Thigh Mass Case Report Rometti, Mary; Bryczkowski, Christopher
Journal of education & teaching in emergency medicine,
10/2022, Volume:
7, Issue:
4
Journal Article
Peer reviewed
Open access
Patients commonly present to the Emergency Department for the evaluation of soft tissues masses of various etiology. Point-of-care ultrasound (POCUS) can aid in the initial evaluation of these masses ...to begin narrowing a given differential. Soft tissue sarcomas are a malignant neoplasm that frequently present in an extremity, and require close follow-up for the evaluation of metastasis and possible resection, among other treatment options. Being able to effectively differentiate between infectious, inflammatory, benign, or potentially malignant pathology for undifferentiated soft tissue masses is critical for Emergency Medicine clinicians to ensure patients receive appropriate treatment and referrals for definitive care. TopicsThigh mass, soft tissue mass, sarcoma, point-of-care ultrasound.
The EM algorithm is a widely used tool in maximum-likelihood estimation in incomplete data problems. Existing theoretical work has focused on conditions under which the iterates or likelihood values ...converge, and the associated rates of convergence. Such guarantees do not distinguish whether the ultimate fixed point is a near global optimum or a bad local optimum of the sample likelihood, nor do they relate the obtained fixed point to the global optima of the idealized population likelihood (obtained in the limit of infinite data). This paper develops a theoretical framework for quantifying when and how quickly EM-type iterates converge to a small neighborhood of a given global optimum of the population likelihood. For correctly specified models, such a characterization yields rigorous guarantees on the performance of certain two-stage estimators in which a suitable initial pilot estimator is refined with iterations of the EM algorithm. Our analysis is divided into two parts: a treatment of the EM and first-order EM algorithms at the population level, followed by results that apply to these algorithms on a finite set of samples. Our conditions allow for a characterization of the region of convergence of EM-type iterates to a given population fixed point, that is, the region of the parameter space over which convergence is guaranteed to a point within a small neighborhood of the specified population fixed point. We verify our conditions and give tight characterizations of the region of convergence for three canonical problems of interest: symmetric mixture of two Gaussians, symmetric mixture of two regressions and linear regression with covariates missing completely at random.
As an alternative standard electromagnetic (EM) field generator, a 4-port TEM (transverse EM) cell can be used for an EM compatibility (EMC) emission and immunity test. However, unwanted EM fields ...generated in a TEM cell deteriorate the results and accuracy of critical EMC tests. A new method to suppress unwanted field components in a 4-port TEM cell is proposed. To reduce the unwanted EM field, the narrow slits in internal septa are inserted, which are transverse with respect to the direction of wave propagation. By introducing the slits, the 4-port TEM cell can provide improved standard EM field distribution with the much-lowered unwanted field component inside the usable test volume.
A case of acute cholecystitis following giant puffball mushroom ingestion is described. A 64-year-old male ingested what was presumed to be a puffball mushroom, developed epigastric pain several ...hours later, and went to the emergency department. Patient blood work yielded elevated liver enzymes and bilirubin levels, with no change in coagulation studies. A mycologist associated with our regional poison center confirmed the mushroom to be a giant puffball mushroom which is recognized as a non-poisonous mushroom. After identification of the mushroom and recognition that it was unlikely the cause of the elevated liver enzymes, the workup was expanded, and the patient was found to have acute cholecystitis on imaging. This case highlights the added value of incorporating mycologists when the mushroom in question is available.
Toxicology, mycology, poison control/center, puffball mushroom, Calvatia, Lycoperdon.
Scanning electron microscopy (SEM) is increasing its application in life sciences for electron density measurements of ultrathin sections. These are traditionally analyzed with transmission electron ...microscopy (TEM); by most labs, SEM analysis still is associated with surface imaging only. Here we report several advantages of SEM for thin sections over TEM, both for structural inspection, as well as analyzing immuno-targeted labels such as quantum dots (QDs) and gold, where we find that QD-labeling is ten times more efficient than gold-labeling. Furthermore, we find that omitting post-staining with uranyl and lead leads to QDs readily detectable over the ultrastructure, but under these conditions ultrastructural contrast was even almost invisible in TEM examination. Importantly, imaging in SEM with STEM detection leads to both outstanding QDs and ultrastructural contrast. STEM imaging is superior over back-scattered electron imaging of these non-contrasted samples, whereas secondary electron detection cannot be used at all. We conclude that examination of ultrathin sections by SEM, which may be immunolabeled with QDs, will allow rapid and straightforward analysis of large fields with more efficient labeling than can be achieved with immunogold. The large fields of view routinely achieved with SEM, but not with TEM, allows straightforward raw data sharing using virtual microscopy, also known as nanotomy when this concerns EM data in the life sciences.
•High resolution and large fields of view via nanotomy or virtual microscopy.•Highly relevant for EM‐datasets where information density is high.•Sample preparation with low contrast good for STEM, not TEM.•Quantum dots now stand out in STEM‐based detection.•10 Times more efficient labeling with quantum dots compared to gold.
In today's rapidly evolving technological landscape, information visualization devices (IVDs) play a crucial role amidst an overwhelming flood of information. However, ensuring the electromagnetic ...(EM) reliability of these devices, especially regarding EM information leakage, is increasingly challenging due to the continuous development of infiltration techniques. While the recently developed DisplayPort protocol provides a relatively robust environment for externally used cables with its complex encoding and scrambling method, internally used protocols like FPD-link remain outdated, relying solely on spread spectrum clocking (SSC) technology. Given the ongoing technological advancements described, conventional countermeasures, such as SSC, once groundbreaking, are now vulnerable to infiltration. If exploited for malicious purposes without public disclosure, this could have severe consequences for anyone living in today's information society. Therefore, aiming to contribute to the existing knowledge base, this article seeks to address an issue arising when applying conventional signal reconstruction techniques, originally designed for EM leakage from devices employing constant clocking, to those utilizing SSC. In addition, it proposes a fundamental concept named periodic nonuniform sampling to mitigate the countermeasure effect given by the SSC. Ultimately, this article aims to raise awareness within the academic community regarding the potential for EM penetration and to facilitate proactive measures to address such occurrences.
High-pressure injection injuries to the hand can be surgical emergencies. The injected material and subsequent edema increase the risk for infection, ischemia, compartment syndrome, and limb loss. ...This is a case report of a 53-year-old male who presented to the emergency department with a superficial two-centimeter laceration to the dorsum of his left hand. He had no obvious signs of infection and the surrounding structures were neurovascularly intact. The patient had been using a gas-powered pressure washer when he sustained the injury to his hand. Physical exam revealed marked crepitus throughout the left hand extending up to the mid forearm. Radiographs of the left hand and left forearm demonstrated extensive subcutaneous emphysema. Hand surgery was emergently consulted and recommended admission for serial exams and antibiotics. This case illustrates a key point: despite initially benign presentations, high-pressure injection injuries should be approached as emergent processes that can be easily overlooked if the proper history and appropriate diagnostic measures are not executed. TopicsHand, orthopedics, x-ray, high-pressure injection injury.
May-Thurner syndrome (MTS) is most commonly caused by the compression of the left iliac vein by the right iliac artery against the lumbar spine, which leads to the development of a partial or ...occlusive deep venous thrombosis (DVT).1 Diagnosis begins with a duplex ultrasound of the lower extremities to evaluate for a femoropopliteal thrombus, and in high-risk patients where a more proximal DVT is suspected and the DVT ultrasound is negative, a computed tomography venogram (CTV) or magnetic resonance venogram (MRV) is performed.1,3 In this case report, a patient presented to the emergency department (ED) with two days of left lower extremity pain and swelling. Initial lower extremity DVT ultrasound was negative, so a CTV was ordered and revealed a thrombus in the left common iliac vein with overlying compression by the right common iliac artery, suggesting the diagnosis of May-Thurner syndrome (Figure 1). Afterwards, a point-of-care ultrasound (POCUS) was performed at bedside to evaluate the caval and iliac arteries and the findings were consistent with the CTV (Figure 2, 3, 4). If the POCUS was performed prior to the CTV, the patient may have been spared the radiation exposure from CT, as well as the risks of intravenous (IV) contrast required for a venogram. Therefore, in high risk patients in whom a negative DVT ultrasound will prompt advanced imaging with CTV or MRV, I propose the addition of a lower abdominal ultrasound using a curvilinear probe to assess the caval and iliac arteries prior to obtaining a CTV or MRV. TopicsMay-Thurner Syndrome, leg swelling, POCUS, ultrasound, deep venous thrombosis.
This is a case report of a 55-year-old woman with a past medical history of hypertension who presented to the emergency department with upper lip and cheek swelling isolated to the right side of her ...face. She was on lisinopril for several years and had never had an episode of swelling in the past. Her vital signs were stable. However, on reassessment, the patient's right sided swelling progressed to the entire upper lip and she complained of swelling in her submandibular space. Although no swelling was appreciated to the submandibular space on physical exam, and the patient still did not have any signs or symptoms of respiratory distress, the decision was made to use a fiberoptic laryngoscope to evaluate her airway. Fiberoptic laryngoscope showed noticeable laryngeal edema which did not improve after treatment, and the patient was admitted to the medical intensive care unit for close airway observation. This case highlights the use of fiberoptic laryngoscope by emergency physicians in the evaluation of patients with relatively benign appearing angioedema. TopicsACE-I, angioedema, fiberoptic laryngoscope, laryngeal edema, tranexamic acid.
Vitreous Hemorrhage Case Report Rometti, Mary; Patti, Laryssa; Bryczkowski, Christopher
Journal of education & teaching in emergency medicine,
07/2022, Volume:
7, Issue:
3
Journal Article
Peer reviewed
Open access
Ocular issues are a common reason to present to the emergency department (ED). This case discusses a patient who presented to the ED with unilateral atraumatic partial vision loss. The patient ...underwent a point of care ultrasound that was concerning for a vitreous hemorrhage. Although vitreous hemorrhages require urgent, rather than emergent evaluation, it is important to differentiate this diagnosis from vitreous and retinal detachment. TopicsVitreous hemorrhage, eye complaint, point of care ultrasound, POCUS.
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