Addition of nisin to high-viscosity glass-ionomer cement: a comparative in vitro study on antibacterial and physical properties

PURPOSE

Nisin is a lantibiotic effective against Gram-positive microorganisms such as Streptococcus mutans. The study aimed to determine the effect of the addition of nisin to high-viscosity glass-ionomer cement (HVGIC) on its antibacterial activity, setting time, surface microhardness, and compressive strength.

METHODS

1 and 3% w/w nisin were added to HVGIC before mixing. Unmodified HVGIC was the control. Agar disc diffusion, direct contact test, and scanning electron microscopy (SEM) analysis were used to evaluate antibacterial activity against S. mutans. Setting time, surface microhardness, and compressive strength were measured using Gilmore needle apparatus, digital microhardness tester, and universal testing machine, respectively. Statistical analysis included Student's t test, one-way ANOVA with Tamhane's post hoc test, and repeated-measures ANOVA.

RESULTS

As evidenced by the agar disc diffusion (p < 0.001), direct contact tests (p = 0.025), and SEM analysis of the S. mutans cell count and cell surface area (p = 0.049 and 0.003), 3% nisin had the strongest antibacterial activity. There was a dose-dependent increase in setting time (p = 0.005) and surface microhardness (p = 0.006), with no significant difference in compressive strength compared to control.

CONCLUSION

The addition of 3% nisin to HVGIC enhances the antibacterial action against S. mutans and surface microhardness without adversely affecting setting time and compressive strength.

Early Childhood Caries and Dental Care Utilization in Mangalore, India: Parents' Perceptions

BACKGROUND

Parents often underuse dental care services for their children with early childhood caries (ECC), resulting in a high burden of untreated dental caries.

AIM

To describe parental perceptions and challenges in dental care utilization for their children with ECC.

DESIGN

A descriptive qualitative study was conducted with parents of children with ECC seeking dental care in Mangalore, India. Data were collected through focus group discussions using an interview guide. Manual line-by-line coding and content analysis methods were used for data analysis.

RESULTS

Three categories were generated from data obtained through 5 focus groups of 27 participants: dental care visiting patterns, the significance of dental visits, and challenges to dental care utilization. Parents would only visit the dentist when they perceived their children's tooth problems. The challenges faced include time constraints, misinformation, lack of awareness and motivation, costs, fear, and anxiety of the children and the parents themselves. Parents perceived improvements in the awareness of their children's oral health and quality of life after dental visits.

CONCLUSION

Attending dental services to treat their children's tooth problems was the primary way of attaining awareness about prevention among the parents of children with ECC. Increased oral health awareness and improved quality of life can motivate parents to seek further dental care for their children. Collaboration with multidisciplinary stakeholders is required to improve oral health awareness among parents of children with ECC.

KNOWLEDGE TRANSFER STATEMENT

The study's results will help plan targeted preventive programs for children with ECC. The study suggests dental care utilization by children with ECC is based on parental perceptions of their children's tooth problems. It outlines the challenges that affect dental visits of children with ECC and the role of multidisciplinary stakeholders. Improved oral health awareness and quality of life following dental treatment can facilitate further dental visits.

The APOE-R136S mutation protects against APOE4-driven Tau pathology, neurodegeneration and neuroinflammation

Apolipoprotein E4 (APOE4) is the strongest genetic risk factor for late-onset Alzheimer's disease (LOAD), leading to earlier age of clinical onset and exacerbating pathologies. There is a critical need to identify protective targets. Recently, a rare APOE variant, APOE3-R136S (Christchurch), was found to protect against early-onset AD in a PSEN1-E280A carrier. In this study, we sought to determine if the R136S mutation also protects against APOE4-driven effects in LOAD. We generated tauopathy mouse and human iPSC-derived neuron models carrying human APOE4 with the homozygous or heterozygous R136S mutation. We found that the homozygous R136S mutation rescued APOE4-driven Tau pathology, neurodegeneration and neuroinflammation. The heterozygous R136S mutation partially protected against APOE4-driven neurodegeneration and neuroinflammation but not Tau pathology. Single-nucleus RNA sequencing revealed that the APOE4-R136S mutation increased disease-protective and diminished disease-associated cell populations in a gene dose-dependent manner. Thus, the APOE-R136S mutation protects against APOE4-driven AD pathologies, providing a target for therapeutic development against AD.

Microglia Depletion Reduces Human Neuronal APOE4-Driven Pathologies in a Chimeric Alzheimer's Disease Model

Despite strong evidence supporting the involvement of both apolipoprotein E4 (APOE4) and microglia in Alzheimer's Disease (AD) pathogenesis, the effects of microglia on neuronal APOE4-driven AD pathogenesis remain elusive. Here, we examined such effects utilizing microglial depletion in a chimeric model with human neurons in mouse hippocampus. Specifically, we transplanted homozygous APOE4, isogenic APOE3, and APOE-knockout (APOE-KO) induced pluripotent stem cell (iPSC)-derived human neurons into the hippocampus of human APOE3 or APOE4 knock-in mice, and depleted microglia in half the chimeric mice. We found that both neuronal APOE and microglial presence were important for the formation of Aβ and tau pathologies in an APOE isoform-dependent manner (APOE4 > APOE3). Single-cell RNA-sequencing analysis identified two pro-inflammatory microglial subtypes with high MHC-II gene expression that are enriched in chimeric mice with human APOE4 neuron transplants. These findings highlight the concerted roles of neuronal APOE, especially APOE4, and microglia in AD pathogenesis.

HIGHLIGHTS

Transplanted human APOE4 neurons generate Aβ and p-tau aggregates in APOE4-KI mouse hippocampus.Human neuronal APOE4 promotes the formation of dense-core Aβ plaques and p-tau aggregates.Microglia is required for human neuronal APOE4-driven formation of p-tau aggregates.scRNA-seq reveals enrichment of MHC-II microglia in mice with human APOE4 neuron transplants.

APOE4-promoted gliosis and degeneration in tauopathy are ameliorated by pharmacological inhibition of HMGB1 release

Apolipoprotein E4 (APOE4) is an important driver of Tau pathology, gliosis, and degeneration in Alzheimer's disease (AD). Still, the mechanisms underlying these APOE4-driven pathological effects remain elusive. Here, we report in a tauopathy mouse model that APOE4 promoted the nucleocytoplasmic translocation and release of high-mobility group box 1 (HMGB1) from hippocampal neurons, which correlated with the severity of hippocampal microgliosis and degeneration. Injection of HMGB1 into the hippocampus of young APOE4-tauopathy mice induced considerable and persistent gliosis. Selective removal of neuronal APOE4 reduced HMGB1 translocation and release. Treatment of APOE4-tauopathy mice with HMGB1 inhibitors effectively blocked the intraneuronal translocation and release of HMGB1 and ameliorated the development of APOE4-driven gliosis, Tau pathology, neurodegeneration, and myelin deficits. Single-nucleus RNA sequencing revealed that treatment with HMGB1 inhibitors diminished disease-associated and enriched disease-protective subpopulations of neurons, microglia, and astrocytes in APOE4-tauopathy mice. Thus, HMGB1 inhibitors represent a promising approach for treating APOE4-related AD.

Lysosomal proteomics reveals mechanisms of neuronal apoE4associated lysosomal dysfunction

ApoE4 is the primary risk factor for Alzheimer's Disease. While apoE is primarily expressed by astrocytes, AD pathology including endosomal abnormalities and mitochondrial dysfunction first occurs in neurons. Lysosomes are poised at the convergence point between these features. We find that apoE4-expressing cells exhibit lysosomal alkalinization, reduced lysosomal proteolysis, and impaired mitophagy. To identify driving factors for this lysosomal dysfunction, we performed quantitative lysosomal proteome profiling. This revealed that apoE4 expression results in lysosomal depletion of Lgals3bp and accumulation of Tmed5 in both Neuro-2a cells and postmitotic human neurons. Modulating the expression of both proteins affected lysosomal function, with Tmed5 knockdown rescuing lysosomal alkalinization in apoE4 cells, and Lgals3bp knockdown causing lysosomal alkalinization and reduced lysosomal density in apoE3 cells. Taken together, our work reveals that apoE4 exerts gain-of-toxicity by alkalinizing the lysosomal lumen, pinpointing lysosomal Tmed5 accumulation and Lgals3bp depletion as apoE4-associated drivers for this phenotype.

Early Feeding and Weaning Practices of Indian Children with Early Childhood Caries: A Qualitative Exploration

OBJECTIVE

To describe the early feeding, weaning, and oral hygiene practices of children with early childhood caries (ECC), their parents' knowledge and attitudes regarding infant feeding, and the feeding-related challenges faced by the parents.

METHODS

This descriptive qualitative study involved parents of children with ECC who sought dental treatment at an academic dental college in India. Data were collected though focus groups conducted with the 27 parents of children with ECC, using a focus group discussion guide. Data were analyzed using the content analysis method.

RESULTS

Community norms, such as learning from the older women in the families or neighborhoods, guided the feeding method, duration of feeding, and weaning. Breastfeeding or bottle-feeding at bedtime beyond 12 mo of age and feeding sugary drinks during weaning were standard practices, despite knowing the risk for dental caries. Parents faced multiple challenges regarding weaning and were unaware of the significance of infant oral hygiene practices.

CONCLUSION

In children with ECC, infant feeding practices included prolonged breastfeeding or bottle-feeding beyond the required age, feeding at bedtime, and feeding sugary drinks. Although the parents knew that these feeding habits could increase the risk for caries, they lacked the self-efficacy to translate their knowledge into action during weaning. Also, they lacked awareness regarding infant oral hygiene practices.

KNOWLEDGE TRANSFER STATEMENT

The study provides information on the feeding habits of infants that can increase the risk for caries, the challenges faced by the parents of these children in altering these risky habits, and their lack of knowledge on infant oral hygiene practices. Policy/decision makers can advocate for pediatricians and pediatric dentists to incorporate anticipatory guidance or motivational interviewing techniques to tailor the preventive program for ECC for Indian children.

Clinical effectiveness of alkasite versus nanofilled resin composite in the restoration of occlusal carious lesions in permanent molar teeth of children: a randomized clinical trial

PURPOSE

To evaluate and compare the clinical effectiveness of alkasite with nanofilled resin composite restorations for occlusal caries lesions in permanent molar teeth of children, at one-year follow-up.

METHODS

In this randomized controlled clinical trial with parallel design, 38 children aged 7-13 years with occlusal caries lesions on 59 first permanent molars were randomly allocated into two groups, Group 1: Filtek™ Z350XT (nanocomposite) and Group 2: Cention N^® (alkasite resin composite). The restorations were evaluated at one year using the United States Public Health Service (USPHS) criteria. Data were analyzed using Chi-square or Fisher's exact test.

RESULTS

All restorations had either Alpha or Bravo scores at one-year follow-up. In Group 1, all restorations scored Alpha, while one restoration each (3.6%) in Group 2 scored Bravo for fracture and marginal adaptation. All restorations in both groups scored Alpha for retention, secondary caries, and post-operative sensitivity. For anatomic form, all restorations in Group 1 scored Alpha, while three (10.7%) restorations in Group 2 had Bravo scores. For marginal discolouration, three restorations in both groups scored Bravo (11.5% and 10.7%, respectively). For surface roughness, one restoration (3.8%) in Group 1 and three restorations in Group 2 (10.7%) scored Bravo. The comparative results between the two groups for all the variables in the USPHS criteria were not statistically significantly different.

CONCLUSIONS

The performances of the nanofilled composite and alkasite were clinically acceptable and comparable. Alkasite can be an alternative material for the restoration of occlusal caries lesions in permanent molars of children.

CLINICAL TRIAL REGISTRATION

The clinical trial was registered at Clinical Trials Registry-India (CTRI Reg no: CTRI/2020/12/029830 Dated: 15/12/2020).

Neuronal APOE4 removal protects against tau-mediated gliosis, neurodegeneration and myelin deficits

Apolipoprotein E4 (APOE4) is the strongest known genetic risk factor for late-onset Alzheimer's disease (AD). Conditions of stress or injury induce APOE expression within neurons, but the role of neuronal APOE4 in AD pathogenesis is still unclear. Here we report the characterization of neuronal APOE4 effects on AD-related pathologies in an APOE4-expressing tauopathy mouse model. The selective genetic removal of APOE4 from neurons led to a significant reduction in tau pathology, gliosis, neurodegeneration, neuronal hyperexcitability and myelin deficits. Single-nucleus RNA-sequencing revealed that the removal of neuronal APOE4 greatly diminished neurodegenerative disease-associated subpopulations of neurons, oligodendrocytes, astrocytes and microglia whose accumulation correlated to the severity of tau pathology, neurodegeneration and myelin deficits. Thus, neuronal APOE4 plays a central role in promoting the development of major AD pathologies and its removal can mitigate the progressive cellular and tissue alterations occurring in this model of APOE4-driven tauopathy.

Screening tool to improve patient referral to acute surgical care from accident and emergency

INTRODUCTION

This study aimed, first, to audit the appropriateness of surgical referrals to an acute surgical unit for urgent assessment and, second, to devise a screening tool for use in the emergency department to categorise patients into those who need an urgent surgical review and those who can be seen in an ambulatory setting within the next few days.

METHODS

The first phase of the study was an audit of surgical referrals between 1 and 18 February 2020 to check the appropriateness of the surgical referral. In the second phase, a tool was designed to screen patients who did not require urgent surgical review and could be seen in the ambulatory clinic. A prospective questionnaire study was conducted from 1 February to 24 March 2020 with patients who were admitted to an acute surgical ward. Based on responses to the screening tool, patients were given the outcome of whether they can be discharged and seen in an ambulatory clinic. The accuracy of the screening tool outcome was assessed and compared with actual patient discharge outcomes by the surgical team evaluating patients' electronic medical records.

RESULTS

In the first audit of referrals to the acute surgical ward, 206 patients were referred to the acute surgical unit and seen by the senior surgeon. Of these, 142 (68.9%) were discharged on the same day with or without follow-up in the ambulatory surgical clinic. In the prospective questionnaire phase of the study, 98 patients completed the questionnaire. The most common presentation was abdominal pain (n=60) followed by urological symptoms (n=11), symptoms of hernia complication (n=10), abscess (n=7), testicular pain (n=2) and trauma (n=2). Of the patients discharged on the same day, 50% were given ambulatory care appointments and 50% were discharged with no further follow-up. The sensitivity and specificity of the screening tool were 100% and 60.7%, respectively; the overall accuracy was 88.4%.

CONCLUSION

A large proportion of patients who are referred to the acute surgical unit can be deferred and seen in the ambulatory clinic. The screening tool used for acute surgical referral had reasonable sensitivity and high specificity to screen patients who can be seen in ambulatory clinics. At the same time, it identified patients who were unwell and required urgent surgical admission.

A novel application of a bioactive material as a pit and fissure sealant: in vitro pilot study evaluating the sealing ability and penetration

PURPOSE

To compare the sealing ability and penetration of a bioactive material used as pit and fissure sealant to those of glass ionomer sealant.

METHODS

This was an in vitro experimental study conducted on 20 permanent teeth. For Group I of ten teeth, ACTIVA BioACTIVE-Base/Liner was applied as a sealant on pits and fissures, and the remaining ten teeth of Group II were sealed using glass ionomer cement. After thermocycling, the apex of the teeth was sealed using composite resin and they were immersed in 1% methylene blue solution, buffered at pH 7 for 24 h. Longitudinal sections were obtained from each tooth for evaluating the sealing ability and penetration, using a binocular light microscope at 4 × magnification. The obtained data were subjected to analysis using the Chi-square test and independent t test.

RESULTS

The comparison of the sealing ability and sealant penetration, between the two groups, showed statistically no significant difference (p = 0.104 and p = 1.0, respectively).

CONCLUSION

Bioactive material as a pit and fissure sealant, performed on par with glass ionomer sealant in terms of tested properties like sealing ability and penetration.

Complications in Device Therapy: Spectrum, Prevalence, and Management

PURPOSE OF REVIEW

Cardiac implantable electronic device implant numbers are continually increasing due to the expanding indications and ageing population. This review explores the complications associated with device therapy and discusses ways to minimise and manage such complications.

RECENT FINDINGS

Complications related to device therapy contribute to mortality and morbidity. Recent publications have detailed clear guidelines for appropriate cardiac device selection, as well as consensus documents discussing care quality and optimal implantation techniques. There have also been advances in device technologies that may offer alternative options to patients at high risk of/or already having encountered a complication. Adherence to guidelines, appropriate training, and selection of device, in addition to good surgical technique are key in reducing the burden of complications and improving acceptability of device therapy.

Quantifying T2-FLAIR Mismatch Using Geographically Weighted Regression and Predicting Molecular Status in Lower-Grade Gliomas

BACKGROUND AND PURPOSE

The T2-FLAIR mismatch sign is a validated imaging sign of isocitrate dehydrogenase-mutant 1p/19q noncodeleted gliomas. It is identified by radiologists through visual inspection of preoperative MR imaging scans and has been shown to identify isocitrate dehydrogenase-mutant 1p/19q noncodeleted gliomas with a high positive predictive value. We have developed an approach to quantify the T2-FLAIR mismatch signature and use it to predict the molecular status of lower-grade gliomas.

MATERIALS AND METHODS

We used multiparametric MR imaging scans and segmentation labels of 108 preoperative lower-grade glioma tumors from The Cancer Imaging Archive. Clinical information and T2-FLAIR mismatch sign labels were obtained from supplementary material of relevant publications. We adopted an objective analytic approach to estimate this sign through a geographically weighted regression and used the residuals for each case to construct a probability density function (serving as a residual signature). These functions were then analyzed using an appropriate statistical framework.

RESULTS

We observed statistically significant (P value = .05) differences between the averages of residual signatures for an isocitrate dehydrogenase-mutant 1p/19q noncodeleted class of tumors versus other categories. Our classifier predicts these cases with area under the curve of 0.98 and high specificity and sensitivity. It also predicts the T2-FLAIR mismatch sign within these cases with an under the curve of 0.93.

CONCLUSIONS

On the basis of this retrospective study, we show that geographically weighted regression-based residual signatures are highly informative of the T2-FLAIR mismatch sign and can identify isocitrate dehydrogenase-mutation and 1p/19q codeletion status with high predictive power. The utility of the proposed quantification of the T2-FLAIR mismatch sign can be potentially validated through a prospective multi-institutional study.

Dentate gyrus and CA3 GABAergic interneurons bidirectionally modulate signatures of internal and external drive to CA1

Specific classes of GABAergic neurons play specific roles in regulating information processing in the brain. In the hippocampus, two major classes, parvalbumin-expressing (PV⁺) and somatostatin-expressing (SST⁺), differentially regulate endogenous firing patterns and target subcellular compartments of principal cells. How these classes regulate the flow of information throughout the hippocampus is poorly understood. We hypothesize that PV⁺ and SST⁺ interneurons in the dentate gyrus (DG) and CA3 differentially modulate CA3 patterns of output, thereby altering the influence of CA3 on CA1. We find that while suppressing either interneuron class increases DG and CA3 output, the effects on CA1 were very different. Suppressing PV⁺ interneurons increases local field potential signatures of coupling from CA3 to CA1 and decreases signatures of coupling from entorhinal cortex to CA1; suppressing SST⁺ interneurons has the opposite effect. Thus, DG and CA3 PV⁺ and SST⁺ interneurons bidirectionally modulate the flow of information through the hippocampal circuit.

MRI Patterns in Pediatric CNS Hemophagocytic Lymphohistiocytosis

BACKGROUND AND PURPOSE

Neuroimaging has an important role in detecting CNS involvement in children with systemic or CNS isolated hemophagocytic lymphohistiocytosis. We characterized a cohort of pediatric patients with CNS hemophagocytic lymphohistiocytosis focusing on neuroradiologic features and assessed whether distinct MR imaging patterns and genotype correlations can be recognized.

MATERIALS AND METHODS

We retrospectively enrolled consecutive pediatric patients diagnosed with hemophagocytic lymphohistiocytosis with CNS involvement treated at 2 pediatric neurology centers between 2010 and 2018. Clinical and MR imaging data were analyzed.

RESULTS

Fifty-seven children (40 primary, 70%) with a median age of 36 months (interquartile range, 5.5-80.8 months) were included. One hundred twenty-three MR imaging studies were assessed, and 2 broad imaging patterns were identified. Pattern 1 (significant parenchymal disease, 32/57, 56%) was seen in older children (P = .004) with worse clinical profiles. It had 3 onset subpatterns: multifocal white matter lesions (21/32, 66%), brainstem predominant disease (5, 15%), and cerebellitis (6, 19%). All patients with the brainstem pattern failed to meet the radiologic criteria for chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids. An attenuated imaging phenotype (pattern 2) was seen in 25 patients (44%, 30 studies) and was associated with younger age.

CONCLUSIONS

Distinct MR imaging patterns correlating with clinical phenotypes and possible genetic underpinnings were recognized in this cohort of pediatric CNS hemophagocytic lymphohistiocytosis. Disruptive mutations and missense mutations with absent protein expression correlate with a younger onset age. Children with brainstem and cerebellitis patterns and a negative etiologic work-up require directed assessment for CNS hemophagocytic lymphohistiocytosis.

In-hospital predictors of 60-day readmission in COVID-19 patients

Introduction

Preventing hospital readmissions can improve a patient's quality of life and decrease healthcare costs. While prior work has focused on pre-existing comorbidities to predict COVID-19 readmissions, the prognostic role of in-hospital data and complications has been less studied.

Methods

Data was collected on adult patients diagnosed with COVID-19 and admitted to a multicenter hospital system in Illinois between March and November 2020. Our cohort consisted of COVID-19 hospitalization survivors excluding those discharged to hospice care. Major adverse events (MAEs) were defined as venous thromboembolism (VTE), myocardial injury (troponin greater than upper limit of normal), stroke, new requirement for renal replacement therapy (RRT), life-threatening arrhythmia, or acute heart failure exacerbation. The primary outcome was readmission within 60 days of initial hospitalization.

Results

From the 1406 survivors of the index hospitalization, 223 (15.9%) patients were readmitted within 60 days. Those readmitted were older and more likely to have underlying comorbidities including atrial fibrillation, coronary artery disease, and hypertension (Table 1). Length of stay between the readmission and non-readmission groups was trending towards statistical significance (10.52 days vs 8.95 days, p=0.053).

Those with one or more MAE during their index hospitalization, when adjusted for age and body mass index, were at an increased risk of readmission (adjusted odds ratio [aOR] 1.90, p&lt;0.01). Readmitted patients were more likely to have VTE during their index hospitalization than those not readmitted (7.2% vs 3.7%, p&lt;0.05). The incidence of new RRT (4.9% vs 2.5%, p=0.083) and myocardial injury (3.6% vs 1.5%, p=0.067) between the groups was also trending towards statistical significance (Table 1). No statistical difference was present between the other individual MAEs; however, this is limited by small sample sizes of certain MAEs. Of the 322 patients with echocardiography during the index admission, 82 (25.5%) were readmitted. In this cohort, left ventricular ejection fraction (LVEF) that was reduced (LVEF &lt;50%) or hyperdynamic (LVEF &gt;65%) was not a statistically significant predictor of readmission (Figure 1).

Lastly, discharge disposition was predictive of readmission as those being sent to acute rehab (OR 2.04, p&lt;0.01), long-term acute care (OR 2.58, p&lt;0.01), or skilled nursing facility (OR 2.67, p&lt;0.001) were at higher risk compared to those who were discharged to home (Figure 1).

Conclusion

In this cohort, the occurrence of any MAE during index COVID-19 hospitalization, particularly VTE, RRT, and myocardial injury, can be used to predict 60-day readmission. Furthermore, discharge disposition, but not LVEF, demonstrated prognostic value in our cohort. Identifying high risk patients prior to discharge helps health care providers focus resources on patients most likely to be readmitted.

Funding Acknowledgement

Type of funding sources: None.

One year outcomes of heart failure multispecialty multidisciplinary team virtual meetings

 

Heart Failure is frequently associated with several comorbidities such as ischaemic heard disease, diabetes mellitus, chronic obstructive pulmonary disease, chronic kidney disease and frailty. This level of complexity is best dealt with by a multispecialty multidisciplinary team (MDT) model.

This was a single centre observational study (January 2020-December 2020) that was undertaken in a British university hospital looking at effect of HF multispecialty virtual MDT meetings on HF outcomes. Patients acted as their own controls outcomes compared for equal period pre versus post MDT meeting. The multi-specialty meeting was conducted once monthly via video-conferencing. It consisted of heart failure cardiologists (from primary secondary and tertiary care), heart failure specialist nurses (hospital and community), nephrologist, endocrinologist, palliative care specialists, chest physician, pharmacist, pharmacologist and geriatrician. Recommendations were made as consensus from the multispecialty meeting. The main outcome measures were 1) number of hospitalisations and 2) outpatient clinic attendances 3) cost savings.

A total of 189 patients were discussed from January-December 2020. This was uninterrupted during the COVID-19 pandemic. The mean age was 70.3±18.1 years and median follow-up 6 months (range 1–13 months). The mean Charlson Co-morbidity score was 5.3±1.2 and Rockwood Frailty Score was 4.9±1. The mean number of outpatient clinic attendances avoided was 1.7±0.4. This reduced inconvenience to patients, saved patients money (transport and parking costs) and led to carbon footprint reduction. The MDT meeting total costs were £15,400 and the 31 clinic appointments they generated cost an estimated £3720. However, the MDT meetings prevented 277 clinic appointments (cost saving £33,352). Finally, the mean number of hospitalisations pre-MDT was 0.7 Vs 0.2 post MDT (p&lt;0.01) with a saving of around 730 bed days (estimated cost-saving £260,000).

The HF multispecialty virtual MDT approach provides seamless integration of primary care community services with secondary and tertiary care. Consensus decision from MDT meetings provides holistic approach for HF patients with comorbidities and frailty, and reduces inconvenience to patients by preventing the need to attend multiple specialty clinics. This approach can also lead to significant cost-savings to the healthcare system.

Funding Acknowledgement

Type of funding sources: None.

Apolipoprotein E and Alzheimer's Disease: Findings, Hypotheses, and Potential Mechanisms

Alzheimer's disease (AD) is a multifactorial neurodegenerative disorder that involves dysregulation of many cellular and molecular processes. It is notoriously difficult to develop therapeutics for AD due to its complex nature. Nevertheless, recent advancements in imaging technology and the development of innovative experimental techniques have allowed researchers to perform in-depth analyses to uncover the pathogenic mechanisms of AD. An important consideration when studying late-onset AD is its major genetic risk factor, apolipoprotein E4 (apoE4). Although the exact mechanisms underlying apoE4 effects on AD initiation and progression are not fully understood, recent studies have revealed critical insights into the apoE4-induced deficits that occur in AD. In this review, we highlight notable studies that detail apoE4 effects on prominent AD pathologies, including amyloid-β, tau pathology, neuroinflammation, and neural network dysfunction. We also discuss evidence that defines the physiological functions of apoE and outlines how these functions are disrupted in apoE4-related AD. Expected final online publication date for the Annual Review of Pathology: Mechanisms of Disease, Volume 17 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Submuscular reburial as an alternative to lead extraction in high risk patients

Funding Acknowledgements

Type of funding sources: None.

Background

The Heart Rhythm Society (HRS) and European Heart Rhythm Association (EHRA) consensus states complete extraction is recommended for all patients with definite cardiac implantable electronic device (CIED) infection. Although complete removal of hardware is the best way to manage infections, lead extraction is a complex procedure with significant risk. As age and complexity of patients increase so too does extraction risk. In very high risk cases conservative management is cited, though little is known on outcomes.

Purpose

We are a high volume tertiary centre which serves a population of 2 million. 2 experienced operators perform 65 extraction procedures per year for the past 10 years. We report our experience of device reburial as initial management of CIED pre-erosion and erosion in cases deemed too high risk for extraction.

Method

We retrospectively reviewed all reburial procedures undertaken over 9 years. Patient and lead factors influencing decisions were assessed. Information on number of leads, dwell time, prior procedure, infective status and comorbidity was collated. The outcomes included morbidity, defined by repeat procedure (revision and/or extraction) and mortality. 

Results

86 patients underwent 96 procedures from March 2013 until August 2020. All patients undergoing device reburial were included. 55.8% of patients were male, mean age was 73. 21 patients died, 7 of these deaths occurred within 12 months of the index reburial procedure. The mean follow up period was 39 months (range 5–90). 65.1% of patients had a procedure (de novo implant, upgrade or replacement) within 12 months prior to revision.

We reviewed patients in 2 subgroups based on revision indication – erosion and pre-erosion. Erosion was defined as externalised lead/device. Pre-erosion was defined as superficial device with skin tethering but no exposure. The former is a definite indication for lead extraction, the latter a relative indication. All in the pre-erosion group were systemically well with no infection evident. One patient with erosion had a positive blood culture.

The mean age in the erosion group was 85 years with a Clinical Frailty Score (CFS) 4.98 and lead dwell time 17.87 years compared to age 68 years, CFS 3.98 and dwell time 8.14 years in the pre-erosion group. Patients in this cohort with an eroded device were deemed too high risk to undergo transvenous lead extraction.

A higher proportion of patients presenting with erosion died within 12 months of the index reburial procedure (16.67% vs 4.84%). 21% with an eroded device and 11% with a pre-eroding device undergoing reburial as first line management required future extraction.

Conclusion

Our 9 year data suggests less invasive intervention is a valid option in high risk groups such as older age, frailty, long lead dwell time, with an acceptable incidence of reintervention and/or extraction. This data can help guide informed consent in the future.

CIED guided HF management : a prospective cohort study

Funding Acknowledgements

Type of funding sources: Public hospital(s). Main funding source(s): Liverpool Clinical Commissioning Group

Background

Heart failure (HF) is associated with significant morbidity and mortality. (1) Cardiac Implantable Electronic Devices (CIED) generated Heart Failure Risk Score (HFRS) alerts may guide management in this complex cohort and help direct resources to appropriate patients. (2)

Aim 

To develop and evaluate an integrated, multidisciplinary approach to HF management for patients with CIED by sharing HFRS alerts directly with the HF teams.

Methods

We undertook a prospective, single centre cohort study of patients who generated high risk HFRS alerts. These alerts were shared with community HF teams responsible for routine care of patient, prompting patient contact and appropriate intervention by the team. Impact of the pathway was evaluated by review of outcomes including hospitalisation and clinical intervention within 4- 6 weeks of the alert and mortality during the follow up period. Ongoing education was provided to help teams deal with alerts. A validated user questionnaire was completed by the stake holders to obtain user feedback.

Results

365 "High risk" alerts were noted in 188 patients in a 2 year period (November 2018 - November 2020). The mean number of alerts per patients was 1.9 and 44 (23%) of patients had &gt;3 "high risk" alerts in the follow up period. Having three or more alerts significantly increased the risk of hospitalisation for heart failure (HR 2.5, CI 1.1–5.6 p = 0.03) but not mortality (HR 2.1 CI 0.6-7.2 p = 0.23). Overall 75 (39%) of patients were hospitalised in the 4-6 week period of the alert – 53 (28%) of these were unplanned of which 24(13%) were for decompensated HF. A further 24(13%) had planned admissions for care to improve therapy (AV node ablation, device and lead replacement) and reduce morbidity (LA appendage occlude, IV Iron therapy). 33(18%) of patients died in the follow up period.  15(8%) received therapy from the device. 18(10%) of patient underwent deactivation of ICD therapy.

Contact was established in 176 (94%) of patients, and alerts actioned appropriately. 55 patients reported being asymptomatic, and in 45 the trends were improving so no further clinical action was taken. 76 patients had an onward referral made for further management including; 32 to a Cardiologist, 20 to primary care, 13 referrals to community HF teams and 11 referrals to palliative care. 23 patients had medications changes instituted. The feedback on the pathway was positive. 

Conclusions 

An integrated approach to HF for patients with CIEDs in situ can facilitate timely risk stratification and intervention in this cohort of patients and potentially reduce unplanned health care utilisation. Intervention in these patients is not limited to HF alone and provides the opportunity for holistic management of this complex cohort Abstract Figure.

Calibrating a chief complaint list for low resource settings: a methodologic case study

BACKGROUND

The chief or presenting complaint is the reason for seeking health care, often in the patient's own words. In limited resource settings, a diagnosis-based approach to quantifying burden of disease is not possible, partly due to limited availability of an established lexicon or coding system. Our group worked with colleagues from the African Federation of Emergency Medicine building on the existing literature to create a pilot symptom list representing an attempt to standardize undifferentiated chief complaints in emergency and acute care settings. An ideal list for any setting is one that strikes a balance between ease of use and length, while covering the vast majority of diseases with enough detail to permit epidemiologic surveillance and make informed decisions about resource needs.

METHODS

This study was incorporated as a part of a larger prospective observational study on human immunodeficiency virus testing in Emergency Departments in South Africa. The pilot symptom list was used for chief complaint coding in three Emergency Departments. Data was collected on 3357 patients using paper case report forms. Chief complaint terms were reviewed by two study team members to determine the frequency of concordance between the coded chief complaint term and the selected symptom(s) from the pilot symptom list.

RESULTS

Overall, 3537 patients' chief complaints were reviewed, of which 640 were identified as 'potential mismatches.' When considering the 191 confirmed mismatches (29.8%), the Delphi process identified 6 (3.1%) false mismatches and 185 (96.9%) true mismatches. Significant chief-complaint clustering was identified with 9 sets of complaints frequently selected together for the same patient. "Pain" was used 2076 times for 58.7% of all patients. A combination of user feedback and expert-panel modified Delphi analysis of mismatched complaints and clustered complaints resulted in several substantial changes to the pilot symptom list.

CONCLUSIONS

This study presented a systematic methodology for calibrating a chief complaint list for the local context. Our revised list removed/reworded symptoms that frequently clustered together or were misinterpreted by health professionals. Recommendations for additions, modifications, and/or deletions from the pilot chief complaint list we believe will improve the functionality of the list in low resource environments.

In Vivo Chimeric Alzheimer's Disease Modeling of Apolipoprotein E4 Toxicity in Human Neurons

Despite its clear impact on Alzheimer's disease (AD) risk, apolipoprotein (apo) E4's contributions to AD etiology remain poorly understood. Progress in answering this and other questions in AD research has been limited by an inability to model human-specific phenotypes in an in vivo environment. Here we transplant human induced pluripotent stem cell (hiPSC)-derived neurons carrying normal apoE3 or pathogenic apoE4 into human apoE3 or apoE4 knockin mouse hippocampi, enabling us to disentangle the effects of apoE4 produced in human neurons and in the brain environment. Using single-nucleus RNA sequencing (snRNA-seq), we identify key transcriptional changes specific to human neuron subtypes in response to endogenous or exogenous apoE4. We also find that Aβ from transplanted human neurons forms plaque-like aggregates, with differences in localization and interaction with microglia depending on the transplant and host apoE genotype. These findings highlight the power of in vivo chimeric disease modeling for studying AD.

Determination of secretory granule maturation times in pancreatic islet β-cells by serial block-face electron microscopy

It is shown how serial block-face electron microscopy (SBEM) of insulin-secreting β-cells in wild-type mouse pancreatic islets of Langerhans can be used to determine maturation times of secretory granules. Although SBEM captures the β-cell structure at a snapshot in time, the observed ultrastructure can be considered representative of a dynamic equilibrium state of the cells since the pancreatic islets are maintained in culture in approximate homeostasis. It was found that 7.2 ± 1.2% (±st. dev.) of the β-cell volume is composed of secretory granule dense-cores exhibiting angular shapes surrounded by wide (typically ≳100 nm) electron-lucent halos. These organelles are identified as mature granules that store insulin for regulated release through the plasma membrane, with a release time of 96 ± 12 h, as previously obtained from pulsed ³⁵S-radiolabeling of cysteine and methionine. Analysis of β-cell 3D volumes reveals a subpopulation of secretory organelles without electron-lucent halos, identified as immature secretory granules. Another subpopulation of secretory granules is found with thin (typically ≲30 nm) electron-lucent halos, which are attributed to immature granules that are transforming from proinsulin to insulin by action of prohormone convertases. From the volume ratio of proinsulin in the immature granules to insulin in the mature granules, we estimate that the newly formed immature granules remain in morphologically-defined immature states for an average time of 135 ± 14 min, and the immature transforming granules for an average time of 130 ± 17 min.

Too Much Tau in Interneurons Impairs Adult Hippocampal Neurogenesis in Alzheimer's Disease

Understanding why adult hippocampal neurogenesis (AHN) is impaired in Alzheimer's disease (AD) is essential for unravelling its role in pathogenesis. In this issue of Cell Stem Cell, Zheng et al. (2020) report that human tau accumulation in dentate gyrus GABAergic interneurons disrupts AHN and strengthening GABAergic signaling restores AHN and improves cognition in an AD mouse model.

Adapting blood glucose meter biosensors for the measurement of lactose in dairy ingredients

Commonly used lactose assays [enzymatic spectrophotometric absorbance (EZA) and HPLC] for dairy ingredients are relatively expensive and time consuming. A blood glucose meter (BGM)-based method has successfully been documented as a rapid lactose assay in milk. However, the BGM-based method has not been evaluated in dairy ingredients. The objective of this study was to evaluate the BGM-based lactose analysis method in whey-derived (WD) and skim milk-derived (SMD) ingredients. The study was carried out in 4 phases. In phase 1, the effect of pH and lactose concentrations on the BGM reading was investigated using a factorial design with 2 factors: pH (6.02-7.50) and lactose (0.2 or 0.4%). We found that BGM readings were significantly affected by lower pH values at both lactose levels. In phase 2, the effect of total solids and ingredient type was investigated using a factorial design with 2 factors: ingredient type (WD or SMD) and total solids (0-8%). It was observed that the BGM reading was significantly affected by ingredient type and total solids. Phase 3 involved developing a linear relationship between the BGM reading and the EZA reference method to ascertain the accuracy of the proposed BGM method. Different ingredient types (WD or SMD) and non-lactose solids (0.5-27%) model ingredient dilutions prepared over a range of lactose contents (0.08-0.62%) were measured using the BGM and EZA methods. The average absolute percentage bias difference between the BGM method and EZA reference method results for these model dilutions was found to be between 2.2 and 7.3%. In phase 4, 15 samples procured from commercial sources ranging from 0.01 to 81.9% lactose were evaluated using the BGM method and EZA reference method. The average absolute percentage bias difference for lactose results between the 2 methods ranged from 3.6 to 5.0% and 5.3 to 9.7% for well-performing and poorly performing meters, respectively. Overall, the BGM method is a promising tool for rapid and low-cost analysis of lactose in both high-lactose and low-lactose dairy ingredients.

AB0006 HYPOMETHYLATION OF THE PROMOTER REGION OF TLR4 GENE AT A SYSTEMIC LEVEL IN PATIENTS WITH RHEUMATOID ARTHRITIS AND PERIODONTITIS

Background:

Periodontitis (PD) has long been linked with Rheumatoid arthritis (RA) [1]. Epigenetic modifications are being recently explored to explain such associations, DNA methylation being one such important mechanism.

Objectives:

To study the effect chronic generalized periodontitis on systemic methylation of TLR4 genes in comparison to only RA and RA with PD patients.

Methods:

Twenty-three RA patients, among which 11 patients had chronic generalized PD, 20 patients with only PD and 15 healthy individuals recruited. DNA was isolated from PBMCs of the participants blood, then were first bisulphite converted and then methylation specific PCR were performed using primers for methylated and um-methylated promoters of TLR4. The DNA amplifications were checked in horizontal gel electrophoresis. The methylation signatures were verified by DNA sequencing (Sanger) of the amplified products.

Results:

The anti-CCP, DAS-CRP and HAQ DI were higher in patients with both RA and PD (220±40, 5.7±0.2, 1.5±0.1 respectively, p<0.05). Control samples had shown amplification bands for methylated primers of TLR4 but not for un-methylated primers of TLR4. However, only RA, only PD and RA with PD samples, had shown amplification for un-methylated primers and not for methylated primers. These results together with DNA sequencing indicated that 4 CpG sites in the promoter ofTLR4 genes were hypo-methylated in the PBMCs of patients whereas those remain methylated in healthy individuals.

Conclusion:

The observations indicated that though PD is a localised disease of the gingiva there is a systemic involvement of TLR mediated pathways in them which is similar to those in RA. However, further validation in larger cohort and down-stream signalling molecules needs to be studied.

References:

[1]Ceccarelli F, Saccucci M, Di Carlo G, Lucchetti R, Pilloni A, Pranno N, Luzzi V, Valesini G, Polimeni A. Periodontitis and rheumatoid arthritis: the same inflammatory mediators?. Mediators of inflammation. 2019;2019.

Disclosure of Interests:

None declared

Foldscope as a primary diagnostic tool for oral and urinary tract infections and its effectiveness in oral health education

Due to its speed, accuracy and cost-effectiveness, microscopy has become an integral part of clinical examination for disease diagnosis. However, modern microscopes are very costly and require skilled personnel for their operation and maintenance, and specimen processing and analysis is labour-intensive. Further, lack of such expensive diagnostic tools in remote areas is a serious concern. Affordable point-of-care diagnostic tools are the most useful for timely disease diagnosis and management. The Foldscope is an affordable origami-based microscopy device composed of a series of paper clippings, which, upon assembly, can hold a specimen slide for observation, and this specimen can be viewed via a mobile phone camera attached to it. The present study evaluated the use of the Foldscope in the clinical diagnosis of oral and urinary tract infections and evaluated its efficacy as a motivational tool for improving oral health among school children in India. We qualitatively compared the Foldscope to a clinical microscope by examining five different types of clinical samples. Of the different types of clinical samples, the Foldscope was effective in detecting infection in dental plaque samples and urine samples. Thus, we further analysed 31 dental plaque samples of patients aged 3-13 years and 25 urine samples of patients aged 11-62 years. We also evaluated the use of the Foldscope as an educational tool for motivating oral hygiene among 80 school children aged 12 years and found that students in the Foldscope intervention group had better measures of oral hygiene than did students in the nonintervention group. In summary, our study indicated that the Foldscope is useful in detecting urinary tract infections and kidney stones in urine samples and is a useful motivational tool for oral health education among school-aged children. Furthermore, it may also be useful in oral health monitoring in resource poor settings. LAY DESCRIPTION: Poor and remote population often suffers due to lack of capacity to buy products or avail services which are expensive. In such a society people are not able to afford even the basic detection of diseases. Foldscope may come to rescue here! Foldscope is a paper-based, use-and-throw, affordable microscope. This study explores the use of Foldscope in clinics and diseases diagnosis using patient samples. Preliminary detection of disease associated symptoms in dental and urinary infections and digital record keeping via storage in mobile phone memory and hospital OPD records for monitoring patient's health are some of the advantages of Foldscope for clinical use in resource poor settings. It identifies that Foldscope not only can be used by students or teachers for educational purposes but it can also pave a path for promotion of dental hygiene among young children. The study also suggests that further improvement in design or resolution of Foldscope will broaden the scope of its application, in future.