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Medical and Biological Applications of Low Energy Accelerators
Published in Vlado Valković, Low Energy Particle Accelerator-Based Technologies and Their Applications, 2022
PET is a non-invasive procedure that is used for imaging tissues and organs of the body and to monitor their functioning. It is based on the in-vivo detection of positron-emitting radioisotopes, which are introduced as tracers into the organ, or tissue of interest. The PET technique offers the unique possibility of studying metabolic and physiologic processes in vivo in humans and animals, without disturbing the investigated system, due to its non-invasive properties. This non-invasive imaging technique is based on the use of compounds of exogenic or endogenic origin labeled with short-lived positron-emitting radionuclides such as 11C (t1/2 = 20.4 min), 13N (t1/2 = 10 min), 15O (t1/2 = 2 min) and 18F (t1/2 = 110 min). PET has evolved as a major non-invasive technique for in vivo studies of biochemical and physiological processes. Apart from being a valuable research tool, PET has also become important in clinical applications where it can be used to distinguish between normal and diseased states.
Gastrointestinal tract and salivary glands
Published in A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha, Clark’s Procedures in Diagnostic Imaging: A System-Based Approach, 2020
A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha
This non-invasive procedure involves the injection of a suitable radiopharmaceutical into the bloodstream, following which any bleeding into the GI tract can be detected over a period of time, dependent on the rate of bleeding. Autologous red cells are labelled with technetium in vivo or in vitro. For the in vivo method, two injections are necessary. The patient is first given an IV injection of a stannous salt for in vivo loading of erythrocytes with stannous ion. Then after a period of 20–30 minutes, 99mTcO4– is injected into the bloodstream where it becomes bound to the stannous ion in the red blood cells. This technetium-labelling method allows immediate image acquisition, with the procedure being best performed when the patient presents with symptoms of bleeding.
Wound healing angiogenesis: An overview on mathematical models
Published in J. Belinha, R.M. Natal Jorge, J.C. Reis Campos, Mário A.P. Vaz, João Manuel, R.S. Tavares, Biodental Engineering V, 2019
A.C. Guerra, J. Belinha, R.M. Natal Jorge
Mathematical models became a focus of interest since they allow to study biological processes with a non-invasive procedure. For the development of a mathematical model for wound healing angiogenesis some simplifications, assumptions and decisions have to be considered. The spatial dimensional is an important aspect to deliberate. Frequently, it is considered that wounds are much longer than wide or deep, and in these situations 1D models are a proper approach. In fact, several studies modelled angiogenesis in a 1D framework (Byrne et al. 2000, Flegg et al. 2010, Gaffney et al. 2002, Maggelakis 2003, Olsen et al. 1997, Schugart et al. 2008, Xue et al. 2009). These models are conceptually simpler, numerical tractable and present less computational costs. However, if it is intended to study more realistic geometries, similar to those visualized in real wounds, it is necessary to add more complexity to the model and extend them to two dimensions, as some authors have showed (Javierre et al. 2008, Machado et al. 2011, Matsuya et al. 2016, Peirce et al. 2004, Sun et al. 2005, Valero et al. 2013, Vermolen & Javierre 2011). The 3D models (Bentley et al. 2008, Bookholt et al. 2016) simulate skin structure and cell-ECM interactions more closely to reality and allow an accurate representation of the involved phenomena. Nevertheless, these models are analytically more complex and represent a high computational cost. For these reasons, there is still a lack in the literature of 3D models for the simulation of wound healing angiogenesis.
Wall shear stress indicators influence the regular hemodynamic conditions in coronary main arterial diseases: cardiovascular abnormalities
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
M. Ferdows, K. E. Hoque, M.Z.I. Bangalee, M. A. Xenos
This study focuses to build a framework for patient-based on 3 D model reconstruction and geometric analysis and describes CH properties, for instance, the velocity magnitude with streamlines, mean arterial pressure difference, WSS, TAWSS, OSI, RRT, and cFFR by exploiting open-source tools. The hemodynamic factors allow delineating the intrinsic blood flow in a non-invasive procedure. Our simulation results that show the WSS, TAWSS, and OSI are linearly correlated with the percentage of the AS and WSS magnitude distribution values. We have observed that the multiple sequential stenoses are more critical than the single one, and proximal stenoses are more severe than distal stenoses although the percentage of AS is the same. The cFFR results allow distinguishing the unstenosed and stenosed arterial models produced by the natural phenomena. The WSS values increase with an increase in the velocity magnitude in the stenosis regions. The simulation results are feasible for actual clinical applications, but there are also some limitations in the procedures, which require more studies to overcome them. This technique could be used as a non-invasive, low-risk, and complementary procedure for expensive and risky invasive catheterization.
Medical abortion ratios and gender equality in Europe: an ecological correlation study
Published in Sexual and Reproductive Health Matters, 2021
Since its introduction in the late 1980s, medical abortion (MA) (also known as “drug-induced abortion” or “medication abortion”), in the form of mifepristone (RU486) and misoprostol, has held out the promise of enabling better access to abortion for women* worldwide.1 In the early 2000s, the World Health Organization (WHO) added MA to the list of essential medicines.2 It is now recommended as a safe and effective pregnancy termination method in the first trimester.3 The preferred regimen consists of two doses: one of mifepristone, which stops the pregnancy, and one of misoprostol, which provokes the abortion (misoprostol is widely available for its use in gastroenterology for the prevention of stomach ulcers, and in some contexts in gynaecological and obstetric care to induce labour and for the management of miscarriages). The two drugs are usually taken at an interval of one to two days.3 In most settings, MA requires initial consultation with a health professional during which the first dose is administered. It may be possible for women to take the second dose at home, which can be done safely.4 The efficacy and acceptability of MA in the early weeks of pregnancy are comparable to those of surgical abortion.5,6 MA also presents several advantages from a health and healthcare perspective: it is associated with a more efficient use of resources (performed at the primary care level, outpatient delivery), a reduction in needs for surgical skills, and is a non-invasive procedure.7
Diagnostic and prognostic role of ascitic fluid calprotectin level: six-month outcome findings in cirrhotic patients
Published in Scandinavian Journal of Gastroenterology, 2020
Maryam Nasereslami, Zhila Khamnian, Yaghoub Moaddab, Zahra Jalali
In this cross-sectional study, we initially recruited 90 cases with liver cirrhosis that presented with ascites to the division of Gastroenterology and Hepatology at the Department of Internal Medicine of Tabriz University of Medical Sciences. They were included in the study unless they met any of the exclusion criteria which consisted of developing ascites secondary to congestive heart failure, renal failure, malignancy, etc. Presence of comorbidities (autoimmune condition, immunodeficiency, and malignancy) disqualified three of them from participating in this research. Although no additional invasive or non-invasive procedure was planned, according to ethical requirements, fully informed written consent was obtained from each of the remaining 87 subjects. Ascitic fluids obtained from admitted cirrhotic patients is normally analyzed for its WBCs, PMNs, albumin, and total protein level. However, as an amendment to current guidelines, calprotectin levels were requested to be measured at no extra charge, using the same specimens derived from otherwise routinely indicated ascitic tap. We used Human Calprotectin (CA) ELISA Kit which is designed to detect 1.67 ng/ml of Calprotectin in body fluids, tissue homogenates, or secretions.