818 resultados para Coeficiente Alfa de Cronbach
Resumo:
Background: The fecal neutrophil-derived proteins calprotectin and lactoferrin have proven useful surrogate markers of intestinal inflammation. The aim of this study was to compare fecal calprotectin and lactoferrin concentrations to clinically, endoscopically, and histologically assessed Crohn’s disease (CD) activity, and to explore the suitability of these proteins as surrogate markers of mucosal healing during anti-TNFα therapy. Furthermore, we studied changes in the number and expression of effector and regulatory T cells in bowel biopsy specimens during anti-TNFα therapy. Patients and methods: Adult CD patients referred for ileocolonoscopy (n=106 for 77 patients) for various reasons were recruited (Study I). Clinical disease activity was assessed with the Crohn’s disease activity index (CDAI) and endoscopic activity with both the Crohn’s disease index of severity (CDEIS) and the simple endoscopic score for Crohn’s disease (SES-CD). Stool samples for measurements of calprotectin and lactoferrin, and blood samples for CRP were collected. For Study II, biopsy specimens were obtained from the ileum and the colon for histologic activity scoring. In prospective Study III, after baseline ileocolonoscopy, 15 patients received induction with anti-TNFα blocking agents and endoscopic, histologic, and fecal-marker responses to therapy were evaluated at 12 weeks. For detecting changes in the number and expression of effector and regulatory T cells, biopsy specimens were taken from the most severely diseased lesions in the ileum and the colon (Study IV). Results: Endoscopic scores correlated significantly with fecal calprotectin and lactoferrin (p<0.001). Both fecal markers were significantly lower in patients with endoscopically inactive than with active disease (p<0.001). In detecting endoscopically active disease, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for calprotectin ≥200 μg/g were 70%, 92%, 94%, and 61%; for lactoferrin ≥10 μg/g they were 66%, 92%, 94%, and 59%. Accordingly, the sensitivity, specificity, PPV, and NPV for CRP >5 mg/l were 48%, 91%, 91%, and 48%. Fecal markers were significantly higher in active colonic (both p<0.001) or ileocolonic (calprotectin p=0.028, lactoferrin p=0.004) than in ileal disease. In ileocolonic or colonic disease, colon histology score correlated significantly with fecal calprotectin (r=0.563) and lactoferrin (r=0.543). In patients receiving anti-TNFα therapy, median fecal calprotectin decreased from 1173 μg/g (range 88-15326) to 130 μg/g (13-1419) and lactoferrin from 105.0 μg/g (4.2-1258.9) to 2.7 μg/g (0.0-228.5), both p=0.001. The relation of ileal IL-17+ cells to CD4+ cells decreased significantly during anti-TNF treatment (p=0.047). The relation of IL-17+ cells to Foxp3+ cells was higher in the patients’ baseline specimens than in their post-treatment specimens (p=0.038). Conclusions: For evaluation of CD activity, based on endoscopic findings, more sensitive surrogate markers than CDAI and CRP were fecal calprotectin and lactoferrin. Fecal calprotectin and lactoferrin were significantly higher in endoscopically active disease than in endoscopic remission. In both ileocolonic and colonic disease, fecal markers correlated closely with histologic disease activity. In CD, these neutrophil-derived proteins thus seem to be useful surrogate markers of endoscopic activity. During anti-TNFα therapy, fecal calprotectin and lactoferrin decreased significantly. The anti-TNFα treatment was also reflected in a decreased IL-17/Foxp3 cell ratio, which may indicate improved balance between effector and regulatory T cells with treatment.
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The output of a laser is a high frequency propagating electromagnetic field with superior coherence and brightness compared to that emitted by thermal sources. A multitude of different types of lasers exist, which also translates into large differences in the properties of their output. Moreover, the characteristics of the electromagnetic field emitted by a laser can be influenced from the outside, e.g., by injecting an external optical field or by optical feedback. In the case of free-running solitary class-B lasers, such as semiconductor and Nd:YVO4 solid-state lasers, the phase space is two-dimensional, the dynamical variables being the population inversion and the amplitude of the electromagnetic field. The two-dimensional structure of the phase space means that no complex dynamics can be found. If a class-B laser is perturbed from its steady state, then the steady state is restored after a short transient. However, as discussed in part (i) of this Thesis, the static properties of class-B lasers, as well as their artificially or noise induced dynamics around the steady state, can be experimentally studied in order to gain insight on laser behaviour, and to determine model parameters that are not known ab initio. In this Thesis particular attention is given to the linewidth enhancement factor, which describes the coupling between the gain and the refractive index in the active material. A highly desirable attribute of an oscillator is stability, both in frequency and amplitude. Nowadays, however, instabilities in coupled lasers have become an active area of research motivated not only by the interesting complex nonlinear dynamics but also by potential applications. In part (ii) of this Thesis the complex dynamics of unidirectionally coupled, i.e., optically injected, class-B lasers is investigated. An injected optical field increases the dimensionality of the phase space to three by turning the phase of the electromagnetic field into an important variable. This has a radical effect on laser behaviour, since very complex dynamics, including chaos, can be found in a nonlinear system with three degrees of freedom. The output of the injected laser can be controlled in experiments by varying the injection rate and the frequency of the injected light. In this Thesis the dynamics of unidirectionally coupled semiconductor and Nd:YVO4 solid-state lasers is studied numerically and experimentally.
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Luonnosta haihtuvat orgaaniset yhdisteet, joita pääsee ilmaan etenkin metsistä, voivat vaikuttaa paikalliseen ja alueelliseen ilmanlaatuun, koska ne reagoivat ilmakehässä. Niiden reaktiotuotteet voivat myös osallistua uusien hiukkasten muodostumiseen ja kasvuun, millä voi olla vaikutusta ilmakehän säteilytaseeseen ja tätä kautta myös ilmastoon. Hiukkaset absorboivat ja sirottavat auringon säteilyä ja maapallon lämpösäteilyä minkä lisäksi ne vaikuttavat pilvien säteilyominaisuuksiin, määrään ja elinikään. Koko maapallon mittakaavassa luonnosta tulevat hiilivetypäästöt ylittävät ihmistoiminnan aiheuttamat päästöt moninkertaisesti. Tämän vuoksi luonnon päästöjen arviointi on tärkeää kun halutaan kehittää tehokkaita ilmanlaatu- ja ilmastostrategioita. Tämä tutkimus käsittelee boreaalisen metsän hiilivetypäästöjä. Boreaalinen metsä eli pohjoinen havumetsä on suurin maanpäällinen ekosysteemi, ja se ulottuu lähes yhtenäisenä nauhana koko pohjoisen pallonpuoliskon ympäri. Sille on tyypillistä puulajien suhteellisen pieni kirjo sekä olosuhteiden ja kasvun voimakkaat vuodenaikaisvaihtelut. Työssä on tutkittu Suomen yleisimmän boreaalisen puun eli männyn hiilivetypäästöjen vuodenaikaisvaihtelua sekä päästöjen riippuvuutta lämpötilasta ja valosta. Saatuja tuloksia on käytetty yhdessä muiden boreaalisilla puilla tehtyjen päästömittaustulosten kanssa Suomen metsiä varten kehitetyssä päästömallissa. Malli perustuu lisäksi maankäyttötietoihin, suomen metsille kehitettyyn luokitukseen ja meteorologisiin tietoihin, joiden avulla se laskee metsien hiilivetypäästöt kasvukauden aikana. Suomen metsien päästöt koostuvat koko kasvukauden ajan suurelta osin alfa- ja beta-pineenistä sekä delta-kareenista. Kesällä ja syksyllä päästöissä on myös paljon sabineenia, jota tulee etenkin lehtipuista. Päästöt seuraavat lämpötilan keskimääräistä vaihtelua, ovat suurimmillaan maan eteläosissa ja laskevat tasaisesti pohjoiseen siirryttäessä. Metsän isopreenipäästö on suhteellisen pieni – Suomessa tärkein isopreeniä päästävä puu on vähäpäästöinen kuusi, koska runsaspäästöisten pajun ja haavan osuus metsän lehtimassasta on hyvin pieni. Tässä työssä on myös laskettu ensimmäinen arvio metsän seskviterpeenipäästöistä. Seskviterpeenipäästöt alkavat Juhannuksen jälkeen ja ovat kasvukauden aikana samaa suuruusluokkaa kuin isopreenipäästöt. Vuositasolla Suomen metsien hiilivetypäästöt ovat noin kaksinkertaiset ihmistoiminnasta aiheutuviin päästöihin verrattuna.
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Hantaviruses, members of the genus Hantavirus in the Bunyaviridae family, are enveloped single-stranded RNA viruses with tri-segmented genome of negative polarity. In humans, hantaviruses cause two diseases, hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS), which vary in severity depending on the causative agent. Each hantavirus is carried by a specific rodent host and is transmitted to humans through excreta of infected rodents. The genome of hantaviruses encodes four structural proteins: the nucleocapsid protein (N), the glycoproteins (Gn and Gc), and the polymerase (L) and also the nonstructural protein (NSs). This thesis deals with the functional characterization of hantavirus N protein with regard to its structure. Structural studies of the N protein have progressed slowly and the crystal structure of the whole protein is still not available, therefore biochemical assays coupled with bioinformatical modeling proved essential for studying N protein structure and functions. Presumably, during RNA encapsidation, the N protein first forms intermediate trimers and then oligomers. First, we investigated the role of N-terminal domain in the N protein oligomerization. The results suggested that the N-terminal region of the N protein forms a coiled-coil, in which two antiparallel alpha helices interact via their hydrophobic seams. Hydrophobic residues L4, I11, L18, L25 and V32 in the first helix and L44, V51, L58 and L65 in the second helix were crucial for stabilizing the structure. The results were consistent with the head-to-head, tail-to-tail model for hantavirus N protein trimerization. We demonstrated that an intact coiled-coil structure of the N terminus is crucial for the oligomerization capacity of the N protein. We also added new details to the head-to-head, tail-to-tail model of trimerization by suggesting that the initial step is based on interaction(s) between intact intra-molecular coiled-coils of the monomers. We further analyzed the importance of charged aa residues located within the coiled-coil for the N protein oligomerization. To predict the interacting surfaces of the monomers we used an upgraded in silico model of the coiled-coil domain that was docked into a trimer. Next the predicted target residues were mutated. The results obtained using the mammalian two-hybrid assay suggested that conserved charged aa residues within the coiled-coil make a substantial contribution to the N protein oligomerization. This contribution probably involves the formation of interacting surfaces of the N monomers and also stabilization of the coiled-coil via intramolecular ionic bridging. We proposed that the tips of the coiled-coils are the first to come into direct contact and thus initiate tight packing of the three monomers into a compact structure. This was in agreement with the previous results showing that an increase in ionic strength abolished the interaction between N protein molecules. We also showed that residues having the strongest effect on the N protein oligomerization are not scattered randomly throughout the coiled-coil 3D model structure, but form clusters. Next we found evidence for the hantaviral N protein interaction with the cytoplasmic tail of the glycoprotein Gn. In order to study this interaction we used the GST pull-down assay in combination with mutagenesis technique. The results demonstrated that intact, properly folded zinc fingers of the Gn protein cytoplasmic tail as well as the middle domain of the N protein (that includes aa residues 80 248 and supposedly carries the RNA-binding domain) are essential for the interaction. Since hantaviruses do not have a matrix protein that mediates the packaging of the viral RNA in other negatve stranded viruses (NSRV), hantaviral RNPs should be involved in a direct interaction with the intraviral domains of the envelope-embedded glycoproteins. By showing the N-Gn interaction we provided the evidence for one of the crucial steps in the virus replication at which RNPs are directed to the site of the virus assembly. Finally we started analysis of the N protein RNA-binding region, which is supposedly located in the middle domain of the N protein molecule. We developed a model for the initial step of RNA-binding by the hantaviral N protein. We hypothesized that the hantaviral N protein possesses two secondary structure elements that initiate the RNA encapsidation. The results suggest that amino acid residues (172-176) presumably act as a hook to catch vRNA and that the positively charged interaction surface (aa residues 144-160) enhances the initial N-RNA interacation. In conclusion, we elucidated new functions of hantavirus N protein. Using in silico modeling we predicted the domain structure of the protein and using experimental techniques showed that each domain is responsible for executing certain function(s). We showed that intact N terminal coiled-coil domain is crucial for oligomerization and charged residues located on its surface form a interaction surface for the N monomers. The middle domain is essential for interaction with the cytoplasmic tail of the Gn protein and RNA binding.
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IBD- ja reumasairaudet ovat elämänlaatua merkittävästi heikentäviä, kroonisia tulehduksellisia sairauksia, joiden keskivaikeiden ja vakavien muotojen hoidossa suoneen annettava biologinen TNF-alfa -tulehdustekijän vasta-aine infliksimabi (Remicade®) on vankassa asemassa. Infliksimabin hyvän tehon kääntöpuolena esiintyy yleisesti haittoja, joista infuusion aikana tai pian sen jälkeen ilmenevät allergistyyppiset reaktiot ovat hoitoa hankaloittava ja jopa vaarallinen alaluokka. Infuusioreaktioiden estoon ei nykyisellään ole todistettavasti tehokkaita keinoja. Parasetamoli ja setiritsiini osoittautuivat tässä käyttötarkoituksessa tehottomiksi. HUS:n Lasten ja nuorten sairaalassa aloitettiin 11.3.2009 hoitokokeilu asetosalisyylihapolla (ASA, Disperin®), annosteltuna painonmukaisesti per os, päämääränä selvittää prospektiivisesti ASA:n käyttömahdollisuudet infuusioreaktioiden ehkäisyssä. Tämän tutkielman aineisto kerättiin esilääkekokeilun alun ja 24.6.2010 välisellä ajalla (yhteensä 67 viikkoa) infliksimabi-infuusiossa Lasten ja nuorten sairaalan osasto 2:lla käyneiden IBD- ja reumapotilaiden asiakirjoista. Vain 1 (0,2 %) ASA:n kanssa annetuista infuusioista johti infuusioreaktioon kun aiemmin parasetamolin ja setiritsiinin kanssa todettiin 11 (2,9 %) reaktiota. GraphPad Prism 5 -ohjelmistolla tehdyn tilastoanalyysin perusteella tulokset osoittavat ASA:n olevan erittäin lupaava infuusioreaktioiden estolääke.
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Acute heart failure (AHF) is a complex syndrome associated with exceptionally high mortality. Still, characteristics and prognostic factors of contemporary AHF patients have been inadequately studied. Kidney function has emerged as a very powerful prognostic risk factor in cardiovascular disease. This is believed to be the consequence of an interaction between the heart and kidneys, also termed the cardiorenal syndrome, the mechanisms of which are not fully understood. Renal insufficiency is common in heart failure and of particular interest for predicting outcome in AHF. Cystatin C (CysC) is a marker of glomerular filtration rate with properties making it a prospective alternative to the currently used measure creatinine for assessment of renal function. The aim of this thesis is to characterize a representative cohort of patients hospitalized for AHF and to identify risk factors for poor outcome in AHF. In particular, the role of CysC as a marker of renal function is evaluated, including examination of the value of CysC as a predictor of mortality in AHF. The FINN-AKVA (Finnish Acute Heart Failure) study is a national prospective multicenter study conducted to investigate the clinical presentation, aetiology and treatment of, as well as concomitant diseases and outcome in, AHF. Patients hospitalized for AHF were enrolled in the FINN-AKVA study, and mortality was followed for 12 months. The mean age of patients with AHF is 75 years and they frequently have both cardiovascular and non-cardiovascular co-morbidities. The mortality after hospitalization for AHF is high, rising to 27% by 12 months. The present study shows that renal dysfunction is very common in AHF. CysC detects impaired renal function in forty percent of patients. Renal function, measured by CysC, is one of the strongest predictors of mortality independently of other prognostic risk markers, such as age, gender, co-morbidities and systolic blood pressure on admission. Moreover, in patients with normal creatinine values, elevated CysC is associated with a marked increase in mortality. Acute kidney injury, defined as an increase in CysC within 48 hours of hospital admission, occurs in a significant proportion of patients and is associated with increased short- and mid-term mortality. The results suggest that CysC can be used for risk stratification in AHF. Markers of inflammation are elevated both in heart failure and in chronic kidney disease, and inflammation is one of the mechanisms thought to mediate heart-kidney interactions in the cardiorenal syndrome. Inflammatory cytokines such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) correlate very differently to markers of cardiac stress and renal function. In particular, TNF-α showed a robust correlation to CysC, but was not associated with levels of NT-proBNP, a marker of hemodynamic cardiac stress. Compared to CysC, the inflammatory markers were not strongly related to mortality in AHF. In conclusion, patients with AHF are elderly with multiple co-morbidities, and renal dysfunction is very common. CysC demonstrates good diagnostic properties both in identifying impaired renal function and acute kidney injury in patients with AHF. CysC, as a measure of renal function, is also a powerful prognostic marker in AHF. CysC shows promise as a marker for assessment of kidney function and risk stratification in patients hospitalized for AHF.
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Cancer is becoming the leading cause of deaths in the world. As 90% of all deaths from cancer are caused by metastasis, discovery of the mechanisms behind cancer cell invasion and metastasis is of utmost importance. Only new effective therapies targeting cancer progression can reduce cancer mortality rates. The aim of this study was to identify molecules that are relevant for tumor cell invasion and spreading in fibrosarcomas and melanomas, and to analyze their potential for cancer biomarkers or therapeutic targets. First, the gene expression changes of normal cells and transformed cells showing high invasiveness, S-adenosylmethionine decarboxylase (AdoMetDC)-transfected murine fibroblasts and human melanoma cells, were studied by microarray analyses. The function of the identified candidate molecules were then studied in detail in these cell lines. Finally, the physiological relevance of the identified changes was studied by immunohistochemical analyses of human sarcoma and melanoma specimens or by a mouse xenograft model. In fibrosarcoma cells, the most remarkable change detected was a dramatic up-regulation of the actin-sequestering molecule thymosin beta 4 (TB4), which was shown to be important for the transformed phenotype of the AdoMetDC-transfected cells (Amdc-s and -as). A sponge toxin latrunculin A, inhibiting the binding of TB4 to actin, was found to selectively inhibit the migration and invasion of these cells. Further, Amdc-s-induced mouse tumors and human high-grade sarcomas were found to show intense TB4 immunostaining. In addition to TB4, integrin subunits alfa 6 and beta 7 (ItgA6 and ItgB7) were found to be up-regulated in Amdc-s and -as cells. ItgA6 was shown to dimerize mainly with ItgB1 in Amdc-s. Inhibition of ItgA6 or ItgB1 function with neutralizing antibodies fully blocked the invasiveness of Amdc-s cells, and importantly also human HT-1080 fibrosarcoma cells, in three-dimensional (3D)-Matrigel mimicking tumor extracellular matrix (ECM). By immunohistochemical analyses, strong staining for ITGA6 was detected in human high-grade fibrosarcomas and other sarcomas, especially at the invasion fronts of the tumors. In the studied melanoma cell lines, the expression levels of the adhesion-related ECM proteins tenascin-C (TN-C), fibronectin (FN), and transforming growth factor beta-induced (TGFBI) were found to be highly up-regulated. By immunohistochemistry, intense TN-C and FN staining was detected in invasive and metastatic melanoma tumors, showing co-localization (together with procollagen-I) in tubular meshworks and channels around the invading melanoma cells. In vitro, TN-C and FN were further found to directly stimulate the migration of melanoma cells in 3D-collagen-I matrix. The third candidate protein, TGFBI, was found to be an anti-adhesive molecule for melanoma cells, and knockdown of its expression in metastatic melanoma cells (TGFBI-KD cells) led to dramatically impaired tumor growth in immunocompromized mice. Interestingly, the control tumors showed intense TGFBI immunostaining in the invasion fronts, showing partial co-localization with the fibrillar FN staining, whereas the small TGFBI-KD cell-induced tumors displayed amorphous, non-fibrillar FN staining. These data suggest an important role for TGFBI in FN fibrillogenesis and melanoma progression. In conclusion, we have identified several invasion-related molecules, which show potential for cancer diagnostic or prognostic markers, or therapeutic targets. Based on our previous and present fibrosarcoma studies, we propose the possibility of using ITGA6 antagonists (affecting tumor cell adhesion) in combination with TB4 inhibitors (affecting tumor cell migration) and cathepsin L inhibitors (affecting the degradation of basement membrane and ECM proteins) for the treatment of fibrosarcomas and other tumors overexpressing these molecules. With melanoma cells, in turn, we point to the importance of three secreted ECM proteins, TN-C, FN, and TGFBI, in melanoma progression. Of these, especially the potential of TN-C as a prognostic melanoma biomarker and TGFBI as a promising therapeutic target molecule are clearly worth additional studies.
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The upstream proinflammatory interleukin-1 (IL-1) cytokines, together with a naturally occurring IL-1 receptor antagonist (IL-1Ra), play a significant role in several diseases and physiologic conditions. The IL-1 proteins affect glucose homeostasis at multiple levels contributing to vascular injuries and metabolic dysregulations that precede diabetes. An association between IL-1 gene variations and IL-1Ra levels has been suggested, and genetic studies have reported associations with metabolic dysregulation and altered inflammatory responses. The principal aims of this study were to: 1) examine the associations of IL-1 gene variation and IL-1Ra expression in the development and persistence of thyroid antibodies in subacute thyroiditis; 2) investigate the associations of common variants in the IL-1 gene family with plasma glucose and insulin concentrations, glucose homeostasis measures and prevalent diabetes in a representative population sample; 3) investigate genetic and non-genetic determinants of IL-1Ra phenotypes in a cross-sectional setting in three independent study populations; 4) investigate in a prospective setting (a) whether variants of the IL-1 gene family are predictors for clinically incident diabetes in two population-based observational cohort studies; and (b) whether the IL-1Ra levels predict the progression of metabolic syndrome to overt diabetes during the median follow-up of 10.8 and 7.1 years. Results from on patients with subacte thyroiditis showed that the systemic IL-1Ra levels are elevated during a specific proinflammatory response and they correlated with C-reactive protein (CRP) levels. Genetic variation in the IL-1 family seemed to have an association with the appearance of thyroid peroxidase antibodies and persisting local autoimmune responses during the follow-up. Analysis of patients suffering from diabetes and metabolic traits suggested that genetic IL-1 variation and IL-1Ra play a role in glucose homeostasis and in the development of type 2 diabetes. The coding IL-1 beta SNP rs1143634 was associated with traits related to insulin resistance in cross-sectional analyses. Two haplotype variants of the IL-1 beta gene were associated with prevalent diabetes or incident diabetes in a prospective setting and both of these haplotypes were tagged by rs1143634. Three variants of the IL-1Ra gene and one of the IL-1 beta gene were consistently identified as significant, independent determinants of the IL-1Ra phenotype in two or three populations. The proportion of the phenotypic variation explained by the genetic factors was modest however, while obesity and other metabolic traits explained a larger part. Body mass index was the strongest predictor of systemic IL-1Ra concentration overall. Furthermore, the age-adjusted IL-1Ra concentrations were elevated in individuals with metabolic syndrome or diabetes when compared to those free of metabolic dysregulation. In prospective analyses the systemic IL-1Ra levels were found as independent predictors for the development of diabetes in people with metabolic syndrome even after adjustment for multiple other factors, including plasma glucose and CRP levels. The predictive power of IL-1Ra was better than that of CRP. The prospective results also provided some evidence for a role of common IL-1 alpha promoter SNP rs1800587 in the development of type 2 diabetes among men and suggested that the role may be gender specific. Likewise, common variations in the IL-1 beta coding region may have a gender specific association with diabetes development. Further research on the potential benefits of IL-1Ra measurements in identifying individuals at high risk for diabetes, who then could be targeted for specific treatment interventions, is warranted. It has been reported in the recent literature that IL-1Ra secreted from adipose tissue has beneficial effects on glucose homeostasis. Furthermore, treatment with recombinant human IL-1Ra has been shown to have a substantial therapeutic potential. The genetic results from the prospective analyses performed in this study remain inconclusive, but together with the cross-sectional analyses they suggest gender-specific effects of the IL-1 variants on the risk of diabetes. Larger studies with more extensive genotyping and resequencing may help to pinpoint the exact variants responsible and to further elucidate the biological mechanisms for the observed associations. This would improve our understanding of the pathways linking inflammation and obesity with glucose and insulin metabolism.
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The neuronal cell adhesion molecule ICAM-5 ICAM-5 (telencephalin) belongs to the intercellular adhesion molecule (ICAM)-subgroup of the immunoglobulin superfamily (IgSF). ICAMs participate in leukocyte adhesion and adhesion-dependent functions in the central nervous system (CNS) through interacting with the leukocyte-specific b2 integrins. ICAM-5 is found in the mammalian forebrain, appears at the time of birth, and is located at the cell soma and neuronal dendrites. Recent studies also show that it is important for the regulation of immune functions in the brain and for the development and maturation of neuronal synapses. The clinical importance of ICAM-5 is still under investigation; it may have a role in the development of Alzheimer s disease (AD). In this study, the role of ICAM-5 in neuronal differentiation and its associations with a-actinin and N-methyl-D-aspartic acid (NMDA) receptors were examined. NMDA receptors (NMDARs) are known to be involved in many neuronal functions, including the passage of information from one neuron to another one, and thus it was thought important to study their role related to ICAM-5. The results suggested that ICAM-5 was able to induce dendritic outgrowth through homophilic adhesion (ICAM-5 monomer binds to another ICAM-5 monomer in the same or neighbouring cell), and the homophilic binding activity appeared to be regulated by monomer/multimer transition. Moreover, ICAM-5 binding to a-actinin was shown to be important for neuritic outgrowth. It was examined whether matrix metalloproteinases (MMPs) are the main enzymes involved in ICAM-5 ectodomain cleavage. The results showed that stimulation of NMDARs leads to MMP activation, cleavage of ICAM-5 and it is accompanied by dendritic spine maturation. These findings also indicated that ICAM-5 and NMDA receptor subunit 1 (NR1) compete for binding to a-actinin, and ICAM-5 may regulate the NR1 association with the actin cytoskeleton. Thus, it is concluded that ICAM-5 is a crucial cell adhesion molecule involved in the development of neuronal synapses, especially in the regulation of dendritic spine development, and its functions may also be involved with memory formation and learning.
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The aim of this thesis was to study ecology of Baltic Sea ice from two perspectives. In the first two studies, sea-ice ecology from riverine-influenced fast ice to drift ice in the Bothnian Bay was investigated, whereas the last two studies focus on the sensitivity of sea-ice bacteria and algae to UVA examined in situ. The seasonal sea ice cover is one of the main characteristics of the Baltic Sea, and despite the brackish parental water, the ice structure is similar to polar ice with saline brine inclusions, the sea ice habitat. The decreasing seawater salinity from the northern Baltic Sea to the Bothnian Bay translates to decreasing brine volumes along the gradient, governing the size and community structure of the food webs in ice. However, the drift and fast ice in the Bothnian Bay may differ greatly in this sense, as drift ice may have been formed at more southern locations. Rafting and the formation of snow ice are common processes in the ice field of the Bothnian Bay. As evidenced in this thesis, rafting altered the vertical distribution of organisms and snow-ice formation provided habitable space in the better-illuminated, nitrogen-rich surface layer. The divergence between fast and drift ice became apparent at the more advanced stages, and chlorophyte biomass decreased from fast to drift ice, while the opposite held true for protozoan and metazoan biomass. The brine volumes affected the communities somewhat, and a higher percentage of flagellate species was generally linked to lower brine volumes, whereas chain-forming diatoms were mostly concentrated in layers with larger brine volumes. These results add to knowledge of the ecological significance of the ice cover lasting up to 7 months per year in this area. Sea-ice food webs are generally light-limited, but while increasing light irradiances typically enhance the primary production and further, the secondary production in sea ice, any increase in solar radiation also includes an increase in harmful UVA radiation. The Baltic Sea ice microbial communities were clearly sensitive to UVA and the responses were strongly linked to the earlier light history, as well as to the solar irradiances they were exposed to. The increased biomass of chlorophytes and pennate diatoms, when UVA was excluded, indicates that their normally minor contribution to the biomass in the upper layers of sea ice might be partly dictated by UVA. The effects of UVA on bacterial production in Baltic Sea ice mostly followed the responses in algal growth, but occasionally the exposure to UVA even enhanced the bacterial production. The dominant bacterial class, Flavobacteria, seemed to be UVA-tolerant, whereas all the Alpha-, Beta- and Gammaproteobacteria present in the surface layer showed UVA sensitivity. These results indicate that changes in the light field of ice may alter the community structure and affect the functioning of ice food webs, and are of importance when the effects of thinning of the ice cover are assessed.
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Tutkielman kirjallisuuskatsauksessa tarkasteltiin kauran leivontateknologisia ominaisuuksia, entsyymiaktiivista leivontaa ja ruismaltaan hyödyntämistä vähägluteenisessa leivonnassa. Kokeellisessa osiossa tutkittiin ruismallashapantaikinasta valmistetun uutteen vaikutusta kaurataikinan viskositeettiin ja kauraleivän ominaisuuksiin. Työn tarkoituksena oli kehittää maultaan ja rakenteeltaan onnistunut rukiinmakuinen kauraleipä. Ruismaltaan entsyymien annettiin pilkkoa keliaakikolle haitallisia rukiin prolamiineja hapantaikinaprosessissa. Hapantaikinasta erotettiin uute sentrifugoimalla. Leivontakokeisiin käytettiin entsyymiaktiivista ja kuumentamalla inaktivoitua uutetta. Uutteella korvattiin taikinavettä 15, 25 ja 30 % (taikinan painosta). Leivonta toteutettiin miniatyyrikoossa, vuokaleivontana 20 g:n taikinapaloja käyttäen. Taikinoiden viskositeetti mitattiin tarkoituksena seurata beetaglukaanin hydrolyysiä. Rukiin makua mitattiin koulutetun raadin avulla. Happaman uutteen lisäys laski taikinan pH-arvoa noin 5,8:sta noin 4,4:ään. Entsyymiaktiivisen uutteen lisäys laski taikinan viskositeettia ja inaktivoitu uute puolestaan kasvatti sitä. Leipien sisus tiivistyi, jolloin mitatut sisuksen kovuudet kasvoivat uutteen lisäyksen myötä. Uutelisäys paransi leipien makua ja aromia. Uutteen vaikutuksesta leipien huokoset olivat pienempiä ja ne jakaantuivat tasaisemmin leipämatriisiin. Jos uutetta käytettiin inaktivoituna, leipien murenevuus kasvoi. Tutkimuksessa kehitetyn teknologian avulla oli mahdollista valmistaa hyvänlaatuinen, rukiinmakuinen kauraleipä myös ilman että uutteen entsyymit inaktivoitiin keittämällä. Tähän vaikutti ilmeisesti taikinan alhainen pH, joka inhiboi alfa-amylaasia, ja kauratärkkelyksen korkea liisteröitymislämpötila, jolloin entsyymien inaktivoituminen paiston aikana tapahtui ennen kuin tärkkelys tuli alttiiksi liialliselle pilkkoutumiselle. Tämä mahdollistaa uutteen käytön osana leivontaprosessia ilman inaktivointia. Hapantaikinafermentaatio osana gluteenitonta leivontaa havaittiin toimivaksi yhdistelmäksi, sillä se paransi leivän väriä, makua ja rakennetta. Myös leivän homeeton aika parani jo vähäisenkin uutelisäyksen vaikutuksesta. Näyttää siltä, että tämän teknologian avulla on mahdollista tuoda esille pitkään kaivattua rukiin makua vähägluteenisten kauraleipien valikoimassa. Laskennallisesti ja aiempiin tuloksiin tukeutuen, voitiin päätellä, että leivän prolamiinipitoisuudessa on mahdollista päästä tasolle 63,5 mg/kg, mutta jatkokehityksen avulla päästäisiin luultavasti vielä parempiin tuloksiin.
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Hypertension is one of the major risk factors for cardiovascular morbidity. The advantages of antihypertensive therapy have been clearly demonstrated, but only about 30% of hypertensive patients have their blood pressure (BP) controlled by such treatment. One of the reasons for this poor BP control may lie in the difficulty in predicting BP response to antihypertensive treatment. The average BP reduction achieved is similar for each drug in the main classes of antihypertensive agents, but there is a marked individual variation in BP responses to any given drug. The purpose of the present study was to examine BP response to four different antihypertensive monotherapies with regard to demographic characteristics, laboratory test results and common genetic polymorphisms. The subjects of the present study are participants in the pharmacogenetic GENRES Study. A total of 208 subjects completed the whole study protocol including four drug treatment periods of four weeks, separated by four-week placebo periods. The study drugs were amlodipine, bisoprolol, hydrochlorothiazide and losartan. Both office (OBP) and 24-hour ambulatory blood pressure (ABP) measurements were carried out. BP response to study drugs were related to basic clinical characteristics, pretreatment laboratory test results and common polymorphisms in genes coding for components of the renin-angiotensin system, alpha-adducin (ADD1), beta1-adrenergic receptor (ADRB1) and beta2-adrenergic receptor (ADRB2). Age was positively correlated with BP responses to amlodipine and with OBP and systolic ABP responses to hydrochlorothiazide, while body mass index was negatively correlated with ABP responses to amlodipine. Of the laboratory test results, plasma renin activity (PRA) correlated positively with BP responses to losartan, with ABP responses to bisoprolol, and negatively with ABP responses to hydrochlorothiazide. Uniquely to this study, it was found that serum total calcium level was negatively correlated with BP responses to amlodipine, whilst serum total cholesterol level was negatively correlated with ABP responses to amlodipine. There were no significant associations of angiotensin II type I receptor 1166A/C, angiotensin converting enzyme I/D, angiotensinogen Met235Thr, ADD1 Gly460Trp, ADRB1 Ser49Gly and Gly389Arg and ADRB2 Arg16Gly and Gln27Glu polymorphisms with BP responses to the study drugs. In conclusion, this study confirmed the relationship between pretreatment PRA levels and response to three classes of antihypertensive drugs. This study is the first to note a significant inverse relation between serum calcium level and responsiveness to a calcium channel blocker. However, this study could not replicate the observations that common polymorphisms in angiotensin II type I receptor, angiotensin converting enzyme, angiotensinogen, ADD1, ADRB1, or ADRB2 genes can predict BP response to antihypertensive drugs.
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Isoflavonoids are naturally occurring plant derived biochemicals, which act as phytoalexins. Isoflavonoids are of interest due to their estrogenic and other potential physiological properties, particularly in mammals that typically consume isoflavonoid rich nutrients such as soy and red clover. The literature review of this thesis mainly focuses on the reduced metabolites of hydroxy and/or methoxy substituted isoflavones with four groups: isoflavan-4-ols, isoflav-3-enes, isoflavans and α-methyldeoxybenzoins (1,2-diarylpropan-1-ones), which are all reduced metabolites of food derived isoflavones in mammals. Related isoflavan-4-ones are briefly discussed. Results of an extensive survey of the literature concerning the synthesis of polyhydroxy- or methoxysubstituted isoflavonoids and especially asymmetric approaches are discussed. The experimental section describes new synthetic methods to prepare polyphenolic reduced isoflavonoid structures such as isoflav-3-enes, isoflavan-4-ones, cis- and trans-isoflavan-4-ols, 1,2-diarylpropan-1-ones and isoflavans by various hydride reagents and hydrogenations. The specific reactivity differences of various hydride reagents toward isoflavonoids are discussed. The first enantioselective synthesis of natural (S)-(-)-equol and the opposite enantiomer (R)-(+)-equol is also described by the asymmetric iridium PHOX catalysed hydrogenation of isoflav-3-enes. Both of these equol enantiomers are found to possess biological activity in mammals due to estrogen receptor binding activity. The natural enantiomer prefers estrogen receptor β and the R-enantiomer prefers the estrogen receptor α. Also the precursor, isoflav-3-ene, is found to possess positive biological effects on mammals. In connection with the synthetic work, the (S)-(-)-equol was discovered from serum of ewes after isoflavone rich red clover feeding. The chiral HPLC method was developed to identify natural equol enantiomer for the first time in this species. The first synthesis of natural isoflavonoid (R)-(-)-angolensin and its enantiomer (S)-(+)-angolensin is desribed by the use of recyclable chiral auxiliaries (chiral pseudoephedrines). The method offers a general approach also to other natural polyphenolic 1,2-diarylpropan-1-ones and to further study isoflavonoid metabolism in human and other mammals. The absolute configurations of these new chiral isoflavonoid metabolites were determined by X-ray spectroscopy. Also thorough NMR and MS analysis of synthesised structures are presented.
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Bile acids are important steroid-derived molecules essential for fat absorption in the small intestine. They are produced in the liver and secreted into the bile. Bile acids are transported by bile flow to the small intestine, where they aid the digestion of lipids. Most bile acids are reabsorbed in the small intestine and return to the liver through the portal vein. The whole recycling process is referred to as the enterohepatic circulation, during which only a small amount of bile acids are removed from the body via faeces. The enterohepatic circulation of bile acids involves the delicate coordination of a number of bile acid transporters expressed in the liver and the small intestine. Organic anion transporting polypeptide 1B1 (OATP1B1), encoded by the solute carrier organic anion transporter family, member 1B1 (SLCO1B1) gene, mediates the sodium independent hepatocellular uptake of bile acids. Two common SNPs in the SLCO1B1 gene are well known to affect the transport activity of OATP1B1. Moreover, bile acid synthesis is an important elimination route for cholesterol. Cholesterol 7α-hydroxylase (CYP7A1) is the rate-limiting enzyme of bile acid production. The aim of this thesis was to investigate the effects of SLCO1B1 polymorphism on the fasting plasma levels of individual endogenous bile acids and a bile acid synthesis marker, and the pharmacokinetics of exogenously administered ursodeoxycholic acid (UDCA). Furthermore, the effects of CYP7A1 genetic polymorphism and gender on the fasting plasma concentrations of individual endogenous bile acids and the bile acid synthesis marker were evaluated. Firstly, a high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for the determination of bile acids was developed (Study I). A retrospective study examined the effects of SLCO1B1 genetic polymorphism on the fasting plasma concentrations of individual bile acids and a bile acid synthesis marker in 65 healthy subjects (Study II). In another retrospective study with 143 healthy individuals, the effects of CYP7A1 genetic polymorphism and gender as well as SLCO1B1 polymorphism on the fasting plasma levels of individual bile acids and the bile acid synthesis marker were investigated (Study III). The effects of SLCO1B1 polymorphism on the pharmacokinetics of exogenously administered UDCA were evaluated in a prospective genotype panel study including 27 healthy volunteers (Study IV). A robust, sensitive and simple HPLC-MS/MS method was developed for the simultaneous determination of 16 individual bile acids in human plasma. The method validation parameters for all the analytes met the requirements of the FDA (Food and Drug Administration) bioanalytical guidelines. This HPLC-MS/MS method was applied in Studies II-IV. In Study II, the fasting plasma concentrations of several bile acids and the bile acid synthesis marker seemed to be affected by SLCO1B1 genetic polymorphism, but these findings were not replicated in Study III with a larger sample size. Moreover, SLCO1B1 polymorphism had no effect on the pharmacokinetic parameters of exogenously administered UDCA. Furthermore, no consistent association was observed between CYP7A1 genetic polymorphism and the fasting plasma concentrations of individual bile acids or the bile acid synthesis marker. In contrast, gender had a major effect on the fasting plasma concentrations of several bile acids and also total bile acids. In conclusion, gender, but not SLCO1B1 or CYP7A1 polymorphisms, has a major effect on the fasting plasma concentrations of individual bile acids. Moreover, the common genetic polymorphism of CYP7A1 is unlikely to influence the activity of CYP7A1 under normal physiological conditions. OATP1B1 does not play an important role in the in vivo disposition of exogenously administered UDCA.
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El presente estudio se realizó en la Granja Porcina de la Universidad Nacional Agraria (UNA), ubicada en el kilómetro 13, Carretera Norte, desvió a Sabana Grande, Managua, Nicaragua La realización del ensayó duró 12 semanas comprendidas entre los meses de septiembre-y diciembre de 1998 El objetivo del mismo fue evaluar el comportamiento productivo de cerdos en crecimiento, desarrollo y engorde al utilizar diferentes raciones: concentrado (T1) desperdicios de cocina (T2) y desperdicios de cocina más desperdicios de galleta (T3) Se utilizaron 24 cerdos- híbridos formándose grupos de 8 cerdos por tratamiento, (4 hembras y 4 machos) Los cerdos se pesaron al inicio y luego cada 28 días hasta el final del experimentó, Con las ganancias de peso y conversión alimenticia de los diferentes lotes de cerdos, se efectuó el análisis estadístico correspondiente al diseño experimental completamente al azar (DCA). Los cerdos que presentaron una ganancia de peso más alta, fueron los que se alimentaron con la ración formulada con fuente comercial (tratamiento l) dando una ganancia de peso promedio de 0.693 kg; Los cerdos alimentados con l00% de desperdicios de cocina alcanzaron una ganancia de peso promedio de 0.540 kg, mientras que los del tratamiento 3 alimentados con 50.% con desperdicios de cocina más 50% de desperdicios de galleta alcanzaron una ganancia media de peso promedio de 0,629 kg. El análisis de la ganancia media diaria mostró que hubo diferencia significativa con un alfa de 0.05% entre el tratamiento l y tratamiento 2 y entre los tratamientos 2 y 3, no mostrando diferencia entre los tratamientos 1 y 3, obteniendo el tratamiento 1 la rmejor ganancia media diaria. La conversión de los alimentados bajo el tratamiento de concentrado comercial, fue la más eficiente con un valor de 3.804 Los cerdos bajo el tratamiento 2 presentaron una conversión de 9.691 y el lote de cerdos en el tratamiento 3 presentó una conversión de 7.417. El análisis estadístico mostró que las diferencias en conversión alimenticia son altamente significativas entre el tratamiento l y tratamiento 2 y el tratamiento 1 y el tratamiento 3 y no significativas entre el tratamiento 2 y 3, obteniendo mejor resultado el tratamiento I (concentrado) a un alfa de 0.05%. En la estimación de los costos de los alimentos, el tratamiento 2 produjo los mayores beneficios económicos; debido al bajo costo del alimento con un valor de C$ 9, 856.