the community in convergence with existing healthcare delivery system. High compliance to initial diagnostic evaluation and treatment was achieved by making the services available close to the doorsteps of the women. The reasons for low compliance to yearly follow-up were lack of understanding of future cancer risk, unwilling to undergo speculum examination again, and lack of cooperation of spouse/family.

Reconfigurable Topological Phases in Next-Nearest-Neighbor Coupled Resonator Lattices

We present a reconfigurable topological photonic system consisting of a 2D lattice of coupled ring resonators, with two sublattices of site rings coupled by link rings, which can be accurately described by a tight-binding model. Unlike previous coupled-ring topological models, the design is translationally invariant, similar to the Haldane model, and the nontrivial topology is a result of next-nearest couplings with nonzero staggered phases. The system exhibits a topological phase transition between trivial and spin Chern insulator phases when the sublattices are frequency detuned. Such topological phase transitions can be easily induced by thermal or electro-optic modulators, or nonlinear cross phase modulation. We use this lattice to design reconfigurable topological waveguides, with potential applications in on-chip photon routing and switching.