812 research outputs found
Identification of pollen types of beekeeping interest by non-targeted mass spectrometry
No full textBackground
The identification of pollen is important in the field of beekeeping for the determination of the botanical origin of bee products and investigations of bee diet. Until now, it has been performed by melissopalynology, the microscopic examination of pollen grains. However, this technique has some limitations, such as the necessity of experienced analysts and identification restricted to the family level for some pollen types. Although many techniques have been proposed as alternatives or complements to melissopalynology and omics techniques have been explored to gather information on the botanical origin of honey, no study has yet been conducted on a large set of pollen types.
Results
The study dataset consisted of 34 different pollen types of pellets collected by honeybees in Switzerland and analyzed in multiple biological replications, leading to 150 observations. The pollen samples were analyzed after tryptic digestion using a non-targeted mass spectrometry-based method. Liquid chromatography coupled with mass spectrometry (LC–MS) was employed to identify pollen, and melissopalynology was used as a reference method for the identification. We built an OPLS-DA prediction model for the 34 pollen types. The model clearly identified new samples in their membership group (Acer sp., n = 10) and a new pollen type at the species-specific level for Quercus sp. Less predictable results were achieved for Composita H and pollen collected directly from the plant.
Conclusion
The use of a non-targeted mass spectrometry-based method and chemometrics resulted in a promising tool for pollen identification as a replacement/supplement method to traditional melissopalynology
From food to physiology characterization and in vitro digestion of milk products and investigation of postprandial metabolism and inflammation after a high-fat meal intake in a human nutrition intervention study
No full textAccording to the World Health Organization worldwide obesity has more than doubled since 1980. The World health statistics 2012 report shows that one in six adults is obese, one in ten diabetic and one in three has a raised blood pressure. Overweight and obesity are major risk factors for cardiovascular diseases,According to the World Health Organization worldwide obesity has more than doubled since 1980. The World health statistics 2012 report shows that one in six adults is obese, one in ten diabetic and one in three has a raised blood pressure. Overweight and obesity are major risk factors for cardiovascular diseases, diabetes and some cancers. The causes of overweight and obesity are mainly a decrease in physical activity and an increased intake of energy-dense foods leading to a positive energy balance. Not only dietary patterns play a major role in the development of obesity. Food composition also directly impacts on postprandial metabolism and inflammation and, in long term, may contribute to systemic low-grade inflammation, a characteristic associated with the obese state. Thus it is not surprising that there is a growing interest in better understanding the effect of different foods and food compounds on human metabolism and health. The aim of the NutriChip project is to develop a microfluidic chip device to screen foods and their compounds for health promoting, e.g. immune-modulatory, properties. Milk products have been chosen as a food model because their consumption has been shown to be associated with decreased levels of inflammatory markers (1), and also because technological and microbiological transformations allow the realization of various products, such as yoghurt and cheese, having potentially different physiological effects. This thesis covers the biochemical (products characterization and in vitro digestion) and physiological (human nutrition study) aspects of the NutriChip project. Initially, differently heat-treated and fermented milk products were characterized by a proteomic approach. Various fractionation methods were used for selectively enriching minor milk and bacterial proteins in different dairy products. Proteins were separated and identified by two dimensional (2D) gel-electrophoresis and liquid chromatography coupled to mass spectrometry (LC-MS/MS) analysis. All data are collected in an interactive platform, called protein atlas, which is now publicly available on http://www.foodle.ch/de/proteinstart. Currently, the database contains more than 200 different milk proteins and about 250 bacterial proteins. For a better in depth characterization of fermented products, a method for the enrichment of living bacterial cells has been developed. This method allows the investigation of bacterial proteomes under different fermentation conditions. The method was used to monitor the adaption of the yoghurt bacteria Lactobacillus bulgaricus and Streptococcus thermophilus during milk fermentation. Some well-known stress response proteins (chaperone proteins GroEL and DnaK) and various enzymes involved in the glycolysis pathway have been identified as a proof of concept. Another experiment aimed to investigate the bacterial proteome during cheese production with special regards towards the identification of enzymes involved in the formation of the cheese flavor compound 3-methylbutanal. An aminotransferase that catalyzes the first step in the conversion pathway from the amino acid leucine to the flavor compound 3-methylbutanal could be identified. A prerequisite for screening foods for health-modulating activity was the development of a static, three-step in vitro digestion model. The aim was to keep the model as physiological as possible and ideally perform the digestion on a small scale (volume < 15 mL). The digestion model has been thoroughly validated using pasteurized whole milk. The degradation of fat, carbohydrates and proteins into their basic constituents was consistent with human physiological values found in the literature. The system has been used to digest various milk products. With the two proteins α-s1-casein and β-lactoglobulin, a representative of the caseins and whey proteins, respectively, the influence of the fat content, heat treatment and fermentation of the products on their digestibility has been monitored. Particularly we also looked at the generation of bioactive peptides during the digestion process. Towards this aim, the identified peptides in the digestion experiments were compared with bioactive peptide sequences from the literature using the statistic program R. Over 50 milk protein-derived peptides containing bioactive peptide sequences, with e.g. antihypertensive, immune- and cyto-modulatory, opioid functions, could be identified. The next step in simulating the human digestive system is the intestinal transport. Therefore, a cell culture model mimicking the last step of digestion and final absorption of the nutrients, both steps being mediated by intestinal enterocytes, was established. For this aim, Caco-2 cells were used in a Transwell system with an upper and lower compartment containing cell culture medium. Digested milk products were added on top of the Caco-2 cell monolayer and medium was collected from the basolateral chamber for identification of transported, potential bioactive peptides. The final validation of the in vitro models needs the comparison with a human nutrition intervention study. We designed and conducted a dose-response intervention study to determine the caloric dose (500 kcal, 1’000 kcal, 1’500 kcal) of a high-fat meal needed to induce a postprandial metabolic and inflammatory response in normal weight and obese subjects. In our study, we investigated postprandial metabolism and inflammation by measuring classical clinical parameters such as glucose, insulin and triglycerides, as well as the inflammation markers C-reactive protein (CRP), interleukine-6 (IL-6) and endotoxin before and at various time points after the test meals consumption. Our study provided valuable clinical, mechanistic, and methodological insights into the metabolic response of subjects, varying in their metabolic health status, to increasing doses of a high-fat meal. This represents the basis for future studies aiming to investigate health-promoting properties of foods in general, as also their capability in lowering postprandial inflammation, a normal response mechanism after food ingestion. v diabetes and some cancers. The causes of overweight and obesity are mainly a decrease in physical activity and an increased intake of energy-dense foods leading to a positive energy balance. Not only dietary patterns play a major role in the development of obesity. Food composition also directly impacts on postprandial metabolism and inflammation and, in long term, may contribute to systemic low-grade inflammation, a characteristic associated with the obese state. Thus it is not surprising that there is a growing interest in better understanding the effect of different foods and food compounds on human metabolism and health. The aim of the NutriChip project is to develop a microfluidic chip device to screen foods and their compounds for health promoting, e.g. immune-modulatory, properties. Milk products have been chosen as a food model because their consumption has been shown to be associated with decreased levels of inflammatory markers (1), and also because technological and microbiological transformations allow the realization of various products, such as yoghurt and cheese, having potentially different physiological effects. This thesis covers the biochemical (products characterization and in vitro digestion) and physiological (human nutrition study) aspects of the NutriChip project. Initially, differently heat-treated and fermented milk products were characterized by a proteomic approach. Various fractionation methods were used for selectively enriching minor milk and bacterial proteins in different dairy products. Proteins were separated and identified by two dimensional (2D) gel-electrophoresis and liquid chromatography coupled to mass spectrometry (LC-MS/MS) analysis. All data are collected in an interactive platform, called protein atlas, which is now publicly available on http://www.foodle.ch/de/proteinstart. Currently, the database contains more than 200 different milk proteins and about 250 bacterial proteins. For a better in depth characterization of fermented products, a method for the enrichment of living bacterial cells has been developed. This method allows the investigation of bacterial proteomes under different fermentation conditions. The method was used to monitor the adaption of the yoghurt bacteria Lactobacillus bulgaricus and Streptococcus thermophilus during milk fermentation. Some well- known stress response proteins (chaperone proteins GroEL and DnaK) and various enzymes involved in the glycolysis pathway have been identified as a proof of concept. Another experiment aimed to investigate the bacterial proteome during cheese production with special regards towards the identification of enzymes involved in the formation of the cheese flavor compound 3-methylbutanal. An aminotransferase that catalyzes the first step in the conversion pathway from the amino acid leucine to the flavor compound 3-methylbutanal could be identified. v A prerequisite for screening foods for health-modulating activity was the development of a static, three-step in vitro digestion model. The aim was to keep the model as physiological as possible and ideally perform the digestion on a small scale (volume < 15 mL). The digestion model has been thoroughly validated using pasteurized whole milk. The degradation of fat, carbohydrates and proteins into their basic constituents was consistent with human physiological values found in the literature. The system has been used to digest various milk products. With the two proteins α-s1-casein and β-lactoglobulin, a representative of the caseins and whey proteins, respectively, the influence of the fat content, heat treatment and fermentation of the products on their digestibility has been monitored. Particularly we also looked at the generation of bioactive peptides during the digestion process. Towards this aim, the identified peptides in the digestion experiments were compared with bioactive peptide sequences from the literature using the statistic program R. Over 50 milk protein-derived peptides containing bioactive peptide sequences, with e.g. antihypertensive, immune- and cyto-modulatory, opioid functions, could be identified. The next step in simulating the human digestive system is the intestinal transport. Therefore, a cell culture model mimicking the last step of digestion and final absorption of the nutrients, both steps being mediated by intestinal enterocytes, was established. For this aim, Caco-2 cells were used in a Transwell system with an upper and lower compartment containing cell culture medium. Digested milk products were added on top of the Caco-2 cell monolayer and medium was collected from the basolateral chamber for identification of transported, potential bioactive peptides. The final validation of the in vitro models needs the comparison with a human nutrition intervention study. We designed and conducted a dose-response intervention study to determine the caloric dose (500 kcal, 1’000 kcal, 1’500 kcal) of a high-fat meal needed to induce a postprandial metabolic and inflammatory response in normal weight and obese subjects. In our study, we investigated postprandial metabolism and inflammation by measuring classical clinical parameters such as glucose, insulin and triglycerides, as well as the inflammation markers C-reactive protein (CRP), interleukine-6 (IL-6) and endotoxin before and at various time points after the test meals consumption. Our study provided valuable clinical, mechanistic, and methodological insights into the metabolic response of subjects, varying in their metabolic health status, to increasing doses of a high-fat meal. This represents the basis for future studies aiming to investigate health- promoting properties of foods in general, as also their capability in lowering postprandial inflammation, a normal response mechanism after food ingestion.LMIS
Behavior of the Chiral Herbicide Imazamox in Soils: pH-Dependent, Enantioselective Degradation, Formation and Degradation of Several Chiral Metabolites
No full textMany pesticides show a pronounced
biphasic degradation in soil,
typically with a faster initial phase, followed by a slower decline.
For chiral compounds, a biphasic decline of the total concentration
may result from enantioselective degradation. In this study with the
chiral herbicide imazamox, biphasic degradation was observed in most
of the 18 soils investigated. In neutral soils, degradation was, in
fact, enantioselective with faster degradation of (+)-imazamox. In
slightly acidic soils, differences between enantiomers were not pronounced,
and in strongly acidic soils, degradation was again enantioselective,
but with reversed preference. Additional experiments with pure enantiomers
indicated no interconversion. Enantioselective degradation thus contributed
to the biphasic decline of the total concentration in certain soils.
However, this was not the only factor since degradation of the individual
enantiomers was biphasic in itself. In addition to the observed correlation
between enantioselectivity and pH, degradation was generally faster
in neutral than in acidic soils with half-lives ranging from only
2 to >120 days. Half-lives were also determined for two known metabolites
and a further chiral metabolite, the structure of which was characterized
by high resolution tandem mass spectrometry. As for the parent compound,
half-lives of the metabolites varied considerably in the different
soils
Turning placenta into brain: placental mesenchymal stem cells differentiate into neurons and oligodendrocytes
No full textObjective
We aimed to induce neural stem (NSC) and progenitor cells (NPC) from human placental tissues.
Study Design
Placental stem cells from first-trimester placental chorionic villi and term chorion were isolated. Neural differentiation was initiated with plating on collagen, retinoic acid, and/or human brain-derived neurotrophic factor and epidermal and fibroblast growth factor. Differentiation into neurons, oligodendrocytes, and astrocytes was monitored by immunohistochemistry. Two-dimensional polyacrylamide gel electrophoresis, high-performance liquid chromatography, and tandem mass spectrometry were used to identify proteins involved in the differentiation.
Results
Differentiated cells were mostly immediately postmitotic with some more but not fully mature postmitotic neurons. Neurons had dopaminergic or serotonergic character. Some cells differentiated into predominantly immature oligodendrocytes. Upon differentiation, neuron-specific proteins were up-regulated, whereas placental proteins were reduced.
Conclusion
Stem cells derived from human placenta can be differentiated into neural progenitors
Purification and functional reconstitution of the human Wilson copper ATPase, ATP7B
No full textAbstractWilson disease is a disorder of copper metabolism, due to inherited mutations in the Wilson copper ATPase gene ATP7B. To purify and study the function of the ATPase, the enzyme was truncated by five of the six metal binding domains and endowed with an N-terminal histidine-tag for affinity purification. This construct, Δ1–5WNDP, was able to functionally complement a yeast strain defective in its native copper ATPase CCC2. Δ1–5WNDP was purified by Ni-affinity chromatography and reconstituted into proteoliposomes. This allowed, for the first time, the functional study of the Wilson ATPase in a purified, reconstituted system
Giedion and America: Repositioning the History of Modern Architecture
No full textSigfried Giedion (1888–1968), one of the main protagonists of the architectural avant-garde in Europe, paradoxically achieved this reputation in America, far from his homeland. Nearly all of Giedion’s books written after his initial stay at Harvard University were published in English long before they became available in his native German. Reto Geiser sheds new light on Giedion’s life and reassesses his work through the lens of cultural transformation and modernization processes. The author questions the unbroken line of developments portrayed in the historiography of modern architecture, and argues that Giedion’s position in between two cultural spheres not only caused ruptures and contradictions in his work but also productively shaped its reception on either side of the Atlantic
Reto y confrontación en el enfoque centrado en la persona
No full textIn this article the role of the challenge in the person centered approach is analized. With this aim the author has planned a small-scale research study using an open questionaire with a sample of 10 therapists and 15 clients. From this study it would appear that challenge, in terms of the opportunities and freedoms offered by the core conditions, is an integral part of the person centered approach.En este artículo la autora reflexiona sobre el papel que juegan el reto y la confrontación en el enfoque centrado en la persona. A este fin se plantea un estudio a pequeña escala a través de un cuestionario suministrado a una muestra reducida de diez terapeutas y quince clientes. Del análisis de sus resultados se deduce que reto y confrontación, en términos de nuevas oportunidades y alternativas son elementos nucleares del enfoque centrado en la persona
Structural model of the CopA copper ATPase of Enterococcus hirae based on chemical cross-linking
No full textThe CopA copper ATPase of Enterococcus hirae belongs to the family of heavy metal pumping CPx-type ATPases and shares 43% sequence similarity with the human Menkes and Wilson copper ATPases. Due to a lack of suitable protein crystals, only partial three-dimensional structures have so far been obtained for this family of ion pumps. We present a structural model of CopA derived by combining topological information obtained by intramolecular cross-linking with molecular modeling. Purified CopA was cross-linked with different bivalent reagents, followed by tryptic digestion and identification of cross-linked peptides by mass spectrometry. The structural proximity of tryptic fragments provided information about the structural arrangement of the hydrophilic protein domains, which was integrated into a three-dimensional model of CopA. Comparative modeling of CopA was guided by the sequence similarity to the calcium ATPase of the sarcoplasmic reticulum, Serca1, for which detailed structures are available. In addition, known partial structures of CPx-ATPase homologous to CopA were used as modeling templates. A docking approach was used to predict the orientation of the heavy metal binding domain of CopA relative to the core structure, which was verified by distance constraints derived from cross-links. The overall structural model of CopA resembles the Serca1 structure, but reveals distinctive features of CPx-type ATPases. A prominent feature is the positioning of the heavy metal binding domain. It features an orientation of the Cu binding ligands which is appropriate for the interaction with Cu-loaded metallochaperones in solution. Moreover, a novel model of the architecture of the intramembranous Cu binding sites could be derived
Farmacetiskā aprūpe un tās uzlabošanas iespējas Reto slimību pacientiem
No full textVeselības vadībaVeselības aprūpeHealth ManagementHealth CareFarmaceitiskā aprūpe un tās būtiskā nozīme pacientu veselības aprūpē ir jau gadiem aktuāla tēma farmaceitu darba ikdienā. Pieaugot reto slimību diagnostikai, pētniecībai un ārstēšanas iespējām, aptiekās pieaug arī medikamentu pieejamība šo slimību pacientiem. To, kādas ir farmaceitu zināšanas par reto slimību pacientiem, to diagnozēm un pielietojamo medikamentozo terapiju, pētīja darba autore.
Maģistra darba tēma ir “Farmaceitiskā aprūpe un tās uzlabošanas iespējas reto slimību pacientiem Latvijā”. Maģistra darba mērķis bija izpētīt farmaceitisko aprūpi reto slimību pacientiem un izstrādāt priekšlikumus tās pilnveidošanai Latvijā.
Pētījuma jautājumi:
1. Kādas konceptuālās pieejas pastāv un kāda ir starptautiskā prakse reto slimību pacientu farmaceitiskajā aprūpē?
2. Kāds ir reto slimību pacientu aprūpes un medikamentozās ārstēšanas nodrošinājums Latvijā?
3. Kāds ir farmaceitu pieejamās informācijas, zināšanu un profesionālās pieredzes līmenis par retajām slimībām un to medikamentozo ārstēšanu?
Hipotēze: Farmaceitiskā aprūpe reto slimību pacientiem būtiski atšķiras no tradicionālās farmaceitiskās aprūpes. Hipotēze tiek apstiprināta ar šādiem pētījuma secinājumiem:
1. 38% respondentu jeb 43 farmaceiti daļēji iztaujā pacientus par viņu diagnozēm un lietotajiem medikamentiem, savukārt 23% jeb 26 farmaceiti neuzdod pacientiem jautājumus par blakusslimībām vai lietotajiem medikamentiem, kā arī pacienti farmaceitiem neatklāj savas diagnozes, tādējādi neveidojas dialogs, kura laikā var tikt sniegta kvalitatīva farmaceitiskā aprūpe.
2. 70% jeb 80 farmaceitu uzskata, ka farmaceitiskās aprūpes plāns retu slimību pacientam ir nepieciešams, 83% jeb 5 eksperti uzskata, ka nav nepieciešams, kā arī 100% jeb visi 4 pacienti atbildēja, ka aptiekā nav nepieciešams farmaceitiskās aprūpes plāns reto slimību pacientiem.
Maģistra darbā ir 95 lappuses, 3 pielikumi, 22 tabulas, 14 attēli un 57 literatūras avoti.Pharmaceutical care and its essential role in patient health care has been a topical issue in the daily work of pharmacists for years. As the diagnosis, research and treatment options for rare diseases increase, so does the availability of medicines in pharmacies.
What is the knowledge of pharmacists about patients with rare diseases, their diagnoses and applicable drug therapy researched by the author of the paper.
Master's thesis topic Pharmaceutical care and its improvement opportunities for rare disease patients in Latvia.
The aim of the master's thesis is to study pharmaceutical care for patients with rare diseases and to develop proposals for its improvement in Latvia.
Research questions
1. What conceptual approaches exist and what is the international practice in pharmaceutical care for patients with rare diseases?
2. What is the provision of care and medical treatment for patients with rare diseases in Latvia?
3. What is the level of information, knowledge and professional experience available to pharmacists on rare diseases and their medical treatment?
Hypothesis: Pharmaceutical care for patients with rare diseases differs significantly from traditional pharmaceutical care. The hypothesis is confirmed by the following conclusions of the study:
1. 38% of respondents, or 43 pharmacists, partially ask patients about their diagnoses and medications, 23% or 26 pharmacists do not ask patients questions about co-morbidities or medications used, patients do not disclose their diagnoses to pharmacists, thus there is no dialogue during which quality pharmaceutical care can be provided.
2. 70% or 80 pharmacists believe that a pharmaceutical care plan for a rare disease patient is necessary, 83% or 5 experts believe that it is not necessary, as well as 100% or all 4 patients answered that a pharmacy does not need a pharmaceutical care plan for a rare disease patient.
Master's thesis consists of 95 Pages, 3 Appendice, 22 tables, 14 figures, and 57 literature sources
CopY-like copper inducible repressors are putative 'winged helix' proteins
No full textCopY of Enterococcus hirae is a well characterized copper-responsive repressor involved in copper homeostasis. In the absence of copper, it binds to the promoter. In high copper, the CopZ copper chaperone donates copper to CopY, thereby releasing it from the promoter and allowing transcription of the downstream copper homeostatic genes of the cop operon. We here show that the CopY-like repressors from E. hirae, Lactococcus lactis, and Streptococcus mutans have similar affinities not only for their native promoters, but also for heterologous cop promoters. CopZ of L. lactis accelerated the release of CopY from the promoter, suggesting that CopZ of L. lactis acts as copper chaperone, similar to CopZ in E. hirae. The consensus binding motif of the CopY-like repressors was shown to be TACAxxTGTA. The same binding motif is present in promoters controlled by BlaI of Bacillus licheniformis, MecI of Staphylococcus aureus and related repressors. BlaI and MecI have known structures and belong to the family of 'winged helix' proteins. In the N- terminal domain, they share significant sequence similarity with CopY of E. hirae. Moreover, they bind to the same TACAxxTGTA motif. NMR analysis of the N-terminal DNA binding domain of CopY of L. lactis showed that it contained the same alpha-helical content like the same regions of BlaI and MecI. These findings suggest that the DNA binding domains of CopY-like repressors are also of the 'winged helix' type
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