A glycolytic metabolite bypasses "two-hit" tumor suppression by BRCA2

Knudson's "two-hit" paradigm posits that carcinogenesis requires inactivation of both copies of an autosomal tumor suppressor gene. Here, we report that the glycolytic metabolite methylglyoxal (MGO) transiently bypasses Knudson's paradigm by inactivating the breast cancer suppressor protein BRCA2 to elicit a cancer-associated, mutational single-base substitution (SBS) signature in nonmalignant mammary cells or patient-derived organoids. Germline monoallelic BRCA2 mutations predispose to these changes. An analogous SBS signature, again without biallelic BRCA2 inactivation, accompanies MGO accumulation and DNA damage in Kras-driven, Brca2-mutant murine pancreatic cancers and human breast cancers. MGO triggers BRCA2 proteolysis, temporarily disabling BRCA2's tumor suppressive functions in DNA repair and replication, causing functional haploinsufficiency. Intermittent MGO exposure incites episodic SBS mutations without permanent BRCA2 inactivation. Thus, a metabolic mechanism wherein MGO-induced BRCA2 haploinsufficiency transiently bypasses Knudson's two-hit requirement could link glycolysis activation by oncogenes, metabolic disorders, or dietary challenges to mutational signatures implicated in cancer evolution.

New Au/chitosan nanocomposite modified carbon paste sensor for voltammetric detection of nicotine

A profoundly touchy voltammetric sensor for detection of nicotine (NIC) in urine and tobacco specimens has been developed in light of the boosted electrochemical response of NIC at gold and chitosan nanocomposite modified carbon paste electrode (ACMCPE). Material characterization techniques Scanning Electron Microscope and Energy Dispersive X-ray (SEM & EDX) were utilized to describe the ACMCPE surface material. The impedance spectroscopy technique (EIS), cyclic voltammetry (CV), chronoamperometry (CA), and differential pulse voltammetry (DPV) were employed to explore the electrochemical sensing of NIC at ACMCPE. The created sensor exhibits an exceptional electrochemical sensitivity to NIC in a universal Britton-Robinson (B-R) buffer solution with a pH range of 2.0 to 8.0. The sensor shows a linear response over NIC concentration ranges of 4.0-320.0 µM, with the detection limit (LOD) of 7.6 µM. The prepared sensor has been shown to be exceptionally viable in detecting NIC with amazing selectivity and reproducibility. We suggest it as a trustworthy and useful electrochemical sensor for NIC location.

A transcriptional response to replication stress selectively expands a subset of Brca2-mutant mammary epithelial cells

Germline BRCA2 mutation carriers frequently develop luminal-like breast cancers, but it remains unclear how BRCA2 mutations affect mammary epithelial subpopulations. Here, we report that monoallelic Brca2mut/WT mammary organoids subjected to replication stress activate a transcriptional response that selectively expands Brca2mut/WT luminal cells lacking hormone receptor expression (HR-). While CyTOF analyses reveal comparable epithelial compositions among wildtype and Brca2mut/WT mammary glands, Brca2mut/WT HR- luminal cells exhibit greater organoid formation and preferentially survive and expand under replication stress. ScRNA-seq analysis corroborates the expansion of HR- luminal cells which express elevated transcript levels of Tetraspanin-8 (Tspan8) and Thrsp, plus pathways implicated in replication stress survival including Type I interferon responses. Notably, CRISPR/Cas9-mediated deletion of Tspan8 or Thrsp prevents Brca2mut/WT HR- luminal cell expansion. Our findings indicate that Brca2mut/WT cells activate a transcriptional response after replication stress that preferentially favours outgrowth of HR- luminal cells through the expression of interferon-responsive and mammary alveolar genes.

New View on Nonlinear Picture Fuzzy Integral Equations

In this article, we solve the second type of nonlinear Volterra picture fuzzy integral equation (NVPFIE) using an accelerated form of the Adomian decomposition method (ADM). Based on (α,δ,β)-cut, we convert the NVPFIE to the nonlinear Volterra integral equations in a crisp form. An accelerated version of the ADM is used to solve this transformed system, which is based on a new formula for the Adomian polynomial. The sufficient condition that guarantees a unique solution is obtained using this new Adomian polynomial, error estimates are given, and the convergence of the series solution is proven. Numerical cases are discussed to illustrate the effectiveness of this approach.

Correction to: 'Current strategies with implementation of 3D cell culture: The challenge of quantification' (2022) by Temple et al

[This corrects the article DOI: 10.1098/rsfs.2022.0019.][This corrects the article DOI: 10.1098/rsfs.2022.0019.].

Current strategies with implementation of three-dimensional cell culture: the challenge of quantification

From growing cells in spheroids to arranging them on complex engineered scaffolds, three-dimensional cell culture protocols are rapidly expanding and diversifying. While these systems may often improve the physiological relevance of cell culture models, they come with technical challenges, as many of the analytical methods used to characterize traditional two-dimensional (2D) cells must be modified or replaced to be effective. Here we review the advantages and limitations of quantification methods based either on biochemical measurements or microscopy imaging. We focus on the most basic of parameters that one may want to measure, the number of cells. Precise determination of this number is essential for many analytical techniques where measured quantities are only meaningful when normalized to the number of cells (e.g. cytochrome p450 enzyme activity). Thus, accurate measurement of cell number is often a prerequisite to allowing comparisons across different conditions (culturing conditions or drug and treatment screening) or between cells in different spatial states. We note that this issue is often neglected in the literature with little or no information given regarding how normalization was performed, we highlight the pitfalls and complications of quantification and call for more accurate reporting to improve reproducibility.

Citraconate inhibits ACOD1 (IRG1) catalysis, reduces interferon responses and oxidative stress, and modulates inflammation and cell metabolism

Although the immunomodulatory and cytoprotective properties of itaconate have been studied extensively, it is not known whether its naturally occurring isomers mesaconate and citraconate have similar properties. Here, we show that itaconate is partially converted to mesaconate intracellularly and that mesaconate accumulation in macrophage activation depends on prior itaconate synthesis. When added to human cells in supraphysiological concentrations, all three isomers reduce lactate levels, whereas itaconate is the strongest succinate dehydrogenase (SDH) inhibitor. In cells infected with influenza A virus (IAV), all three isomers profoundly alter amino acid metabolism, modulate cytokine/chemokine release and reduce interferon signalling, oxidative stress and the release of viral particles. Of the three isomers, citraconate is the strongest electrophile and nuclear factor-erythroid 2-related factor 2 (NRF2) agonist. Only citraconate inhibits catalysis of itaconate by cis-aconitate decarboxylase (ACOD1), probably by competitive binding to the substrate-binding site. These results reveal mesaconate and citraconate as immunomodulatory, anti-oxidative and antiviral compounds, and citraconate as the first naturally occurring ACOD1 inhibitor.

Graphite based sensor amended with fumed silica for electro-detecting Azithromycin

Azithromycin (AM) detection has become of great interest as being one of the prescribed medicines in the medication protocol in Egypt for the recent COVID-19 pandemic. Herein, a carbon paste electrode (CPE) was simply amended with fumed silica (FS) for determining AM. The characterization of the new material was done by different techniques including scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electrochemical impedance spectroscopy (EIS). The newly modified fumed silica carbon paste electrode (FSCPE) exhibited a highly sensitive response towards the oxidation of 1.0 mM AM in phosphate buffer solution (PBS) for a pH range of 5.0 - 10.0. The effect of varying AM concentrations was studied in PBS of pH 7.4 with a detection limit of 11 µM and a quantification limit of 37 µM. Eventually, the recently amended electrode attained reasonable sensitivity and constancy for AM detection in actual trials like blood plasma and pharmaceutical drugs.

BRCA2 deficiency reveals that oxidative stress impairs RNaseH1 function to cripple mitochondrial DNA maintenance

Oxidative stress is a ubiquitous cellular challenge implicated in aging, neurodegeneration, and cancer. By studying pathogenic mutations in the tumor suppressor BRCA2, we identify a general mechanism by which oxidative stress restricts mitochondrial (mt)DNA replication. BRCA2 inactivation induces R-loop accumulation in the mtDNA regulatory region and diminishes mtDNA replication initiation. In BRCA2-deficient cells, intracellular reactive oxygen species (ROS) are elevated, and ROS scavengers suppress the mtDNA defects. Conversely, wild-type cells exposed to oxidative stress by pharmacologic or genetic manipulation phenocopy these defects. Mechanistically, we find that 8-oxoguanine accumulation in mtDNA caused by oxidative stress suffices to impair recruitment of the mitochondrial enzyme RNaseH1 to sites of R-loop accrual, restricting mtDNA replication initiation. Thus, oxidative stress impairs RNaseH1 function to cripple mtDNA maintenance. Our findings highlight a molecular mechanism that links oxidative stress to mitochondrial dysfunction and is elicited by the inactivation of genes implicated in neurodegeneration and cancer.

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BRCA2-deficient cells accumulate mtDNA R-loops due to oxidative stress

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This stress creates 8-oxoguanine lesions impairing RNaseH1 recruitment to mtDNA

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RNaseH1 impairment triggers R-loop formation and restricts mtDNA replication

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Other sources of oxidative stress also cripple mtDNA maintenance via this mechanism

High-throughput surface marker screen on primary human breast tissues reveals further cellular heterogeneity

BACKGROUND

Normal human breast tissues are a heterogeneous mix of epithelial and stromal subtypes in different cell states. Delineating the spectrum of cellular heterogeneity will provide new insights into normal cellular properties within the breast tissue that might become dysregulated in the initial stages of cancer. Investigation of surface marker expression provides a valuable approach to resolve complex cell populations. However, the majority of cell surface maker expression of primary breast cells have not been investigated.

METHODS

To determine the differences in expression of a range of uninvestigated cell surface markers between the normal breast cell subpopulations, primary human breast cells were analysed using high-throughput flow cytometry for the expression of 242 cell surface proteins in conjunction with EpCAM/CD49f staining.

RESULTS

We identified 35 surface marker proteins expressed on normal breast epithelial and/or stromal subpopulations that were previously unreported. We also show multiple markers were equally expressed in all cell populations (e.g. CD9, CD59, CD164) while other surface markers were confirmed to be enriched in different cell lineages: CD24, CD227 and CD340 in the luminal compartment, CD10 and CD90 in the basal population, and CD34 and CD140b on stromal cells.

CONCLUSIONS

Our dataset of CD marker expression in the normal breast provides better definition for breast cellular heterogeneity.

Time-resolved single-cell analysis of Brca1 associated mammary tumourigenesis reveals aberrant differentiation of luminal progenitors

It is unclear how genetic aberrations impact the state of nascent tumour cells and their microenvironment. BRCA1 driven triple negative breast cancer (TNBC) has been shown to arise from luminal progenitors yet little is known about how BRCA1 loss-of-function (LOF) and concomitant mutations affect the luminal progenitor cell state. Here we demonstrate how time-resolved single-cell profiling of genetically engineered mouse models before tumour formation can address this challenge. We found that perturbing Brca1/p53 in luminal progenitors induces aberrant alveolar differentiation pre-malignancy accompanied by pro-tumourigenic changes in the immune compartment. Unlike alveolar differentiation during gestation, this process is cell autonomous and characterised by the dysregulation of transcription factors driving alveologenesis. Based on our data we propose a model where Brca1/p53 LOF inadvertently promotes a differentiation program hardwired in luminal progenitors, highlighting the deterministic role of the cell-of-origin and offering a potential explanation for the tissue specificity of BRCA1 tumours.

Moxifloxacin Hydrochloride Electrochemical Detection at Gold Nanoparticles Modified Screen-Printed Electrode

It appeared that either the carbon paste or the screen-printed carbon electrodes that were modified with gold nanoparticles (AuNPs) gave rise to the largest current responses after a rapid screening of various nanomaterials as modifiers of carbon composite electrodes in view of designing an electrochemical sensor for Moxifloxacin Hydrochloride (Moxi). The screen-printed electrode (SPE) support was preferred over the carbon paste one for its ability to be used as disposable single-use sensor enabling the circumvention of the problems of surface fouling encountered in the determination of Moxi. The response of AuNPs modified SPE to Moxi was investigated by cyclic voltammetry (CV) (including the effect of the potential scan rate and the pH of the medium), chronoamperometry, and differential pulse voltammetry (DPV) after morphological and physico-chemical characterization. DPV was finally applied to Moxi detection in phosphate buffer at pH 7, giving rise to an accessible concentration window ranging between 8 µM and 0.48 mM, and the detection and quantification limits were established to be 11.6 µM and 38.6 µM, correspondingly. In order to estimate the applicability of Moxi identification scheme in actual trials, it was practiced in a human baby urine sample with excellent recoveries between 99.8 % and 101.6 % and RSDs of 1.1-3.4%, without noticeable interference.

Facile caffeine electrochemical detection via electrodeposited Ag nanoparticles with modifier polymers on carbon paste sensor at aqueous and micellar media

The analysis and detection of caffeine (Caf) is very useful due to its widespread usage in several daily consumed beverages, food products, and pharmacological preparations with various physiological effects. The preparation of a newly electrodeposited Ag nanoparticles – cellulose acetate phthalate (CAP) – chitosan (Chit) modified carbon paste (ACCMCP) sensor for sensitive determination of Caf in 0.01 mol L−1 H3PO4 solution (pH 1.0–5.0) both in aqueous and micellar media (0.5 mmol L−1 SDS) was achieved. The interaction of Caf was monitored using electrochemical techniques such as cyclic voltammetry, differential pulse voltammetry, electrochemical impedance spectroscopy, and chronoamperometry, and surface characterization was carried out using X-ray diffraction, scanning electron microscope, and energy dispersive X-ray techniques. The linear detection range of Caf was between 4 and 500 μmol L−1 (r2 = 0.955) and the limit of detection obtained from the calibration plot was 0.252 μmol L−1. The sensor was applicable for detecting Caf in numerous real samples with recoveries from 98.03% to 101.60% without interference of any accompanying species, which ensures high method selectivity.

P1521 Prosthetic heart valve-related stroke: a single center experience

OnBehalf

YIG-CVR

Introduction

Thromboembolic events or bleeding are by far the most frequent complications of prosthetic heart valves. Cerebrovascular stroke is one of the major thromboembolic complications of anticoagulation-related issues of prosthetic heart valves.

Aim of the work

To determine the pattern and risk factors of acute stroke in patients with prosthetic heart valves.

Methods and Patients

A retrospective single-center analysis of the database registry of consecutive acute stroke patients with mitral or aortic heart valve prostheses admitted to a tertiary care stroke specialized center from 01/01/2012 to 01/12/2017.

All patients were examined by a certified neurologist and underwent a complete work-up evaluation (Computed Tomography or Magnetic Resonance Imaging, Carotid Doppler ultrasound examination, complete blood tests, and electrocardiogram) and a transthoracic echocardiography (TTE) examination as well as transesophageal echocardiography (TOE) if valve dysfunction or thrombosis were suspected.

Results

214 patients with mitral or aortic valve prostheses were admitted by acute stroke in the duration from 01/01/2012 to 01/12/2017 with a mean age of 44 ± 15 years, 132 were males (61.7%) and 178 patients had mechanical valves (83.2%). 135 patients had mitral prosthesis (63.1%) and ischemic stroke was encountered in 151 patients (70.6%).

Conclusion

In a single center experience, mechanical prosthesis at the mitral valve position was associated with higher incidence of ischemic stroke. Proper close follow-up of INR levels as well as the surgical shift to biological instead of mechanical valve should decrease significantly the incidence of prosthetic valve related strokes.

Baseline, clinical and other parameters Patients (n = 214) Age (years) 44 ± 15 Mechanical valve 178 (83.2%) Atrial Fibrillation 101 (47.2%) Rheumatic Heart Disease 175 (81.8%) Left ventricular ejection fraction (%) 54 ±13 Mitral Only 135 (63.1%) Aortic Only 51 (23.8%) Double Valve Prosthesis 28 (13.1%) Ischemic stroke 151 (70.6%) Hemorrhagic stroke 47 (22%) Both ischemic and hemorrhagic stroke 16 (7.4%) Data are represented as mean(±SD) or number (Percentage)

Abstract P1521 Figure. Valve sites

P1506 The correlation between left atrial volume index and cerebrovascular stroke

OnBehalf

YIG-CVR

Introduction

Increased left atrial (LA) size was associated with poor cardiovascular outcomes such as the development of heart failure, atrial fibrillation (AF), and stroke in the elderly.

Aim of the work

To determine the relation between left atrial volume index (LAVI) and the occurrence of ischemic cerebrovascular stroke (CVS) in patients with sinus rhythm.

Patients and Methods

A prospective analysis of the data of patients admitted to a tertiary care center. Left atrial volume index (LAVI) was measured in 1222 patients admitted to our center with first attack of acute ischemic cerebrovascular stroke (CVS) and the data was matched with 1222 patients admitted by diagnoses other than acute ischemic stroke.

Patients with valvular heart diseases, history of AF and with known cardio-embolic source of stroke as left ventricular thrombi or masses were excluded from both groups.

Results

The mean age was 61.1 ± 14.4 years in the CVS group and 61.5 ± 12.4 years in the control group, males were 806 (71.43%) in the CVS group and 852 (73.47%) in the control group. LAVI was 35 ± 10.3 ml/m2 in the CVS group while it was only 25.8 ± 6.4 ml/m2 in the control group which was statistically significant (P value= 0.002).

Conclusion

LAVI is a strong parameter that can be used to predict the occurrence of CVS in patients with sinus rhythm.

Total (n = 2444) Acute CVS (n = 1222) No CVS (n = 1222) P-value Age (years) 61.1 ± 14.4 61.5 ± 12.4 0.75 Sex (Males) 806 (66%) 852 (70%) 0.65 Diabetes 655 (53.6%) 603 (49.3%) 0.6 Hypertension 702 (57.5%) 675 (55.2%) 0.55 Smoking 599 (49%) 564 (46.2%) 0.71 Dyslipidemia 310 (25.4%) 299 (24.5%) 0.81 Mean BP (mmHg) 122 ± 15 119 ± 17 0.88 Heart rate (bpm) 82 ± 16 85 ± 18 0.76 Hemoglobin (g/dl) 12.3 ± 1.3 12.9 ± 1.7 0.61 Platelets (103/l) 255 ± 110 235 ± 95 0.35 INR 1.15 ± 0.11 1.09 ± 0.18 0.75 Ejection fraction (%) 55 ± 12 51 ± 11 0.41 LAVI (ml/m2) 35 ± 10.3 25.8 ± 6.4 0.002* Results are represented as number (%) or mean ± standard deviation, BP = Blood Pressure, INR = International Normalization Ratio, * significant P value < 0.05

Abstract P1506 Figure. Comparison between both groups

P843 A rare cause of chest pain: paradoxical embolism in Ebstein"s anomaly

Introduction

Ebstein’s anomaly is characterized by displacement of the proximal attachments of the tricuspid valve from the atrioventricular ring into the right ventricle. This structural abnormality divides the right ventricle into an ‘atrialized’ portion and a distal ‘ventricularized’ portion. The severity is variable and accounts for the broad clinical spectrum, from severe disease causing fetal or neonatal death to mild disease compatible with natural survival as late as the eighth decade of life. Ebstein’s anomaly is an uncommon defect occurring in less than 1% of patients with congenital heart disease, but it is disproportionately represented in the adult congenital heart disease population because of its favourable natural history

Case report

A 55 year old man with no previous cardiac history .He presented to our medical facility complaining of acute retrosternal squeezing retrosternal chest pain few hours before admission. On clinical examination, he had a pansystolic murmur over the tricuspid area .ECG showed right bundle branch block. Laboratory results were unremarkable except elevated cardiac enzymes. 2D Transthoracic Echocardiography revealed a small well-functioning right ventricle, 15 mm/m2 apical displacement of the tricuspid septal leaflet with severe tricuspid regurgitation . 2D and 3D transesophageal echocardiography with intravenous agitated saline injection revealed patent foramen ovale with right to left shunt with immediate crossing of bubbles.Coronary angiography revealed normal coronaries.

The patient refused intervention and he was maintained on warfarin treatment .

Conclusion

The clinical presentation of Ebstein’s anomaly is highly variable—depending on anatomic severity, haemodynamics ,and degree of interatrial shunting. The majority of patients have shunting through a secundum ASD or patent-foramen ovale. Paradoxical embolism maybe an indication for PFO/ ASD closure

Abstract P843 Figure.

P911 3D echo imaging of tricuspid valve: new look at the tricuspid valve

Aim

To use different modes of three dimensional (3D TTE) to assess TV in three standard views in different diseases.

Methods : 6 patients with different tricuspid valve diseases (mean age is 29 ± 18 years, 3 were women)were studied.We used three-dimensional echocardiography to acquire zoomed mode and multi-beat, full-volume data sets of the TV to assess the leaflets and commissures. .Moreover, tricuspid valve area(TVA) was assessed by direct planimetry of the valve orifice at the level of the leaflets tips at end diastolic frame in cases of TV stenosis.

Results

Direct visualization of the leaflets motion and number, commissures and TVA were achieved in all patients.Tricuspid valve posterior leaflet prolapse was seen in two patients (figures A, B).2 patients had tricuspid valve stenosis ; one showed characteristic commissural fusion in a rheumatic heart (3D TVA= 1.2 cm2 )(Figure D) and the other has a peculiar commissural sparing in a carcinoid pathology (3D TVA = 1.9 cm2) (Figure E) .One patient revealed rudimentary anterior leaflet suggesting unguarded TV orifice (Figure F). Regarding the numerical variations: one patient got 4 leaflets (Figure C) while another one had 2 leaflets only.

Conclusion

Simultaneous visualization of the three TV leaflets is limited by using 2DE.On the other hand, RT-3DE allows better understanding of the anatomy and mechanisms of the TV diseases .Comprehensive assessment of the morphology and function using RT-3DE can provide a valuable road map to guide the intervention according to each individual case.

Abstract P911 Figure. Different TV morpholgies.

P1465 Ventricular septal defect and pulmonary artery aneurysm; How does it look by three dimensional echocardiography

Introduction

Pulmonary artery (PA) aneurysms (PAAs) are rare and infrequently diagnosed . The upper limit of the main PA diameter (29 mm) was defined as a PAA.

Congenital causes have been recognized as the major reason for PAA formation. More than 50% of all cases were associated with congenital heart disease. The 3 most frequent congenital heart defects associated with a PAA are, in decreasing order, persistent ductus arteriosus (PDA), ventricular septal defects (VSD) , and atrial septal defects (ASD).En face visualization of the whole circumference of the VSD and its relation to the surrounding structures can help in better understanding of the shear stress that promote PAA formation.

Case report

A 35 year old female patient with no previous cardiac history .She presented to our medical facility complaining of exertional dyspnea since 2 years . On clinical examination, she had harsh pansystolic murmur heard over left parasternal area . 2D Transthoracic Echocardiography revealed an aneurysmally dilated pulmonary artery (40mm in maximum diameter) and a wide VSD. 3D transthoracic and transesophageal echocardiography showed a wide subarterial VSD which is immediately located below the pulmonary valve. Therefore , that increased flow caused by left-to-right shunt caused by the intimate location of the VSD to the pulmonary valve results in increased hemodynamic shear stress on the vessel walls and therefore promotes aneurysm formation .Surgical closure of the VSD was done successfully with no residual defects.

Conclusion

PAAs seldom occur, are rarely diagnosed, and do not present with distinct symptoms. With the help of 3D echocardiography , direct visualization of the surrounding septal defects helps better understanding of mechanism of the aneurysm formation.

Abstract P1465 Figure.

P1464 A case of cortriatriatum dexter accidentally discovered in an adult

Introduction

Cor triatriatum dexter, or partitioning of the right atrium (RA) to form a triatrial heart, is an extremely rare congenital anomaly that is caused by the persistence of the right valve of the sinus venosus. The incidence of cor triatriatum is approximately 0.1% of congenital heart malformation. Typically, the right atrial partition is due to exaggerated fetal eustachian and the besian valves, which together form an incomplete septum across the lower part of the atrium. This septum may range from a reticulum to a substantial sheet of tissue

Case report:

45-years old female patient with history of surgical closure of an atrial septal defect at the age of 14 years .She presented to our medical facility complaining of exertional dyspnea and bilateral lower limb edema for 4 years. On clinical examination, she had bilateral congested neck veins, a pansystolic murmur over the tricuspid area and a tender hepatomegaly. 2D Transthoracic Echocardiography revealed an unusual membranous structure that stretched across the right atrium with attachments superiorly at the free wall and inferiorly at the inter-atrial septum with a severe tricuspid regurgitation (Panel A)Intravenous agitated saline injection revealed an incomplete membrane. (Panel B).2D Transesophageal echocardiography showed an unusually prominent eustachian valve arose normally from the ostium of the inferior vena cava (IVC) and was pointing towards the interatrial septum just below the level of the fossa ovalis and no residual ASD could be seen. (Panel C) . 3D transesophageal echocardiography with zoomed mode from right atrial perspective confirmed the presence of an incomplete membrane extending transversely from the ostium of IVC and interatrial septum immediately below the fossa ovalis but not reaching RA free wall (arrow), no obstruction to the flow of the IVC, superior vena cava (SVC) , coronary sinus (CS) and the tricuspid valve (TV) was seen .(Panels D,E,F).

Conclusion

Since many patients are asymptomatic, the diagnosis of cor triatriatum dexter often is determined at postmortem examination. Antemortem diagnosis can be determined by echocardiography. 3D transesophageal echocardiography was able to detect cor triatriatum dexter that can be easily missed by 2D echocardiography.

Abstract P1464 Figure.

P5581In patients with aortic valve regurgitation, left ventricular geometry and strain, more than pulmonary artery systolic pressure, affect right ventricular function

Background

Left ventricular (LV) overload due to aortic valve (AR) regurgitation may affect right ventricular (RV) function. Elevation of pulmonary artery pressures secondary to isolated AR is not common. Thus, the effects of chronic LV overload due to AR on RV function remains to be clarified.

Purpose

To assess the determinants of RV dysfunction in chronic AR.

Methods

We studied 36 patients with moderate or severe AR (53±18 years, 81% were men). We used 3D echocardiography to acquire multi-beat, full-volume data sets of LV and RV and to measure volumes and EF. RV fractional area change (FAC) was calculated. LV global longitudinal strain (GLS) and RV peak longitudinal strain (RVLS) were assessed by 2D speckle tracking echocardiography.

Results

RV EF and RV FAC were 40±6% and 34±9%. LV GLS and peak RVLS were reduced (Table). LV EDVi showed negative correlations with RV function (RV EF: r=−0.545, p<0.001; RV FAC: r=−0.816, p<0.001). LV sphericity index showed negative correlations with RV function (RVFAC: r=−0.608, P=0.001; RV EF: r=−0.469, P=0.004). Moreover, LV GLS and RVLS correlated positively with RV function (FAC: for GLS: r=0.475, p=0.003 and for RVLS: r=0.389, p=0.019) (RV EF: for GLS: r=0.526, p=0.001 and for RVLS: r=0.475, p=0.003). On multivariable linear regression analysis, LV EDVi, LV sphericity index, LV GLS and peak RVLS were found to be the only independent predictors of RV EF and FAC.

Left and right ventricular volumes and function in patients with chronic aortic regurgitation AR (n=36) Control (n=25) p value LV end-diastolic volume (ml/m2) 106±36 56±8 <0.001 LV end-systolic volume (ml/m2) 50±28 22±4 <0.001 LV ejection fraction (%) 54±10 60±4 <0.001 LV sphericity index 0.53±0.11 0.38±0.08 <0.001 Pulmonary artery systolic pressure (mm Hg) 27±8 RV end-diastolic volume (ml/m2) 59±12 35±7 <0.001 RV end-systolic volume (ml/m2) 31±9 17±3 <0.001 RV ejection fraction (%) 40±6 50±4 <0.001 RV fractional area change (%) 34±9 44±6 <0.001 LV GLS (%) −18±3 21±1 <0.001 Peak RVLS (%) −26±5 −31±3 <0.001

Conclusions

RV remodeling in chronic LV overload due to AR occurs independent on PASP values. LV size, shape and strain are the only independent predictors of RV function.

EARLY ASSESSMENT OF RENAL TRANSPLANTS USING BOLD-MRI: PROMISING RESULTS

Non-invasive evaluation of renal transplant function is essential to minimize and manage renal rejection. A computer-assisted diagnostic (CAD) system was developed to evaluate kidney function post-transplantation. The developed CAD system utilizes the amount of blood-oxygenation extracted from 3D (2D + time) blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI) to estimate renal function. BOLD-MRI scans were acquired at five different echo-times (2, 7, 12, 17, and 22) ms from 15 transplant patients. The developed CAD system first segments kidneys using the level-sets method followed by estimation of the amount of deoxyhemoglobin, also known as apparent relaxation rate (R2*). These R2* estimates were used as discriminatory features (global features (mean R2*) and local features (pixel-wise R2*)) to train and test state-of-the-art machine learning classifiers to differentiate between non-rejection (NR) and acute renal rejection. Using a leave-one-out cross-validation approach along with an artificial neural network (ANN) classifier, the CAD system demonstrated 93.3% accuracy, 100% sensitivity, and 90% specificity in distinguishing AR from non-rejection . These preliminary results demonstrate the efficacy of the CAD system to detect renal allograft status non-invasively.

Identifying the murine mammary cell target of metformin exposure

The heterogeneity of breast cancer makes current therapies challenging. Metformin, the anti-diabetic drug, has shown promising anti-cancer activities in epidemiological studies and breast cancer models. Yet, how metformin alters the normal adult breast tissue remains elusive. We demonstrate metformin intake at a clinically relevant dose impacts the hormone receptor positive (HR+) luminal cells in the normal murine mammary gland. Metformin decreases total cell number, progenitor capacity and specifically reduces DNA damage in normal HR+ luminal cells, decreases oxygen consumption rate and increases cell cycle length of luminal cells. HR+ luminal cells demonstrate the lowest levels of mitochondrial respiration and capacity to handle oxidative stress compared to the other fractions, suggesting their intrinsic susceptibility to long-term metformin exposure. Uncovering HR+ luminal cells in the normal mammary gland as the major cell target of metformin exposure could identify patients that would most benefit from repurposing this anti-diabetic drug for cancer prevention/therapy purposes.

Androgen Receptor Signalling Promotes a Luminal Phenotype in Mammary Epithelial Cells

Androgens influence mammary gland development but the specific role of the androgen receptor (AR) in mammary function is largely unknown. We identified cell subsets that express AR in vivo and determined the effect of AR activation and transgenic AR inhibition on sub-populations of the normal mouse mammary epithelium by flow cytometry and immunohistochemistry. Immunolocalisation of AR with markers of lineage identity was also performed in human breast tissues. AR activation in vivo significantly decreased the proportion of basal cells, and caused an accumulation of cells that expressed a basal cell marker but exhibited morphological features of luminal identity. Conversely, in AR null mice the proportion of basal mammary epithelial cells was significantly increased. Inhibition of AR increased basal but not luminal progenitor cell activity in vitro. A small population of AR-positive cells in a basal-to-luminal phenotype transition was also evident in human breast lobules. Collectively, these data support a role for AR in promoting a luminal phenotype in mammary epithelial cells.

A novel electrochemical analysis of the legal psychoactive drug caffeine using a zeolite/MWCNT modified carbon paste sensor

Caffeine (Caf) is a natural central nervous system stimulant categorized by the US Food and Drug Administration as a safe drug and its maximal amount in soft drinks has been approximately determined to be lower than 200 mg L⁻¹.

Proliferative heterogeneity of murine epithelial cells in the adult mammary gland

Breast cancer is the most common cancer in females. The number of years menstruating and length of an individual menstrual cycle have been implicated in increased breast cancer risk. At present, the proliferative changes within an individual reproductive cycle or variations in the estrous cycle in the normal mammary gland are poorly understood. Here we use Fucci2 reporter mice to demonstrate actively proliferating mammary epithelial cells have shorter G1 lengths, whereas more differentiated/non-proliferating cells have extended G1 lengths. We find that cells enter into the cell cycle mainly during diestrus, yet the expansion is erratic and does not take place every reproductive cycle. Single cell expression analyses feature expected proliferation markers (Birc5, Top2a), while HR+ luminal cells exhibit fluctuations of key differentiation genes (ER, Gata3) during the cell cycle. We highlight the proliferative heterogeneity occurring within the normal mammary gland during a single-estrous cycle, indicating that the mammary gland undergoes continual dynamic proliferative changes.

Synthesis of a simply modified electrochemical nicotine sensor based on silver nanoparticles

An innovative electrochemical nicotine modified sensor was created by chemically mixing a carbon paste with silver nano powder to prepare an Ag nanoparticle modified carbon paste electrode. Different electrochemical techniques including cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy in both aqueous and micellar media were used. The surface morphology was also detected using scanning electron microscope and energy dispersive X-ray analysis techniques. Nicotine measurements were investigated in Britton–Robinson buffer solutions with a pH range of 2.0–8.0 containing 1.0 mmol/L sodium dodecyl sulfate. The electrode-based NIC sensor exhibited a high sensitivity in quantitative analysis, and its detection limit could be as low as 0.0036 μmol/L with linearity ranging from 0.8 μmol/L to 800 μmol/L. In addition, due to its good reproducibility, anti-interference performance, and long-term stability, the proposed sensor is capable of detecting trace levels of nicotine in urine samples and different brands of commercial cigarettes.

Mammary molecular portraits reveal lineage-specific features and progenitor cell vulnerabilities

Casey et al. integrate epigenomic, transcriptomic, and proteomic profiling of primary basal and luminal mammary cells to identify master epigenetic regulators of the mammary epithelium and uncover stem and progenitor cell vulnerabilities. They develop a pipeline to identify drugs that abrogate progenitor cell activity in normal and high-risk breast cancer patient samples in vitro and in vivo.

The mammary epithelium depends on specific lineages and their stem and progenitor function to accommodate hormone-triggered physiological demands in the adult female. Perturbations of these lineages underpin breast cancer risk, yet our understanding of normal mammary cell composition is incomplete. Here, we build a multimodal resource for the adult gland through comprehensive profiling of primary cell epigenomes, transcriptomes, and proteomes. We define systems-level relationships between chromatin–DNA–RNA–protein states, identify lineage-specific DNA methylation of transcription factor binding sites, and pinpoint proteins underlying progesterone responsiveness. Comparative proteomics of estrogen and progesterone receptor–positive and –negative cell populations, extensive target validation, and drug testing lead to discovery of stem and progenitor cell vulnerabilities. Top epigenetic drugs exert cytostatic effects; prevent adult mammary cell expansion, clonogenicity, and mammopoiesis; and deplete stem cell frequency. Select drugs also abrogate human breast progenitor cell activity in normal and high-risk patient samples. This integrative computational and functional study provides fundamental insight into mammary lineage and stem cell biology.

Liposomal Doxorubicin in Breast Cancer

Drug-delivery carriers represent an important step in the development of targeted therapy. Encapsulation of drug into liposomes represents such a carrier, and helps to minimize side effects of conventional doxorubicin by improving the tumor-specific biodistribution profile. We review the development of the two liposomal doxorubicin formulations, pegylated liposomal doxorubicin and liposomal-encapsulated doxorubicin citrate from reconstitution and comparative pharmacokinetics to pivotal Phase III trials, with special emphasis in breast cancer. The relative differences in the toxicity profile can be attributed to their differences in the liposomal formulations. Areas of special interest include the reduction in cardiac toxicities and the improved efficacy, such as in the treatment of ovarian cancer. These improvements have also increased the potential of these liposomal formulations of doxorubicin for combination and sequencing with other biological and cytotoxic agents for clinical benefit.

Stem and progenitor cell division kinetics during postnatal mouse mammary gland development

The cycling properties of mammary stem and progenitor cells is not well understood. To determine the division properties of these cells, we administered synthetic nucleosides for varying periods of time to mice at different stages of postnatal development and monitored the rate of uptake of these nucleosides in the different mammary cell compartments. Here we show that most cell division in the adult virgin gland is restricted to the oestrogen receptor-expressing luminal cell lineage. Our data also demonstrate that the oestrogen receptor-expressing, milk and basal cell subpopulations have telomere lengths and cell division kinetics that are not compatible with these cells being hierarchically organized; instead, our data indicate that in the adult homeostatic gland, each cell type is largely maintained by its own restricted progenitors. We also observe that transplantable stem cells are largely quiescent during oestrus, but are cycling during dioestrus when progesterone levels are high.

Giant haemangioma of the liver with haemangiodudenal fistula: the first reported case in literature

Giant liver haemangiomas are usually asymptomatic with normal liver function, which makes the course long and uneventful. The most commonly reported complications of giant haemangiomas are rupture with intraperitoneal haemorrhage that is either traumatic or non-traumatic, consumption coagulopathy, Budd-Chiari syndrome and congestive heart failure. We describe the first reported complications of a giant liver haemangioma as a fistula between the haemangioma and the gastrointestinal tract.

Combined Single-Cell Functional and Gene Expression Analysis Resolves Heterogeneity within Stem Cell Populations

Heterogeneity within the self-renewal durability of adult hematopoietic stem cells (HSCs) challenges our understanding of the molecular framework underlying HSC function. Gene expression studies have been hampered by the presence of multiple HSC subtypes and contaminating non-HSCs in bulk HSC populations. To gain deeper insight into the gene expression program of murine HSCs, we combined single-cell functional assays with flow cytometric index sorting and single-cell gene expression assays. Through bioinformatic integration of these datasets, we designed an unbiased sorting strategy that separates non-HSCs away from HSCs, and single-cell transplantation experiments using the enriched population were combined with RNA-seq data to identify key molecules that associate with long-term durable self-renewal, producing a single-cell molecular dataset that is linked to functional stem cell activity. Finally, we demonstrated the broader applicability of this approach for linking key molecules with defined cellular functions in another stem cell system.

A novel electrochemical nicotine sensor based on cerium nanoparticles with anionic surfactant

A novel promising electrochemical nicotine (NIC) sensor was prepared by electrodeposition of Ce-Nanoparticles on a carbon paste electrode (CPE).

Cardioprotective effects of intracoronary adenosine in diabetic patients undergoing elective percutaneous coronary intervention

AIM

Myocardial injury commonly occurs during percutaneous coronary intervention (PCI). Several agents that mimic ischemic preconditioning could help minimize this phenomenon. This study evaluated the cardio-protective role of intracoronary Adenosine in elective PCI.

METHODS

A total of 100 diabetic patients with chronic stable angina were prospectively enrolled, then randomly assigned to undergo PCI with intracoronary Adenosine; 100 µg/stented vessel (group-A, 50 patients) or standard PCI (group-B, 50 patients). Cardiac troponin I (cTnI) and creatine kinase-MB (CK-MB) levels were measured before and 6, 12 and 24 hours post-PCI.

RESULTS

Mean age of the study cohort was 57±8 years (males=63%). cTnI level was significantly lower in group-A (6 hours: 7.5±0.2 vs. 15.5±0.5 pg/mL, 12 hours: 13.7±0.7 vs. 25.5±0.6 pg/mL and 24 hours: 7.6±0.5 vs. 16±0.3 pg/mL, P<0.001). After 3 months, the same group showed significantly higher left ventricle ejection fraction (LVEF %), i.e. 64.5±5.7 vs. 56.5±5.3 (P<0.05). There was no statistically significant difference between both groups of patients regarding incidence of major adverse cardiac events (MACE).

CONCLUSION

In diabetic patients undergoing elective PCI, intracoronary Adenosine was associated with decreased incidence of PCI-related myocardial injury & improvement of LVEF% after 3 months.

Mammary stem cells have myoepithelial cell properties

Contractile myoepithelial cells dominate the basal layer of the mammary epithelium and are considered to be differentiated cells. However, we observe that up to 54% of single basal cells can form colonies when seeded into adherent culture in the presence of agents that disrupt actin-myosin interactions, and on average, 65% of the single-cell-derived basal colonies can repopulate a mammary gland when transplanted in vivo. This indicates that a high proportion of basal myoepithelial cells can give rise to a mammary repopulating unit (MRU). We demonstrate that myoepithelial cells, flow-sorted using two independent myoepithelial-specific reporter strategies, have MRU capacity. Using an inducible lineage-tracing approach we follow the progeny of myoepithelial cells that express α-smooth muscle actin and show that they function as long-lived lineage-restricted stem cells in the virgin state and during pregnancy.

The influence of tamoxifen on normal mouse mammary gland homeostasis

INTRODUCTION

Lineage tracing using inducible genetic labeling has emerged to be a powerful method for interrogating the developmental fate of cells in intact tissues. A common induction mechanism is the use of tamoxifen-dependent Cre recombinase (CreER and CreERT2), but the effects of tamoxifen at doses normally used in lineage-tracing studies on normal adult mammary gland homeostasis are not known.

METHODS

We used flow cytometry and immunostaining of intact glands to determine whether varying doses of tamoxifen skew the distribution and the apoptosis and proliferation status of different types of mammary epithelial cells in vivo. We also examined how tamoxifen influences the number of progenitor and mammary repopulating units (MRUs).

RESULTS

Our results indicate that ≥5 mg/25 g body weight of tamoxifen induces a transient increase in cell proliferation and in the number of basal cells in the adult mammary epithelium up to 7 days after tamoxifen administration. However, in the medium term (3 weeks), all doses of tamoxifen≥1 mg/25 g body weight result in a decrease in the number of basal and EpCAM+CD49b- luminal cells and a decrease in progenitor cell function. Tamoxifen at doses≥5 mg/25 g body weight induced a transient increase in caspase-3-mediated apoptotic cell death within the mammary epithelium. However, mammary epithelial cell numbers in all subpopulations were restored to their original levels by 8 weeks. No long-lasting effects of tamoxifen on MRU numbers or on pubertal ductal development were observed.

CONCLUSION

Tamoxifen can skew the distribution of mammary cell types in a dose-dependent manner, and thus caution must be taken when interpreting lineage-tracing studies using high doses of tamoxifen, particularly when short-duration analyses of a quantitative nature are being performed.