Rosai-Dorfman disease of the oral cavity

First described by J Rosai and R F Dorfman in 1969, Rosai-Dorfman disease (RDD) is a benign, self-limiting histiocytosis of unknown etiology. It is usually seen in the first two decades of life. The most frequent clinical presentation is painless, bilateral cervical lymphadenopathy accompanied by fever, weight loss, and an elevated ESR. However, RDD without nodal involvement is extremely rare, and the most common extranodal location is the head and neck region, mainly affecting the nasal cavity, pharynx, and paranasal sinuses. Oral location of RDD is occasional; according to our knowledge, only 17 cases of oral Rosai-Dorfman disease without lymph node involvement have been found in the literature. Because of the rarity of these isolated oral presentations, the clinical and radiological aspects need to be more studied. This article aims to present a rare case of oral Rosai-Dorfman disease without nodal involvement, detail the clinical and radiological signs, and the treatment strategy used in our patient

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Improved Modeling of Temperature Evolution during Lung Cancer Tumor Thermal Ablation

Microwave ablation (MWA) represents one of the most powerful tools in cancer treatment. This therapeutic modality process is governed by the temperature and absorbed dose of radiation of the cell tissue. This study was performed to control the temperature effect using simulation during the MWA thermal damage of lung tumor. For this reason, a two-dimensional (2D) computational modeling generated for adaptive lung tissue was designed and analyzed using the finite element method (FEM). Different approaches, such as first-order Arrhenius rate equations, Maxwell equations, and the bioheat equation, have been used to simulate necrosis in cells. To control the heat, a proportional–integral–derivative (PID) controller was used to moderate the input microwave power source and to maintain the temperature of the target tip at a lower level of the initial temperature data. Furthermore, full cancer tissue necrosis was also evaluated by processing time and thermal damage fraction. The obtained data proved that the target tip temperature was affected by the temperature distribution and specific absorption rate (SAR). However, a specific treatment period of tumor ablation is required to control and decrease the damage of surrounding healthy tissue to ensure a safe operation without any risk

Numerical Study of the Blood Flow in a Deformable Human Aorta

In this work, we present a numerical investigation of blood flow in a portion of the human vascular system. More precisely, the present work analyzed the blood flow in the upper portion of the aorta. The aorta and its ramified blood vessels are surrounded by the cardiac muscle. The blood flow generates pressure on the internal surfaces of the artery and its ramifications, thereby causing deformation of the cardiac muscle. The numerical analysis used the Navier–Stokes equations as the governing equations of blood flow for the calculation of the velocity field and pressure distribution in the blood. The neo-Hookean hyperelastic model was used for the description of the behavior of the vessel walls. The velocity and pressure distributions were analyzed. The deformation of the vessel was also investigated. The numerical results could be used to better understand and predict the factors that trigger cardiovascular diseases and distortions of the aorta and as a diagnostic tool in clinical applications

Theoretical evaluation of a fiber-optic SPR biosensor based on a gold layer treated with thiol acid

In the present work, we have investigated the surface plasmons resonance (SPR) biosensor based on optical fiber applied for the detection of pathogenic bacteria (Escherichia coli), in order to overcome the stresses caused by the massive prism and to obtain a reliable and efficient miniature device. The modeling procedure is based on a matrix formalism developed for the optical studies of multilayer media. We have tested the response of the fiber optic biosensor based on a golden substrate functionalized with thiol acid. The results show that the SPR biosensor sensitivity is improved by treating the gold electrode with thiol. An improved SPR biosensor with a high resolution is obtained

Modeling of heat transfer distribution in tumor breast cancer during microwave ablation therapy

Microwave (MW) ablation is a strong tool that has been used in clinical therapy for numerous cancer tumors. This method takes advantage of the heat from MW energy produced by an antenna to destroy cancer cells without causing damage to the healthy tissue. This technique's efficiency is correlated to the temperature reached during the MW process. The antenna immersed in a tissue radiates a power that heats the living tissue, that is, the cancer cells and their environment. The administered power leads to a temperature increase that should attain a particular level to enable the killing of the dangerous cancer cells. On the other hand, it should not exceed another level to preserve healthy cells. Bioheat and electromagnetic equations are used to model the thermal ablation process. The finite element method is used to solve the governing equations used to model the process. This article is devoted to studying the influence of the type of antenna on the temperature distribution in the breast tissue, the specific absorption rate (SAR), and the amount of the necrotic tissue. Two configurations have been investigated, namely, a single- or a double-slot antenna. The obtained results reveal that the temperature, SAR, and the fraction of necrotic of the breast tissue are higher when a single-slot antenna is used. In addition, the input MW power has an important effect on the results. Some precautions should be taken in advance to prevent the temperature from rising to 50°C, which may induce damage to healthy cells

Varactor diode-based dual-band frequency tunable multiple-input multiple-output antenna

A microstrip feed line‐based continuous frequency‐tunable dual‐band multiple‐input multiple‐output (MIMO) antenna is proposed in this article. The proposed antenna comprises four hook‐shaped radiators placed orthogonally to one another. The overall dimensions of the antenna are 45 × 45 × 1.6 mm3 (0.77λg × 0.77λg × 0.027λg [where λg is the guided wavelength at the lower tunable resonant frequency]). The proposed antenna operates at dual‐band, while tunability in the resonant frequencies is achieved by connecting varactor diodes with the radiating patches. The lower resonant band of the antenna can be tuned from 2.45 to 2.83 GHz (with the isolation of more than 17 dB in the whole operating band) and the upper frequency band is tunable from 5.14 to 6.3 GHz (with the isolation of more than 22 dB in the whole operating band). The properties of the antenna such as reflection coefficients, mutual couplings, radiation patterns, channel capacity losses, and multiplexing efficiencies are verified by measuring the fabricated prototype. The envelope correlation coefficient of the antenna is <0.11 for the lower frequency band and is <0.16 for the higher frequency band for all tuning cases. The proposed antenna is suitable for use in compact multiband MIMO applications because of its small size, dual‐band characteristics, continuous frequency tuning capability, and good MIMO parameters