Gadolinium in Medical Imaging - Usefulness, Toxic Reactions and Possible Countermeasures - A Review

Gadolinium (Gd) is one of the rare-earth elements. The properties of its trivalent cation (Gd3+) make it suitable to serve as the central ion in chelates administered intravenously to patients as a contrast agent in magnetic resonance imaging. Such Gd-chelates have been used for more than thirty years. During the past decades, knowledge has increased about potential harmful effects of Gd-chelates in patients with severe renal dysfunction. In such patients, there is a risk for a potentially disabling and lethal disease, nephrogenic systemic fibrosis. Restricting the use of Gd-chelates in persons with severely impaired renal function has decreased the occurrence of this toxic effect in the last decade. There has also been an increasing awareness of Gd-retention in the body, even in patients without renal dysfunction. The cumulative number of doses given, and the chemical structure of the chelate given, are factors of importance for retention in tissues. This review describes the chemical properties of Gd and its medically used chelates, as well as its toxicity and potential side effects related to injection of Gd-chelates. Keywords: chelates; contrast induced nephropathy; gadolinium; gadolinium induced respiratory distress syndrome; gadolinium kinetics; gadolinium toxicity; nephrogenic systemic fibrosis; side effects of gadolinium chelates; treatment of gadolinium toxicity. © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/ 4.0/).Gadolinium in Medical Imaging - Usefulness, Toxic Reactions and Possible Countermeasures - A ReviewpublishedVersio

Injury morbidity in an urban and a rural area in Tanzania: an epidemiological survey

BACKGROUND: Injuries are becoming a major health problem in developing countries. Few population based studies have been carried out in African countries. We examined the pattern of nonfatal injuries and associated risk factors in an urban and rural setting of Tanzania. METHODS: A population-based household survey was conducted in 2002. Participants were selected by cluster sampling. A total of 8,188 urban and 7,035 rural residents of all ages participated in the survey. All injuries reported among all household members in the year preceding the interview and resulting in one or more days of restricted activity were included in the analyis. RESULTS: A total of 206 (2.5%) and 303 (4.3%) persons reported to have been injured in the urban and rural area respectively. Although the overall incidence was higher in the rural area, the incidence of major injuries (≥ 30 disability days) was similar in both areas. Males were at a higher risk of having an injury than females. Rural residents were more likely to experience injuries due to falls (OR = 1.6; 95% CI = 1.1 – 2.3) and cuts (OR = 4.3; 95% CI = 3.0 – 6.2) but had a lower risk of transport injuries. The most common causes of injury in the urban area were transport injuries and falls. In the rural area, cuts and stabs, of which two thirds were related to agriculture, formed the most common cause. Age was an important risk factor for certain types of injuries. Poverty levels were not significantly associated with experiencing a nonfatal injury. CONCLUSION: The patterns of injury differ in urban and rural areas partly as a reflection of livelihoods and infrastructure. Rural residents are at a higher overall injury risk than urban residents. This may be important in the development of injury prevention strategies

A Review of Metallothionein Isoforms and their Role in Pathophysiology

The Metallothionein (MT) is a protein which has several interesting biological effects and has been demonstrated increase focus on the role of MT in various biological systems in the past three decades. The studies on the role of MT were limited with few areas like apoptosis and antioxidants in selected organs even fifty years after its discovery. Now acknowledge the exploration of various isoforms of MT such as MT-I, MT-II, MT-III and MT-IV and other isoforms in various biological systems

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Handbook on the Toxicology of Metals (Fifth Edition) Volume II: Specific Metals. Chapter 30 - Silver

Silver compounds may be absorbed through inhalation, but there are no quantitative human data on the extent of this phenomenon. Silver salts may be absorbed by up to 10%–20% after ingestion. After ingestion in humans, the highest concentrations of silver are usually found in the liver and spleen, but also to some extent in the muscles, skin, and brain. Silver may also be absorbed through dermal exposure, especially via wound care. The biological half-time for silver ranges from a few days for animals up to approximately 50days for the human liver; it is possible that skin deposits have an even longer half-time, but there are no quantitative data on this for humans. Silver binds to high molecular weight proteins and metallothionein in tissue cytosol fractions. Excretion of silver from the body is primarily biliary. Silver nanoparticles have been shown to be absorbed by both inhalation and oral routes, and only to a minor extent via the dermal route, resulting in deposition in various organ systems. Monitoring of exposure is possible by determinations of levels in whole blood. High-dose repeated exposure of animals to silver and silver compounds may produce anemia, cardiac enlargement, growth retardation, and degenerative changes in the liver. Water-soluble silver compounds such as silver nitrate have a local corrosive effect and may cause fatal poisoning in humans if injected or infused into the uterus. Chronic exposure of humans leads to argyria, a clinical entity characterized by gray-blue pigmentation of the skin and other body viscera. Similar changes in the eye after local treatment with eye drops containing silver compounds are named argyrosis. Allergic contact dermatitis to silver is rare. Genotoxic effects, in terms of direct DNA strand breaks via oxidative stress, have been reported in vitro. Tests indicating genotoxicity (Comet assay) and oxidative stress were positive in one study on silver-workers