Mechanistic Link between Vitamin B12 and Alzheimer’s Disease

Alzheimer’s disease (AD) is the most common form of dementia in the elderly population, affecting over 55 million people worldwide. Histopathological hallmarks of this multifactorial disease are an increased plaque burden and tangles in the brains of affected individuals. Several lines of evidence indicate that B12 hypovitaminosis is linked to AD. In this review, the biochemical pathways involved in AD that are affected by vitamin B12, focusing on APP processing, Aβ fibrillization, Aβ-induced oxidative damage as well as tau hyperphosphorylation and tau aggregation, are summarized. Besides the mechanistic link, an overview of clinical studies utilizing vitamin B supplementation are given, and a potential link between diseases and medication resulting in a reduced vitamin B12 level and AD are discussed. Besides the disease-mediated B12 hypovitaminosis, the reduction in vitamin B12 levels caused by an increasing change in dietary preferences has been gaining in relevance. In particular, vegetarian and vegan diets are associated with vitamin B12 deficiency, and therefore might have potential implications for AD. In conclusion, our review emphasizes the important role of vitamin B12 in AD, which is particularly important, as even in industrialized countries a large proportion of the population might not be sufficiently supplied with vitamin B12.

Comparison of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli Isolates From Rooks (Corvus frugilegus) and Contemporary Human-Derived Strains: A One Health Perspective

During winter, a large number of rooks gather and defecate at the park of a university clinic. We investigated the prevalence of extended-spectrum beta-lactamase (ESBL)–producing Escherichia coli in these birds and compared recovered isolates with contemporary human isolates. In 2016, fecal samples were collected from 112 trap-captured rooks and investigated for presence of ESBL producers using eosin methylene blue agar supplemented by 2 mg/L cefotaxime; 2,455 contemporary human fecal samples of patients of the clinics sent for routine culturing were tested similarly. In addition, 42 ESBL-producing E. coli isolates collected during the same period from inpatients were also studied. ESBL genes were sought for by PCR and were characterized by sequencing; E. coli ST131 clones were identified. Epidemiological relatedness was determined by pulsed-field gel electrophoresis and confirmed using whole genome sequencing in selected cases. Thirty-seven (33%) of sampled rooks and 42 (1.7%) of human stools yielded ESBL-producing E coli. Dominant genes were blaCTX–M–55 and blaCTX–M–27 in corvid, blaCTX–M–15 and blaCTX–M–27 in human isolates. ST162 was common among rooks. Two rook-derived E. coli belonged to ST131 C1-M27, which was also predominant (10/42) among human fecal and (15/42) human clinical isolates. Another potential link between rooks and humans was a single ST744 rook isolate grouped with one human fecal and three clinical isolates. Despite possible contact, genotypes shared between rooks and humans were rare. Thus, rooks are important as long-distance vectors and reservoirs of ESBL-producing E. coli rather than direct sources of infections to humans in our setting.

Gluten, Inflammation, and Neurodegeneration

Growing evidence supports a potential link between dietary gluten intake and neurodegenerative disease in susceptible populations. Observational data supporting this link are described along with interventional study data evaluating the effects of restricting gluten from the diet in patients with neurologic disorders. Suggested underlying mechanisms between gluten intake and neurodegeneration are discussed.

Altered succinylation of mitochondrial proteins, APP and tau in Alzheimer’s disease

Abnormalities in brain glucose metabolism and accumulation of abnormal protein deposits called plaques and tangles are neuropathological hallmarks of Alzheimer’s disease (AD), but their relationship to disease pathogenesis and to each other remains unclear. Here we show that succinylation, a metabolism-associated post-translational protein modification (PTM), provides a potential link between abnormal metabolism and AD pathology. We quantified the lysine succinylomes and proteomes from brains of individuals with AD, and healthy controls. In AD, succinylation of multiple mitochondrial proteins declined, and succinylation of small number of cytosolic proteins increased. The largest increases occurred at critical sites of amyloid precursor protein (APP) and microtubule-associated tau. We show that in vitro, succinylation of APP disrupted its normal proteolytic processing thereby promoting Aβ accumulation and plaque formation and that succinylation of tau promoted its aggregation to tangles and impaired microtubule assembly. In transgenic mouse models of AD, elevated succinylation associated with soluble and insoluble APP derivatives and tau. These findings indicate that a metabolism-linked PTM may be associated with AD.

Alzheimer: A Complex Genetic Background

Alzheimer is a complex, multifactorial disease with an ever increasing impact in modern medicine. Research in this area has revealed a lot about the biological and environmental underpinnings of this disease, especially its correlation with Β-Amyloid and Tau related mechanics; however, the precise biological pathways behind the disease are yet to be discovered. Recent studies evidenced how several mechanisms, including neuroinflammation, oxidative stress, autophagy failure and energy production impairments in the brain, −--- have been proposed to contribute to this pathology. In this section we will focus on the role of these molecular pathways and their potential link with Alzheimer Disease.

Potential link between playing wind instruments and vocal tract disorders. A literature review

Introduction and purpose: Currently, we can distinguish three basic groups of instruments. These are wind instruments, percussion instruments, and plucked instruments. In the case of wind instruments, the source of sound is a vibrating column of air, which is created by blowing by the player. It is suspected that such vibration may cause specific vocal and laryngeal symptoms. The aim of the study was to present the current state of knowledge regarding the potential relation between playing wind instruments and vocal tract disorders. Material and methods: The article reviews 19 publications available on the PubMed and Google Scholar, Web of Science databases meeting assumed criteria: published as a full text, without time limit and conducted on humans. The studies were found using initially established searching strategies as well as subsequent manual searching in order not to miss adequate articles. State of knowledge: Laryngeal symptoms may be combined with vocal symptoms. The main raised vocal manifestations among instrumentalists are dysphonia, hoarseness, and altered voice quality. Comparing a group that used wind instruments with control, VHI-10 (Voice Handicap Index) and F0 (fundamental frequency) and HNR (harmonics-to-noise ratio) were higher while jitter % and shimmer %, which are perturbation parameters, were lower in the study group. The majority of studies has a limitation because they were performed in a limited number of volunteers. Conclusions: The symptoms of the vocal tract related to playing wind instruments are characterized by a low frequency of occurrence and intensity. However, further research is needed to assess this relation.

Utilization of continental transforms in break-up: observations, models, and a potential link to magmatism

Reactivation of continental transform faults (hereafter; transforms) is identified herein as a significant factor in continental break-up, based on a global review of divergent margins and numerical modelling. Divergent margins that have reactivated transforms are characterized by linear and abrupt terminations of thick continental crust. Transforms represent some of the largest structures on Earth, and these megastructures represent major lithospheric weaknesses and are therefore prone to reactivation upon changes in the stress field, which typically occur during plate break-up. The blunt termination of the margins is consistent with observations of very limited pre-breakup lithospheric thinning of such margins. This mode of break-up appears to occur abruptly, and contrasts notably with highly tapered and slowly extended divergent margins. Magma leakage along transforms is well-known worldwide where divergence occurs across such features. This leakage may evolve to dike injections, further reducing the plate strength. We observe that many of the blunt margins we attribute to transform reactivation have been prone to above-normal magmatism and are marked by seaward dipping reflectors underlain by high-velocity lower crustal intrusions. The magmatism may be directly related to the separation of abruptly terminated margins, whereby the large resulting lateral thermal gradients trigger edge-driven convection and melt addition.Supplementary material at https://doi.org/10.6084/m9.figshare.c.5756724

Accumulation of meningeal lymphocytes, but not myeloid cells, correlates with subpial cortical demyelination and white matter lesion activity in progressive MS patients

Subpial cortical demyelination is an important component of multiple sclerosis (MS) pathology contributing to disease progression, yet mechanism(s) underlying its development remain unclear. Compartmentalized inflammation involving the meninges may drive this type of injury. Given recent findings identifying substantial white matter (WM) lesion activity in patients with progressive MS, elucidating whether and how WM lesional activity relates to meningeal inflammation and subpial cortical injury is of interest. Using post-mortem formalin-fixed paraffin-embedded tissue blocks (range, 5-72 blocks; median, 30 blocks) for each of 27 progressive MS patients, we assessed the relationship between meningeal inflammation, the extent of subpial cortical demyelination, and the state of subcortical WM lesional activity. Meningeal accumulations of T cells and B cells, but not myeloid cells, were spatially adjacent to subpial cortical lesions and greater immune-cell accumulation was associated with higher subpial lesion numbers. Patients with a higher extent of meningeal inflammation harboured a greater proportion of active and mixed (active-inactive) WM lesions, and an overall lower proportion of inactive and remyelinated WM lesions. Our findings support the involvement of meningeal lymphocytes in subpial cortical injury, and also point to a potential link between inflammatory subpial cortical demyelination and pathological mechanisms occurring in the subcortical white matter.

Vitamin D effects on androgen levels in men

Background. Accumulating evidence from animal and human studies suggests that vitamin D is involved in many functions of the reproductive system. Considering the potential link between vitamin D and human fertility, authors performed this review summarizing current literature on vitamin D and possible mechanisms explaining the link of vitamin D with androgen metabolism in men. The purpose of this review was to provide an overview on the effects of vitamin D on androgen metabolism in men. Methods. Author performed a systematic literature search in PubMed for relevant English language publications published from January 2011 until September 2021. Results. The vitamin D receptor and vitamin D-metabolizing enzymes are found in reproductive tissues. In men, vitamin D status has been associated with androgen levels and hypogonadism. Further, there is some evidence for a favorable effect of vitamin D supplementation on testosterone concentrations, although others failed to show a significant effect on testosterone levels. Vitamin D might play an important role in androgen metabolism. Existing evidence from available trials evaluating the effect of vitamin D supplementation on androgen levels in men is insufficient to recommend measurement of 25(OH)D levels or vitamin D supplementation in hypogonadal men. We cannot exclude vitamin D effects on androgen levels in men with low TT levels or in men with severe vitamin D deficiency. This question remains to be answered in future investigations. Conclusions. Vitamin D deficiency is associated with adverse fertility outcomes including hypogonadism, but the evidence is insufficient to establish causality. High-quality trials are needed to further evaluate the effects of vitamin D supplementation on androgen levels in men.

The Calcivis story - enamel caries activity assessment from technology to practice

The Calcivis story is one of innovation and collaboration to deliver new technology capable of helping dentists improve patient care through solving an unmet clinical need in assessing the activity of caries lesions in enamel. Presently, there is no system routinely used in dental practice that can, in a single visit, determine whether a non-cavitated caries lesion is active or not. Calcivis has evolved since 2005, when a potential link between basic science in luminescence and differentiating initial-stage caries lesions that are actively demineralising and likely to progress, from other lesions which are inactive and currently do not need interventive care, was recognised. The 16-year journey has involved clinical academic dentists, scientists and entrepreneurs, general practitioners and their patients, together with serial investors and a core team working to patent, refine, assess and develop products to submit to regulatory approval and take to the international dental market. This journey has been made possible through effective long-term collaborations between disparate groups all sharing a common vision for the possibilities of harnessing new technology to help dental professionals provide better care for their patients.