Serum magnesium and calcium levels in relation to ischemic stroke : Mendelian randomization study

ObjectiveTo determine whether serum magnesium and calcium concentrations are causally associated with ischemic stroke or any of its subtypes using the mendelian randomization approach.MethodsAnalyses were conducted using summary statistics data for 13 single-nucleotide polymorphisms robustly associated with serum magnesium (n = 6) or serum calcium (n = 7) concentrations. The corresponding data for ischemic stroke were obtained from the MEGASTROKE consortium (34,217 cases and 404,630 noncases).ResultsIn standard mendelian randomization analysis, the odds ratios for each 0.1 mmol/L (about 1 SD) increase in genetically predicted serum magnesium concentrations were 0.78 (95% confidence interval [CI] 0.69-0.89; p = 1.3 7 10-4) for all ischemic stroke, 0.63 (95% CI 0.50-0.80; p = 1.6 7 10-4) for cardioembolic stroke, and 0.60 (95% CI 0.44-0.82; p = 0.001) for large artery stroke; there was no association with small vessel stroke (odds ratio 0.90, 95% CI 0.67-1.20; p = 0.46). Only the association with cardioembolic stroke was robust in sensitivity analyses. There was no association of genetically predicted serum calcium concentrations with all ischemic stroke (per 0.5 mg/dL [about 1 SD] increase in serum calcium: odds ratio 1.03, 95% CI 0.88-1.21) or with any subtype.ConclusionsThis study found that genetically higher serum magnesium concentrations are associated with a reduced risk of cardioembolic stroke but found no significant association of genetically higher serum calcium concentrations with any ischemic stroke subtype

Ultraviolet-inactivation of conidia from heterokaryons of Neurospora crassa containing uv-sensitive mutations

From 7th neurospora information conference; Asilomar, California, USA (25 Mar 1974). The effect of three uv-sensitive mutations of Neurospora crassa, upr-1, uvs-4 and uvs-6, on the ultraviolet-inactivation of conidia from two- component heterokaryons was investigated. In twocomponent heterokaryons with wild-type sensitivity to radiation inactivation, all three conidial fractions exhibited similar ultraviolet-inactivation curves. Each uv-sensitive mutation studied uniquely modified the ultraviolet-inactivation curves of conidia from two- component heterokaryons. In heterokaryons heterokaryotic for upr-1, the upr-1 mutation was recessive and the repair function determined by the wild-type allele was functional to some degree in homokaryotic upr-1 conidia. All three conidial fractions of heterokaryons containing upr-1 in both components showed increased sensitivity to ultraviolet light. The uvs-4 mutation was recessive and resulted in conidia with increased uv-sensitivity only when included in both components of a heterokaryon. Homokaryotic uvs-4 conidia, which arose from heterokaryons containing both uvs-4 and wild-type components, exhibited wild-type survival. Therefore, as with upr-1, there was a carryover of the repair capability to conidia which were genetically uv-sensitive. The uvs-6 mutation, when included in one component of a two-component heterokaryon, resulted in increased uv- sensitivity of both heterokaryotic and homokaryotic uvs-6 conidia. When both components contained uvs-6, the uv-sensitivity of all three conidial fractions was increased and all showed similar inactivation curves. Thus, as with upr-1 and uvs-4, there was a carryover of the wildtype repair capability to geneticaily uvs-6 conidia. Heterokaryon tests for complementation between two non-allelic uv- sensitive mutations showed that in heterokaryotic conidia, complete complementation occurred between upr-1 and uvs-4. (auth

Nano- and microplastics : a comprehensive review on their exposure routes, translocation, and fate in humans

Contamination of the environment with nano-and microplastic particles (NMPs) and its putative adverse effects on organisms, ecosystems, and human health is gaining increasing scientific and public attention. Various studies show that NMPs occur abundantly within the environment, leading to a high likelihood of human exposure to NMPs. Here, different exposure scenarios can occur. The most notable exposure routes of NMPs into the human body are via the airways and gastrointestinal tract (GIT) through inhalation or ingestion, but also via the skin due to the use of personal care products (PCPs) containing NMPs. Once NMPs have entered the human body, it is possible that they are translocated from the exposed organ to other body compartments. In our review article, we combine the current knowledge on the (1) exposure routes of NMPs to humans with the basic understanding of the potential (2) translocation mechanisms into human tissues and, consequently, their (3) fate within the human body. Regarding the (1) exposure routes, we reviewed the current knowledge on the occurrence of NMPs in food, beverages, personal care products and the air (focusing on indoors and workplaces) and found that the studies suggest an abundant presence of MPs within the exposure scenarios. The overall abundance of MPs in exposure matrices relevant to humans highlights the importance of understanding whether NMPs have the potential for tissue translocation. Therefore, we describe the current knowledge on the potential (2) translocation pathways of NMPs from the skin, GIT and respiratory systems to other body compartments. Here, particular attention was paid to how likely NMPs can translocate from the primary exposed organs to secondary organs due to naturally occurring defence mechanisms against tissue translocation. Based on the current understanding, we conclude that a dermal translocation of NMPs is rather unlikely. In contrast, small MPs and NPs can generally translocate from the GIT and respiratory system to other tissues. Thus, we reviewed the existing literature on the (3) fate of NMPs within the human body. Based on the current knowledge of the contamination of human exposure routes and the potential translocation mechanisms, we critically discuss the size of the detected particles reported in the fate studies. In some cases, the particles detected in human tissue samples exceed the size of a particle to overcome biological barriers allowing particle translocation into tissues. Therefore, we emphasize the importance of critically reading and discussing the presented results of NMP in human tissue samples