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Cancer Biology and Genetics for Non-Biologists
Published in Trevor F. Cox, Medical Statistics for Cancer Studies, 2022
Roentgen discovered X-rays in 1895. The fact that X-rays could burn skin, soon led to radiotherapy using radium to destroy tumour cells. Radiotherapy has improved immensely since the early days, and now we have different types, such as: 3D conformal radiotherapy: CT scans help create a three-dimensional computer model of the area to be treated. This helps to reduce the amount of healthy tissue that also gets radiated.Intensity-modulated radiotherapy (IMRT): Photon beams are applied from several directions so that the strength of the beams can be adjusted.Electron beam therapy (EBT): Electrons are used instead of photons.Proton beam therapy: Protons are used instead of photons.Brachytherapy: A radioactive source is planted in or near the tumour.
Cardiac CT and MRI: State of the Art
Published in Phillip M. Boiselle, Charles S. White, New Techniques in Cardiothoracic Imaging, 2007
Most initial work with noninvasive coronary assessment was performed with electron beam tomography (EBT). Developed in the early 1980s, the EBT configuration has no moving parts and thus permits temporal resolution of approximately 100 ms (1). EBT has proved valuable in the evaluation of coronary calcium burden, but its inferior spatial resolution and moderate image noise have prevented its widespread adoption for detailed delineation of the coronary arteries.
The Coronary Arteries: Atherosclerosis and Ischaemic Heart Disease
Published in Mary N. Sheppard, Practical Cardiovascular Pathology, 2022
Calcification is common in atherosclerotic plaques, increasing steadily in degree both with the extent of plaque formation and with age. Two distinct patterns occur. In one, nodular masses of calcium form within the lipid core; in the other, plates of calcification develop in the connective tissue deep in the intima close to the medial/intimal junction. While formerly regarded as a passive precipitation of calcium phosphate crystals, plaque calcification is now recognized as a regulated process in which osteopontin, osteonectin and osteocalcin are involved. Both macrophages and smooth muscle cells are involved in the production of these bone-promoting substances. Evidence of osteoclast- and osteoblast-like differentiation occurs in plaques and bone may be laid down. Vascular calcification has pleiotropic properties such as pro-inflammatory ‘microcalcification’ and anti-inflammatory ‘macrocalcification’. Plaque calcification develops by the inflammation-dependent mechanisms involved in progression and regression of atherosclerosis. Macrophages can undergo two distinct polarization states, that is, pro-inflammatory M1 phenotype in progression and anti-inflammatory M2 phenotype in regression. In plaque progression, predominant M1 macrophages promote the initial calcium deposition within the necrotic core of the lesions, called microcalcification, through not only vesicle-mediated mineralization as the result of apoptosis of macrophages and vascular smooth muscle cells (VSMCs), but also VSMC differentiation into early phase osteoblasts. On the other hand, in plaque regression, M2 macrophages are engaged in the healing response to plaque inflammation. In association with the resolution of chronic inflammation, M2 macrophages may facilitate macroscopic calcium deposition, called macrocalcification, through induction of osteoblastic differentiation and maturation of VSMCs. Oncostatin M, which has been shown to promote osteoblast differentiation in bone, may play a pivotal role in the development of plaque calcification. Clinically, two types of plaque calcification have distinct implications. Macrocalcification leads to plaque stability, while microcalcification is more likely to be associated with plaque rupture. Statin therapy, which reduces cardiovascular mortality, has been shown to exert its dual actions on plaque morphology, by regression of atheroma and increase in macrocalcification.3 The current view is that the extent of calcification roughly relates to the amount of atherosclerosis, but not to the degree of arterial narrowing. Calcification has no direct causal link to thrombosis, with one exception. In old age (>75 years), diffuse intimal atherosclerosis and calcification are often associated with diffuse ectasia (dilatation) of the coronary arteries. Intimal tears at the margins of plates of calcium due to shear stress may then cause thrombosis. New methods, including electron beam tomography and CT angiography, are now being used noninvasively in screening for calcification and, by implication, the atherosclerotic load within coronary arteries.
Utilization and cost of electronic brachytherapy by dermatologists from 2012 to 2015
Published in Journal of Dermatological Treatment, 2019
Katelyn Peloza, Richard Duszak, Andrew B. Rosenkrantz, Travis W. Blalock, Howa Yeung
This study does not contain any patient-level information and does not require IRB approval. Utilization and cost by Current Procedural Terminology (CPT) codes related to EBT were obtained from the 2012–2015 Medicare Physician and Other Suppliers Public Use Files (POSPUF) (3). EBT utilization was identified by CPT code 0182T for ‘high dose rate electronic brachytherapy, per fraction.’ Additional radiation delivery CPT codes potentially associated with EBT were added as sensitivity analyses (4). Costs were estimated by Medicare payment amounts. Numbers of services and costs were adjusted by Medicare Part B fee-for-service enrollees and the Bureau of Labor Statistic’s Consumer Price Index to January 2015 values, respectively (5). Analysis and visualization were performed using Microsoft Excel 2011, SAS 9.3, and Tableau Desktop 10.5.
Nurse-like cells in rheumatoid arthritis: Formation of survival niches cooperating between the cell types
Published in Modern Rheumatology, 2019
Takahiro Ochi, Takashi Sawai, Kenya Murakami, Akihisa Kamataki, Miwa Uzuki, Tetsuya Tomita, Hideki Tsuboi, Kensuke Ochi, Kosuke Ebina, Shunsei Hirohata, Peter E. Lipsky
The features of RA-NLCs in vivo in synovial tissues were observed by TEM alone and in combination with serial block-face scanning electron microscopy (SB-SEM) and double-axis electron beam tomography (DA-ET) [12]. In these studies, ultrathin sections of the deeper layer of RA synovial tissue were examined. By conventional TEM, numerous synovial dendritic cells exhibiting long slender cytoplasmic process were observed in close juxtaposition to plasma cells (PCs) (Figure 2). Among these, the characteristic dendritic cells (the DCs) were observed by higher magnification to attach closely and possibly fuze with spines or fingerlike protrusions to the cell membrane of the adjacent PCs (Figure 3). Even by more precise analyses using DA-ET, the boundary between the process of the DCs and PCs could not be identified in any visual fields, and it is possible that membranes of these two different types of cells were fused or at least tightly approximated. Three-dimensional morphologies of the physical interactions between the DCs and PCs were visualized by SB-SEM [12]. The cytoplasmic processes of the DC were observed to closely surround approximately half, but not the entire surface area of the adjacent PC.
Comparative outcome of overhead and total body phototherapy for treatment of severe neonatal jaundice in Nigeria
Published in Paediatrics and International Child Health, 2020
Hippolite O. Amadi, Ruqayya A. Abdullahi, Olugbenga A. Mokuolu, Obumneme B. Ezeanosike, Christiana T. Adesina, Isyaku L. Mohammed, Eyinade K. Olateju, Amina L. Abubakar, Mustapha A. Bello, Augusta U. Eneh, Emeka Onwe Ogah, Bessie C. Eziechila, Assumpta U. Chapp-Jumbo, Abdulrasheed Jimoh, Jacob J. Udo
In the C1 dataset, 32 cases, 12 of whom were <2 kg or <35 w, qualified for inclusion and in the T1 dataset, 34 cases, 11 of whom were <2 kg or <35 w, qualified for inclusion. Two-tailed t-tests comparing the two datasets did not demonstrate any significant differences between birthweight, gestation, age on admission or TSB on admission; however, there was a significant difference in duration of treatment with averages of Day 2 and Day 6, respectively (p < 0.0001) (Table 4). There were higher rates of EBT use in the overhead phototherapy group and EBT was not required for any of the 11 neonates who were <2 kg or <35 w in the TBPE group (Figure 5).