Versatility of Basal Cortical Screw Implants with Immediate Functional Loading

Background

The purpose of this study is to evaluate the survival rate of the basal cortical screw (BCS) implant system inserted in healed edentulous ridges (E) or extraction sockets (ES) with immediate loading functional protocol in varying clinical situations.

Methods

A total of 125 BCS implants were placed in 14 patients, immediately loaded and observed for 20.07(± 4.23) months. Ninety-four were placed in E sites and 31 were placed in ES sites. They were evaluated for bone loss, soft tissue shrinkage around the prosthesis, improvement in quality of life (QOL), and their survival after 1 year.

Results

Total of 121/125(96.8%) implants survived while 4/125(3.2%) failed at the end of follow-up. Average bone loss after 1 year was 0.33 mm (E) and - 1.57 mm (ES), average soft tissue shrinkage was 0.50 mm (E) and 1.42 mm (ES) and average Patient's Global Impression of Change (PGIC) scale score was 6.36(± 0.63) at 1 year. The complications observed were mobility {3(2.4%)}, pain/discomfort {1(0.8%)} and fracture of abutment at the neck {1(0.8%)}, prosthesis loosening {2(9%)} and requirement of relining {3(13%)}. No periimplantitis was observed.

Conclusion

This is the only study to report the marginal bone loss and soft tissue changes around BCS implants and an index-based improvement in QOL of such patients. The BCS implant system with immediate functional loading protocol is a versatile modality to rehabilitate a single tooth, a segment or a full arch with healed ridges as well as extraction sites; it gives high success rate and minimal complications.

Bilateral Biplanar Distraction Osteogenesis in Facial Deformity Secondary to Temporomandibular Ankylosis

Background

The purpose of this single-centre prospective clinical study was to evaluate the correction of severe facial deformity and Obstructive sleep apnoea hypopnoea syndrome (OSAHS) in 22 patients aged from 9 to 42 years (mean 20.09) of bilateral Temporomandibular joint ankylosis.

Materials and Methodology

Patients underwent multisegment distraction using external bilateral bidirectional distractors. Facial deformity was evaluated clinically in terms of mouth opening and neck chin angle and cephalometrically in terms of corpus length (gonion-pogonion), ramal height (articulare-gonion), chin deficiency (N perpendicular to Pog and SNB). OSAHS was evaluated through Epworth sleepiness scale, Berlin's questionnaire, pharyngeal airway space, apnoeic hypoapnoeic index, oxygen desaturation index, average arterial oxygen saturation and minimal fall in O2 saturation. Patients were followed up for a period of 13-74 months (mean 28.68).

Results

Statistically highly significant results were obtained in all parameters. Complications encountered were pin infection (13.63%), loosening of pins (4.5%), wound dehiscence (9.09%), tooth fracture (4.5%) and parotid fistula (9.09%). Intermediate segment necrosis and vector loss were not observed.

Conclusion

This study is a large case series using two corticotomy cuts for external bilateral bidirectional distracters with concomitant neo callous moulding in patients both pre- and post-ankylosis release. It is extremely efficient in correcting mandibular corpal and ramal deficiency as well as improving OSAHS.

Effect of lockdown amid second wave of COVID-19 on environmental noise scenario of the megacity Delhi, India

This paper analyzes the impact of second wave of COVID-19 lockdown on environmental noise levels of 25 sites in Delhi city and compares the noise scenario during pre-lockdown, lockdown, and post-lockdown periods. The study utilized the noise monitoring data acquired from 25 real-time ambient noise monitoring stations, installed by the Delhi Pollution Control Committee, Delhi, at various sites throughout Delhi city. A significant reduction of up to 10 and 3 dB(A) in day and night equivalent noise levels, respectively, had been observed during the lockdown period as compared to the pre-lockdown and post-lockdown periods. The study also revealed that only nine sites, including four industrial and five commercial zone sites, complied with the ambient noise standards during lockdown period, and no silence or residential zone sites complied with the ambient noise standards even during the lockdown period. A roadmap for environmental noise management and control is suggested. The study also reports the community's perception toward the change in acoustic environment of Delhi city during the lockdown period by conducting an environmental noise perception survey. The present study should be helpful in devising noise control action plans and policy interventions for environmental noise management and control in the metropolitan city Delhi, India.

Female sterilization reversal in the era of in-vitro fertilization

PURPOSE OF REVIEW

Regret after female sterilization is not uncommon in the United States. Prior to the development of assisted reproductive technology (ART), surgical reversal of sterilization was the only option for patients interested in fertility. First performed in 1972, this procedure has since been refined over the years by gynaecologic surgeons. With in-vitro fertilization (IVF) gaining popularity, interest in sterilization reversal has waned. However, sterilization reversal should remain an important option in patients seeking pregnancy after tubal ligation.

RECENT FINDINGS

A direct comparison between IVF and sterilization reversal is challenging due to inherent differences in reporting fertility outcomes. However, sterilization reversal may optimize fertility in younger women, whereas IVF may be more effective in older women. The surgical approach to sterilization reversal can be laparotomic, laparoscopic or robotic. Clinical decision making should include consideration of the risk of ectopic pregnancy, interval from sterilization to reversal, type of sterilization procedure, planned anastomotic site and projected remaining tubal length.

SUMMARY

In the era of IVF, sterilization reversal still has a place in the management in restoring fertility. Creating awareness of the role of sterilization reversal is the first step in improving access to adequate training in this procedure for the next generation of reproductive surgeons.

POS0945 IMPROVEMENT OF ENDOTHELIAL DYSFUNCTION AND INFLAMMATION IN ANKYLOSING SPONDYLITIS: IMPROVE-AS STUDY

Background

Cardiovascular (CV) disease is the leading cause of death in Ankylosing Spondylitis (AS)1. The chronic inflammatory-driven endothelial dysfunction and accelerated atherosclerosis contribute to the enhanced CV risk in AS. However, the therapeutic options to treat the enhanced CV risk are limited.

Objectives

To investigate the impact of Olmesartan and Rosuvastatin on endothelial dysfunction and inflammation in AS.

Methods

60 consequtive AS patients were randomized to receive 24-weeks of treatment with Olmesartan (OLME) (10 mg/day, n=20), Rosuvastatin (Rvs) (10 mg/day, n=20), or placebo (PL) (n=20) as an adjunct to existing stable csDMARDs. Endothelial function was assesed by brachial artery flow-mediated dilatation (FMD) using AngioDefender. EPCs (CD34+/CD133+) were estimated by flow cytometry. Serum nitrite, TBARS, ICAM-1, VCAM-1 and lipids levels estimated at baseline and after treatment. Inflammatory measures included: ASDAS, BASDAI, BASFI, ESR and CRP, pro-inflammatory cytokines. Quality of life and CV 10-year risk (SCORE high risk charts) were estimated using standard tools.

Results

Baseline levels of FMD and EPC population were impaired indicating endothelial dysfunction. Basal concentrations of inflammatory markers, pro-inflammatory cytokines and markers of endothelial dysfunction were elevated among three groups. After 24-weeks of treatment, FMD improved significantly in the rosuvastatin and olmesartan group as compared to placebo from their baseline levels: {OLME vs. PL (p≤0.01), Rvs vs. PL (p<0.01), Rvs vs. OLME (p=0.10) (Figure 1A). EPCs and nitrite (Figure 1B) levels improved significantly in both rosuvastatin and olmesartan groups. A significant reduction found in ICAM-1 after rosuvastatin treatment (p<0.01) where as olmesartan significantly decreased VCAM-1 (p=0.04) levels. Both rosuvastatin and olmesartan resulted in significant reductions of ASDAS, BASDAI, BASFI, ESR, CRP, IL-6 (Figure 1C) and TNF-α (Figure 1D) as compared to placebo. A significant reduction found in TBARS concentration after olmesartan treatment (p<0.01) as compared with rosuvastatin and placebo. There was a significant reduction in SCORE, HAQ-DI & SF-36 (PH) after treatment with rosuvastatin and olmesartan.

Conclusion

Olmesartan and rosuvastatin improve endothelial dysfunction and vascular inflammation and QoL in AS patients. Olmesartan and Rosuvastatin lower the proinflammatory cytokines, especially TNF-α, that upregulate eNOS and downregulates the production of adhesion molecules, CRP and nitric oxide which, in turn, improves endothelial dysfunction. Both drugs also decrease nitrite concentration and improve the EPC population in AS patients. The augmentation of EPCs by olmesartan and rosuvastatin represents a fascinating new approach for the management of AS. However, Rosuvastatin in addition also favorably impacted ICAM-1 and lipid abnormalities. In contrast, olmesartan has beneficial effect on blood pressure. Thus, both rosuvastatin and olmesartan have anti-inflammatory, immunomodulatory, vasculoprotective and cardioprotective effects in AS mediated through anti-proinflammatory cytokine action. These findings suggests that both drugs could mediate modest but clinically apparent anti-inflammatory effects with modification of CV risk in the context of high-grade autoimmune inflammation of AS and may provide a novel strategy to prevent cardiovascular events in these patients.

References

[1]Azevedo VF, Pecoits-Filho R. Atherosclerosis and endothelial dysfunction in patients with ankylosing spondylitis. Rheumatol Int 2010;30(11):1411–1416

Disclosure of Interests

None declared

Randomized comparison of proximal and distal radial access for coronary angiography and interventions

Funding Acknowledgements

Type of funding sources: None.

Introduction

Vascular access for coronary procedures is of paramount important not only for successful procedure but also to prevent complications. In comparison to femoral access, proximal radial artery (PRA) access at wrist is associated with decreased bleeding complications and mortality.  The most important complication of PRA access is radial artery occlusion Use of the proximal radial artery (PRA) approach at wrist has several limitations:  the need to supinate the hand, which can exacerbate chronic joint pain, the depth of the radial artery in large arms, which could make arterial puncture challenging even under ultrasound guidance, the risk of sporadic bleeding in the forearm, and the risk of radial artery occlusion. All above limitations can be overcome by distal radial artery (DRA) access in anatomical snuff box.  Randomized Studies are lacking for the comparison between DRA and PRA approach in coronary procedures.

Aims and objective

To compare safety, efficacy and feasibility between PRA and DRA approach in randomized fashion.

Material and methods

This was single center randomized controlled trial. 320 patients were randomized in PRA and DRA groups. PRA approach was in wrist and DRA approach was in anatomical snuff box. Primary endpoint was cannulation failure (failure to achieve radial access) and transradial failure (failure to complete procedure after successful access). Secondary safety outcome includes major (compartment syndrome, need for vascular surgery, hand dysfunction, nerve palsy ,arteriovenous fistula, hematoma requiring blood transfusion, proximal radial artery occlusion) and minor (radial artery spasm, hematoma not requiring transfusion or causing compartment syndrome, ecchymosis, local edema, paresthesia, pseudoaneurysm) complications; secondary efficacy outcome were puncture attempts, cannulation time, procedure time, radiation dose, hemostasis time  and quality of life endpoint  was pain score .

Results

 Each group was having 160 patients. In DRA group 73.9 % were CAG and 26.1 % were PCI; in PRA group and 75.7 were CAG and 24.3 were PCI. Cannulation failure was more in DRA group (7.5 % vs 2.5 %, P &lt; 0.001) without difference in transradial failure (n = 3 vs 4, p =0.764). There were no major complications in both groups except PRAO which was significantly less in DRA group (0 % vs 5.2 %, p= 0.007). Puncture attempts, cannulation time, pain score were more in DRA (1.65 vs 1.29, P &lt; 0.001;3.23 vs 2.62 minutes, p &lt; 0.001;25.5 vs 21.6 minutes, p = 0.039 respectively). There was no significant difference for minor complications in both groups.

Conclusion

DRA approach is as safe and feasible as PRA approach and causes significantly less PRAO. DRA approach may be advocated as default approach where radial access is chosen for coronary procedures. Abstract Figure. primary outcome  Abstract Figure. Procedural characteristic

Clinical significance of epicardial fat in suspected angina pectoris: an observational study

Funding Acknowledgements

Type of funding sources: None.

Background

Epicardial adipose tissue (EAT) is the visceral fat between pericardium and visceral epicardium and is the source of several endocrine and inflammatory mediators. It also has paracrine affects in the neighboring coronary arteries.

Objective

 To evaluate the association of EAT with subclinical atherosclerosis (carotid intima media thickness & flow mediated vasodilation), ultrasonic and anthropometric measures of abdominal fat, metabolic syndrome and coronary artery disease (CAD) concurrently.

Material and methods

Patients who underwent computed tomography (CT) coronary angiography for suspected CAD were prospectively included. All underwent anthropometric measurements, laboratory investigations, ultrasonic measurement of liver fat grade & B-mode hepatorenal ratio, carotid intima media thickness (CIMT), flow mediated vasodilation (FMD), CT measurement of epicardial fat thickness (EFT) & epicardial fat volume (EFV) along with CT coronary angiography. Study population was divided into 2 groups on the basis of presence or absence of CAD and were compared. The relationship between risk factors and presence of CAD was assessed by logistic regression analysis. To define EFT and EFV value predictive of the presence of significant CAD, the area under (AUC) the receiver operating characteristic (ROC) curve was calculated. Correlation between EFT as well as EFV with anthropometric and laboratory parameters, CIMT and FMD were assessed by Pearson correlation coefficient.

Results

Total 54 patients were included in study. Mean age was 54 years, 66% were diabetic and 33% were hypertensive. Mean CIMT, FMD, EFT and EFV were 0.70 + 0.27 cm; 5.64 + 2.64%; 5.51 + 2.50 mm and 60.6 + 28.6 cc, respectively. Total 34 (62.96%) patients were detected to have CAD. EFT as well as EFV were significantly higher in CAD group (3.31 + 2.34 vs 6.24 + 1.91mm; p= &lt;0.001, 72.5 + 22.3 vs 40.4 + 27.1cc; p= &lt;0.001); in patients with metabolic syndrome (83.3 + 18.4 vs 49.2 + 26.1cc; p &lt; 0.001, 7.13 + 1.49 vs 4.16 + 2.32mm; p &lt; 0.001). Both, EFV & EFT were significantly correlated with the abdominal fat, CIMT and FMD. Smoking, age and EFV were the independent predictors for CAD.  EFV &gt;31.65cc predicted the presence of CAD (sensitivity 91.25%, specificity 60%, AUC = 0.798, 95% CI = 0.665-0.930) and EFT &gt;2.85mm predicted the presence of CAD (sensitivity 94.1%, specificity 65%, AUC= 0.820, 95% CI= 0.687-0.953).

Conclusions

Epicardial fat is significantly associated with presence of CAD, metabolic syndrome, visceral fat, CIMT and FMD. CT measured epicardial fat may be included with CT based CAD lesion assessment and CT coronary calcium score to screen the patients of suspected angina pectoris. Abstract Figure. Epicardial adipose tissue  Abstract Figure. EFV and CAD

Impact of COVID-19 lockdown on ambient noise levels in seven metropolitan cities of India

The paper analyzed the impact of lockdown on the ambient noise levels in the seventy sites in the seven major cities of India and ascertained the noise scenario in lockdown period, and on the Janta Curfew day in comparison to the pre-lock down period and year 2019 annual average values. It was observed that the majority of the noise monitoring sites exhibited a decrement in ambient day and night equivalent noise levels on the national Janta Curfew day and Lockdown period as compared with the normal working days attributed to the restricted social, economical, industrial, urbanization activity and reduced human mobility. A mixed pattern was observed at a few sites, wherein the ambient day and night equivalent noise levels during Janta curfew day and Lockdown period had been reported to be higher than that on the normal working days. The study depicts the noise scenario during the lockdown and pre-lockdown period for seventy sites in India and shall be instrumental in analyzing the consequences and implications of imposing lockdowns in future on the environmental noise pollution in Indian cities.

In hospital outcomes of orbital/rotational coronary atherectomy in diabetic vs non-diabetic population: insights from the nationwide inpatient sample

Background

Atherectomy (AT) using an orbital/rotational system is useful in altering calcified plaque thereby facilitating stent placement and optimal stent expansion. Patients with diabetes mellitus (DM) are known to have a higher rate of complications after percutaneous coronary intervention. We aimed to assess the incidence of major adverse cardiovascular events after atherectomy in the diabetic population using a nationwide inpatient sample (NIS).

Methods

NIS-HCUP database from 2015–2017 was used to identify patients who underwent atherectomy. A cohort of patients with and without diabetes was identified. Demographics, in-hospital outcomes, complications in both groups were compared. Statistical significance was assigned at p&lt;0.05.

Results

Out of 6184 patients who underwent AT, 3134 (50.6%) patients had DM. Baseline characteristics have been outlined in the table below. Complications were comparable between the two groups except for higher incidence of post-procedure VTE in Diabetic patients. In-hospital mortality was lower among patients with DM (2.24% vs 3.29%, p-0.27), while the mean length of stay (5.92 vs 4.91 days, p-0.002) and the hospitalization charges ($165118.4 vs 151226, p-0.04) were higher, but this difference in length of stay and hospitalization charges were nullified on multivariate regression.

Conclusion

Our study suggests that an AT for severely calcified plaque in the coronary artery is a safe option in patients with DM with comparable in-hospital complications and outcomes to non-DM patients.

Funding Acknowledgement

Type of funding sources: None. Demographics and Outcomes of Atherectomy

Distal radial access in the right anatomical snuffbox for coronary angiography and interventions: a prospective observational study

Background

Distal radial access in the anatomical snuffbox is a novel technique for vascular access. However, limited clinical data is available, mainly limited to the left distal radial access. In view of the paucity of data on right distal radial access; this study was conducted to assess the feasibility, efficacy and safety of the right distal radial approach as a default access route for transradial catheterization.

Methods

We enrolled 159 consecutive patients with a palpable right distal radial pulse prospectively at a single center. A detailed clinical evaluation, laboratory tests and echocardiographic examination was done. Doppler examination of distal radial artery for its patency and size was done before puncture attempt. The right distal radial artery was punctured using the back wall technique. Primary outcome was successful puncture of distal right radial artery. Secondary outcomes were number of puncture attempts, pain score, radial artery spasm, forearm and distal radial hematoma, proximal and distal radial artery occlusion, bleeding and other vascular complications, access site crossover due to distal radial access failure, contrast volume used, and radiation dose.

Results

Distal radial puncture was successful in 144/159 (90.1%) patients. The mean distal radial artery diameter was 2.2±0.25 mm. Mean pain score by visual analogue scale was 2.36±1.9. There were no bleeding events. Snuffbox hematoma was seen in 11 (7.6%) patients and forearm hematoma occurred in 5 (3.5%) patients. There were 9 (6.3%) cases of radial spasm, 4 (2.8%) cases of radial occlusion at distal access site and 1 (0.7%) forearm radial artery occlusion.

Conclusions

The right distal radial access is a feasible, safe and efficacious alternative approach for coronary angiogram and interventions.

Funding Acknowledgement

Type of funding sources: None.

POS0205 AMELIORATION OF ENDOTHELIAL DYSFUNCTION WITH JAK INHIBITION IN RHEUMATOID ARTHRITIS: JAK CV-RISK REDUCTION STUDY

Background:

Cardiovascular (CV) disease is the leading cause of premature mortality and sudden death in Rheumatoid Arthritis (RA). Conventional CV risk factors and disease specific risk factors are responsible for endothelial dysfunction (ED) in RA. ED is the barometer of CV health and key initial event in atherosclerosis. Tofacitinib, a JAK inhibitor, is in clinical use since 2012 and has had the most extensive development program in RA, but its impact on ED has not yet been explored in humans.

Objectives:

To investigate the impact of tofacitinib on endothelial dysfunction in RA

Methods:

40 RA patients fulfilling the 2010 Rheumatoid Arthritis classification criteria with active disease (DAS28>3.2) were randomized to receive 24 weeks of treatment with Tofacitinib (5mg bd, n=20) and placebo (n=20) as an adjunct to existing stable antirheumatic drugs. Primary endpoints included endothelial dysfunction assessed by FMD using Angiodefender and lipids were estimated at baseline and after 12 weeks of treatment. The secondary end points included: DAS28, ESR, CRP, HAQ-DI and cardiovascular risk using SCORE chart assessed at week 0 and 12.

Results:

At baseline, endothelial function was impaired and levels of inflammatory measures were elevated in both groups. CV risk SCORE was high and HAQ-DI was impaired at baseline. After treatment, FMD improved significantly in the tofacitinib group from (8.16±1.38% to 10.98±2.33%, p≤0.05) as compared to placebo (7.12±0.25% to 8.04±0.30%, p=0.35) (Fig. 1A). DAS28 (Fig. 1B), ESR and CRP (Fig. 1C) levels improved significantly in tofacitinib group as compared to placebo (p≤0.05). Tofacitinib significantly decreased HAQ-DI and SCORE (Fig. 1D) values as compared to placebo. There was significant increase in HDL (p≤0.05) after treatment with tofacitinib as compared to placebo. After 12 weeks of treatment, FMD and HDL increased by 34.55% and 13.58% respectively where as DAS28, ESR and CRP decreased by 37.40%, 36.10% and 76.59% respectively in the tofacitinib group. Significant negative correlation was observed between FMD and DAS28 (r= -0.50, p≤0.05) and CRP (r= -52, p≤0.05) after treatment with tofacitinib where as no such correlation was found in placebo group.

Figure 1.

Impact of Tofacitinib on FMD, DAS 28, CRP & SCORE

Conclusion:

First study to show that tofacitinib, apart from its anti inflammatory activity, improves endothelial dysfunction and cardiovascular risk in RA. Thus, JAK inhibition with tofacitinib has vasculoprotective and cardioprotective effect mediated through anti-inflammatory and probably other mechanisms. This study would stimulate further research in exploring the vasculoprotective and cardioprotective potential of tofacitinib in RA.

References:

[1]Tofacitinib reversed endothelial dysfunction in rheumatoid arthritis: mechanistic insights from the rat adjuvant-induced arthritis model. http://dx.doi.org/10.1136/annrheumdis-2020-eular.2747

Disclosure of Interests:

None declared

POS1011 PREDICTORS OF ENDOTHELIAL DYSFUNCTION IN ANKYLOSING SPONDYLITIS

Background:

Cardiovascular (CV) disease is the leading cause of death in Ankylosing Spondylitis (AS). Chronic systemic inflammation driven endothelial dysfunction leading to accelerated atherosclerosis results in premature mortality. Endothelial dysfunction is potentially treatable hence a therapeutic target. Predictive biomarkers for endothelial dysfunction would allow tailoring therapy to the individual.

Objectives:

To assess the endothelial dysfunction in AS in context of markers of inflammation and oxidative stress in AS patients.

Methods:

Sub group–analysis of our previous studies of AS1-3 was carried out and 80 AS patients were compared with 40 healthy controls matched for age and sex that were also part of these studies.2,3 Such analysis had so far not been performed in this cohort. Patients with traditional CV risk factors had been excluded in these studies. Flow-mediated dilatation (FMD), as a measure of endothelial function, was assessed by AngioDefender (Everist Health, Ann Arbor, MI). Inflammatory measures included: Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Ankylosing Spondylitis Disease Activity Score (ASDAS) in AS. We also assayed markers of inflammation, including C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), proinflammatory cytokines (interleukin [IL]-1, IL-6, and tumor necrosis factor [TNF]-α), and endothelial dysfunction, including lipids and nitrite and marker of oxidative stress, TBARS.

Results:

FMD was significantly lower in AS patients compared with controls [(5.80±0.35% vs. 9.09±0.35%, p≤0.05) reduced by approximately 36%] whereas serum nitrite, TBARS, total cholesterol and LDL levels were significantly higher in AS compared with controls (p≤0.05). Compared with controls, AS patients had significantly high BASDAI, ASDAS and increased concentrations of ESR, CRP, TNF-α, and IL-6. In AS, FMD inversely correlated with ASDAS, CRP (Figure 1A), TNF-α (Figure 1B), nitrite (Figure 1C) and TBARS (Figure 1) and positively correlated with HDL (p≤0.05).

Figure 1.

Correlation of FMD with CRP, TNF-α, Nitrite and TBARS

Conclusion:

In AS, FMD was impaired, indicating endothelial dysfunction. ASDAS, CRP, TNF-α, nitrite, and TBARS were independent predictors of FMD in AS. AS-related inflammatory mechanisms (TNF-α, IL-6) and markers of vascular function and oxidative stress (CRP, nitrite and TBARS) may all be involved in the development of cardiovascular disease in AS and these predictors could serve as a novel therapeutic targets for preventing CV risk in AS.

References:

[1]Garg N, Krishan P, Syngle A. Rosuvastatin improves endothelial dysfunction in ankylosing spondylitis. Clin Rheumatol. 2015;34:1065-1071.

[2]Verma I, Syngle A, Krishan P, Garg N. Endothelial Progenitor Cells as a Marker of Endothelial Dysfunction and Atherosclerosis in Ankylosing Spondylitis. International Journal of Angiology. 2017;26:36–42.

[3]Verma I, Krishan P, Syngle A. Predictors of Atherosclerosis in Ankylosing Spondylitis. Rheumatol Ther. 2015;2(2): 173–182.

Disclosure of Interests:

None declared.

Prakriti Analysis of COVID 19 Patients: An Observational Study

RATIONALE & OBJECTIVE

The concept of Prakriti is unique to Ayurveda, which is used for deciding the preventive and curative strategy to be adopted in the treatment of patients. It is the total of anatomical, physiological, and psychological domains of an individual. The diseases often manifest by susceptibility that depends upon Prakriti of individuals. COVID 19 is a new disease, where the status of the susceptibility of its victim in terms of Prakriti is not known. This study has been undertaken to determine the Prakriti of COVID 19 positive patients.

METHOD

The validated instrument CCRAS Prakriti assessment scale has been applied to the COVID 19 positive patients admitted between 16 May 2020 to 10 June 2020 at COVID hospital.

RESULT

Data of 117 patients aged 10 to 80 years have been analyzed. The ratio of male-female patients was 1.8:1. Most patients belonged to Vata-KaphaPrakriti (27%).Individuals with their Prakriti found in order of frequency were Pitta-Kapha (21%), Kapha (20%), Vata (13%), Vata-Pitta (11%), Sama (4%) and Pitta (3%).

CONCLUSION

Patients with Vata-Kapha, Pitta-Kapha, and Kapha dominant Prakriti have been found more in COVID19. The treatment strategies can be accordingly decided in respect of each patient.

Heterogeneity in COVID-19 Patients at Multiple Levels of Granularity: From Biclusters to Clinical Interventions

Several studies have shown that COVID-19 patients with prior comorbidities have a higher risk for adverse outcomes, resulting in a disproportionate impact on older adults and minorities that fit that profile. However, although there is considerable heterogeneity in the comorbidity profiles of these populations, not much is known about how prior comorbidities co-occur to form COVID-19 patient subgroups, and their implications for targeted care. Here we used bipartite networks to quantitatively and visually analyze heterogeneity in the comorbidity profiles of COVID-19 inpatients, based on electronic health records from 12 hospitals and 60 clinics in the greater Minneapolis region. This approach enabled the analysis and interpretation of heterogeneity at three levels of granularity (cohort, subgroup, and patient), each of which enabled clinicians to rapidly translate the results into the design of clinical interventions. We discuss future extensions of the multigranular heterogeneity framework, and conclude by exploring how the framework could be used to analyze other biomedical phenomena including symptom clusters and molecular phenotypes, with the goal of accelerating translation to targeted clinical care.

Challenges in Sensors Technology for Industry 4.0 for Futuristic Metrological Applications

The current advances and innovations in sensor technologies attributed to Industry 4.0 serve as the backbone for the inclusive growth of industry and ramping up the economy of any country. Industry 4.0 was basically conceptualized by introducing the Internet of Things (IoT) and Information and Communication technologies (ICT) that serve as an interface between digital and physical world through the fusion of smart sensors. The role of smart sensors and IoT-enabled industrial infrastructure is pivotal for adapting to the advanced technologies based on fusion of smart sensors. Digital meteorological traceability and uses of intelligent sensors, instrumentation and machinery in Industry 4.0, Smart Cities, Digital India and AtmaNirbhar Bharat missions of the government of India, are not only highly important but also in huge demand, which is going to increase manifolds in the years to come. The present paper is an attempt to provide a terse review and perspectives related to the advanced technological developments in this field and the challenges therein.

Assessment of various endodontic instrumentation systems on the amount of apically extruded bacteria - An in vitro study

Aim:

The objective of this in vitro study was to assess the effect of different endodontic instrumentation systems on the amount of apically extruded bacteria.

Materials and Methods:

One hundred and twenty freshly extracted human mandibular premolars with single canal were collected. Endodontic access cavities were prepared and then contaminated with an Enterococcus faecalis suspension (ATCC 29212). After incubation at 37°C for 24 h, the root canals were instrumented with K flare files, F360 Single file system, K3XF files, Heroshaper files, Protaper Next files, and Hyflex EDM Single file system. During instrumentation, apically extruded bacteria were collected in the vials containing 0.9% NaCl. Samples were taken from the vials and incubated in brain–heart infusion agar medium for 24 h.

Statistical Analysis:

The number of colony-forming units was determined, and data were statistically analyzed using one-way analysis of variance and post hoc Tukey test.

Conclusions:

Both rotary and hand instrumentation systems extruded intracanal bacteria through the apical foramen, Group 1 (Hand K Flare files) showed maximum, whereas, Group 5 (Protaper Next) and Group 6 (Hyflex EDM) showed the least extrusion.

California Cardiovascular Screening Tool: Findings from Initial Implementation

Objective  American College of Obstetricians and Gynecologists (ACOG) recently published the California (CA) cardiovascular disease (CVD) screening algorithm for pregnant and postpartum women. We aim to prospectively determine screen-positive and true-positive rates of CVD among women across two populations. Study Design  This is a prospective cohort study of obstetrical patients from April 2018 to July 2019 at academic medical centers in CA and New York (NY). We attempted to screen all patients at least once during their pregnancy care (prenatal or postpartum). Women who screened positive ("Red Flags," >3-4 moderate risk factors, abnormal physical examination, and persistent symptoms) underwent further testing. The primary outcome was the screen-positive rate. Secondary outcomes included the true-positive rate and the strength of each moderate factor in predicting a positive CVD screen. Results  We screened 846 women. The overall screen-positive rate was 8% (5% in CA vs. 19% in NY). The sites differed in ethnicity, that is, African American women (2.7% in CA vs. 35% in NY, p  < 0.01) and substance use (2.7 vs. 5.6%, p  < 0.04). The true-positive rate was 1.5% at both sites. The percentage of screen-positive patients who did not complete follow-up studies was higher in NY (70%) than in CA (27%). CVD was confirmed in 30% with positive screens with complete follow-up. Combinations of moderate factors were the main driver of screen-positive rates in both populations. Conclusion  This is the first data describing the performance of the CVD screening algorithm in a general obstetric population. Factors, such as proportion of African American women affect the likelihood of a positive screen. The screening algorithm highlights patients at higher lifetime risk of CVD and may identify a group that could be targeted for more direct care transitions postpartum. Data may be used to design a larger validation study.

AB0577 ENDOTHELIAL DYSFUNCTION AND ATHEROSCLEROSIS IN SYSTEMIC SCLEROSIS: A MULTIPARAMETRIC ANALYSIS USING IMAGING TECHNIQUE AND LABORATORY MARKERS OF INFLAMMATION AND VASCULAR FUNCTION: SCLERODERMA CV RISK STUDY

Background:

Systemic sclerosis (SSc) patients have an increased risk for atherosclerotic cardiovascular disease (CVD), possibly mediated by inflammatory and fibrotic mechanisms1. However, pathogenesis of accelerated atherosclerosis in SSc remains to be elucidated. Endothelial dysfunction is the key initial event in atherosclerosis. Predictors for rapid evolution of cardiovascular complications would be highly desirable for CV risk stratification. This study aims to assess endothelial function and atherosclerosis in SSc, in context of markers of inflammation and vascular function in SSc patients.

Objectives:

To assess endothelial function and atherosclerosis in SSc in context of markers of inflammation and vascular function in SSc patients.

Methods:

A cross-sectional study was performed in 20 SSc patients meeting the 2013 European League Against Rheumatism (EULAR) and American College of Rheumatology (ACR) classification criteria and 18 healthy controls matched for age and sex. Flow-mediated dilatation (FMD) assessed by AngioDefender and CIMT measured ultrasonographically. Disease-specific measures included: Disease duration, Modified Rodnan Skin Score (mRSS), EUSTAR activity score in SSc. We also assayed markers of inflammation, including C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), proinflammatory cytokines (interleukin IL-1, IL-6, and IL-17), and endothelial dysfunction including lipids, serum nitrite and TBARS (marker of oxidative stress). Quality of life measured by Scleroderma Health Assessment Questionnaire (SHAQ).

Results:

FMD is significantly lower in SSc patients compared with controls (6.13±0.35% vs. 9.12±0.25%, p≤0.05). CIMT is significantly higher in SSc patients compared with controls (0.071±0.04cm vs. 0.035±0.02cm p≤0.05). Compared with controls, SSc patients had significantly (p≤0.05) elevated mRSS, EUSTAR score, ESR, CRP, IL-1, IL-6, IL-17, nitrite, TBARS and SHAQ whereas HDL levels are significantly reduced in SSc compared with controls (p≤0.05). In SSc, FMD inversely correlated with EUSTAR score, mRSS, IL-6 (Fig. 1A), serum nitrite (Fig. 1B), TBARS (Fig. 1C) and CIMT (Fig. 1D). CIMT positively correlated with age (Fig. 2A), disease duration, CRP (Fig. 2B) and IL-17 (Fig. 2C) and inversely correlated with HDL (Fig. 2D) (p< 0.05).

Conclusion:

In the present study, FMD and CIMT are impaired in SSc, indicating endothelial dysfunction and accelerated atherosclerosis, respectively. EUSTAR score, mRSS, IL-6, serum nitrite, CIMT and TBARS predicted endothelial dysfunction. Age, disease duration, CRP, IL-17, HDL and impaired FMD predicted accelerated atherosclerosis. SSc-related inflammatory mechanisms (IL-6, IL-17) and markers of vascular function (CRP, serum nitrite and TBARS) may all be involved in the development of vascular disease in SSc. Cytokine-triggered inflammation mediated by nitrite and TBARS is associated with endothelial dysfunction and accelerated atherosclerosis in SSc. These markers would possibly serve as predictors of endothelial dysfunction and atherosclerosis and more importantly therapeutic targets to prevent premature atherosclerosis and cardiovascular disease in SSc.

References:

[1]Pagkopoulou E, Poutakidou M, Garyfallos A, Kitas G, Dimitroulas T. Cardiovascular risk in systemic sclerosis: Micro- and Macro-vascular involvement. Indian Journal of Rheumatology 2017;12:S211-7.

Acknowledgments:

None

Disclosure of Interests:

None declared

AB0613 AUTONOMIC NEUROPATHY AND ITS PREDICTORS IN SYSTEMIC SCLEROSIS

Background:

Systemic sclerosis (SSc), a chronic autoimmune disease, is associated with autonomic neuropathy1. Autonomic neuropathy, especially cardiovascular autonomic neuropathy (CAN) is significant risk predictor of sudden cardiac death. However, its relationship with disease specific measures remains unexplored in SSc.

Objectives:

To assess cardiovascular autonomic neuropathy and sudomotor function and its predictors in systemic sclerosis.

Methods:

In this cross-sectional study, 16 SSc patients meeting the 2013 European League Against Rheumatism (EULAR) and American College of Rheumatology (ACR) classification criteria and 15 age and sex-matched healthy controls were recruited. Cardiovascular autonomic function assessed by five cardiovascular reflex tests according to Ewing. Peripheral sympathetic autonomic function assessed by FDA approved Sudoscan (Impeto Medical, Paris) through measurement of electrochemical skin conductance. Disease-specific measures (Disease duration, Modified Rodnan Skin Score (mRSS), EUSTAR activity score), and inflammatory measures (ESR, CRP) were determined. Quality of life measured by Scleroderma Health Assessment Questionnaire (SHAQ).

Results:

Systemic sclerosis patients had significantly impaired parasympathetic [Heart rate response to deep breath (HRD) (Fig. 1A), Heart rate response to standing (HRS) (Fig. 1B) and Heart rate response to valsalva manoeuvre (Fig. 1C)] and symapathetic [BP response to hand grip (BPH) (Fig. 1D)] function as compared to healthy controls. Scleroderma patients had significantly impaired sudomotor function (p<0.05) as compared to healthy controls. Levels of mRSS, EUSTAR score, ESR, CRP and SHAQ were significantly higher in SSc patients as compared to healthy controls (p≤0.05). Parasympathetic (HRD & HRS) dysfunction inversely correlated with ESR, CRP and mRSS. Sudomotor function positively correlated with mRSS, disease duration and CRP.

Conclusion:

CAN and Sudomotor function are significantly impaired in SSc. Parasympathetic dysfunction is more pronounced than sympathetic dysfunction in SSc. CAN and Sudomotor dysfunction are associated with disease-duration, skin-score, ESR and CRP. These could serve as potential predictors of Cardiovascular Autonomic neuropathy and sudomotor dysfunction in SSc.

References:

[1]Dessein PH, Joffe BI, Metz RM, Millar DL, Lawson M, Stanwix AE. Autonomic dysfunction in systemic sclerosis: sympathetic overactivity and instability. The American journal of medicine. 1992;93(2):143-50.

Acknowledgments:

None

Disclosure of Interests:

None declared

Seeded droplet microfluidic system for small molecule crystallization

A microfluidic approach to seeded crystallization has been demonstrated using abacavir hemisulfate, a nucleoside analog reverse transcriptase inhibitor, in droplet reactors to control polymorphism and produce particles with a low particle size distribution. Two techniques are introduced: (1) the first technique involves an emulsion system consisting of a dispersed phase solvent and a continuous phase, which holds slight solubility of the dispersed phase solvent. The dispersed phase contains both a dissolved active pharmaceutical ingredient (API) and seeds of the desired polymorph. While the continuous phase enables solvent extraction, the negligible solubility of the API allows for growth of seeds inside droplets via extraction and subsequent API saturation. This technique demonstrates the ability to crystallize the API in spherical agglomerates via slow extraction of droplets. (2) The second technique utilizes a combined dispersed phase by joining in-flow a seed suspension stream with a supersaturated active pharmaceutical ingredient (API) stream. The combined dispersed phase is emulsified in a continuous phase for which the dispersed phase solvent and the API are both insoluble - droplets are incubated at temperatures below their saturation limit to induce crystal growth. Decreasing the concentration of seeds in its input stream resulted in a decreased number of crystals per droplet, increase in crystal size, and decrease in PSD. Temperature cycling was utilized as a proof of concept to demonstrate the ability to reduce the number of seeds per droplet where the optimal goal is to obtain a single seed per droplet for all droplets. Utilizing this approach in conjunction with the ability to produce monodispersed droplet reactors allows for enhanced control of particle size distribution (PSD) by precisely controlling the available mass for each individual seed crystal. The development of this technique as a proof-of-concept for crystallization can be expanded to manufacturing scales in a continuous manner using parallelized droplet generators and flow reactors to precisely control the temperature and crystal growth kinetics of individual droplets.

Hormone Replacement Therapy Prescription after Premature Surgical Menopause

STUDY OBJECTIVE

To assess hormone replacement therapy (HRT) prescription pattern in patients undergoing premature surgical menopause on the basis of surgical indication.

DESIGN

Retrospective cohort study.

SETTING

Academic tertiary care center.

PATIENTS

Surgically menopausal patients aged ≤45 years who underwent a minimally invasive hysterectomy with salpingo-oophorectomy.

INTERVENTIONS

HRT prescription in the 6-week postoperative period.

MEASUREMENTS AND MAIN RESULTS

A total of 63 patients met inclusion criteria. Of these, 52% (n = 33) were prescribed HRT in the 6-week postoperative period. Indications for surgical menopause included pelvic pain or endometriosis (31.7%), gynecologic malignancy (20.6%), BRCA gene mutation (17.4%), breast cancer (9.5%), Lynch syndrome (4.8%), and other (15.8%). In total, 80% of patients with pelvic pain, 25% with gynecologic malignancies, 45% with BRCA gene mutations, 33.3% with breast cancer, and 66.6% with Lynch syndrome used HRT postoperatively. In patients who used HRT postoperatively, 76% were offered preoperative HRT counseling. This is in contrast with those patients who did not use HRT postoperatively, of whom only 33% were offered HRT counseling (p <.001). Perioperative complications were not predictive of HRT use postoperatively. In patients who did not use HRT postoperatively, 13.3% used alternative nonhormonal therapy.

CONCLUSION

In patients who underwent premature surgical menopause, 52% used HRT postoperatively. Patients with pelvic pain and Lynch syndrome were more likely to use HRT, whereas those with gynecologic or breast malignancies and BRCA gene mutations were less likely to use HRT. Preoperative HRT counseling was associated with postoperative HRT use.

P41 Correlation of doppler ultrasound assessment of carotid femoral pulse wave velocity with coronary artery disease

Funding Acknowledgements

self

Background

Arterial stiffness is an important cardiovascular risk factor. Carotid femoral pulse wave velocity (cfPWV) is simple noninvasive  method to determine aortic stiffness. Arterial stiffness measures, cfPWV in particular,  have been found to be correlate with stroke and peripheral artery disease. Usually SphygmoCor or Complior are used to calculate cfPWV. Doppler ultrasound can serve as an alternative to these methods. 

Purpose

To assess cfPWV using doppler ultrasound and study its correlation with coronary artery disease and its severity. 

Methods

cfPWV was assessed by ultrasound Doppler in patient aged 20-70 years undergoing coronary angiography.  cfPWV was measured by sequential recordings of arterial pressure waveform at the carotid and femoral arteries with a Doppler ultrasound with ECG gating and calculated as the distance between the carotid and the femoral sampling site divided by the time interval. 

Result

Of the 358 subjects studied, 243 had coronary artery disease(CAD) (&gt;50% diameter stenosis) and were further divided into single, double or triple vessel disease groups. 115 patients  had mild CAD (&lt; 50% stenosis) or no CAD and served as controls. Baseline characteristics were similar except diabetes (more common in CAD group)(39.09% v/s 27.82%). cfPWV was found to increase with age in all groups. cfPWV was not significantly affected  by sex, diabetes, dyslipidemia, BMI, smoking or hypothyroidism. Mean cfPWV was significantly higher in patients with CAD (8.99 v/s 6.51 m/s, p &lt; 0.001) and hypertensives (8.71 v/s 7.83 m/s, p &lt; 0.001). Patients with triple vessel disease(TVD) had significantly higher cfPWV (10.12 m/s) than those with double(DVD)(8.84 m/s) or single vessel disease(SVD)(8.28m/s)(p &lt; 0.001). Multinomial logistic regression revealed an odds ratio of 2.00, 2.375 and 3.368 respectively for SVD, DVD and TVD groups in comparison to controls (p &lt; 0.001). cfPWV value &gt; 7.25 m/s predicted CAD with sensitivity 78.6 % and specificity 74.8% (AUC =0.848, P &lt; 0.001). 

Conclusion

Carotid femoral pulse wave velocity can be measured noninvasively by ultrasound Doppler. cfPWV increases with age and hypertension and has strong correlation with coronary artery disease and its severity. The cfPWV can be an independent risk factor and may be utilized for cardiovascular risk prediction.

Abstract P41 Figure. cfPWV in various subgroups.

Association between multiple respiratory viral infections and pediatric intensive care unit admission among infants with bronchiolitis

Background

It is unclear whether multiple respiratory viral infections are associated with more severe bronchiolitis requiring pediatric intensive care unit (PICU) admission. We aimed to identify the association between multiple respiratory viral infections and PICU admission among infants with bronchiolitis.

Methods

We performed a 1:1 case-control study enrolling previously healthy full-term infants (≤12 months) with bronchiolitis admitted to the PICU as cases and those to the general pediatric ward as controls from 2015 to 2017. Multiplex polymerase chain reaction (PCR) was used for detection of the respiratory viruses. We summarized the characteristics of infants admitted to the PICU and the general pediatric unit. Multivariable logistic regression analysis was used to fit the association between multiple respiratory viral infections (≥2 strains) and PICU admission.

Results

A total of 135 infants admitted to the PICU were compared with 135 randomly selected control infants admitted to the general pediatric unit. The PICU patients were younger (median: 2.2 months, interquartile range: 1.3–4.2) than the general ward patients (median: 3.2 months, interquartile range: 1.6–6.4). Respiratory syncytial virus (74.1%), rhinovirus (28.9%), and coronavirus (5.9%) were the most common viruses for bronchiolitis requiring PICU admission. Patients with bronchiolitis admitted to the PICU tended to have multiple viral infections compared with patients on the general ward (23.0% vs. 10.4%, P < 0.001). In the multivariable logistic regression analysis, bronchiolitis with multiple viral infections was associated with higher odds of PICU admission (adjusted odds ratio: 2.56, 95% confidence interval: 1.17–5.57, P = 0.02).

Conclusion

Infants with multiviral bronchiolitis have higher odds of PICU admission compared with those with a single or nondetectable viral infection.

P1496Use of strain, strain rate, tissue velocity imaging and endothelial function for early detection of cardiovascular involvement in young diabetics

Background

Subtle structural and functional changes may precede the onset of overt global left ventricular dysfunction and obvious reduction of ejection fraction (EF), especially in young diabetics. Data pertaining to tissue velocity indices (TVI) and strain imaging to assess regional myocardial function and flow mediated vasodilatation is limited in young patients with diabetes.

Purpose

To evaluate conventional echocardiography parameters, tissue doppler indices, global and regional strain, carotid intimal medial thickness (CIMT), endothelial dependent (FMD) and independent function (NMD) of brachial artery in young patients (age <18 years) with type 1 diabetes and compare them with matched controls.

Methods

Conventional echocardiography parameters, tissue velocity indices (TVI) parameters along with strain (S), and strain rate (SR) in basal and mid left ventricular (LV) lateral wall, right ventricular (RV) lateral wall and septum were measured in 50 young diabetics (age 15.16±2.95 years, mean HBA1c 8.15±1.37 gm %) and 25 controls (age 15.60±2.51 years). Flow-mediated dilatation (FMD), nitrate mediated dilatation and carotid intimal media thickness (CIMT) were also estimated.

Results

Conventional echocardiography parameters were similar in patients and controls however deceleration time of the mitral inflow velocity (EDT) was significantly shorter in patients when compared with controls (149.06±31.66 vs. 184.56±19.27 ms, p<0.05). Lateral early diastolic myocardial velocity (LV-Em) was significantly lower (10.30±0.99 vs. 11.67±3.21, p<0.05) whereas lateral late diastolic myocardial velocity (LV-Am) was significantly higher than controls (11.73±1.44 vs. 8.82±1.69, p<0.05), thus a significantly lower ratio of early/late diastolic velocity at the basal segment of lateral LV (LV-Em/Am). Lower strain values at the basal lateral LV (21.39±4.12 vs. 23.78±2.02; p<0.05), mid lateral LV (21.43±4.27 vs. 23.17±1.92; p<0.05), basal septum (20.59±5.28 vs. 22.91±2.00; p<0.05), and mid septum (22.06±4.75 vs. 24.10±1.99; p<0.05) as compared to controls. SR at the basal and mid segments of the lateral LV wall and at the basal septum were also significantly lower in diabetic subjects. Strain rate (SR) in mid septal, basal and mid RV were lower than controls although not statistically significant. Patients also had significantly lower flow mediated dilatation (FMD) (8.36±4.27 vs. 10.57±4.12, p<0.05) implying endothelial dysfunction.

Strain rate in diabetic patient

Conclusion

Left ventricular strain indices are impaired in asymptomatic children and adolescents with type 1 DM despite absence of overt heart failure and normal ejection fraction. Early detection of subclinical regional myocardial dysfunction by deformation analysis including strain and strain rate may be useful in the asymptomatic diabetic population. In addition, evidence of endothelial dysfunction in the form of impaired flow mediated vasodilatation was observed in the diabetic children.

Acknowledgement/Funding

None

Nucleases of bacterial pathogens as virulence factors, therapeutic targets and diagnostic markers

New frontiers of therapy are being explored against the upcoming bacterial diseases rendered untreatable due to multiple, extreme and pan- antibiotic resistance. Nucleases are ubiquitous in bacterial pathogens performing various functions like acquiring nucleotide nutrients, allowing or preventing uptake of foreign DNA, controlling biofilm formation/dispersal/architecture, invading host by tissue damage, evading immune defence by degrading DNA matrix of neutrophil extracellular traps (NETs) and immunomodulating the host immune response. Secretory nucleases also provide means of survival to other bacteria like iron-reducing Shewanella and such functions help them adapt and survive proficiently. Other than their pro-pathogen roles in survival, nucleases can be used directly as therapeutics. One of the powerful armours of pathogens is the formation of biofilms, thus helping them resist and persist in the harshest of environments. As eDNA forms the structural and binding component of biofilm, nucleases can be used against the adhering component, thus increasing the permeability of antimicrobial agents. Nucleases have recently become a model system of intense study for their biological functions and medical applications in diagnosis, immunoprophylaxis and therapy. Rational implications of these enzymes can impact human medicine positively in future by opening new ways for therapeutics which have otherwise reached saturation due to multi drug resistance.

Abstract 321: RBFOX2 is critical for maintaining alternative polyadenylation patterns in cardiomyoblasts

Background: The RNA binding protein RBFOX2 is implicated in human heart diseases. However, RBFOX2-regulated RNA networks are not well defined. RBFOX2 has a well-characterized role in alternative splicing (AS) while accumulating evidence suggests that RBFOX2 may also have a role in alternative polyadenylation (APA). Recent studies showed that RBFOX2 binds to regions close to poly(A) sites in the 3’UTR of pre-mRNAs. In addition, RBFOX2 binds to the cleavage and polyadenylation specificity factors. Therefore, we aimed to determine whether RBFOX2 has a role in regulating APA.

Method: We employed poly(A)click sequencing (PAC-seq) and DPAC (Differential Poly(A) Cluster analysis) computational pipeline to identify differential poly(A) usage and mRNA abundance. We also used nanopore sequencing to identify different spliced variants and the coordinated AS and APA events.

Results: We report that knockdown of RBFOX2 in embryonic rat heart derived cells leads to altered alternative polyadenylation (APA) of hundreds of genes. RBFOX2-mediated APA changes impacted both mRNA levels and generation of different gene isoforms. Nanopore sequencing identified full-length transcripts regulated by RBFOX2 and revealed RBFOX2-mediated isoform switches via both APA and AS in cardiac cells. Notably, RBFOX2-regulated APA networks affect genes such as Tpm1 and Tnnt1 involved in cardiac contractility. Identification of RBFOX2-regulated RNA networks provides novel insights into the pathogenesis of heart diseases in which RBFOX2 is involved and pave the way for designing therapeutics.

Conclusions: RBFOX2 regulates alternative polyadenylation via splicing dependent and independent mechanisms. RBFOX2-mediated APA affects mRNA levels of contractile genes.

Conduction block in immune-mediated neuropathy: paranodopathy versus axonopathy

BACKGROUND AND PURPOSE

Conduction block is a pathognomonic feature of immune-mediated neuropathies. The aim of this study was to advance understanding of pathophysiology and conduction block in chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN).

METHODS

A multimodal approach was used, incorporating clinical phenotyping, neurophysiology, immunohistochemistry and structural assessments.

RESULTS

Of 49 CIDP and 14 MMN patients, 25% and 79% had median nerve forearm block, respectively. Clinical scores were similar in CIDP patients with and without block. CIDP patients with median nerve block demonstrated markedly elevated thresholds and greater threshold changes in threshold electrotonus, whilst those without did not differ from healthy controls in electrotonus parameters. In contrast, MMN patients exhibited marked increases in superexcitability. Nerve size was similar in both CIDP groups at the site of axonal excitability. However, CIDP patients with block demonstrated more frequent paranodal serum binding to teased rat nerve fibres. In keeping with these findings, mathematical modelling of nerve excitability recordings in CIDP patients with block support the role of paranodal dysfunction and enhanced leakage of current between the node and internode. In contrast, changes in MMN probably resulted from a reduction in ion channel density along axons.

CONCLUSIONS

The underlying pathologies in CIDP and MMN are distinct. Conduction block in CIDP is associated with paranodal dysfunction which may be antibody-mediated in a subset of patients. In contrast, MMN is characterized by channel dysfunction downstream from the site of block.

CT Texture Analysis of Cervical Lymph Nodes on Contrast-Enhanced [18F] FDG-PET/CT Images to Differentiate Nodal Metastases from Reactive Lymphadenopathy in HIV-Positive Patients with Head and Neck Squamous Cell Carcinoma

BACKGROUND AND PURPOSE

Differentiating nodal metastases from reactive adenopathy in HIV-infected patients with [¹⁸F] FDG-PET/CT can be challenging because lymph nodes in HIV-positive patients often show increased [¹⁸F] FDG uptake. The purpose of this study was to assess CT textural analysis characteristics of HIV-positive and HIV-negative lymph nodes on [¹⁸F] FDG-PET/CT to differentiate nodal metastases from disease-specific nodal reactivity.

MATERIALS AND METHODS

Nine HIV-positive patients with head and neck squamous cell carcinoma (7 men, 2 women; 29-62 years of age; median age, 48 years) with 22 lymph nodes (≥1 cm) who underwent contrast-enhanced CT with [¹⁸F] FDG-PET followed by pathologic evaluation of cervical lymph nodes were retrospectively reviewed. Twenty-six HIV-negative patients with head and neck squamous cell carcinoma with 61 lymph nodes were evaluated as a control group. Each lymph node was manually segmented, and an in-house-developed Matlab-based texture analysis program extracted 41 texture features from each segmented volume. A mixed linear regression model was used to compare the pathologically proved malignant lymph nodes with benign nodes in the 2 enrolled groups.

RESULTS

Thirteen (59%) lymph nodes in the HIV-positive group and 22 (36%) lymph nodes in the HIV-negative control group were confirmed as positive for metastases. There were 7 histogram features (P = .017-0.032), 3 gray-level co-occurrence features (P = .009-.025), and 9 gray-level run-length features (P < .001-.033) that demonstrated a significant difference in HIV-positive patients with either benign or malignant lymph nodes.

CONCLUSIONS

CT texture analysis may be useful as a noninvasive method of obtaining additional quantitative information to differentiate nodal metastases from disease-specific nodal reactivity in HIV-positive patients with head and neck squamous cell carcinoma.

Anti-EGFR-resistant clones decay exponentially after progression: implications for anti-EGFR re-challenge

BACKGROUND

Colorectal cancer (CRC) has been shown to acquire RAS and EGFR ectodomain mutations as mechanisms of resistance to epidermal growth factor receptor (EGFR) inhibition (anti-EGFR). After anti-EGFR withdrawal, RAS and EGFR mutant clones lack a growth advantage relative to other clones and decay; however, the kinetics of decay remain unclear. We sought to determine the kinetics of acquired RAS/EGFR mutations after discontinuation of anti-EGFR therapy.

PATIENTS AND METHODS

We present the post-progression circulating tumor DNA (ctDNA) profiles of 135 patients with RAS/BRAF wild-type metastatic CRC treated with anti-EGFR who acquired RAS and/or EGFR mutations during therapy. Our validation cohort consisted of an external dataset of 73 patients with a ctDNA profile suggestive of prior anti-EGFR exposure and serial sampling. A separate retrospective cohort of 80 patients was used to evaluate overall response rate and progression free survival during re-challenge therapies.

RESULTS

Our analysis showed that RAS and EGFR relative mutant allele frequency decays exponentially (r2=0.93 for RAS; r2=0.94 for EGFR) with a cumulative half-life of 4.4 months. We validated our findings using an external dataset of 73 patients with a ctDNA profile suggestive of prior anti-EGFR exposure and serial sampling, confirming exponential decay with an estimated half-life of 4.3 months. A separate retrospective cohort of 80 patients showed that patients had a higher overall response rate during re-challenge therapies after increasing time intervals, as predicted by our model.

CONCLUSION

These results provide scientific support for anti-EGFR re-challenge and guide the optimal timing of re-challenge initiation.