Research Spotlight

Kassabji, A., Tahmasbi, M., Augsburger, R.A., Nair, M., Kesterke, M.J. and Jalali, P. (2021). “Evaluation of Cone-beam Computed Tomography Artifacts Produced by Metal Objects Located Within and Outside the Field of View.” J Endod Dec 8;S0099-2399(21)00869-4. [Epub ahead of print].

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INTRODUCTION: Artifacts created by the presence of metal objects in the jaw negatively affect the cone-beam computed tomographic image quality. This study compares artifacts produced by metal objects outside of the field of view (FOV) in a small FOV CBCT image with those produced in a large FOV image in which the metal object is within the FOV. METHODS: We methodically placed 4 titanium implant-sized rods and 4 zirconium crown-sized disks on 1 side of a human cadaver mandible. Using the Accuitomo 170 CBCT machine (J Morita, Irvine, CA), a total of 18 scans (9 with a small FOV and 9 with a large FOV) were made. Ten axial slices from each scan were transferred to ImageJ software (National Institutes of Health, Bethesda, MD) for analysis. The mean standard deviation of all voxel values of a fixed region of interest (ie, uniform air located lingual to tooth #30) was compared between small and large FOV slices. Two blinded observers subjectively rated the images for diagnostic quality and the presence of artifacts. RESULTS: The Wilcoxon signed rank test showed that the standard deviation for both small and large FOV slices increases as the number of metal objects increases. The mean of the standard deviation for small and large FOVs is 3.6 and 2.5, respectively (P = .0000). Fifty-three percent of the small FOV slices had more artifacts in the subjective analysis. One hundred percent of the small FOV slices were rated as higher quality. CONCLUSION: Metal objects outside of the FOV in the contralateral quadrant do affect the quality of small FOV images. However, small FOV images have a higher resolution compared with large FOV images.

Zeynalyan, A.A., Kolasani, B., Naik, C., Sigakis, C.J.G., Silhan, L. and Mathai, S.K. (2021). “Rapidly progressive respiratory failure after helminth larvae ingestion.” BMC Pulm Med 21(1): 422.

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BACKGROUND: Self-administration of helminths has gained attention among patients as a potential but unproven therapy for autoimmune disease. We present a case of rapidly progressive respiratory failure in a patient with systemic sclerosis (SSc) and pulmonary arterial hypertension (PAH) as a result of self-administration of parasitic organisms. CASE: A 45-year-old woman with a history of interstitial lung disease and PAH due to limited cutaneous SSc presented to pulmonary clinic with worsening dyspnea, cough, and new onset hypoxemia. Three months prior to presentation she started oral helminth therapy with Necator americanus as an alternative treatment for SSc. Laboratory evaluation revelaed eosinophilia and elevated IgE levels. IgG antibodies to Strongyloides were detected. High resolution computed tomography of the chest revealed progressive ILD and new diffuse ground glass opacities. Transthoracic echocardiogram and right heart catheterization illustrated worsening PAH and right heart failure. The patient was admitted to the hospital and emergently evaluated for lung transplantation but was not a candidate for transplantation due to comorbidities. Despite aggressive treatment for PAH and right heart failure, her respiratory status deteriorated, and the patient transitioned to comfort-focused care. CONCLUSION: Although ingestion of helminths poses a risk of infection, helminth therapy has been investigated as a potential treatment for autoimmune diseases. In this case, self-prescribed helminth ingestion precipitated fatal acute worsening of lung inflammation, hypoxemia, and right heart dysfunction, highlighting the risk of experimental helminth therapy in patients, especially those with underlying respiratory disease.

Tolia, V.N., Powers, G.C., Kelleher, A.S., Walker, M.W., Herrman, K.K., Ahmad, K.A., Buchh, B., Egalka, M.C., Hinkes, M., Ma, M., Richards, M., Rudine, A.C., Sato, R.Y., Shaffer, K.M. and Clark, R.H. (2022). “Low Rate of Spontaneous Closure in Premature Infants Discharged with a Patent Ductus Arteriosus: A Multicenter Prospective Study.” J Pediatr 240: 31-36.e32.

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OBJECTIVES: To assess the rate of spontaneous closure and the incidence of adverse events in infants discharged home with a patent ductus arteriosus. STUDY DESIGN: In a prospective multicenter study, we enrolled 201 premature infants (gestational age of 23-32 weeks at birth) discharged home with a persistently patent ductus arteriosus (PDA) and followed their PDA status at 6-month intervals through 18 months of age. The primary study outcome was the rate and timing of spontaneous ductal closure. Secondary outcomes included rate of assisted closure and the incidence of serious adverse events. RESULTS: Spontaneous ductal closure occurred in 95 infants (47%) at 12 months and 117 infants (58%) by 18 months. Seventeen infants (8.4%) received assisted closure with surgical ligation or device assisted occlusion. Three infants died (1.5%). Although infants with spontaneous closure had a higher mean birth weight and gestational age compared with infants with a persistent PDA or assisted closure, we did not identify other factors predictive of spontaneous closure. CONCLUSIONS: Spontaneous closure of the PDA occurred in slightly less than one-half of premature infants discharged with a patent ductus by 1 year, lower than prior published reports. The high rate of assisted closure and/or adverse events in this population warrants close surveillance following discharge. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02750228.

Roberts, W.C. and Khan, O.S. (2021). “The Syndrome of Large Healed Single Discrete Myocardial Infarct with Severe Narrowing of Only One Major Epicardial Coronary Artery and Leading to Severe Chronic Heart Failure and Orthotopic Heart Transplantation.” Am J Cardiol 161: 1-11.

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Described herein are clinical and cardiac morphologic findings in 12 patients (age 43 to 70 years) (7 men) who underwent orthotopic heart transplantation (OHT) because of severe heart failure (HF) resulting from a single large discrete acute myocardial infarct that healed and was associated with severe narrowing of only one major epicardial coronary artery. Most myocardial infarcts are associated with severe narrowing of >1 major epicardial coronary artery and result in smaller myocardial infarcts. Another unusual feature was the total infarction of the ventricular septum in 3 of the 12 patients.

Qi, D., Liu, Y., Li, J., Huang, J.H., Hu, X. and Wu, E. (2021). “Salinomycin as a potent anticancer stem cell agent: State of the art and future directions.” Med Res Rev Nov 16. [Epub ahead of print].

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Cancer stem cells (CSCs) are a small subpopulation of cells within a tumor that can both self-renew and differentiate into other cell types forming the heterogeneous tumor bulk. Since CSCs are involved in all aspects of cancer development, including tumor initiation, cell proliferation, metastatic dissemination, therapy resistance, and recurrence, they have emerged as attractive targets for cancer treatment and management. Salinomycin, a widely used antibiotic in poultry farming, was identified by the Weinberg group as a potent anti-CSC agent in 2009. As a polyether ionophore, salinomycin exerts broad-spectrum activities, including the important anti-CSC function. Studies on the mechanism of action of salinomycin against cancer have been continuously and rapidly published since then. Thus, it is imperative for us to update its literature of recent research findings in this area. We here summarize the notable work reported on salinomycin’s anticancer activities, intracellular binding target(s), effects on tumor microenvironment, safety, derivatives, and tumor-specific drug delivery; after that we also discuss the translational potential of salinomycin toward clinical application based on current multifaceted understandings.