Feasibility and safety of bipolar radiofrequency track cautery during percutaneous image-guided abdominal biopsy procedures.

PURPOSE: The purpose of this study was to assess the feasibility and safety of using a bipolar radiofrequency track cautery device during percutaneous image-guided abdominal biopsy procedures in at-risk patients. METHODS: Forty-two patients (26-79 years old; female 44%) with at least one bleeding risk factor who underwent an abdominal image-guided (CT or US) biopsy and intended bipolar radiofrequency track cautery (BRTC) were retrospectively studied. An 18G radiofrequency electrode was inserted through a 17G biopsy introducer needle immediately following coaxial 18G core biopsy, to cauterize the biopsy track using temperature control. Bleeding risk factors, technical success, and adverse events were recorded. RESULTS: BRTC was technically successful in 41/42 (98%) of procedures; in one patient, the introducer needle retracted from the liver due to respiratory motion prior to BRTC. BRTC following percutaneous biopsy was applied during 41 abdominal biopsy procedures (renal mass = 12, renal parenchyma = 10, liver mass = 9, liver parenchyma = 5, splenic mass or parenchyma = 4, gastrohepatic mass = 1). All patients had one or more of the following risk factors: high-risk organ (spleen or renal parenchyma), hypervascular mass, elevated prothrombin time, renal insufficiency, thrombocytopenia, recent anticoagulation or anticoagulation not withheld for recommended interval, cirrhosis, intraprocedural hypertension, brisk back bleeding observed from the introducer needle, or subcapsular tumor location. No severe adverse events (grade 3 or higher) occurred. Two (2/41, 5%) mild (grade 1) bleeding events did not cause symptoms or require intervention. CONCLUSION: Bipolar radiofrequency track cautery was feasible and safe during percutaneous image-guided abdominal biopsy procedures. IRB approval: MBG 2022P002277.

Development, Implementation, and Assessment of a Quality, Research, Education, and Wellness (QREW) Professional Development Lecture Series for Radiology Faculty.

RATIONALE AND OBJECTIVES: Professional development is important to academic radiologists. We developed, implemented, and assessed an internal professional development lecture series focusing on the non-interpretative themes of Quality, Research, Education, and Wellness (QREW). MATERIALS AND METHODS: The faculty of a 29-member abdominal radiology division at an academic hospital were invited to deliver 1-hour virtual lectures on noninterpretative topics to division colleagues. Topics were curated by division leadership based on the perceived needs of faculty. Anonymous feedback was collected from attendees for quality improvement purposes and analyzed using descriptive statistics and Fisher's exact test. RESULTS: Over 17 months, 13 QREW lectures were delivered. In total, 91 feedback forms were completed by faculty (mean 7 forms, range 2-12 per session). Of these, 57 responses (63%) were by those <7 years post training ("junior faculty"), 34 responses (37%) by those ≥ 7 years from training ("senior faculty"). Most respondents reported low levels of prior instruction (80/90, 89%) and personal knowledge (49/91, 54%) on topics. Compared to senior faculty, a greater proportion of junior faculty reported less prior instruction (73% vs 98%, P < 0.001) and less personal knowledge (32% vs 65%, P < 0.01). Most respondents agreed or strongly agreed that the topics were important to their clinical practice (87/90, 97%), professional development (86/90, 96%), and personal well-being (82/91, 90%). Faculty identified the QREW program as a major contributor to their professional development. CONCLUSION: A noninterpretative professional development lecture series delivered by radiology faculty in a virtual, interactive format is feasible and effective, particularly for junior faculty.

Can 3-Phase Computed Tomography Urography Be Used to Characterize Adrenal Nodules? Results in 145 Patients.

OBJECTIVE: The aim of the study is to determine whether computed tomography (CT) urography (CTU) can characterize incidental adrenal nodules. METHODS: This retrospective cohort study was performed at an academic medical center. Patients were identified by free text search of CTU reports that contained the terms "adrenal mass" "adrenal nodule" and "adrenal lesion." Computed tomography urography technique consisted of unenhanced images and postcontrast images obtained at 100 seconds and 15 minutes. The final cohort included 145 patients with 151 adrenal nodules. Nodules were considered lipid-rich adenomas or myelolipomas based on unenhanced imaging characteristics. Absolute and relative washout values were calculated for the remaining nodules, using a cutoff of 60% and 40%, respectively, to diagnose adenomas. Reference standard for lipid-poor adenomas and malignant nodules was histopathology or imaging/clinical follow-up. Mann-Whitney U test was used for comparison of continuous variables, and Fisher exact test was used for categorical variables. RESULTS: One hundred nodules were lipid-rich adenomas and 3 were myelolipomas. Forty-eight nodules were indeterminate at unenhanced CT, corresponding to 39 lipid-poor adenomas and 9 malignant nodules based on reference standards. Both absolute and relative washout correctly characterized 71% of nodules (34/48), with a sensitivity of 67% and specificity of 89%. Overall, 91% of all adrenal nodules (137/151) were correctly characterized by CTU alone. Lipid-poor adenomas were smaller than malignant nodules ( P < 0.01) and were lower in attenuation on unenhanced and delayed images ( P < 0.01). CONCLUSIONS: Adrenal nodules detected at 3-phase CTU can be accurately characterized, potentially eliminating the need for subsequent adrenal protocol CT or magnetic resonance imaging.

Clinical course and outcome among patients with acute pancreatitis and COVID-19.

BACKGROUND: The data on clinical course and outcome of acute pancreatitis among patients with coronavirus disease 2019 (COVID-19) are sparse. In this study, we analyzed the clinical profiles of patients with COVID 19 and acute pancreatitis. METHODS: This retrospective study was conducted on Research Patient Data Registry data which was pooled from five Mass General Brigham Healthcare Network hospitals. We extracted data on demographics, symptoms, ICU transfer, mechanical ventilation, laboratories' profiles, imaging findings, and patient outcomes. RESULT: Of 985 screened adult patients, 17 were eligible for the study, 9 (52.9%) were admitted primarily for respiratory failure and developed acute pancreatitis after a median of 22.5 days (13-76 days) from the onset of COVID-19 symptoms. On contrary, eight patients presented with typical symptoms and were diagnosed with acute pancreatitis, the majority with mild severity (62.5%) on admission. Patients who were admitted primarily with severe COVID-19 illness were younger (median age 57 vs. 63 years), females (55.6 vs. 25%), of Hispanic ethnicity (55.6 vs. 25%), and obese (88.9 vs. 37.5%). The median peak lipase, C reactive protein, ferritin, lactate dehydrogenase, D-dimer were higher among patients who developed acute pancreatitis later during hospitalization. Patients who developed acute pancreatitis later also experienced higher episodes of necrotizing pancreatitis (11.1% vs. 0), thromboembolic complications (55.6 vs. 12.5%), and higher mortality (37.5 vs. 12.5%). CONCLUSION: Acute pancreatitis is not common among patients with COVID-19. Patients with COVID-19 who had acute pancreatitis on admission had more benign course and overall better outcome as compared to the patients who developed acute pancreatitis during hospitalization.

SARS-CoV-2 Uses CD4 to Infect T Helper Lymphocytes

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the agent of a major global outbreak of respiratory tract disease known as coronavirus disease-2019 (COVID-19). SARS-CoV-2 infects the lungs and may cause several immune-related complications such as lymphocytopenia and cytokine storm which are associated with the severity of the disease and predict mortality . The mechanism by which SARS-CoV-2 infection may result in immune system dysfunction is not fully understood. Here we show that SARS-CoV-2 infects human CD4+ T helper cells, but not CD8+ T cells, and is present in blood and bronchoalveolar lavage T helper cells of severe COVID-19 patients. We demonstrated that SARS-CoV-2 spike glycoprotein (S) directly binds to the CD4 molecule, which in turn mediates the entry of SARS- CoV-2 in T helper cells in a mechanism that also requires ACE2 and TMPRSS2. Once inside T helper cells, SARS-CoV-2 assembles viral factories, impairs cell function and may cause cell death. SARS-CoV-2 infected T helper cells express higher amounts of IL-10, which is associated with viral persistence and disease severity. Thus, CD4-mediated SARS-CoV-2 infection of T helper cells may explain the poor adaptive immune response of many COVID- 19 patients.

Trainee and Attending Perspectives on Remote Radiology Readouts in the Era of the COVID-19 Pandemic.

RATIONALE AND OBJECTIVES: Social distancing mandates due to COVID-19 have necessitated adaptations to radiology trainee workflow and educational practices, including the radiology "readout." We describe how a large academic radiology department achieved socially distant "remote readouts," provide trainee and attending perspectives on this early experience, and propose ways by which "remote readouts" can be used effectively by training programs beyond COVID-19. MATERIALS AND METHODS: Beginning March 2020, radiologists were relocated to workspaces outside of conventional reading rooms. Information technologies were employed to allow for "remote readouts" between trainees and attendings. An optional anonymous open-ended survey regarding remote readouts was administered to radiology trainees and attendings as a quality improvement initiative. From the responses, response themes were abstracted using thematic analysis. Descriptive statistics of the qualitative data were calculated. RESULTS: Radiologist workstations from 14 traditional reading rooms were relocated to 36 workspaces across the hospital system. Two models of remote readouts, synchronous and asynchronous, were developed, facilitated by commercially available information technologies. Thirty-nine of 105 (37%) trainees and 42 of 90 (47%) attendings responded to the survey. Main response themes included: social distancing, technology, autonomy/competency, efficiency, education/feedback and atmosphere/professional relationship. One hundred and forty-eight positive versus 97 negative comments were reported. Social distancing, technology, and autonomy/competency were most positively rated. Trainees and attending perspectives differed regarding the efficiency of remote readouts. CONCLUSION: "Remote readouts," compliant with social distancing measures, are feasible in academic radiology practice settings. Perspectives from our initial experience provide insight into how this can be accomplished, opportunities for improvement and future application, beyond the COVID-19 pandemic.

Structural properties of a haemophore facilitate targeted elimination of the pathogen Porphyromonas gingivalis.

Porphyromonas gingivalis is a keystone bacterial pathogen of chronic periodontitis. P. gingivalis is unable to synthesise the porphyrin macrocycle and relies on exogenous porphyrin, including haem or haem biosynthesis intermediates from host sources. We show that under the iron-limited conditions prevailing in tissue environments, P. gingivalis expresses a haemophore-like protein, HusA, to mediate the uptake of essential porphyrin and support pathogen survival within epithelial cells. The structure of HusA, together with titration studies, mutagenesis and in silico docking, show that haem binds in a hydrophobic groove on the α-helical structure without the typical iron coordination seen in other haemophores. This mode of interaction allows HusA to bind to a variety of abiotic and metal-free porphyrins with higher affinities than to haem. We exploit this unusual porphyrin-binding activity of HusA to target a prototypic deuteroporphyrin-metronidazole conjugate with restricted antimicrobial specificity in a Trojan horse strategy that effectively kills intracellular P. gingivalis.

Proposal for Observing the Unruh Effect using Classical Electrodynamics.

Although the Unruh effect can be rigorously considered as well tested as free quantum field theory itself, it would be nice to provide experimental evidence of its existence. This is not easy because the linear acceleration needed to reach a temperature 1 K is of order 10^{20} m/s^{2}. Here, we propose a simple experiment reachable under present technology whose result may be directly interpreted in terms of the Unruh thermal bath. Instead of waiting for experimentalists to perform it, we use standard classical electrodynamics to anticipate its output and fulfill our goal.

α-Hemoglobin-stabilizing protein (AHSP) perturbs the proximal heme pocket of oxy-α-hemoglobin and weakens the iron-oxygen bond.

α-Hemoglobin (αHb)-stabilizing protein (AHSP) is a molecular chaperone that assists hemoglobin assembly. AHSP induces changes in αHb heme coordination, but how these changes are facilitated by interactions at the αHb·AHSP interface is not well understood. To address this question we have used NMR, x-ray absorption spectroscopy, and ligand binding measurements to probe αHb conformational changes induced by AHSP binding. NMR chemical shift analyses of free CO-αHb and CO-αHb·AHSP indicated that the seven helical elements of the native αHb structure are retained and that the heme Fe(II) remains coordinated to the proximal His-87 side chain. However, chemical shift differences revealed alterations of the F, G, and H helices and the heme pocket of CO-αHb bound to AHSP. Comparisons of iron-ligand geometry using extended x-ray absorption fine structure spectroscopy showed that AHSP binding induces a small 0.03 Å lengthening of the Fe-O2 bond, explaining previous reports that AHSP decreases αHb O2 affinity roughly 4-fold and promotes autooxidation due primarily to a 3-4-fold increase in the rate of O2 dissociation. Pro-30 mutations diminished NMR chemical shift changes in the proximal heme pocket, restored normal O2 dissociation rate and equilibrium constants, and reduced O2-αHb autooxidation rates. Thus, the contacts mediated by Pro-30 in wild-type AHSP promote αHb autooxidation by introducing strain into the proximal heme pocket. As a chaperone, AHSP facilitates rapid assembly of αHb into Hb when ßHb is abundant but diverts αHb to a redox resistant holding state when ßHb is limiting.

Comment on "Trouble with the Lorentz law of force: incompatibility with special relativity and momentum conservation".

A Comment on the Letter by M. Mansuripur, Phys. Rev. Lett. 108, 193901 (2012). The authors of the Letter offer a Reply.

Gravity-induced vacuum dominance.

It has been widely believed that, except in very extreme situations, the influence of gravity on quantum fields should amount to just small, subdominant contributions. This view seemed to be endorsed by the seminal results obtained over the last decades in the context of renormalization of quantum fields in curved spacetimes. Here, however, we argue that this belief is false by showing that there exist well-behaved spacetime evolutions where the vacuum energy density of free quantum fields is forced, by the very same background spacetime, to become dominant over any classical energy-density component. By estimating the time scale for the vacuum energy density to become dominant, and therefore for backreaction on the background spacetime to become important, we argue that this (infrared) vacuum dominance may bear unexpected astrophysical and cosmological implications.

Awaking the vacuum in relativistic stars.

Void of any inherent structure in classical physics, the vacuum has revealed to be incredibly crowded with all sorts of processes in relativistic quantum physics. Yet, its direct effects are usually so subtle that its structure remains almost as evasive as in classical physics. Here, in contrast, we report on the discovery of a novel effect according to which the vacuum is compelled to play an unexpected central role in an astrophysical context. We show that the formation of relativistic stars may lead the vacuum energy density of a quantum field to an exponential growth. The vacuum-driven evolution which would then follow may lead to unexpected implications for astrophysics, while the observation of stable neutron-star configurations may teach us much on the field content of our Universe.

Quantitative assessment of tooth wear, alveolar-crest height and continuing eruption in a Romano-British population.

Although measurements from cement-enamel junction (CEJ) to alveolar crest (AC) have been used in assessing changes in alveolar-crest height as age or chronic inflammatory periodontal disease (CIPD) progresses, there is evidence from ancient populations that the position of AC remains almost constant throughout life and continuing eruption to compensate for attrition may explain why CEJ-AC measurements increase with age. Measurements of occlusal attrition and relationship of CEJ to AC were made on the cheek teeth of 500 Romano-British skulls by direct measurement or by reference to the fixed line of the inferior alveolar canal (IAC) on radiographs. Direct measurements indicated that there were usually no statistical differences between the vertical amounts of tooth substance lost by attrition and the change in the distance CEJ-AC as age progressed. Measurements on radiographs showed that posterior teeth continued to erupt to compensate for attrition and the AC remained static as age progressed. Bone deposition at the AC was seen in the majority of ground sections. Thus tooth wear appears to be compensated by continuing movement of teeth in an occlusal direction. The position of the AC remained almost constant throughout life; AC bone lost by CIPD seemed to be replaced during continuing tooth eruption.