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News Article | December 1, 2016
Site: www.eurekalert.org

Chemical analyses of Tycho Brahe's exhumed remains have revealed that the world-renowned astronomer was regularly exposed to large quantities of gold until shortly before his death. The Renaissance astronomer Tycho Brahe truly lived a gilded life, according to a team of chemists who have analysed his hair. - We found traces of gold in Tycho Brahe's hair, and we can establish that he was exposed to gold while these hairs were still on his body, said Kaare Lund Rasmussen, Associate Professor at Department of Physics, Chemistry and Pharmacy, University of Southern Denmark. Rasmussen and his team obtained permission to analyse pieces of hair from the scalp, beard and eyebrows of the astronomer, whose remains are today located in the City of Prague Museum in Prague. The findings have been published in the scientific journal Archaeometry. Analyses of three separate hair samples showed a gold content of ca. 20 to 100 times higher than what one would expect to find in a typical person today. There are no natural sources that could explain this high level of exposure to gold, such as earth or water, which means that Brahe must have been regularly exposed to gold in his everyday life. - It may have been the cutlery and plates of gold, or maybe the wine he drank contained gold leaf. It's also possible that he concocted and consumed elixirs containing gold, or that he worked with alchemy, Rasmussen said. Gold was not the only metal the researchers found traces of. Brahe's hair also contained traces of iron, cobalt, arsenic and silver in concentrations exceeding what is common today - albeit not to the same degree as the gold content in his hair. The concentration of metals is lower in the younger parts of the hairs, which allows the researchers to conclude that he was not exposed to these metals (approximately) the last 2 months before his death. The reason for that may be because he was too weak to work in his laboratory in his final weeks and months. - What this tells us is that he did not suffer from an acute and fatal poisoning. This is not a particularly unusual cause of death in a period where the toxicity of metals was still unknown. Sir Isaac Newton, for instance, was subjected to mercury and lead poisoning, Rasmussen explained. Today, we know that certain metals - and especially heavy metals - can be outright toxic, but in Tycho Brahe's time, the 1600s, no one was aware of this yet. In fact, people were keen to incorporate these valuable metals into their everyday lives, as they could be used for many different things. Clay plates and dishes, for example, were lead-glazed to give them a water-repellent surface, and mercury was used as medicine or tonic elixirs. Unfortunately, these were also heavy metals which could damage one's internal organs and nervous system. Tycho Brahe also lived in an era where many in the natural scientists were conducting experiments with various elements in the laboratory. Alchemy was at the cutting edge of contemporary scientific research, and because the toxicity of these elements had yet to be discovered, many alchemists ended up poisoning themselves as a consequence of their work. What did he NOT die of The analyses of Brahe's remains also allowed researchers to establish with certainty that he did not have a number of metabolic diseases. Earlier analyses by Rasmussen and his colleagues have shown that Brahe did not die of mercury poisoning, which has been a prevailing theory for some time. The theory was finally debunked in 2012 when Rasmussen and his colleagues conducted tests on the astronomer's remains and found no traces of mercury in his hair, teeth or bones. The latest analyses also did not find any traces of mercury. - What Tycho Brahe died of is therefore still uncertain, Rasmussen said. The samples from Tycho Brahe's grave: In 2010, a team of Danish and Czech researchers exhumed Brahe's body from its resting place in the Church of Our Lady Before Tyn in Prague, Czech Republic. The team took a number of samples from his hair, teeth, bones and clothes, after which he was buried again. Tycho Brahe (1546-1601): Danish astronomer who founded the observatories Uranienborg and Stjerneborg on the island of Ven. Samples from the grave: In 2010, a team of Danish and Czech researchers exhumed Brahe's body from its resting place in the Church of Our Lady Before Tyn in Prague, Czech Republic. The team took a number of samples from his hair, teeth, bones and clothes, after which he was buried again.


News Article | February 23, 2017
Site: www.eurekalert.org

For the first time a "tipping point" molecular link between the blood sugar glucose and Alzheimer's disease has been established by scientists, who have shown that excess glucose damages a vital enzyme involved with inflammation response to the early stages of Alzheimer's. Abnormally high blood sugar levels, or hyperglycaemia, is well-known as a characteristic of diabetes and obesity, but its link to Alzheimer's disease is less familiar. Diabetes patients have an increased risk of developing Alzheimer's disease compared to healthy individuals. In Alzheimer's disease abnormal proteins aggregate to form plaques and tangles in the brain which progressively damage the brain and lead to severe cognitive decline. Scientists already knew that glucose and its break-down products can damage proteins in cells via a reaction called glycation but the specific molecular link between glucose and Alzheimer's was not understood. But now scientists from the University of Bath Departments of Biology and Biochemistry, Chemistry and Pharmacy and Pharmacology, working with colleagues at the Wolfson Centre for Age Related Diseases, King's College London, have unraveled that link. By studying brain samples from people with and without Alzheimer's using a sensitive technique to detect glycation, the team discovered that in the early stages of Alzheimer's glycation damages an enzyme called MIF (macrophage migration inhibitory factor) which plays a role in immune response and insulin regulation. MIF is involved in the response of brain cells called glia to the build-up of abnormal proteins in the brain during Alzheimer's disease, and the researchers believe that inhibition and reduction of MIF activity caused by glycation could be the 'tipping point' in disease progression. It appears that as Alzheimer's progresses, glycation of these enzymes increases. The study is published in the journal Scientific Reports. Professor Jean van den Elsen, from the University of Bath Department of Biology and Biochemistry, said: "We've shown that this enzyme is already modified by glucose in the brains of individuals at the early stages of Alzheimer's disease. We are now investigating if we can detect similar changes in blood. "Normally MIF would be part of the immune response to the build-up of abnormal proteins in the brain, and we think that because sugar damage reduces some MIF functions and completely inhibits others that this could be a tipping point that allows Alzheimer's to develop. Dr Rob Williams, also from the Department of Biology and Biochemistry, added: "Knowing this will be vital to developing a chronology of how Alzheimer's progresses and we hope will help us identify those at risk of Alzheimer's and lead to new treatments or ways to prevent the disease. Dr Omar Kassaar, from the University of Bath, added: "Excess sugar is well known to be bad for us when it comes to diabetes and obesity, but this potential link with Alzheimer's disease is yet another reason that we should be controlling our sugar intake in our diets." Globally there are around 50 million people with Alzheimer's disease, and this figure is predicted to rise to more than 125 million by 2050. The global social cost of the disease runs into the hundreds of billions of dollars as alongside medical care patients require social care because of the cognitive effects of the disease. The study was funded by the Dunhill Medical Trust. Human brain tissue for this study was provided through Brains for Dementia Research, a joint initiative between Alzheimer's Society and Alzheimer's Research UK in association with the Medical Research Council. For further information, please contact Chris Melvin in the University of Bath Press Office on +44 (0)1225 386 319 or c.m.melvin@bath.ac.uk Copies of the paper available on request. The University of Bath celebrates its 50th anniversary this year as one of the UK's leading universities both in terms of research and our reputation for excellence in teaching, learning and graduate prospects. In the REF 2014 research assessment 87 per cent of our research was defined as 'world-leading' or 'internationally excellent'. From making aircraft more fuel efficient, to identifying infectious diseases more quickly, or cutting carbon emissions through innovative building solutions, research from Bath is making a difference around the world. Find out more: http://www. Well established as a nurturing environment for enterprising minds, Bath is ranked highly in all national league tables. We were chosen as the UK's top university in the Times Higher Education Student Experience Survey 2015. The Dunhill Medical Trust is a charity which supports innovation in the care of older people and research into the causes and treatments of disease, disability and frailty related to ageing. It welcomes high quality grant applications, particularly those within the following areas: care of older people, including rehabilitation and palliative care; and research into the causes and treatments of disease, disability and frailty related to ageing. The Dunhill Medical Trust is a grant-making charitable company limited by guarantee (company no. 7472301; charity no. 1140372). It is a member of the Association of Medical Research Charities (AMRC) and a recognised charity partner of the National Institute for Health Research (NIHR).


News Article | February 24, 2017
Site: www.biosciencetechnology.com

For the first time a "tipping point" molecular link between the blood sugar glucose and Alzheimer's disease has been established by scientists, who have shown that excess glucose damages a vital enzyme involved with inflammation response to the early stages of Alzheimer's. Abnormally high blood sugar levels, or hyperglycaemia, is well-known as a characteristic of diabetes and obesity, but its link to Alzheimer's disease is less familiar. Diabetes patients have an increased risk of developing Alzheimer's disease compared to healthy individuals. In Alzheimer's disease abnormal proteins aggregate to form plaques and tangles in the brain which progressively damage the brain and lead to severe cognitive decline. Scientists already knew that glucose and its break-down products can damage proteins in cells via a reaction called glycation but the specific molecular link between glucose and Alzheimer's was not understood. But now scientists from the University of Bath Departments of Biology and Biochemistry, Chemistry and Pharmacy and Pharmacology, working with colleagues at the Wolfson Centre for Age Related Diseases, King's College London, have unraveled that link. By studying brain samples from people with and without Alzheimer's using a sensitive technique to detect glycation, the team discovered that in the early stages of Alzheimer's glycation damages an enzyme called MIF (macrophage migration inhibitory factor) which plays a role in immune response and insulin regulation. MIF is involved in the response of brain cells called glia to the build-up of abnormal proteins in the brain during Alzheimer's disease, and the researchers believe that inhibition and reduction of MIF activity caused by glycation could be the 'tipping point' in disease progression. It appears that as Alzheimer's progresses, glycation of these enzymes increases. The study is published in the journal Scientific Reports. Professor Jean van den Elsen, from the University of Bath Department of Biology and Biochemistry, said: "We've shown that this enzyme is already modified by glucose in the brains of individuals at the early stages of Alzheimer's disease. We are now investigating if we can detect similar changes in blood. "Normally MIF would be part of the immune response to the build-up of abnormal proteins in the brain, and we think that because sugar damage reduces some MIF functions and completely inhibits others that this could be a tipping point that allows Alzheimer's to develop. Dr. Rob Williams, also from the Department of Biology and Biochemistry, added: "Knowing this will be vital to developing a chronology of how Alzheimer's progresses and we hope will help us identify those at risk of Alzheimer's and lead to new treatments or ways to prevent the disease. Dr. Omar Kassaar, from the University of Bath, added: "Excess sugar is well known to be bad for us when it comes to diabetes and obesity, but this potential link with Alzheimer's disease is yet another reason that we should be controlling our sugar intake in our diets." Globally there are around 50 million people with Alzheimer's disease, and this figure is predicted to rise to more than 125 million by 2050. The global social cost of the disease runs into the hundreds of billions of dollars as alongside medical care patients require social care because of the cognitive effects of the disease. The study was funded by the Dunhill Medical Trust. Human brain tissue for this study was provided through Brains for Dementia Research, a joint initiative between Alzheimer's Society and Alzheimer's Research UK in association with the Medical Research Council.


Svane S.,Chemistry and Pharmacy | Kryuchkov F.,Campusvej | Lennartson A.,Chemistry and Pharmacy | McKenzie C.J.,Chemistry and Pharmacy | Kjeldsen F.,Campusvej
Angewandte Chemie - International Edition | Year: 2012

Complex protection: Fragmentation of phosphorylated peptide ions by collision-activated dissociation (CAD) is possible without facile detachment of the phosphate ester group when it is protected by a digallium complex (see scheme). The application of this dimetal phosphate ester stabilization (DIMPES) approach is believed to hold enormous potential for application in phosphoproteomics. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Becucci L.,University of Florence | Valensin D.,Chemistry and Pharmacy | Innocenti M.,University of Florence
Soft Matter | Year: 2014

The mechanism of membrane permeabilization by dermcidin (DCD-1L), an antimicrobial peptide present in human sweat, was investigated at a mercury-supported monolayer of dioleoylphosphatidylcholine (DOPC) or dioleoylphosphatidylserine (DOPS) and at a mercury-supported tethered bilayer lipid membrane (tBLM) consisting of a thiolipid (DPTL) with a DOPC or DOPS monolayer self-assembled on top of it. In an unbuffered solution of pH 5.4, DCD-1L is almost neutral and permeabilizes a DPTL/DOPS tBLM at transmembrane potentials, φtrans, which are physiological. In a pH 7 buffer solution DCD-1L bears two negative charges and has no effect on a DPTL/DOPC tBLM, whereas it permeabilizes a DPTL/DOPS tBLM only outside the physiological φtrans range; however, the presence of zinc ion induces DCD-1L to permeabilize the DPTL/DOPS tBLM at physiological φtrans values. The effect of zinc ions suggests a DCD-1L conformation with its positive N-terminus embedded in the lipid bilayer and the negative C terminus floating on the membrane surface. This conformation can be stabilized by a zinc ion bridge between the His38 residue of the C terminus and the carboxyl group of DOPS. Chronocoulometric potential jumps from φtrans ≅ +160 mV to sufficiently negative values yield charge transients exhibiting a sigmoidal shape preceded by a relatively long "foot". This behavior is indicative of ion-channel formation characterized by disruption of DCD-1L clusters adsorbed on top of the lipid bilayer, incorporation of the resulting monomers and their aggregation into hydrophilic pores by a mechanism of nucleation and growth. © 2014 The Royal Society of Chemistry.


Rossi C.,Chemistry and Pharmacy | Rossi C.,University of Florence | Bonechi C.,Chemistry and Pharmacy | Bonechi C.,University of Florence | And 4 more authors.
Macromolecular Symposia | Year: 2014

Biomacromolecules in solution modify the structure and the dynamics of the bulk water at the solute-solvent interface. The ordering effects of biomolecules, in particular proteins, are extended for several angstroms. The role of the hydration shells around a protein has yet to be completely understood. Hydrated proteins maintain more dynamic flexibility with respect to the dried system, which is an important property in protein-protein and/or protein-ligand recognition processes. In this paper we propose a method for analyzing the dynamical properties of the water molecules present in the hydration shells of proteins. The approach is based on analysis of the effects of protein-solvent interactions on water protons NMR relaxation parameters. The water proton spin-lattice relaxation rate in protein solution is analyzed considering all possible dipolar contributions from coupled protons environments. The analysis of both selective and non-selective water spin-lattice relaxation rates allowed the calculation of the average effective correlation time for the water molecules at the protein interface and the evaluation of the long range ordering effect of the protein surface. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Potocki S.,Wrocław University | Valensin D.,Chemistry and Pharmacy | Kozlowski H.,Wrocław University
Dalton Transactions | Year: 2014

The Zrt/Irt-like protein (ZIP) family contributes to the metal homeostasis by regulating the transport of divalent metal cations such as Fe2+, Zn2+, Mn2+, Cd2+ and sometimes even Cu 2+. Most ZIP members have a long variable loop between transmembrane domains (TMDs) III and IV; this region is predicted to be located in the cytoplasm and is postulated to be the metal ion binding site. In this study, we looked at the thermodynamic behavior and coordination chemistry of Zn 2+, Ni2+ and Cu2+ complexes with the histidine-rich domain, Ac-(185)RAHAAHHRHSH(195)-NH2 (HRD), from the yeast TjZNT1 protein, located between TMDs III and IV. The sequence is conserved also in higher species like Thlaspi japonicum. The stability of complexes increases in the series Ni2+ < Zn2+ ≪ Cu 2+. The geometry of complexes is very different for each metal and in the case of Zn2+ complexes, high specificity in binding is observed. Moreover, the stability of HRD-Cu2+ complexes was compared with the five His residues containing peptide from Hpn protein (Helicobacter pylori). The results suggest a high ability of HRD in the binding of all three studied metals. © 2014 The Royal Society of Chemistry.


Stokowa-Soltys K.,Wrocław University | Gaggelli N.,Chemistry and Pharmacy | Nagaj J.,Wrocław University | Szczepanik W.,Wrocław University | And 6 more authors.
Journal of Inorganic Biochemistry | Year: 2013

Three representatives of the distinct antibiotics groups: amoxicillin, apramycin and ristomycin A were studied regarding their impact on hepatitis D virus (HDV) ribozyme both in the metal-free form and complexed with copper(II) ions. Hence the Cu(II)-ristomycin A complex has been characterized by means of NMR, EPR, CD and UV-visible spectroscopic techniques and its binding pattern has been compared with the coordination modes estimated previously for Cu(II)-amoxicillin and Cu(II)-apramycin complexes. It has thus been found that all three antibiotics bind the Cu(II) ion in a very similar manner, engaging two nitrogen and two oxygen donors into coordination with the square planar symmetry in physiological conditions. All three tested antibiotics were able to inhibit the HDV ribozyme catalysis. However, in the presence of the complexes, the catalytic reactions were almost completely inhibited. It was important therefore to check whether the complexes used in lower concentrations could inhibit the HDV ribozyme catalytic activity, thus creating opportunities for their practical application. It turned out that the complexes used in the concentrations of 50 μM influenced the catalysis much less effectively comparing to the 200 micromolar concentration. The kobs values were lower than those observed in the control reaction, in the absence of potential inhibitors: 2-fold for amoxicillin, ristomycin A and 3.3-fold for apramycin, respectively. © 2013 Elsevier Inc.


News Article | December 15, 2016
Site: www.eurekalert.org

A researcher in Germany is studying why fish sometimes smells 'fishy' and why customers often smell other aromas when they buy fish. Mohamed Mahmoud, doctoral candidate at the Department of Chemistry and Pharmacy at FAU, identified various off-flavours of fish raised in aquaculture as part of his doctoral thesis. His goal is to discover how to reduce unpleasant musty notes in the taste of fish. Eating fish as part of a high-protein diet is healthy - which is why more and more people have put salmon and other types of fish on the menu. However, this trend also means that as the demand for wild-caught fish increases, natural resources are gradually depleted. The ecological balance is disturbed, threatening long-term food security around the world. 'This is why aquacultures where fish are raised are important,' explained Prof. Dr. Andrea Büttner from the Chair of Food Chemistry at FAU's Emil Fischer Centre. However, there is one clear disadvantage to farm-raised fish from the consumers' perspective: they often have undesirable flavours. 'Microorganisms can form in aquaculture ponds and other substances can successively break down in the water, creating highly potent aromas which in turn cause deficiencies in the fish,' explained Prof. Büttner. The musty, earthy smell, for example, is typically caused by two substances: geosmin, which has an earthy, musty, or mouldy smell, and the chemical compound 2-methylisoborneol (MIB), which has a rotten fish smell. It was previously assumed that these substances were primarily responsible for off-flavours in fish. It was unclear whether other culprits might be responsible for fishy smells. Manure smell most likely from livestock husbandry Doctoral candidate Mohamed Mahmoud's experiments are intended to find answers to this question. The young researcher recently conducted a successful experiment on rainbow trout aquaculture. In addition to geosmin and MIB, he identified ten other substances with a musty-earthy smell, including one that smells like manure. 'The manure smell most likely comes from livestock husbandry, such as pig farms, but other substances appear to be the result of odour-producing disintegration of pesticides. These substances run off over land into the water and get into the fish,' said Mahmoud. This made it clear that the conventional wisdom on this matter needs to be looked at more critically and that the sources of flavour problems are significantly more complex than previously assumed. Mahmoud's main goal is to discover ways to avoid off-flavours in farm-raised fish, as aquaculture is certain to play an even bigger role in future. The variety of aromas typical for fish The combinations of various aromas typical for fish are of great interest for Mahmoud. 'When you look at the components of fish aromas, it's interesting that you also find unexpected substances.' The young researcher has identified aromas in fish that smell like, for example, geraniums, citrus, eucalyptus, caramel, peach or black pepper. 'It isn't unusual; food aromas are generally very complex and it's difficult to identify the individual components of an overall aroma - unless you use our targeted analytics which allow you to individually identify aromatic substances,' explained Mahmoud. 'Our main goal is still to find, among all the possible substances, exactly those substances that are perceived negatively and that aren't typical for fish - especially in comparison with wild-caught fish. We are working to find more potential causes of off-flavours in aquaculture fish produced in Germany and to identify the links between water quality and aroma profiles.' Together with the Fraunhofer Institute for Process Engineering and Packaging IVV in Freising, Mohamed Mahmoud is conducting sensory tests of fish, aquaculture pond water, and added and drained water. He uses gas chromatography-olfactometry, which allows for odour-producing substances to be detected and analysed.

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