Cardiology Commons^™

Transposition Of The Great Arteries With Intramural Left Main Coronary Artery: Salient Imaging Findings And Description Of Two Operative Techniques, Joshua Holbert, Manasa Gadiraju, Sanket Shah, Edo Bedzra

Posters

Background: Transposition of the great arteries (TGA) is a common cyanotic critical congenital heart disease, with a feasible prenatal diagnosis. Arterial switch operation (ASO) with/without VSD closure is the preferred surgical approach with added challenge when an intramural coronary artery (IMC) is present. ASO is technically quite demanding with IMC, and incidence of post-operative complications and mortality are potentially higher. We present our recent TGA-IMC experience focusing on salient features identified on echocardiography, CT and invasive angiograms, as well as variations in ASO surgical techniques for repair. Methods: Our echo imaging acquisition required high frequency transducers and shallow image depth …

Dynamic Prognosis Prediction For Patients On Dapt After Drug-Eluting Stent Implantation: Model Development And Validation, Fang Li, Laila Rasmy, Yang Xiang, Jingna Feng, Ahmed Abdelhameed, Xinyue Hu, Zenan Sun, David Aguilar, Abhijeet Dhoble, Jingcheng Du, Qing Wang, Shuteng Niu, Yifang Dang, Xinyuan Zhang, Ziqian Xie, Yi Nian, Jianping He, Yujia Zhou, Jianfu Li, Mattia Prosperi, Jiang Bian, Degui Zhi, Cui Tao

School of Medicine Faculty Publications

BACKGROUND: The rapid evolution of artificial intelligence (AI) in conjunction with recent updates in dual antiplatelet therapy (DAPT) management guidelines emphasizes the necessity for innovative models to predict ischemic or bleeding events after drug-eluting stent implantation. Leveraging AI for dynamic prediction has the potential to revolutionize risk stratification and provide personalized decision support for DAPT management. METHODS AND RESULTS: We developed and validated a new AI-based pipeline using retrospective data of drug-eluting stent-treated patients, sourced from the Cerner Health Facts data set (n=98 236) and Optum’s de-identified Clinformatics Data Mart Database (n=9978). The 36 months following drug-eluting stent implantation were …

A Case Of Occlusive Myocardial Infarction Caused By Nephrotic Syndrome In A 26-Year-Old Type 1 Diabetic, Kyle Admire, Charlotta Jornlid, Chelsea Ryan, Rebecca Pauly

Marshall Journal of Medicine

Nephrotic syndrome is a rare condition distinguished by proteinuria exceeding 3g per day. Other associated characteristics include hematuria, hypoalbuminemia, edema, and hyperlipidemia. There is an array of complications of this syndrome, which are primarily due to the profound losses of protein in the urine. One such complication is thromboembolism, with most documented cases in the form of venous thromboembolism of the extremities which is in part due to urinary loss of antithrombin III and increased synthesis of prothrombotic factors. There are limited available data regarding arterial thrombi and especially few reports about coronary thromboses, which can be life-threatening. In this …

Management Of Cryptogenic Stroke Secondary To Large Asd With Percutaneous Occluder Device And Antiplatelet Drugs., Riya Gupta, Naveed Iqbal

Marshall Journal of Medicine

Atrial septal defects (ASD) represent the most common congenital heart disease diagnosed in adult population and can present with variable clinical findings. Recent literature emphasizes the importance of management of ASD especially if it is associated with structural right heart changes such as RV dysfunction, right ventricular enlargement, arrythmias or paradoxical embolism.

The decision between medical therapy versus surgical closure of ASD is a common clinical conundrum especially in the setting of cryptogenic stroke.

Ultrasound – An Underutilized Diagnostic Tool For Ventricular Assist Device Driveline Infections, Kristina Krzelj, Tomislav Tokic, Tomislav Kopjar, Maja Cikes, Davor Milicic, Hrvoje Gasparovic

The VAD Journal

Patients with ventricular assist device (VAD) driveline infections (DLI) have reduced quality of life and increased risk of severe complications, such as sepsis, hemorrhagic or ischemic stroke, and wound infections. The management of VAD patients imposes a significant financial burden due to prolonged in-hospital stays, frequent re-admissions, expensive diagnostics, and the need for antibiotic therapy and/or surgical intervention. There is considerable room for improvement in DLI management, particularly in the early detection and treatment stages. Ultrasound, an easily applicable device available in almost every hospital, offers an unrecognized potential for the early detection of DLI. By increasing awareness about the …

Cardiometabolic Health: Actionable Prevention Strategies And New Care Models, Omar Leonards, David Aguilar

School of Medicine Faculty Publications

No abstract provided.

Social And Psychosocial Determinants Of Racial And Ethnic Differences In Cardiovascular Health: The Masala And Mesa Studies, Nilay S. Shah, Xiaoning Huang, Lucia C. Petito, Michael P. Bancks, Alka M. Kanaya, Sameera Talegawkar, Saaniya Farhan, Mercedes R. Carnethon, Donald M. Lloyd-Jones, Norrina B. Allen, Namratha R. Kandula, Sadiya S. Khan

Student Papers, Posters & Projects

BACKGROUND: Social and psychosocial determinants are associated with cardiovascular health (CVH).

OBJECTIVES: To quantify the contributions of social and psychosocial factors to racial/ethnic differences in CVH.

METHODS: In the Multi-Ethnic Study of Atherosclerosis and Mediators of Atherosclerosis in South Asians Living in America cohorts, Kitagawa-Blinder-Oaxaca decomposition quantified the contributions of social and psychosocial factors to differences in mean CVH score (range 0-14) in Black, Chinese, Hispanic, or South Asian compared with White participants.

RESULTS: Among 7,978 adults (mean age 61 [SD 10] years, 52 % female), there were 1,892 Black (mean CVH score for decomposition analysis 7.96 [SD 2.1]), 804 …

Echocardiographic Parameters Associated With Less Reverse Left Ventricular Remodeling After Transcatheter Aortic Valve Implant In Subjects With Prosthesis Patient Mismatch, Andrew C. Peters, Fei Fei Gong, Ashvita Ramesh, Adin Andrei, Madeline Jankowski, Eric Cantey, Vincent Chen, James D. Thomas, James D. Flaherty, S. Christopher Malaisrie, Kameswari Maganti

Division of Cardiology Faculty Papers

BACKGROUND: Transaortic valve implant (TAVI) is the treatment of choice for severe aortic stenosis (AS). Some patients develop prosthesis patient mismatch (PPM) after TAVI. It is challenging to determine which patients are at risk for clinical deterioration.

METHODS: We retrospectively measured echocardiographic parameters of left ventricular (LV) morphology and function, prosthetic aortic valve effective orifice area (iEOA) and hemodynamics in 313 patients before and 1 year after TAVI. Our objective was to compare the change in echocardiographic parameters associated with left ventricular reverse modeling in subjects with and without PPM. Our secondary objective was to evaluate echo parameters associated with …

Health Equity And Policy Considerations For Pediatric And Adult Congenital Heart Disease Care Among Minoritized Populations In The United States., Keila N. Lopez, Kiona Y. Allen, Carissa M. Baker-Smith, Katia Bravo-Jaimes, Joseph Burns, Bianca Cherestal, Jason F. Deen, Brittany K. Hills, Jennifer H. Huang, Ramiro W. Lizano Santamaria, Carlos A. Lodeiro, Valentina Melo, Jasmine S. Moreno, Flora Nuñez Gallegos, Harris Onugha, Tony A. Pastor, Michelle C. Wallace, Deidra A. Ansah

Manuscripts, Articles, Book Chapters and Other Papers

Achieving health equity in populations with congenital heart disease (CHD) requires recognizing existing disparities throughout the lifespan that negatively and disproportionately impact specific groups of individuals. These disparities occur at individual, institutional, or system levels and often result in increased morbidity and mortality for marginalized or racially minoritized populations (population subgroups (e.g., ethnic, racial, social, religious) with differential power compared to those deemed to hold the majority power in the population). Creating actionable strategies and solutions to address these health disparities in patients with CHD requires critically examining multilevel factors and health policies that continue to drive health inequities, including …

Post-Capillary Pulmonary Hypertension: Clinical Review, Joshua Riley, James Fradin, Douglas Russ, Eric Warner, Yevgeniy Brailovsky, Indranee Rajapreyar

Department of Medicine Faculty Papers

Pulmonary hypertension (PH) caused by left heart disease, also known as post-capillary PH, is the most common etiology of PH. Left heart disease due to systolic dysfunction or heart failure with preserved ejection fraction, valvular heart disease, and left atrial myopathy due to atrial fibrillation are causes of post-capillary PH. Elevated left-sided filling pressures cause pulmonary venous congestion due to backward transmission of pressures and post-capillary PH. In advanced left-sided heart disease or valvular heart disease, chronic uncontrolled venous congestion may lead to remodeling of the pulmonary arterial system, causing combined pre-capillary and post-capillary PH. The hemodynamic definition of post-capillary …

Retrograde Type A　Acute Aortic Dissection With Cerebral Malperfusion Six Years After Thoracic Endovascular Aortic Repair, Hideki Sasaki, Yukihide Numata, Shinji Kamiya, Yoshiaki Sone, Miki Asano

Journal of the Saudi Heart Association

A 59-year-old male with prior thoracic endovascular aortic repair presented with altered mental status. Magnetic resonance imaging showed cerebral infarction, and subsequent computed tomography revealed acute type A aortic dissection and right carotid artery occlusion. He underwent total arch replacement with right carotid artery bypass. After successful intervention, he was transferred to a rehabilitation facility for further improvement.

Systolic Pulmonary Artery Pressure Thresholds Predictive Of Dyspnea On Stress Doppler Echocardiography In Mitral Stenosis, Saléha Lehachi, Fadila Daimellah, Saida Khelil, Zakia Bennoui, Djohar Hannoun, Youcef Laid, Rachid Mechmeche, Mohand Said Issad

Journal of the Saudi Heart Association

Background. On Stress Doppler Echocardiography (SDE) in mitral stenosis, the systolic pulmonary artery pressure (SPAP) threshold at peak exercise recommended by the guidelines as an indication for percutaneous mitral commissurotomy (PMC) used to be 60 mmHg. However, because of the paucity of studies, that threshold has been controversial. The Europeans stopped using the value in 2007, followed by the Americans in 2014.

Objective. Determine SPAP thresholds on SDE at peak exercise and post-exercise predictive of dyspnea as an indication for PMC in mitral stenosis.

Method and results. Three hundred mitral stenosis patients with a mitral valve area (MVA) ≤ 2 …

Common Heart Failure With Preserved Ejection Fraction Animal Models Yield Disparate Myofibril Mechanics, Axel J. Fenwick, Vivek P. Jani, D. Brian Foster, Thomas E. Sharp, Traci T. Goodchild, Kyle Lapenna, Jake E. Doiron, David J. Lefer, Joseph A. Hill, David A. Kass, Anthony Cammarato

School of Medicine Faculty Publications

No abstract provided.

Characteristics Of Patients Undergoing Electrophysiologic Procedures In A Tertiary Hospital In Saudi Arabia, Abdullah A. Aljammaz, Meshaal K. Alghanim, Ibraheem Altamimi, Mohammed A. Alshwieer, Albaraa Sabbagh, Abdulrahman S. Alsayed, Faisal G. Al-Zahrani, Mohammad F. Almanjomi, Sameer Qutub, Wael A. Alqarawi

Journal of the Saudi Heart Association

Introduction: The electrophysiology field has progressed rapidly over the last 2 decades. No study has examined the characteristics of patients and types of electrophysiology procedures performed in the Kingdom of Saudi Arabia. This is important given our distinctly different demographic composition and health system. As such, we sought to describe the characteristics of consecutive patients presenting for electrophysiology procedures in our tertiary care hospital.

Methods: Data was collected from the electrophysiology database at King Khalid University Hospital for procedures performed between April 2016 and November 2022. Patients’ characteristics were retrieved from the electronic medical record. Procedures were categorized into supraventricular …

Epidemiological, Bacteriological, And Evolutive Features Of Children Hospitalized For Infective Endocarditis In A Tertiary Tunisian Pediatric Department, Houda Ajmi, Rahma Herch, Hela Elghali, Dalel Ben Sliman, Mohamed Ben Rejeb, Sameh Mabrouk, Fadoua Majdoub, Salsabil Nouir, Lamia Tilouche, Abdelhalim Trabelsi, Saoussan Abroug, Jalel Chemli

Journal of the Saudi Heart Association

Background: Infective endocarditis is a rare condition in childhood, and there is limited data on this disease in Tunisia.

Objective: This study aims to analyze the epidemiological profile, bacteriological data, and prognosis of infective endocarditis in children admitted to the pediatric department of a University Hospital in Tunisia.

Methods: We conducted a comparative cross-sectional study in the pediatric department of Sahloul Teaching Hospital in Sousse, a tertiary referral hospital in Tunisia. The study included all children aged ≤ 18 years with infective endocarditis admitted to the tertiary referral center for pediatrics in Sahloul University Hospital from January 1994 to December …

Prediction Of Major Adverse Cardiac Events In The Emergency Department Using An Artificial Neural Network With A Systematic Grid Search, Ahmed Raheem Buksh, Nadeem Ullah Khan, Rida Jawed, Shahan Waheed, Musa Karim

Department of Emergency Medicine

Background: The aim of our research was to design and evaluate an Artificial Neural Network (ANN) model using a systemic grid search for the early prediction of major adverse cardiac events (MACE) among patients presenting to the triage of an emergency department.
Methods: This is a single-center, cross-sectional study using electronic health records from January 2017 to December 2020. The research population consists of adults coming to our emergency department triage at Aga Khan University Hospital. The MACE during hospitalization was the main outcome. To enhance the architecture of an ANN using triage data, we used a systematic grid search …

Effects Of Menopause On Coronary Artery Disease, Angelica Gonzales

Nursing | Senior Theses

Menopausal women, 40 to 60 years old, have an increased risk of developing coronary artery disease (CAD) when they experience hormonal changes. Which then can lead to unwanted cardiac events. Within the literature review of this paper, it was found that there are factors of menopause that may further increase the risk of coronary artery disease in menopausal women. Such factors include whether a woman underwent surgical or natural menopause and the timing when menopause began. Additionally, within the review, hormone replacement therapy (HRT) was explored to determine whether the possible intervention can decrease the progression and risk of developing …

A Retrospective Study On The Effect Of Raas Pathway Inhibitors At Decreasing The Risk Of Acute Coronary Syndrome In Hypertensive Patients With Rheumatoid Arthritis As Compared To Other Antihypertensives, Yousuf Sherwani, Asad Risvi, Senthil Thambidorai

North Texas Research Forum 2024

Rheumatoid arthritis (RA) is a chronic multi-system inflammatory disease of which is characterized by articular and extra-articular involvement. Patients with RA have a higher risk of mortality when compared with the general population, which is due predominantly to increased cardiovascular disease. Due to the higher incidence of CVD and MI in RA patients it has been postulated that enhanced systemic inflammation plays an important role in the pathogenesis of CVD in RA patients. Previous studies have shown that ant inflammatory medication such as systemic steroids and immune blockers have been shown to decrease the risk of MI in patients with …

End-Of-Life Care For Patients With End-Stage Heart Failure, Comparisons Of International Guidelines, Frederick Berro Rivera, Sarang Choi, Genquen Philip Carado, Arcel V. Adizas, Nathan Ross B. Bantayan, Gerard Jude P. Loyola, Sung Whoy Cha, John Paul Aparece, Anlene Jane B. Rocha, Siena Placino, Marie Francesca M. Ansay, Gerard Francis E. Mangubat, Mer Lorraine P. Mahilum, Abdullah Al-Abcha, Natasha Suleman, Nishant Shah, Tisha Marie B. Suboc, Annabelle Santos Volgman

Ateneo School of Medicine and Public Health Publications

Heart failure (HF) is a chronic, debilitating condition associated with significant morbidity, mortality, and socioeconomic burden. Patients with end-stage HF (ESHF) who are not a candidate for advanced therapies will continue to progress despite standard medical therapy. Thus, the focus of care shifts from prolonging life to controlling symptoms and improving quality of life through palliative care (PC). Because the condition and prognosis of HF patients evolve and can rapidly deteriorate, it is imperative to begin the discussion on end-of-life (EOL) issues early during HF management. These include the completion of an advance directive, do-not-resuscitate orders, and policies on device …

A Dramatic Case Of Acute Biventricular Failure Secondary To Acute Myocardial Infraction, Heriberto Cantu, Ahmed Mahmood, Luay Alalawi, Thomas Alexander

Gulf Coast Division Research Day 2024

No abstract provided.

Mcs Assisted High Risk Multi-Vessel Percutaneous Intervention In Cardiogenic Shock Patient With Lv Thrombus, Amanpreet Kaur, Akhil Gade, Srinivasan Rajaganapathy, Ruben Abreu, Victor Delprincipe

North Texas Research Forum 2024

Background: Acute coronary syndrome patients presenting with Cardiogenic shock carry a very high mortality risk >70% without appropriate intervention in a timely fashion. Here we present a patient requiring an axial pump mechanical circulatory support despite having an apical thrombus. Case report: 55-year-old male with past medical history of type 2 diabetes mellitus and medication noncompliance was transferred from outside facility for high risk ACS with EKG showing ST segment elevation in inferior and anterolateral leads. Lab showed hsTroponin more than 125K, BG 556, HCO3 17, and Beta hydroxybutyrate of 41.87 indicating DKA. Emergent coronary angiography showed mid LAD artery …

Reducing Food Scarcity: The Benefits Of Urban Farming, S.A. Claudell, Emilio Mejia

Journal of Nonprofit Innovation

Urban farming can enhance the lives of communities and help reduce food scarcity. This paper presents a conceptual prototype of an efficient urban farming community that can be scaled for a single apartment building or an entire community across all global geoeconomics regions, including densely populated cities and rural, developing towns and communities. When deployed in coordination with smart crop choices, local farm support, and efficient transportation then the result isn’t just sustainability, but also increasing fresh produce accessibility, optimizing nutritional value, eliminating the use of ‘forever chemicals’, reducing transportation costs, and fostering global environmental benefits.

Imagine Doris, who is …

Lazarus Syndrome After Aortic Aneurysm Repair, Kevyn Niu, Jamie Lee Aldakkour, Charles Huyghues-Despointes, Yizhi Lin

HCA Healthcare Journal of Medicine

Introduction

Lazarus syndrome is defined as the spontaneous return of circulation after cessation of cardiopulmonary resuscitation (CPR). Though there have been multiple cases of Lazarus syndrome documented in the literature, it is a significantly underreported phenomenon with less than 100 cases reported in the literature since the first case in 1982.

Case Presentation

After elective aortic aneurysm repair, an 88-year-old with a do-not-resuscitate directive had cardiac arrest, briefly showing post-mortem respiration and pulse. Despite resuscitation efforts including pharmacological intervention and CPR, he passed away within an hour. This case highlights complexities in end-of-life care and warrants exploration of post-mortem physiological …

Maternal Western Diet Programs Cardiometabolic Dysfunction And Hypothalamic Inflammation Via Epigenetic Mechanisms Predominantly In The Male Offspring, Mona Elgazzaz, Clara Berdasco, Jone Garai, Melody Baddoo, Shiping Lu, Hisham Daoud, Jovanny Zabaleta, Franck Mauvais-Jarvis, Eric Lazartigues

School of Medicine Faculty Publications

Objective; Maternal exposure during pregnancy is a strong determinant of offspring health outcomes. Such exposure induces changes in the offspring epigenome resulting in gene expression and functional changes. In this study, we investigated the effect of maternal Western hypercaloric diet (HCD) programming during the perinatal period on neuronal plasticity and cardiometabolic health in adult offspring. Methods; C57BL/6J dams were fed HCD for 1 month prior to mating with regular diet (RD) sires and kept on the same diet throughout pregnancy and lactation. At weaning, offspring were maintained on either HCD or RD for 3 months resulting in 4 treatment groups …

Social Determinants Of Health And Disparities In Hypertension And Cardiovascular Diseases, Abhishek Chaturvedi, Anqi Zhu, Naga Vaishnav Gadela, Dorairaj Prabhakaran, Tazeen Jafar

Department of Medicine

High blood pressure causes over 10 million preventable deaths annually globally. Populations in low- and middle-income countries suffer the most, experiencing increased uncontrolled blood pressure and cardiovascular disease (CVD) deaths. Despite improvements in high-income countries, disparities persist, notably in the United States, where Black individuals face up to 4× higher CVD mortality than White individuals. Social determinants of health encompass complex, multidimensional factors linked to an individual's birthplace, upbringing, activities, residence, workplaces, socioeconomic and environmental structures, and significantly affect health outcomes, including hypertension and CVD. This review explored how social determinants of health drive disparities in hypertension and related CVD …

Effect Of Flecainide And Ibutilide Alone And In Combination To Terminate And Prevent Recurrence Of Atrial Fibrillation, Alexander Burashnikov, José M. Di Diego, Bence Patocskai, Debra S. Echt, Luiz Belardinelli, Charles Antzelevitch

Division of Cardiology Faculty Papers

BACKGROUND: There is a need for improved approaches to rhythm control therapy of atrial fibrillation (AF).

METHODS: The effectiveness of flecainide (1.5 µmol/L) and ibutilide (20 nmol/L), alone and in combination, to cardiovert and prevent AF recurrence was studied in canine-isolated coronary-perfused right atrioventricular preparations. We also examined the safety of the combination of flecainide (1.5 µmol/L) and ibutilide (50 nmol/L) using canine left ventricular wedge preparations.

RESULTS: Sustained AF (>1 hour) was inducible in 100%, 60%, 20%, and 0% of atria in the presence of acetylcholine alone, acetylcholine+ibutilide, acetylcholine+flecainide, and acetylcholine+ibutilide+flecainide, respectively. When used alone, flecainide and ibutilide …

Point-Of-Care Ultrasound For The Diagnosis Of Frequent Cardiovascular Diseases: A Review, Ernesto Calderon Martinez, Edna Diarte, Diana Othon, Leonardo Rodriguez Reyes, Daniel A. Aguirre Cano, Carolina Cantu Navarro, Maria G. Ycaza, David Arriaga Escamilla, Jinal Choudhari, George Michel

School of Medicine Publications and Presentations

Point-of-care ultrasound (POCUS) has emerged as an indispensable diagnostic tool in cardiology, particularly within the emergency department. This narrative synthesis provides a comprehensive exploration of POCUS applications in cardiovascular diseases, elucidating its multifaceted roles and addressing challenges. The review delves into the technical attributes of POCUS, emphasizing its noninvasive nature, radiation-free qualities, and suitability for non-radiologists. It navigates through educational strategies, stressing the importance of structured programs for the seamless integration of POCUS into clinical practice. Highlighting its efficacy, the synthesis discusses POCUS applications in various scenarios such as dyspnea, chest pain, cardiac arrest, aortic dissection, pericardial effusion, and pulmonary …

Rare Presentation Of Postpericardiotomy Syndrome After Left Atrial Myxoma Removal, Jessy Feng, Shyama Appareddy, Yaman Gibran, Aryana Garza, Jacqueline Luevano, Gustavo Garcia

School of Medicine Publications and Presentations

Postpericardiotomy syndrome (PPS) is a known complication of cardiac valve surgery, but it has not been commonly reported as a postoperative complication of cardiac myxoma removal. A 78-year-old female with hypertension and atrial fibrillation presenting with angina was found to have a large left atrial myxoma (7.5 cm × 4.4 cm). The myxoma was resected; however, 1-week postoperation hemoglobin and blood pressure decreased with elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). Limited transthoracic echocardiogram (TTE) showed moderate pericardial effusion, confirming the diagnosis of PPS. This case highlights the importance of monitoring patients postremoval of myxoma for symptoms of …

Shorter Duration Of Dual Antiplatelet Therapy Following Second Generation Drug Eluting Stent Placement, Alexandra Coy, Caitlyn M. Murtha

Physician Assistant Capstones, 2020-current

Heart disease is the leading cause of death in both men and women in The United States. Because advanced heart disease is often treated with percutaneous coronary intervention (PCI) for stent implantation, many patients will be put on dual antiplatelet therapy to prevent adverse effects such as stent thrombosis or restenosis. The purpose of this literature review is to determine if the development of second-generation drug eluting stents allows for a shorter, 6-month, duration of dual antiplatelet therapy (DAPT) versus the currently recommended 12 months. The articles discussed in this review were obtained on PubMed and narrowed using search terms …

In Memoriam: Prof. Dr. Rer. Nat. Jeanette Erdmann, Pashmina Wiqar Shah, Satwat Hashmi, Tobias Reinberger, Nadine Odenthal, Luis Eichelmann, Daria Kosenko, Ilyas Ahmad, Jaafar Al-Hasani, Till Joscha Demal, Zouhair Aherrahrou

Department of Biological & Biomedical Sciences

No abstract provided.