The role of shear viscosity as a biomarker for improving chronic kidney disease detection using shear wave elastography: A computational study using a validated finite element model.

The application of ultrasound shear wave elastography for detecting chronic kidney disease, namely renal fibrosis, has been widely studied. A good correlation between tissue Young's modulus and the degree of renal impairment has been established. However, the current limitation of this imaging modality pertains to the linear elastic assumption used in quantifying the stiffness of renal tissue in commercial shear wave elastography systems. As such, when underlying medical conditions such as acquired cystic kidney disease, which may potentially influence the viscous component of renal tissue, is present concurrently with renal fibrosis, the accuracy of the imaging modality in detecting chronic kidney disease may be affected. The findings in this study demonstrate that quantifying the stiffness of linear viscoelastic tissue using an approach similar to those implemented in commercial shear wave elastography systems led to percentage errors as high as 87%. The findings presented indicate that use of shear viscosity to detect changes in renal impairment led to a reduction in percentage error to values as low as 0.3%. For cases in which renal tissue was affected by multiple medical conditions, shear viscosity was found to be a good indicator in gauging the reliability of the Young's modulus (quantified through a shear wave dispersion analysis) in detecting chronic kidney disease. The findings show that percentage error in stiffness quantification can be reduced to as low as 0.6%. The present study demonstrates the potential use of renal shear viscosity as a biomarker to improve the detection of chronic kidney disease.

The strategic uses of collagen in adherent cell cultures.

The culture of adherent mammalian cells involves adhesion to the tissue culture vessel. This requires attachment factors from serum and/or a suitable substrate on the vessel surface. Some cells require collagen or other substrates to promote neurite outgrowth, differentiation or growth. However, laboratories often lack guidance on the selection and/or optimisation of collagen. We model such selection/optimisation work in the PC12 neuronal cell line. PC12 (NS-1 variant) cells require a substrate for adherence. Comparing cell attachment against a series of substrates, we found collagen IV to be optimal. We show by comparison of morphology against a range of concentrations that 10 µg/ml is sufficient for supporting cell attachment, and also differentiation. PC12 cells from Riken Cell Bank do not require a substrate for routine culturing but only for differentiation. As all substrates supported attachment equally well, we used a novel serum-free approach and identified collagen IV as its preferred substrate. For these cells, Dulbecco's modified eagle's medium but not Roswell Park Memorial Institute (RPMI) media supports normal cell attachment. However, coating with collagen IV enabled the cells to grow equally well in RPMI. Hence the strategic use of collagen is essential in laboratories working with anchorage-dependent cell lines.

Phytochemicals from Calophyllum canum Hook f. ex T. Anderson and their neuroprotective effects.

Previous phytochemical investigations reported that Calophyllum spp have biosynthesized a wide range of bioactive phenolics such as xanthones and coumarins. The phytochemical study conducted on the stem bark of C. canum has led to the isolation of eight trioxygenated xanthones namely: 5-methoxytrapezifolixanthone (1), 5-methoxyananixanthone (2), caloxanthone C (3), 1,5-dihydroxy-3-methoxy-4-isoprenylxanthone (4), 6-deoxyisojacareubin (5), euxanthone (6), trapezifolixanthone (7), ananixanthone (8), together with three common triterpenoids, ß-sitosterol (9), friedelin (10), and stigmasterol (11). Furthermore, xanthones 1 and 2 were isolated for the first time as naturally occurring xanthones from the plant extract. The structures of these compounds were identified and elucidated using advanced spectroscopic techniques such as 1 D & 2 D NMR, MS, and FTIR. The neuroprotective property of selected compounds was tested through in vitro stroke model. Among all tested compounds, 1 µm of compounds 8, 9, and 10 showed significant neuroprotective activity via reduction of apoptosis by ∼ 50%.

Problem Based Learning in Medical Education: Handling Objections and Sustainable Implementation.

The introduction of problem-based learning (PBL) in 1969 is considered the greatest innovation in medical education of the past 50 years. Since then, PBL has been implemented in different educational settings across virtually all health professions. However, some PBL schools gradually faced resistance from academic staff who were more familiar with traditional teacher-centred curricula. At times this has resulted in reversion to tradition or compromise whereby PBL is implemented within a lecture-based curriculum. Resistance can also emerge in a traditional school when a PBL curriculum is being considered for implementation. One of the first signs of this erosion is doubts about PBL raised in the form of objections or criticisms. This perspective review describes eight objections raised to assert why PBL is inferior or untenable. The background to each objection is provided together with evidence-informed rebuttals derived from professional practice and the published literature. Best practices are discussed for sustainable management of a PBL-based curriculum. A well-implemented PBL curriculum with appropriate and cost-effective infrastructure, training, teaching-learning activities, and assessment will position schools to harness the full benefit of PBL in training medical and health professionals.

A Case of Bilateral Infected Kidney Stones Presenting With Septic Shock and Acute Kidney Injury.

The incidence of unilateral ureteral calculi has been reported at 20% in the literature; however, cases of bilateral kidney stones are not commonly reported in the urology, nephrology, and emergency medicine literature. Here, we present the case of a 31-year-old female who presented to the emergency department with septic shock and acute kidney injury. Acute kidney injury was initially thought to be prerenal secondary to septic shock but later found to have complete bilateral ureteral obstruction as a cause of septic shock and acute kidney injury. Urinary tract infection and sepsis secondary to bilateral obstructing ureteral stones are some of the few true urological emergencies. Anuria is the common presenting feature of complete urinary tract obstruction, and physicians should have a high index of suspicion for this diagnosis in anuric patients as rare as it is.

A Case of E-cigarette or Vaping Product Use-Associated Lung Injury Mimicking Miliary Tuberculosis.

E-cigarette usage or vaping is becoming more popular as an alternative option to cigarette smoking. Vaping is associated with a wide degree of pulmonary injuries such as asthma, chronic obstructive pulmonary disease or E-cigarette or vaping product use-associated lung injury (EVALI). E-cigarette or vaping product use-associated lung injury is an acute or subacute respiratory illness that can be severe and life-threatening. Miliary tuberculosis, on the other hand, is a rare form of tuberculosis that results from hematogenous dissemination of Mycobacterium tuberculosis, affecting multiple organs and systems. It is characterized by the presence of small, firm white nodules resembling millet seeds. We report a case of a young patient presenting to the hospital with features suggestive of miliary tuberculosis in the CT scan of the chest. Diagnosis of EVALI was reached after extensive diagnostic workup including tuberculosis revealed negative.

A Case of Intracardiac Thrombus in a Recovery Coronavirus Disease 2019 (COVID-19) Patient.

Coronavirus disease 2019 (COVID-19) was thought to mainly affect the respiratory system. However, studies have shown that it can be associated with hypercoagulability leading to thromboembolism. Although venous thromboembolism is a common complication associated with COVID-19, arterial thrombosis and intracardiac thrombosis are not frequently described. We herein report a case of a 54-year-old male with a past medical history of end-stage renal disease, diabetes mellitus, hypertension, heart failure, chronic obstructive pulmonary disease who presented to the emergency department with shortness of breath and was found to have intracardiac thrombus in post-recovery COVID-19 state.

A Case of Postpartum Pulmonary Edema Induced by Oxytocin.

Postpartum dyspnea can be due to many causes, such as pulmonary embolism, amniotic fluid embolism, peripartum cardiomyopathy, but less frequently due to acute pulmonary edema. The incidence of acute pulmonary edema during pregnancy and in the postpartum period has been estimated to be around 0.08%. About half of the cases are attributed to tocolytic therapy. Herein, we present a case of a young woman presenting with acute hypoxia after induction of labor with oxytocin and found to have acute pulmonary edema. This case aims to illustrate and add to a growing body of literature regarding oxytocin-induced acute pulmonary edema and highlights the importance of recognizing the rare complication of oxytocin and necessary interventions to avoid complications. Oxytocin-induced pulmonary edema is a relatively uncommon condition, but physicians should have a high index of suspicion to initiate timely intervention and to avoid fetal complications.

Corticosteroid Management of Coronavirus 2019 (COVID-19) in Patients with Bilateral Adrenalectomy.

Since the World Health Organization (WHO) announced coronavirus 2019 (COVID-19) as a pandemic in March 2020, it has been wreaking havoc across countries, affecting people's lives. Corticosteroids have proven to provide a mortality benefit in patients with COVID-19. Although dexamethasone is the most commonly used glucocorticoid and have shown to have mortality benefit in COVID-19 patients, it cannot be used in patients with adrenal insufficiency due to its lack of mineralocorticoid activity. Herein, we discuss a case of challenging corticosteroid management in a patient with COVID-19 complicated by her medical history of bilateral adrenalectomy.

Unusual Case of Ischemic Colitis Caused by Low-Dose Sumatriptan Therapy in a Generally Healthy Patient After Strenuous Physical Activity.

Ischemic colitis refers to an inflammatory condition of the large bowel caused by ischemia. It usually presents with an acute onset abdominal pain followed by hematochezia. It can occur as a result of arterial occlusion (embolic or thrombotic), venous thrombosis, or hypoperfusion of mesenteric circulation secondary to dehydration, surgery, or medications. Herein, we present an unusual case of sumatriptan-induced ischemic colitis. Sumatriptan succinate is a selective serotonin (5-hydroxytryptamine-1) receptor agonist that is usually prescribed for refractory migraine headaches. This is a 59-year-old female who presented with acute onset abdominal pain followed by bloody diarrhea after vigorous physical activities. She has a past medical history of non-specific colitis (one time, 15 years ago) and chronic migraine for which she was on low-dose sumatriptan therapy (one tab once or twice a week). On the day of the event, the patient took sumatriptan in the morning and had strenuous activities throughout the day, and overnight she developed abdominal pain. It was followed by bouts of bloody diarrhea. The colonoscopy revealed erythematous mucosa with significant ulceration and necrosis involving the distal transverse colon, splenic flexure, descending colon, and proximal colon, suggestive of ischemic colitis. Unlike previously reported cases, this patient was only on low-dose sumatriptan therapy without frequent dosing. So, her risk of ischemic colitis from triptan therapy could have been accelerated by excessive sweating and strenuous physical activities. The patient was treated with intravenous hydration, bowel rest, intravenous antibiotics, and withdrawal of sumatriptan and her condition improved within the next two to three days.

A Difficult and Rare Case of Warfarin Refractory Antiphospholipid Syndrome Presenting With Catastrophic Antiphospholipid Syndrome Complicated by Gastrointestinal Bleeding.

Antiphospholipid syndrome (APS) is managed with warfarin for secondary prophylaxis in patients who have had a thrombotic event in the past. Warfarin has been deemed superior to novel oral anticoagulants in preventing venous and arterial thrombosis in conjunction with aspirin. The catastrophic variant of APS (CAPS) is very rarely reported, especially in those who have been on a therapeutic dose of warfarin therapy. We present a rare case of CAPS in a patient with a history of APS who had been on a therapeutic dose of warfarin along with aspirin therapy. The patient is a 70-year-old male with APS diagnosed 30 years prior when he presented with a pulmonary embolism; aspirin was added to warfarin two years ago when he had a cerebrovascular accident (CVA). He presented to the hospital with acute onset right-sided weakness and aphasia, left lower extremity pain. He had ischemic CVA, acute deep vein thrombosis (DVT), acute renal failure with a creatinine of 2.8, anemia with hemoglobin of 3.8, gastrointestinal bleed (GIB) on EGD, with INR of 3.48 cardiolipin IgM of >140g/L. He was transfused packed red blood cells, fresh frozen plasma, and provided Vit K. Subsequently, he had a cardiac arrest and was intubated and placed on a mechanical ventilator. Given simultaneous multiorgan involvement, acute arterial and venous thrombosis, the patient was diagnosed with CAPS. The patient was started on high-dose dexamethasone, intravenous immunoglobulin (IVIG), and underwent plasma exchange with significant improvement in symptoms, laboratory parameters; and was extubated with near normalization of his speech and motor deficits. He was discharged on enoxaparin and prednisone with sustained clinical improvement two months following discharge. This patient was on the recommended treatment for APS. However, he had presented with a CAPS. This is the first reported case of warfarin refractory CAPS. This case highlights that there might be a subgroup of the population in whom warfarin is not an effective form of treatment modality for an unknown cause, and in fact, it could potently expose a patient to the adverse events related to warfarin therapy as it did in our patient who had significant GIB. This case also highlights the uncommon scenario of spontaneous CAPS with no inciting event as previously reported in the literature, such as infection, recent surgeries, or trauma.

Atypical Presentation of Descending Aortic Dissection in an Acute Heart Failure Patient.

Aortic dissection is relatively uncommon, but often presents with acute severe chest or back pain and acute hemodynamic compromise and is associated with high mortality. We present a case of aortic dissection with an atypical presentation in a heart failure patient and the challenges encountered to make the diagnosis. The patient was a 54-year-old African American female who presented with progressively worsening exertional dyspnea and orthopnea for three days and sensation of indigestion and bloating. The patient denied any recent history of chest pain and she was initially admitted for heart failure exacerbation. Her admission chest x-ray showed severe cardiomegaly with a prominence of pulmonary vascular but there was a borderline widening of mediastinum measuring 8.2 cm. Physical exam showed unequal dorsalis pedis pulses (fainter on the right side) and systolic blood pressure difference of more than 20 mmHg between bilateral upper extremities. Computed tomography angiography (CTA) of chest, abdomen, and pelvis confirmed the diagnosis of dissection of thoracic and abdominal aorta extending from the left subclavian artery to the femoral artery. The patient was managed with labetalol drip and later transferred to a tertiary center for an elevated level of care where the endovascular intervention was performed. The patient then followed up with a vascular clinic for serial CTA and heart failure clinic for optimization of core measures. In conclusion, this case highlights the importance of clinical suspicion of aortic dissection and discusses the various clinical presentations of aortic dissection and its management. Being a highly fatal condition, prompt diagnosis is extremely important and is often life-saving. Therefore, it is important for physicians to be aware of atypical presentations of aortic dissection to initiate timely interventions to avoid catastrophic complications.

A Rare Case of Takotsubo Cardiomyopathy in a Patient With No Identifiable Emotional or Physical Stressors.

Takotsubo cardiomyopathy (TCM) is a cardiac condition that presents with features of acute myocardial infarction and transient systolic dysfunction without angiographic findings of obstructive coronary heart disease. Common presenting symptoms include acute substernal chest pain, dyspnea and syncope. It is usually triggered by recent emotional or physical stress such as head trauma, stroke, sepsis, overproduction of catecholamines such as pheochromocytoma or following Myasthenia crisis. We are here to report a case of TCM who does not have any identifiable emotional or physical stress prior to the event. The patient was a 76-year-old Caucasian female with a past medical history of hypertension who presented to the hospital with chest pain which initially was treated as non-ST elevation myocardial infarction (NSTEMI) with aspirin, ticagrelor and heparin infusion. Cardiac catheterization later revealed non-obstructive coronary artery disease but showed akinesis of inferior, apical and anterior walls with hyperdynamic basal segments indicating TCM.

A Case of Medullary Infarct Causing Central Alveolar Hypoventilation.

Central alveolar hypoventilation (CAH) is a rarely encountered pathology characterized by decreased ventilation due to the loss of autonomic control. Most cases present at birth, as it can be a rare genetic disorder, but we aim to show that it can occur as an acquired condition too. We present a case of a 65-year-old man who developed CAH as a sequela of an ischemic stroke and discuss possible pathophysiology. Increasing awareness and an early detection of this condition can have a significant effect on morbidity and mortality of patients.

Diagnostic Challenges of Pneumocystis Pneumonia during the COVID-19 Pandemic: A Case of a Young Patient with Ground Glass Opacities and Pulmonary Embolism on Chest CT.

The coronavirus disease 2019 (COVID-19) pandemic is wreaking havoc across the globe. This pandemic has given rise to a mindset where physicians tend to neglect other causes of pneumonia, especially if the patient presents with signs and symptoms commonly associated with COVID-19. Herein, we report a case of a young man presenting to the emergency department with common clinical, radiological, and laboratory features of COVID-19 pneumonia such as shortness of breath, hypoxia, pulmonary embolism, elevated D-dimer, and bilateral ground glass opacities on computed tomography of the chest but was later diagnosed with Pneumocystis pneumonia that was treated with appropriate antibiotics and corticosteroids. This case highlights the importance of performing a thorough clinical history and differentiating the clinical and radiological features of COVID-19 pneumonia from pneumonia of other etiologies.

Corrected QT Interval Prolongation, Elevated Troponin, and Mortality in Hospitalized COVID-19 Patients.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has risen to the level of a global pandemic. Growing evidence has proven the cardiac involvement in SARS-CoV-2 infection. This study aims to evaluate the ability of cardiovascular complications determined by elevated troponin and electrocardiogram findings (e.g., corrected QT interval (QTc)) in predicting the severity of SARS-CoV-2 infection among hospitalized patients. METHODS: This is a retrospective review of medical records of 800 patients, admitted to Richmond University Medical Center in Staten Island, NY, and tested positive for SARS-CoV-2 between March 1, 2020 and July 31, 2020. A total of 339 patients met the study inclusion and exclusion criteria and were included in statistical analysis. RESULTS: Elevated serum troponin levels on admission statistically correlated with mortality in SARS-CoV-2 patients. Prolonged QTc was shown to have an independent statistically significant association with mortality among patients hospitalized with SARS-CoV-2. CONCLUSIONS: Growing concern for cardiovascular sequelae of coronavirus disease 2019 (COVID-19) has prompted many researchers to investigate the role of cardiovascular complications in mortality due to SARS-CoV-2. Obtaining a simple electrocardiogram for hospitalized patients with COVID-19 could provide an independent prognostic tool and prompt more coordinated treatment strategies to prevent mortality among patients hospitalized with COVID-19.

Shear Wave Elastography: A Review on the Confounding Factors and Their Potential Mitigation in Detecting Chronic Kidney Disease.

Early detection of chronic kidney disease is important to prevent progression of irreversible kidney damage, reducing the need for renal transplantation. Shear wave elastography is ideal as a quantitative imaging modality to detect chronic kidney disease because of its non-invasive nature, low cost and portability, making it highly accessible. However, the complexity of the kidney architecture and its tissue properties give rise to various confounding factors that affect the reliability of shear wave elastography in detecting chronic kidney disease, thus limiting its application to clinical trials. The objective of this review is to highlight the confounding factors presented by the complex properties of the kidney, in addition to outlining potential mitigation strategies, along with the prospect of increasing the versatility and reliability of shear wave elastography in detecting chronic kidney disease.

A Case of Three-Vessel Coronary Artery Disease Associated With Marijuana Use.

Marijuana is one of the most popular psychotropic drugs among adolescents and young adults. With the recent surge in marijuana use across the United States, it is very important for physicians to understand the clinical implications associated with marijuana use. In this case report, we discuss a case of a young adult who presented to the emergency department with chest pain and was found to have three-vessel coronary artery disease (CAD). The patient did not have any significant past medical history or family history of cardiac diseases but reported a significant history of marijuana use. This case report aims to add to the growing area of research on the association between myocardial infarction (MI) and marijuana use.

Neurocysticercosis Presenting With a New-Onset Seizure: A Case Report.

Neurocysticercosis (NCC) is a common infection that is found worldwide but is often neglected in the United States (US). This case report aims to illustrate the presentation of the disease, provide information on this globally prevalent pathogen, and shed light on the diagnostic workup and treatment of the infection. We discuss the case of a 31-year-old male patient of Central American origin presenting with a new-onset seizure. He had no significant past medical history and had never experienced similar events before. The diagnosis was made through neuroimaging, serum antibody testing, and biopsy of the brain lesion. This case highlights the importance of performing a good clinical history and a proper diagnostic workup that would help in the prompt recognization and treatment of this common worldwide illness that may not be endemic to the clinician's geographical area.

Optimisation of a PC12 cell-based in vitro stroke model for screening neuroprotective agents.

Stroke causes death and disability globally but no neuroprotectant is approved for post-stroke neuronal injury. Neuroprotective compounds can be identified using oxygen glucose deprivation (OGD) of neuronal cells as an in vitro stroke model. Nerve growth factor (NGF)-differentiated PC12 pheochromocytoma cells are frequently used. However, investigators often find their clonal variant undifferentiable and are uncertain of optimal culture conditions. Hence we studied 3 commonly used PC12 variants: PC12 Adh, PC12 from Riken Cell Bank (PC12 Riken) and Neuroscreen-1 (NS-1) cells. We found DMEM the optimal media for PC12 Riken and NS-1 cells. Using a novel serum-free media approach, we identified collagen IV as the preferred adhesive substrate for both cell lines. We found PC12 Adh cells cannot attach without serum and is unable to differentiate using NGF. NS-1 cells differentiated to a maximal 72.7 ± 5.2% %, with substantial basal differentiation. We optimised differentiated NS-1 cells for an in vitro stroke model using 3 h of OGD resulting in ~ 70% viable cells. We screened 5 reported neuroprotectants and provide the first report that serotonin is antiapoptotic in a stroke model and the 5-HT1A agonist 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) is neuroprotective in PC12 cells. Thus we demonstrate the optimisation and validation for a PC12 cell-based in vitro stroke model.