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1
Allen, Marcus Christopher. « Biochemical markers of pulmonary oxygen toxicity ». Thesis, University of Aberdeen, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277226.
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This study has investigated potential biochemical markers of pulmonary oxygen toxicity (POT). Toxicity was investigated in male Sprague Dawley rats exposed to oxygen partial pressures ranging from 0.21-2.5 bars. It is known that prolonged exposure to 1 bar of oxygen damages pulmonary endothelial cells and so the biochemical functions of these cells have been studied. Control isolated perfused rat lungs were able to clear and/or metabolise a wide range of substances including 5-HT, PGE2, bradykinin, and angiotensin 1, all endothelial cell functions. As expected 5-HT clearance was compromised in isolated perfused rat lung obtained from rats exposed to 1 bar of oxygen, confirming endothelial cell damage. However the clearance of 5-HT by lungs obtained from rats exposed to 2.5 bars was normal, implying that the site of toxicity is different at these partial pressures. In addition enhancement of toxicity by vitamin E deficiency was not associated with endothelial cell damage at 2.5 bar. At the molecular level oxygen free radicals are thought to be the causative agents of POT. The radicals are reputed to damage lipids, but a process of peroxidation. One of the lipid fragment products of ω6 polyunsaturated fatty acids is n-pentane, a compound which is excreted on the breath. Monitoring of this compound during exposure to 0.21, 1.0, 2.5 bars of oxygen even in vitamin E deficient rats did not show a rise in pentane expiration in response to oxygen exposure. This implies that peroxidation of ω6 polyunsaturated fatty acids did not take place, although other lipids may have been peroxidised. In conclusion the site of POT may depend on the partial pressure of oxygen. Endothelial cell damage is probably absent during exposure to 2.5 bars of oxygen. In addition n-pentane monitoring, a reputed marker of POT, failed to reveal lipid perodixation during exposure to hyperoxia.
2
Israngkun, na Ayudthaya Porn Paul. « Potential biochemical markers for infantile autism / ». The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487322984315317.
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3
Maissa, Cecile A. « Biochemical markers and contact lens wear ». Thesis, Aston University, 1999. http://publications.aston.ac.uk/9627/.
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The project objective was to develop a reliable selection procedure to match contact lens materials with individual wearers by the identification of a biochemical marker for assessment of in-eye performance of contact lenses. There is a need for such a procedure as one of the main reasons for contact lens wearers ceasing wearing contact lenses is poor end of day comfort i.e. the lenses become intolerable to the wearer as the day progresses. The selection of an optimal material for individual wearers has the potential benefit to reduce drop Qut, hence increasing the overall contact lens population, and to improve contact lens comfort for established wearers. Using novel analytical methods and statistical techniques, we were able to investigate the interactions between the composition of the tear film and of the biofilm deposited on the contact lenses and contact lens performance. The investigations were limited to studying the lipid components of the tear film; the lipid layer, which plays a key role in preventing evaporation and stabilising the tear film, has been reported to be significantly thinner and of different mixing characteristics during contact lens wear. Different lipid families were found to influence symptomatology, in vivo tear film structure and stability as well as ocular integrity. Whereas the symptomatology was affected by both the tear film lipid composition and the nature of the lipid deposition, the structure of the tear film and its stability were mainly influenced by the tear film lipid composition. The ocular integrity also appeared to be influenced by the nature of the lipid deposition. Potential markers within the lipid species have been identified and could be applied as follows: When required in order to identify a problematic wearer or to match the contact lens material to the contact lens wearer, tear samples collected by the clinician could be dispatched to an analytical laboratory where lipid analysis could be carried out by HPLC. A colorimetric kit based on the lipid markers could also be developed and used by clinician directly in the practice; such a kit would involve tear sampling and classification according to the colour into "Problem", "Border line" and "Good" contact lens wearers groups. A test kit would also have wider scope for marketing in other areas such as general dry-eye pathology.
4
Branca, Francesco. « Biochemical markers of skeletal growth in children ». Thesis, University of Aberdeen, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282683.
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This work focused on the application to growth studies of the assay for pyridinium crosslinks in urine. The study showed the existence of a nyctohermeral rhythm of crosslink excretion in children, with a peak during the night or early in the morning, and pointed out between-day fluctuations of excretion (17% for Pyd and 19% for Dpd). The study also showed that urinary crosslinks were significantly related to anthropometric estimates of skeletal mass and that such estimates should be used to account for size differences between individuals. Cross-sectional observations on 272 children (3-18 years) showed a parallelism between the height velocity curve and the age profile of crosslink excretion. In 3-5 year old children, the study pointed out a positive relationship with monthly height velocity (R = 0.20); 5-month integrated values of excretion were also correlated to 5-month height velocity (R = 0.78 for Pyd; R = 0.73 for Dpd). Urinary crosslinks were normal in 53 children (124±34 months) affected by miscellaneous conditions leading to growth defects, in 14 children (117±47 months) affected by coeliac disease, nor in 20 children affected by GH deficiency or short stature (aged 117±20 months); they were in the high range in 7 girls with Turner's syndrome, in 58 malnourished boys (14±14 months), urinary crosslinks were proportional to the degree of wasting and were positively correlated to the rate of height gain during hospitalisation. In children treated with Growth Hormone, except those affected by Turner's syndrome, crosslinks could predict 6-month growth after the first month of therapy.
5
Åkesson, Kristina. « Fracture and biochemical markers of bone metabolism ». Lund : University of Lund, Dept. of Orthopaedics, Malmö General Hospital, Sweden, 1995. http://books.google.com/books?id=Ib9qAAAAMAAJ.
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6
McCoy, Paula K. « Psychological Hardiness and Biochemical Markers of Acute Stress ». Thesis, University of North Texas, 2001. https://digital.library.unt.edu/ark:/67531/metadc2884/.
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The establishment of physiological norms for psychologically hardy vs. non-hardy individuals was attempted by examination of levels of salivary cortisol and urinary norepinephrine before and after a mid-term examination stressor. Normative data was collected on the reported frequency of stressors and their severity one week prior to the examination, and self-reported ratings of stress immediately prior to the examination. Performance on the examination as a function of hardiness was explored. Associations between demographic variables and psychological hardiness were also studied. Results from this study were inconclusive in establishing physiological norms for psychologically hardy individuals. Associations were found between: 1) hardiness and frequency of stressors; 2) hardiness and age; and 3) self-reported ratings of stress and anxiety as measured by the State-Trait Anxiety Inventory (STAI).
7
Lovercamp, Kyle W. « Arachidonate 15-lipoxygenase and ubiquitin as potential fertility markers in boars ». Diss., Columbia, Mo. : University of Missouri-Columbia, 2004. http://hdl.handle.net/10355/5811.
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Thesis (M.A.)--University of Missouri-Columbia, 2004.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (June 30, 2006) Vita. Includes bibliographical references.
8
Morgan, Tanya G. « Biochemical and mobility markers in osteoarthritis of the knee ». Thesis, University of Sunderland, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269194.
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Glassbrook, Norman J. « Biochemical markers for the detection and classification of Aspergillus ». Thesis, Cardiff University, 2008. http://orca.cf.ac.uk/54802/.
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The genus Aspergillus includes a diverse group of filamentous fungi that are widely distributed in nature, commonly found in soil. The Aspergilli include species that can be beneficial or detrimental to humans, so detection and accurate identification of these organisms can be very important. Morphology and genetic sequence analysis are well established methods for classifying and identifying fungi, but morphology remains a widely used technique that generally works well for Aspergilli. However, some organisms may be misidentified due to atypical morphology and some hidden (cryptic) species may not be recognized as different from named species based on readily observable traits. In this study, reference strains of different Aspergillus species,
10
Stangland, Jenna Emily. « Biochemical Markers of Iron Status in Recreational Female Runners ». The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1374168831.
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Plata-Muñoz, Juan José. « Clinical, biochemical and molecular markers of injury before transplantation ». Thesis, University of Oxford, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.572681.
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The use of organs from donors after circulatory death (DCD) has been recommended as one strategy to enlarge the donor pool and raise the transplant rate. However, DCD allografts had higher incidence of early post-transplant dysfunction. The general aim of this research project was to develop clinical and experimental strategies to reduce the incidence of early post-transplant dysfunction of kidney and liver allografts from DCD. First the ability of a clinical scoring system based on donor data for identifying DCD kidneys with high-risk of post-transplant dysfunction was evaluated using the Oxford and the UK National DCD kidney transplant cohorts. This works suggest that stratification of DCD kidneys before transplantation might allow early identification of kidneys in which lower graft function and survival could be expected if any additional therapeutic intervention is implemented. Second, as it has been suggested that hypothermic machine perfusion (HMP) may protect DCD kidneys from additional preservation injury and improve their outcome after transplantation, this work explored the benefit of HMP as preservation technique fo DCD kidneys in Oxford and discusses the potential of this technique for reducing the incidence of post-transplant dysfunction in DCD kidneys. The Oxford. Liver Group has provided evidence of the benefit of preservation with normothermic machine perfusion (NMP) on post-transplant function and survival of DCD liver allografts. In this work, the molecular mechanisms associated with this benefit were characterized using micro array technology. This analysis suggests that the beneficial effect ofNMP may be associated with the induction of the ischaemic preconditioning phenomenon and highlights a group of genes with potential for gene therapy. Finally, this works provides the "proof-of-concept" that the use of a non-mammalian viral vector for gene transfer of kidneys and livers during conventional cold preservation is feasible and is not associated with additional tissue injury.
12
Newby, Deborah. « Biochemical markers and the pathophysiology of chromosomally abnormal pregnancies ». Thesis, University of Glasgow, 1997. http://theses.gla.ac.uk/38930/.
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The feto-placental unit synthesises a variety of proteins and hormones which are secreted into the maternal circulation and amniotic fluid from early pregnancy. In pregnancies where the fetus has an autosomal trisomy, the normal concentration profiles of these markers in maternal serum and amniotic fluid are disturbed. These marker changes can be used to estimate the risk that a pregnancy is affected by Down's syndrome (or Trisomy 18) and thus allow the parents to make an informed decision regarding prenatal diagnosis by invasive testing. However, the factors which give rise to the varying patterns of marker concentrations in chromosomally abnormal pregnancies are poorly understood. The aim of this project was to investigate the underlying causes of abnormal marker concentrations in Down's syndrome, Trisomy 13, and Trisomy 18 pregnancies. The results of this investigation indicate that in Down's syndrome pregnancies, maternal serum levels of placental products reflect those found in the placenta; intact hCG, FβhCG and SP1 levels were elevated while PAPP-A and placental ALP levels were little changed. This suggests that transport of these proteins from the placenta into the maternal circulation is not affected but there is altered synthesis of hCG subunits and SP1. Hepatic synthesis of AFP does not appear to be altered in Down's syndrome pregnancies, but increased placental and reduced maternal serum levels of AFP point to a possible placental transport defect specific to AFP. Similarly reduced GGT levels in fetal intestine and in corresponding amniotic fluid from Down's syndrome pregnancies suggest that amniotic fluid GGT activity is of fetal intestinal origin since GGT activity was elevated in fetal liver and placental from the same series of Down's syndrome pregnancies.
13
Cantone, Mariagiovanna. « Vascular dementia : from clinical to biochemical and neurophysiological markers ». Doctoral thesis, Università di Catania, 2015. http://hdl.handle.net/10761/3783.
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BACKGROUND: Vascular Dementia can be considered the second most common cause of dementia after Alzheimer s disease. However, unlike the degenerative dementias, it s possible to carry out preventive strategies. Recently, neurophysiological techniques and in particular transcranial magnetic stimulation (TMS), have been tested in patients with dementia in order to pick up early cerebral functional changes. The present research aimed to investigate cortical excitability in elderly patients with leukoaraiosis
METHODS: Motor cortex excitability, intracortical inhibition and facilitation circuits and central cholinergic function were evaluated in patients with a clinical features of vascular cognitive impairment-no dementia. The neuropsychological profile and the vascular burden at brain magnetic resonance imaging were concomitantly explored.
RESULTS: No differences were found for measures of motor cortex excitability between patients and controls. A significant enhancement of intracortical facilitation was observed in patients. Moreover central cholinergic circuits seem to be spared in patients.
DISCUSSION AND CONCLUSION: This study provides the first evidence of functional changes in intracortical excitatory neuronal circuits in patients with vascular cognitive impairment-no dementia, a finding which is in line with previous research on vascular dementia. Central cholinergic functioning seems to be spared in patients. This functional integrity differs from that reported in patients with Alzheimer s disease or mild cognitive impairment, underlying the distinctive involvement of the cholinergic pathway in degenerative dementia and vascular form, even in their early or preclinical stage. The non-invasive evaluation of the pathophysiological and neurochemical mechanisms underlying dementia highlights the emerging role of TMS as a powerful tool in the diagnosis and management of different dementing processes.
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Carpita, Barbara. « INVESTIGATING BIOCHEMICAL MARKERS OF ADULT AUTISM SPECTRUM DISORDER PHENOTYPES ». Doctoral thesis, Università di Siena, 2022. http://hdl.handle.net/11365/1194483.
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Background: Recently, in the framework of a dimensional approach to autism-related psychopathology, increasing attention has been paid on investigating specific features of Autism spectrum disorder (ASD) during adulthood. Particular interest was paid on milder forms of ASD, without intellectual and language impairment, which may remain under-detected in early life. Moreover, several reports highlighted the presence of significant autistic-like traits in non-affected first-relatives of subjects with ASD, leading to the conceptualization of a “Broad autism phenotype” (BAP). Despite an increasing body of data from neuroimaging studies reported neurostructural and neurofunctional alterations in BAP, there is still a lack of evidence about potential biochemical correlates of ASD-like traits. The first attempts in researching biochemical markers of ASD focused on neurotransmitters and in particular on serotonin (5-HT), reporting possible different alterations between adulthood and childhood and/or between different kinds of biological samples. Brain-derived neurotrophic factor (BDNF), tryptophan (TRP), and metabolites of the TRP-derived kynurenine (KYN) shunt were also found altered in ASD children, and authors hypothesized their possible involvement in increased excitotoxicity or inflammatory activity. Other research also reported immune system activation among ASD children: results in this field seem promising, with studies stressing an association of cytokine levels with different grades of clinical severity and specific clusters of symptoms. Moreover, altered homocysteine (HCY) metabolism and altered trans-sulfuration and methylation processes are acquiring growing interest as possible metabolic signatures of ASD. Despite that, for most of these parameters scant research focused on adult samples and/or on BAP, without studies comparing adult ASD patients with their adult relatives. Aims: The aim of this work was to identify possible biochemical correlates for sub-threshold and over-threshold ASD symptomatology in adults. In particular, the study aimed to: evaluate presence and features of ASD symptoms in adult ASD patients without language or intellectual impairment and their first-degree relatives, as well as in controls, through suitable psychometric scales; evaluate levels of various biochemical parameters, among the three groups, and in particular: circulating levels of 5-HT, TRP, KYN, quinolinic acid (QA), chinurenic acid (KYNA), BDNF, IL-6, HCY; evaluate the possible correlations between clinical features, as measured by the psychometric scales, and biochemical parameters.
Methods: A sample of adult ASD patients (ASD group) and first-degree relatives of the ASD probands (BAP group) were recruited among patients followed at the Psychiatric Section of Azienda Ospedaliera Universitaria Pisana, whereas unrelated controls (CTL group) were recruited on a voluntary basis. All subjects underwent a psychiatric and biochemical assessment. The psycometric instruments employed were: the Structured Clinical Interview for DSM-5, the Adult Autism Sub-threshold Spectrum (AdAS Spectrum), the Autism-Spectrum Quotient (AQ), the Ritvo Autism Asperger Diagnostic Scale,14-item version (RAADS-14), the Ruminative Response Scale (RRS) as well as the Work and Social Adjustment Scale (WSAS). A sample of peripheral venous blood was withdrawn from all the subjects and then processed for obtaining the different analytical specimen for biochemical assessment: the platelet poor plasma (PPP), platelet pellets and serum. All these parameters were measured by means of dedicated Enzyme-linked immunosorbent assay (ELISA) procedures. Results: ASD patients reported significantly higher total scores (greater severity of autistic traits/functional impairment) than the other groups on all psychometric scales. The BAP group reported intermediate scores, significantly higher than the CTL group. At the same time ASD patients reported significantly lower intra-platelet 5-HT, PPP 5-HT and TRP levels than BAP and CTL groups. Significant differences depending on pharmacological treatment within groups were reported for intra-platelet 5-HT levels only, and no difference in intra-platelet 5-HT was found when exluding subjects in treatment with antidepressants from the analysis. Moreover, significantly lower levels of KYNA were reported in both ASD and BAP group when compared with CTL subjects. IL-6 and HCY were instead significantly higher in the ASD group than in the CTL one, with BAP group showing intermediate levels, not significantly different from those reported in the other two groups. A multinomial logistic regression analysis identified higher levels of HCY and IL-6 as the statistically predictive variables of being in the ASD group, while increased IL-6 was statitstically predictive also of being in the BAP group. Specific patterns of association were found between autistic symptoms and biochemical variables. The biochemical parameters most associated with functional impairment were the increased levels of HCY and IL-6. Conclusions: our results confirm the need of further research on alterations of TRP metabolism in ASD and highlight the value of assessing the association of ASD with specific immune system alterations and impaired HCY-related metabolism, which may affect trans-sulfuration/methylation processes in this population. Moreover, our results confirm the presence of intermediate alterations in relatives of ASD patients also from a biochemical point of view, thus providing more support to the presence of a continuum between sub-threshold and full-threshold ASD phenotypes. Finally, our results stress the importance of evaluating metabolomics/proteomic signatures in the field of ASD patients’ care and management.
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Yeung, Wai-yin Jamius. « Evaluation of RNA/DNA ratio in the green-lipped mussel Perna viridis as a potential biomonitoring tool ». View the Table of Contents & ; Abstract, 2009. http://sunzi.lib.hku.hk/hkuto/record/B44212963.
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Lee, Yi-Ching Dickstein Rebecca. « Physical map between marker 8O7 and 146O17 on the Medicago truncatula linkage group 1 that contains the NIP gene ». [Denton, Tex.] : University of North Texas, 2007. http://digital.library.unt.edu/permalink/meta-dc-5152.
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Lin, Sheng. « Cyclometalated iridium (III) complexes and their applications in the detection of biomarkers ». HKBU Institutional Repository, 2019. https://repository.hkbu.edu.hk/etd_oa/621.
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Luminescent transition metal complexes have arisen as viable alternatives to organic dyes for sensory applications due to their notable advantages. This thesis aimed to synthesize different kinds of iridium(III) complexes, explore their interactions with DNAs and investigate their application for the construction of oligonucleotide-based sensing platforms for important biomarkers. A series of iridium(III) complexes incorporating a variety of C^N and N^N donor ligands were synthesized and were demonstrated to possess G-quadruplex-selective binding properties via emission titration, UV/vis titration, fluorescence resonance energy transfer melting and G-quadruplex fluorescent intercalator displacement experiments. These G-quadruplex-selective iridium(III) complexes were utilized as signal transducers to monitor the conformational changes of oligonucleotides in oligonucleotide-based luminescent detection platforms for protein tyrosine kinase-7, interferon-gamma, sialic acidbinding immunoglobulin-likelectin-5 and thymine DNA glycosylase. And these designed platforms could work effectively in the diluted cell extract as the results in this thesis indicated.
18
Moy, Allison. « Comparison of zeocin and G418 resistance markers in Pichia pastoris ». Scholarly Commons, 2009. https://scholarlycommons.pacific.edu/uop_etds/736.
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Noble, Donald D. « Biophysical, biochemical and cellular markers of airway inflammation in asthma ». Thesis, University of Edinburgh, 2008. http://hdl.handle.net/1842/25029.
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Respiratory heat and moisture loss (RHML) is proposed as a novel biophysical marker of AI. In a cross-sectional study of 23 patients with stable persistent asthma, 19 patients with acute asthma and 18 controls, RHML was significantly elevated in stable asthma (p=<0.01) and correlated with sputum eosinophil percentage (r=0.73; p=<0.01). Paradoxically, RHML was not elevated in acute asthma, and a number of possible explanations are discussed. The exhaled gases nitric oxide (NO) and carbon monoxide (CO), and exhaled breath condensate (EBC) pH and nitrite were examined in a cross-sectional study of 32 patients with stable asthma, 25 patients with acute asthma and 25 controls. NO was significantly increased in stable asthma compared with controls (p=<0.01). EBC pH was significantly lower in stable asthma than controls (p=<0.05) and there was a further decrease in acute asthma (p=<0.01). CO and EBC nitrite were not elevated in stable or acute asthma. Induced sputum differential cell counts were investigated in a cross-sectional study of patients with stable asthma (n=42), acute asthma (n=11), chronic obstructive pulmonary disease (n=26), bronchiectasis (n=14) and healthy controls (n=25). The percentage of eosinophils was significantly greater in stable asthma and acute asthma compared with other groups (p=<0.01). There was no difference in the percentage of eosinophils between patients with mild/moderate asthma and severe asthma. However, sputum neutrophil percentage was higher in severe persistent asthma (p=<0.01). To investigate the sensitivity of these markers to short term changes in airway inflammation, serial measurements were made during the resolution of an acute exacerbation of asthma. Exhaled NO decreased and EBC increased by day 7-9 of an exacerbation. The changes in these markers lagged behind changes in FEV1, suggesting that AI persisted beyond the principal period of bronchoconstriction.
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Stephanson, Niclas Nikolai. « Liquid chromatography-mass spectrometry study of two biochemical alcohol markers / ». Stockholm, 2007. http://diss.kib.ki.se/2007/978-91-7357-141-8/.
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Pelizzola, V. « TRACEABILITY OF MOUNTAIN CHEESES : IDENTIFICATION AND CHARACTERIZATION OF BIOCHEMICAL MARKERS ». Doctoral thesis, Università degli Studi di Milano, 2010. http://hdl.handle.net/2434/150180.
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Food traceability and knowledge of the relationship between production processing and food composition have become subjects of great interest during the last decade, due to the increasing demand for genuineness, high quality, and origin assurance of food. In the last few years several researchers have approached the problem of food authenticity and, in the dairy field, many papers dealing with the traceability of the origin of milk and cheese have been published. In particular, studies have been carried out to differentiate between highland cheeses, produced by animals feeding on pasture, and cheeses of lowland origin by examining the volatile compounds that can be transferred from forage into milk and cheese. Besides volatile compounds, extensively considered in literature as biochemical markers of origin, even non-volatile hydrocarbons molecules could be of interest to evaluate cheese traceability.
Therefore this PhD thesis focused on the study of the composition of the non-volatile minor components of the neutral lipid fraction in mountain dairy products, obtained from animals feeding on pasture, and in milk and cheese samples produced from cows under intensive breeding, fed with concentrates and silages. These neutral components were separated, by silica gel column chromatography, from the whole lipid matrix and analyzed by GC/MS. The main compounds detected, in all the samples analyzed, belonged to the following chemical classes: n-alkanes, fatty acid ethyl esters, fatty acid methyl esters, saturated and unsaturated isoprenoid hydrocarbons, cholesteryl esters and phytyl esters. According to the aim of this work, i.e. the detection of possible markers of traceability, the attention was focussed on the compounds having a proved relationship with the feeding and not influenced by technological processes. Thus the isoprenoid hydrocarbon 1-phytene, 2-phytene and neophytadiene (phytenes) and the n-alkanes were selected for further evaluation. Phytenes molecules derived, through different biosynthetic pathways, from dietary phytol of chlorophyll by the action of rumen bacteria. Since n-alkanes are important components of vegetable matrix, they are abundant in plant cuticular waxes and they are inert in the digestive tract of ruminants. Milk and cheese samples of highland origin were characterized by higher amounts of these molecules than those of lowland origin. In order to provide a parameter able to differentiate the two groups of dairy products, independent on usual factors affecting the natural variability particularly of mountain pasture (botanical composition, phenological stage, meteorology conditions etc.), some ratios between n-alkanes and phytenes were tested. The ratio obtained between the sum of phytenes (1-phytene, 2-phytene and neophytadiene) and octadecane allowed a good discrimination according to the feeding system adopted. Since the hydrocarbon fraction of highland dairy products resulted particularly rich in n-alkanes and phytenes, it was investigated whether the concentration of these compounds in cheese could be affected by different types of mountain pasture. Two typical alpine dairy productions were studied: Asiago and Toma Piemontese. For both productions, the cheeses were obtained from milk of two groups of animals fed on different vegetation types: rich fescue (P) and poor fescue (M) for Asiago d’Allevo; red fescue (F) and alpine clover (T) for Toma Piemontese. The results allowed, throughout two years of experimentation, a different relationship between the concentration of some constituents of the hydrocarbon fraction, which was closely related to the different botanical composition of the vegetation types. In particular, the ratio 1-phytene/2-phytene allowed a good discrimination between the two groups of the Asiago cheese, while the ratio between nonacosane and heptacosane was more effective to differentiate the two groups of Toma Piemontese cheese.
Moreover the fatty acid composition of Asiago and Toma Piemontese cheeses was studied. It was evaluated whether the fatty acids were able to differentiate the same cheese, but produced by feeding cows with a different pasture.
The results obtained are an important starting point for the advancement of studies on the relationship between "pasture and cheese". Above all, the identification of reliable and repeatable markers to define mountain dairy products traceability could be useful for the development of typical mountain productions.
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Ngqwala, Nosiphiwe Patience. « Interaction of metallic nanoparticles with biomedical enzyme target : neuronal nitric oxide synthase ». Thesis, Rhodes University, 2013. http://hdl.handle.net/10962/d1001536.
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Alzheimer's disease (AD) is the most common type of dementia characterized by intracellular appearance of neurofibrillary tangles, synaptic and neuronal loss; and extracellular accumulation of amyloid-β (Aβ) peptide in senile plaques. The initial causes leading to AD are unknown, and the available treatments are only effective at slowing the degeneration process. The accumulation of arginine in the brain of Alzheimer patients indicates a possible disruption of enzymes responsible for its metabolism. One such enzyme is neuronal nitric oxide synthase (nNOS) and controlling its activity by interacting with nanoparticles may lead to a delay in the onset of the disease. Neuronal nitric oxide synthase was purified using DEAE-Sephacel ion exchange resulting in 10 % yield, 0.43 fold recovery and specific activity 0.09 U/mg. The enzyme was found to be a dimer with a molecular mass of 150 kDa. Characterisation of the nNOS showed an optimum temperature and pH of 50°C and 7.5 respectively, and it was relatively stable at the optimum conditions (t½ = 100 min). The purity was analysed by SDS-PAGE followed by Western blot. Purified nNOS was challenged with 3-7 nm silver and 4-15 nm gold nanoparticles of between synthesized chemical using AgNO3 and either sodium borohydride or sodium citrate. Results showed that gold nanoparticles are more effective at low concentration (5 μM) than silver nanoparticles due to their size difference. Incubation of different concentration of nanoparticles (5, 15, 25, 50 μM) with the purified nNOS showed an initial decrease of 5% in enzyme activity which over time was restored to 80%. This suggests that different nanoparticles are produced in different sizes and interaction over a given time may result in enzyme association–dissociation mechanism. Inhibition studies showed a strong binding of both nanoparticles with Ki values of 1.4 μM and 0.2 μM for silver and gold, respectively. Both nanoparticles inhibited the activity of nNOS extensively as they bound strongly to the inhibition site on the enzyme and were more in contact with fluorophores nanoparticles. This was confirmed by fluorimetry with binding constants of 0.0084 μM and 0.01092 μM for silver and gold, respectively. Results of this study suggest that silver and gold nanoparticles competitively inhibit nNOS.
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Mahmoodi, Majid. « Search for Surrogate Marker(s) of Immunity Following Vaccination with Experimental Vaccine (Autoclaved Leishmania Major + Bacille Calmette-Guérin) in Human Volunteers ». Thesis, University of North Texas, 1998. https://digital.library.unt.edu/ark:/67531/metadc935616/.
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Cutaneous leishmaniasis (CL) is usually a self-limiting lesion on the skin while visceral leishmaniasis is a progressive, systemic disease with high mortality even if treated. The problem associated with treatment and vector control justifies a search for an effective vaccine which seems to be the only practical means to control the disease. The aim of this study is to identify immunological surrogate marker(s) associated with protection against Leishmania infection. The results indicate that a single dose of ALM+BCG induced Thl-like response but the level of such response is not sufficient for full protection. Accordingly, further evaluation of the vaccine is necessary other strategies multiple injections or changing the adjutant.
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Al, Awam Khaled. « The study of biomarkers for psychiatric disorders and their potential application in clinical and forensic psychiatry ». Thesis, Swansea University, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.678476.
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Ngai, H. Y. Heidi. « Proteomics analysis of potential biomarkers and pathogenic mechanisms of membranous nephropathy in a rat model of passive Heymann nephritis ». Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/hkuto/record/B38827372.
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Juchelka, Charlotte Milada. « Rapid toxicity assessment using ingestion rate as a sublethal biomarker ». Thesis, Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/25413.
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Kennedy, Alan Keith. « Urinary peptides in autism ». Thesis, University of Sunderland, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339546.
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Roberts, Fiona Jane. « Trace metals in blood and urine as potential markers of bone breakdown in patients with bone metastases ». Thesis, University of Plymouth, 1997. http://hdl.handle.net/10026.1/2350.
Texte intégralRésumé :
In the western world cancer is the second most important cause of death, after heart disease, accounting for 20-25% of all mortalities, and is today probably one of the most feared diseases. Approximately one third of all cancer patients will develop skeletal metastases (secondary bone cancer). Early diagnosis and effective monitoring during treatment is therefore essential in terms of making any impact on survival rates and developing new cancer therapies. Unfortunately, the current methods for diagnosing and measuring bone metastases, such as bone scans and urinary hydroxyproline determinations, lack sensitivity and specificity. The urinary pyridinium crosslinks, pyridinoline (PYD) and deoxypyridinoline (DPYD), have recently been identified as sensitive and specific markers of bone breakdown. However the analysis of the pyridinium crosslinks using high performance liquid chromatography (HPLC) has proved far from ideal for routine clinical assessment. The results from studies to critically evaluate this method are presented and particular problems encountered when the crosslinks are extracted from the urine samples are discussed. The tedious, time consuming and cumbersome sample preparation procedure are also shown to adversely effect the robustness and reproducibility of the method. The recent introduction of an immunoassay method potentially overcomes many of the inherent problems with the HPLC analysis. This enzyme linked immunoasorbant assay (ELISA) is evaluated and found to compare favourably with the HPLC method, offering several distinct advantages. The method is quick, simple, robust, demonstrates good accuracy and precision, is less prone to interferences and can be easily introduced into clinical laboratories on a routine basis. In addition it also minimises sample preparation time. However, there is still a requirement for alternative and better biochemical markers to measure bone breakdown. It is well known that bone is an active, living tissue and that bone metabolism and remodelling are tightly coupled processes, where the rate of bone formation equals the rate of bone resorption in healthy bone. When an imbalance occurs, this leads to unhealthy bone and ultimately a clinical disease of the skeleton. Some trace metals, e.g lead, accumulate in the bone and since the development of bone metastases results in extensive bone breakdown, the subsequent release of these metals into the blood and urine may potentially serve as markers. In this work inductively coupled plasma-mass spectrometry (ICP-MS) has been used and methods developed to determine such metals in clinical matrices. The development of a simple dilution method is described for use in preliminary trials to measure the blood lead levels and other trace metal profiles, in patients with bone metastases. The blood lead results attained agree closely with a certified reference material, and the method is shown to remain under analytical control. The trial results are presented and discussed with reference to further and more detailed investigations. The selection criteria for other suitable elements such as AI, Ba, Cd, Ce, Pb, Sr, and Zr in blood and urine, along with an assessment of the analytical and clinical praticalities of the methodology which must be considered for subsequent full clinical trials is also discussed following a critical evaluation. Finally the results obtained in a extended clinical trial are presented. The crosslink levels (serving as the reference marker), measured by ELISA, were compared with the trace metal levels (Cd, Pb and Sr) in blood and urine samples, measured by ICP-MS, in order to assess their diagnostic potential and effectiveness in monitoring treatment. The blood lead levels were found to offer the greatest potential, correlating well with the DPYD values in the majority of cases. The blood strontium levels also showed some promise. However the blood cadmium and the urinary trace metal levels proved less suitable. The results attained in this feasibility study support a more detailed clinical investigation, on a much larger scale, and over a longer period of time. The need to incorporate a full statistical evaluation of all factors that can influence the final results is highlighted.
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Li, feifei. « Effects of maximal intermittent exercise in normoxic and hypoxic environments on the release of cardiac biomarkers and the potential mechanism ». HKBU Institutional Repository, 2014. https://repository.hkbu.edu.hk/etd_oa/41.
Texte intégralRésumé :
The purposes of this study were 1) to investigate the release of cardiac biomarkers resulting from acute bouts of maximal intermittent exercise in a laboratory-based setting and set up an exercise-induced cardiac biomarker release (EICBR) model; 2) to compare the changes in cardiac biomarkers in normoxic and hypoxic environments and determine the effects of hypoxia; 3) to investigate the changes in oxidative stress biomarkers resulting from acute bouts of maximal intermittent exercise in normoxic and hypoxic environments at multiple time points; and 4) to observe the relationship between oxidative stress and EICBR and explore the hypothesis that lipid peroxidation triggers the release of cardiac biomarkers from the cytosolic pool. The maximal oxygen consumption (VO2max) and the corresponding velocity of VO2max (vVO2max) of ten well-trained male marathon runners (age 22.1±2.6 y, body mass 64.0±4.9 kg and height 177.3±3.9 cm) was determined under normoxic (FIO2=21.0%, VO2max_N=64.72±5.63 ml∙kg-1∙min-1 and vVO2max_N=18.2±1.0 km∙h-1) and hypoxic (FIO2=14.4%, VO2max_H=62.16±6.74 ml∙kg-1∙min-1 and vVO2max_H=16.7±0.7 km∙h-1) conditions in two experimental trials. One set of conditions was tested in each trial. The order in which each participant faced each trial was selected at random and the trials were separated by 72 h. The ten participants also completed three maximal intermittent exercise protocols, under normoxic (trial N, FIO2=21.0%), absolutely hypoxic (trial AH, FIO2=14.4%) and relatively hypoxic (trial RH, FIO2=14.4%) conditions. The order in which the participants faced the three conditions was once again selected at random and the protocols were separated by at least 7 d. Each bout of maximal intermittent exercise in trials N and AH consisted of a hard run of 16.4±0.9 km∙h-1 (90% vVO2max_N) for 2 min, followed by an easy run of 9.1±0.5 km∙h-1 (50% vVO2max_N) for 2 min with a 2% slope. In trial RH, each bout of exercise consisted of a hard run of 15.0±0.6 km∙h-1 (90% vVO2max_H) for 2 min, followed by an easy run of 8.4±0.3 km∙h-1 (50% vVO2max_H) for 2 min with a 2% slope. Each of the three trials consisted of 23 bouts of maximal intermittent exercise, performed over 92 min. Measurements of the serum of the antecubital venous blood were performed pre- and post- (0 h, 2 h, 4 h and 24 h) exercise. The measurements were taken at five time points for each of the three conditions. The cardiac damage biomarkers of high sensitivity cardiac troponin T (hs-cTnT) and cardiac troponin I (cTnI) and the oxidative stress biomarkers of malondialdehyde (MDA), lipid hydroperoxide (LH), superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and total antioxidant capacity (TAOC) were analysed. Heart rate (HR) and arterial oxygen saturation (SaO2) were recorded before and during exercise. Due to the skewed distribution of the data (P<0.05), a non-parametric Friedman’s test was used to compare the differences in the levels of hs-cTnT and cTnI between pre- and post-exercise and at each time point for the three conditions. MDA, LH, SOD, CAT, GSH, TAOC and HR were normally distributed (P>0.05) and were analysed using one-way repeated ANOVA tests. Pearson’s product moment correlation coefficients were used to determine the degree of association between the peak levels of hs-cTnT and cTnI, and MDA, LH, SOD, CAT, GSH and TAOC. In trial N, the level of hs-cTnT was elevated 0 h post-exercise (9.628±3.797 pg∙ml-1 was significantly different from the pre-exercise level of 5.118±1.857 pg∙ml-1, P=0.005), reached its peak level 2 h post-exercise (24.290±18.628 pg∙ml-1 was significantly different from the pre-exercise level, P=0.005) and returned to the baseline level at 24 h post-exercise (5.978±1.849 pg∙ml-1). The peak levels of hs-cTnT (N, AH 37.001±31.995 pg∙ml-1, RH 28.614±23.628 pg∙ml-1) and cTnI (N 0.0375±0.0437 ng∙ml-1, AH 0.0475±0.0533 ng∙ml-1, RH 0.0345±0.0375 ng∙ml-1) did not significantly differ under the three conditions. In trial AH, the peak levels of hs-cTnT (2 h, 4 h) and cTnI (2 h, 4 h) were highly related to the MDA_0h and the TAOC_24h. In trial RH, the peak levels of hs-cTnT (2 h, 4 h) and cTnI (2 h, 4 h) were highly related to the TAOC_4h. It was concluded that maximal intermittent exercise can be used to trigger EICBR. The stimulus of hypoxia did not induce more cardiac damage in this exercise model. Maximal intermittent exercise potentially triggers EICBR through oxidative stress, especially lipid peroxidation. Keywords: cardiac biomarkers, hs-cTnT, cTnI, oxidative stress, hypoxia
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Varghese, Sibu. « Biomarkers for risk stratification in Barrett's oesophagus ». Thesis, University of Cambridge, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708774.
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Zhu, Rui. « Liver-intestine cadherin (CDH17) in hepatocellular carcinoma molecular analysis and clinical implications / ». Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B43703793.
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Baldwin, Samantha, et n/a. « Models for genetic analysis of polyploid plant species ». University of Otago. Department of Biochemistry, 2008. http://adt.otago.ac.nz./public/adt-NZDU20090826.092431.
Texte intégralRésumé :
A number of major crop species, such as allohexaploid wheat and autotetraploid potato are polyploid. Potato is the fourth most important crop in terms of production and has become an important food source in many countries. Therefore, the molecular analysis was directed towards investigating ways to develop markers to assist the potato breeding process; for example breeding for powdery scab disease resistance, and tolerance to cold induced sweetening. Polyploids have more possible genotypes per population, allele dosage effects and increased marker complexity compared to diploids. Potato is also outcrossing and therefore highly heterozygous.
Various methods for detecting marker-trait associations including, linkage, quantitative trait locus (QTL) and association mapping were studied and protocols developed. A mapping population was produced and a number of traits were measured including powdery scab resistance. Powdery scab disease assays were carried out over six seasons and markers associated with disease resistance were identified. Markers associated with resistance to powdery scab were identified on chromosomes I, IV, V, VI, VIII and IX using analysis of variance (ANOVA). Linkage maps were produced for each parent of the population and QTL associated with resistance and susceptibility to disease were identified using interval mapping, which revealed QTL on chromosomes II, V, VII , VIII, IX and an unanchored linkage group. QTL were detected across years on regions of chromosomes VIII and IX. These QTL results had some overlap with the marker-trait associations that were identified using ANOVA analysis. Another marker identification technique was tested, known as association or linkage disequilibrium mapping. Alleles of candidate genes were tested for association with cold-induced sweetening using a germplasm collection. The alleles identified as important were of the apoplastic invertase and UGPase genes and a unique interaction between alleles of the apoplastic invertase and apoplastic invertase inhibitor was also detected.
This thesis describes the first study into the genetics of powdery scab resistance and the markers identified as associated with resistance will be validated for use in a marker-assisted selection (MAS) programme. The tools and resources developed as part of this thesis are vital to the potato breeding programme that requires the identification of associated molecular markers.
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Duda, Charles D. « Dietary and Biochemical Markers of Folate in the Consideration of Depression ». University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1337350909.
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Carstens, Karin. « Determination of distinctness among citrus cultivars using biochemical and molecular markers ». Thesis, Rhodes University, 1995. http://hdl.handle.net/10962/d1004082.
Texte intégralRésumé :
Citrus is among the most important fruit crops worlstwide, and therefore the preservation and improvement of citrus germplasm is of the essence. Citrus breeders are often faced with the difficulty of distinguishing between new and existing cultivars because of the ambiguous nature of morphological traits due to environmental influences and error in human judgement. The protection of new varieties is very important to the breeder. New varieties cannot be patented in South Africa, but it can be protected by Plant Breeders' Rights, only if it is genetically distinguishable and significantly different economically from existing varieties. Cultivars in four genera (c. sinensis, C. paradisi, C. grandis and C. reticulata) included in the Citrus Improvement Programme (CIP) or cultivars awaiting recognition of Plant Breeders' Rights by the International Union for the Protection of New Plant Varieties (UPOV) were analyzed with Isoenzymes, Restriction Fragment Length Polymorphism (RFLP) and Random Amplified Polymorphic DNA (RAPD). Five enzyme systems (PGM, PGI, MDH, GOT and IDH) were analyzed and founded to be suitable for grouping together cultivars belonging to the same genera. It was not suited for routine discrimination of cultivars in a particular genus. RFLP studies were conducted on five grapefruit cultivars, using cDNA clones from a genomic library of Rough Lemon. RFLP studies were valuable for the discrimination of closely related cultivars which probably originated from a common ancestor by bud mutations. This technique was, however, abandoned due to its biohazardous nature and replaced by the PeR-based Random Amplified Polymorphic DNA. RAPDs are easy to perform and gave promisin& results which were exploited to reveal polymorphisms between cultivars within the various groups. Although the interpretation of data produced by this method is often suspicious, it is the best method currently available for cultivar identification. It can playa complementary role in the protection of new varieties when classical morphological interpretation of differences is not capable of determining sufficient distinctness for the awarding of Plant Breeders' Rights.
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Mahsud-Dornan, Samina Shaheen. « An evaluation of biochemical markers in the prediction of pre-eclampsia ». Thesis, Queen's University Belfast, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.501311.
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Banzola, Irina <1974>. « Novel potential molecular and biochemical markers for non-invasive prenatal screenings ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amsdottorato.unibo.it/701/1/Tesi_Banzola_Irina.pdf.
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Banzola, Irina <1974>. « Novel potential molecular and biochemical markers for non-invasive prenatal screenings ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amsdottorato.unibo.it/701/.
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Monti, L. « CHARACTERISATION OF PDO CHEESE SAMPLES THROUGH THE IDENTIFICATION OF BIOCHEMICAL MARKERS ». Doctoral thesis, Università degli Studi di Milano, 2010. http://hdl.handle.net/2434/150167.
Texte intégralRésumé :
Bitto and Valtellina Casera are two PDO cheeses whose origin and production is strongly rooted in the Alpine area, since cows are fed using only local forage and pastures and milk is processed on place. They both are middle-hard, middle-ripened, but different production and storage conditions lead to different physical, chemical and microbiological changes during cheese ripening. In particular, the cooking temperature (48-52°Cx30min for Bitto and 40-45°Cx30min for Valtellina Casera) can influence the microflora growing and the associated biochemical events.
Bitto cheese is produced in summer, exclusively in the mountain, in itinerant huts, within 1 hour from milking, using raw full-fat cow milk, and a maximum of 10% of goat milk can be added. Ripening starts in the mountain to conclude in the valley, following natural climatic conditions. Valtellina Casera is a middle-fat cheese produced all year long in social dairy firms, collecting milk from one or two milking. Spontaneous acidification or the addition of starter cultures is used. Cheese ripening is made under controlled conditions. The two products are ripened at least 70 days before labelling and trading.
The aim of this PhD work was to improve knowledge on these two products, considering the evolving dairy techniques applied during their production and the poorness of data about their composition. The challenge was to improve and update information in order to identify a set of specific biochemical markers related to the process/product which could be used to classify and assess quality of products for authentication purposes.
In this perspective, Bitto and Valtellina Casera cheese samples representative of the current productive reality, were analysed to assess their chemical composition (moisture, protein, fat and ash contents). Particular attention was paid to determine nitrogen fractions and their quantification, since proteolysis is one of the most important biochemical events taking place during cheese ripening. Chemical data showed a high variability due to the traditional technologies adopted during cheese-making and to the different ripening time of samples. Anyway, the presence of significant differences between the two kinds of cheese, although belonging to the same variety, with regard to chemical parameters has been demonstrated. Significant differences (p<0.001) were observed in their moisture, proteins, ash, moisture/solids non-fat, proteins/DM and MFFS (moisture in the fat-free substance) contents, indicating that the interaction between the main cheese constituents in Bitto and Valtellina Casera is different. Valtellina Casera showed significantly higher values (p<0.001) of NCN and NPN, which indicate a more extensive degradation of caseins if compared to Bitto cheese.
Protein pattern was evaluated in detail by Capillary Zone Electrophoresis (CZE): an extensive hydrolysis of beta-caseins into the gamma-caseins by means of plasmin was evidenced. Also alpha s1-casein was highly degraded and a peak at the same migration time as alpha s1-I-casein appeared, suggesting some residual activity of chymosin or cathepsin D. Protein profile was a useful fingerprint for product characterization and a valuable tool to differentiate the two products: some peptides characterised the two cheese profiles either for presence/absence or for variation in their concentration and contributed to the partial distribution of samples in a PCA plot.
Free amino acids (FAA) quantification by HPLC analysis evidenced strong differences in the proteolysis behaviour, which was by far deeper in Valtellina Casera, confirming results obtained for nitrogen fractions. The two varieties showed very different concentration values of single amino acids but the same relative percentage distribution: Glu, Val, Phe, Leu, Orn and Lys confirmed to be the most relevant ones in both cheese productions, representing 67.6% of total FAA in Bitto and 64% in Valtellina Casera. Anyway, amino acids which allowed samples separation in PCA plot were those which showed most significantly different values in the two products.
Organic acids content was investigated. Results showed a very high variability and PCA simultaneously applied to all the variables could not differentiate between the two cheese productions. Anyway, through pair-wise comparison, Bitto cheese showed higher butyrate concentrations, while Valtellina Casera had higher lactate, pyruvate and pyroglutamate contents.
In conclusion, since the final aim of this work was Bitto and Valtellina Casera cheese characterisation and differentiation, PCA was applied to all parameters found to be highly significant (p<0.001) in order to test the whole data set for cheese classification. PCA explained 72% of the total variance and correctly grouped samples into two classes.
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Kunutsor, Setor Kwadzo. « Markers of liver dysfunction and risk of coronary heart disease ». Thesis, University of Cambridge, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708216.
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Engelbrecht, Albertus Hermanus. « Biological markers for major depressive disorder in children and adolescents ». Thesis, Cape Technikon, 1986. http://hdl.handle.net/20.500.11838/1481.
Texte intégralRésumé :
Thesis (Masters Diploma (Technology)--Cape Technikon, Cape Town, 1986Child psychiatrists have become increasingly aware of the existence. of affective disorders in prepubertal and pubertal patients. This has led to the investigation of possible biological factors contributing to the disorders. Due to the lack of availability of human brain material, different parameters have been investigated in the periphery in order to obtain information regarding the aetiology of major depressive disorder. The neurotransmitters, NA, 5-HT and DA have been implicated in depression. Levels of the metabolites of these transmitters have been measured in plasma, urine and CSF of adult depressed patients. Two other peripheral "tools" used in the study of major depressive disorder are blood platelets and lymphocytes. The former contain cr 2 -adrenoceptors and imipramine binding sites (indicative of 5-HT uptake into the platelet) and the latter S-adrenoceptors. Platelets have been widely used as a model for indirectly evaluating changes in central cr2-adrenoceptor and imipramine binding whereas lymphocytes have been used to measure changes in S-adrenoceptor binding and activity in adults with major depressive disorder.
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Arthurson, Catherine Therese. « The relationship between psychological distress and biochemical markers in students undergoing exams / ». Title page, table of contents and abstract only, 2003. http://web4.library.adelaide.edu.au/theses/09SSPS/09sspsa7912.pdf.
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Barlow, Robert D. « Studies on biochemical markers of oral medicine compliance and cigarette smoke intake ». Thesis, Queen Mary, University of London, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361888.
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Al-Ansari, Salwa. « Clinical evaluation of biochemical markers of cardiovascular disease : an evidence based approach ». Thesis, University of Aberdeen, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.408785.
Texte intégralRésumé :
Introduction: Laboratory markers play an important role in early risk stratification diagnosis and management for patients presenting with different heart problems. However, the role of such markers as diagnostic tests remains unclear when applied to real life patient’s cohorts, especially when it is accompanied by incorrect time of measurement and interpretation of final results. Methods: We have assessed the role of a variety of markers (hFABP, myoglobin, cTnI, PAPP-A, hsCRP, hsp70, and ADP/ATP) with respect to their diagnostic and prognostic value using an evidence-based approach in pragmatic real life cohorts (patients with ACS, patienst undergoing cardiac surgery and patients with AF). Results: Measurement of myoglobin and hFABP in patients presenting with ACS offers no additional value to the measurement of cTnI on admission and at 12 hours. PAPP-A measurement may be useful at detecting unstable plaque disease. Post-operative measurement of cTnI in patients undergoing cardiac surgery is useful at detecting post-operative complications and at predicting subsequent mortality. An inflammatory component, as indicated by the measurement of hsCRP may be associated with the initiation of AF. Conclusions: The evaluation of biochemical marker in real-life patients cohorts is essential to understand the true relationships present in the exact patient cohorts that the tests will subsequently be used in. Larger studies are required for both new and current markers.
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Evason, David John. « Biochemical markers for storage abuse in raw black tiger prawns (Penaeus monodon) ». Thesis, London South Bank University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312654.
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Kappala, Shanthi Sharon. « Risk factors and blood-borne biochemical markers in type 2 diabetes mellitus ». Thesis, University of Central Lancashire, 2012. http://clok.uclan.ac.uk/6723/.
Texte intégralRésumé :
The burden of Diabetes Mellitus (DM) is increasing worldwide and it is estimated to reach indefinite proportions of about 450 million by year 2030. Patients with type 2 diabetes mellitus (T2DM) have a significantly increased risk of developing cardiovascular diseases (CVD). Moreover, CVD is the major cause of mortality and morbidity (75%) in T2DM patients. DM itself has been long recognised as an independent risk factor for several forms of CVD including coronary heart disease (CHD), peripheral arterial disease, cardiomyopathy and congestive heart failure in both men and women. It is well-known that T2DM is associated with several factors including hyperglycaemia, hypertension, dyslipidemia, obesity all of which contribute to CVD. In order to prevent CVD, early intervention on cardiovascular risk factors is vital during clinical assessment of T2DM patients. A major role of inflammation has been well described in the development of CVD in T2DM patients. Inflammatory process and factors which contribute to CVD in T2DM patients have recently become a focus in diabetic research. Elucidation of common patho-physiological mechanisms among T2DM patients might emphasize the role of inflammation in CVD. The main purpose of this study was to investigate any patho-physiological changes in red blood cells (RBC), white blood cells (neutrophils and lymphocytes) and plasma, measuring RBC membrane fragility and proteins, intracellular free calcium concentrations [Ca2+]i and several cations including Na+, Mg2+, Ca2+, Fe2+, Zn2+ and Cu2+, biochemical parameters and inflammatory mediators which normally serve as independent predisposing risk factors for CVD among T2DM patients compared to age-match healthy controls. The results have shown that fura-2 loaded neutrophils and lymphocytes in blood from T2DM patients contain significantly (p<0.05) less [Ca2+]i than neutrophils and lymphocytes from healthy subjects upon stimulation with physiological doses of either fMLP or thapsigargin indicating a derangement in cellular calcium homeostasis during T2DM. Similarly, RBC membranes from T2DM patients contained significantly (p<0.05) more spectrin, ankyrin, band 3, band 4.1, glycophorin etc compared to RBC membranes from age-matched healthy control subjects. The results also show that the RBCs from T2DM patients were more fragile compared to RBC from healthy controls. Measurement of protein glycation in plasma have revealed significantly (p<0.05) more fluorescence in proteins form T2DM patients compared to control. In relation to plasma cations and intracellular markers and mediators, the results show that plasma from T2DM patients contain significantly (p<0.05) more Na+, Mg2+ , Ca2+, Fe2+, Zn2+ and Cu2+ compared to plasma levels from age-match healthy controls. Similarly, the concentrations of kidney and liver function markers such as urea, creatinine, alkaline phosphatase, ALT, AST, GGT, total protein and albumin increased significantly (p<0.05) compared to healthy controls. The same is also true for glucose, total cholesterol, triglycerides, CRP, HBA1C, WBC where the blood from T2DM patients contained elevated concentrations compared to blood from healthy age-matched control patients. Together, the results of this study have clearly demonstrated marked and significant changes in cellular calcium homeostasis in white blood cells, RBC membrane proteins and fragility, plasma protein glycation and in plasma levels of cations, intracellular markers and mediators of T2DM patients compared to healthy controls. Therefore, it is proposed that an early integrated and multi-factorial intervention of risk factors and inflammatory markers must be done in order to reduce the risk of CVD and possible mortality of T2DM patients.
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Chetty, Maya. « Novel biochemical markers in the diagnosis and management of early pregnancy problem ». Thesis, University of Newcastle upon Tyne, 2012. http://hdl.handle.net/10443/1463.
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Background and purpose: Early pregnancy problems, including miscarriage, ectopic pregnancy and pregnancy of unknown location, occur commonly and have significant medical, psychological and economic consequences. Biochemical markers are increasingly being used as an adjunct to ultrasonography and this thesis describes three studies exploring the use of novel biochemical markers in the diagnosis and management of early pregnancy problems. Materials and methods: These are observational studies of women in early pregnancy recruited at Sunderland Royal Hospital and King’s College Hospital. Serum samples were taken from women in early pregnancy and lectin affinity chromatography used to characterise the glycosylation of hCG by gestational age and by pregnancy outcome. Women with a diagnosis of a miscarriage, ectopic pregnancy or pregnancy of unknown location had serum levels of hCG, progesterone, inhibin A, IGFBP-1 and inhibin proαC quantified, and statistical analysis was used to see if spontaneous resolution of the pregnancies could be predicted. Results: Lectin-affinity chromatography reveals five major glyco-isoforms of hCG in early pregnancy, the expression of which changes with gestational age and by pregnancy outcome. The novel markers of the luteo-trophoblastic axis inhibin A, IGFBP-1 and inhibin proαC are found not to be clinically useful in the prediction of spontaneously resolving PULs although when used in the decision trees developed by Elson in 2005, they are useful for predicting spontaneous resolution of miscarriages and failed pregnancies. Conclusions: Novel biochemical markers have the potential to be a useful addition in the management of early pregnancy problems. Further studies are required to explore the physiological basis of these findings and the clinical applicability of these tools.
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Elson, Claire Janine. « The use of ultrasound and biochemical markers in prediction of pregnancy outcome ». Thesis, University of Leicester, 2006. http://hdl.handle.net/2381/29511.
Texte intégralRésumé :
The aims of this thesis were to develop novel approaches to the management of early pregnancy complications and to identify a subgroup of women who develop various pregnancy complications in the second and third trimester. The thesis is based on four studies of women in the first trimester of pregnancy. These studies examine the value of ultrasound and serum biochemistry in the prediction of outcome in women with an anembryonic gestational sac (Chapter 4), with ectopic pregnancies (Chapter 5), with failing pregnancies (Chapter 6) and women developing later complications (Chapter 7). Statistical models comprising of logistic regression or decision tree analysis were developed for each study. In women with anembryonic gestation sacs the probability of a viable pregnancy can be calculated using a logistic regression model, decision tree analysis or progesterone alone with equal accuracy. These models were validated prospectively. Decision tree analysis was used to develop a model for the prediction of successful expectant management of ectopic pregnancy, based on both a single serum hCG measurement or using serial measurement. These models were also validated prospectively. A novel approach to the prediction of the success of expectant management of miscarriages was developed using decision tree analysis and IGFBP-1 and inhibin A. A raised serum value of 17 OH progesterone appeared to identify those women at risk of developing hypertensive disorders later in pregnancy. This thesis has developed algorithms that can be used in clinical practise to predict the success of expectant management in women with failing pregnancies. It has identified that novel biochemical markers may have a role to play in the prediction of successful expectant management of women with miscarriages and the prediction of pregnancy complications developing in the second and third trimesters.
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BUCKLEY, ARTHUR RALPH JR. « EFFECTS OF PROLACTIN ON BIOCHEMICAL MARKERS OF HEPATIC PRENEOPLASIA IN THE RAT ». Diss., The University of Arizona, 1986. http://hdl.handle.net/10150/183834.
Texte intégralRésumé :
Prolactin (PRL) may be a key mammalian growth and developmental hormone. Hepatic receptors bind PRL implicating the liver as a PRL target. Recent evidence suggests that PRL triggers hepatic ornithine decarboxylase (ODC) induction, a marker of a trophic response. This suggests that in the liver PRL may contribute to neoplasia. To test this theory, PRL modulation of plasminogen activator (PA), DNA synthesis, cytochrome P450 (P450), liver hypertrophy and enzyme altered foci (EAF) was assessed. Cyclosporine, a PRL receptor antagonist, attenuated PRL-stimulated PA induction. PRL-stimulation of PA and ODC activity reflected age dependence. PRL administration to young rats stimulated hepatic microsomal P450 content 39% above control, an effect camparable to phenobarbital. Incubation of microsomes from PRL-treated rats with warfarin produced a metabolic pattern unique to PRL. PRL stimulated hepatic DNA synthesis up to 400%. This effect was shown to be specific for hepatic parenchymal cells. PRL for 6 weeks produced hepatic hypertrophy, an effect augmented by diethylnitrosamine (DEN). Additionally, incresed hepatic GGTase activity and EAF were demonstrated in rats treated with chronic PRL after DEN. Extrahepatic neoplasia was increased by partial hepatectomy PH and chronic PRL. PRL receptor coupling was investigated in PRL-dependent Nb₂ node lymphoma cells. ODC induction and proliferation were found to be coupled to protein kinase C (PKC) and calmodulin (CM) in experiments using pharmacological agents. Phosphatidylinositol (PI) turnover and ionic flux alterations were also implicated. These results suggest PRL receptor coupling to PI turnover and PKC activation in Nb₂ cells. PRL may be a key liver growth hormone. PRL induces PA, ODC and P450. Furthermore, its ability to promote EAF strongly implicates PRL in the ontogeny of hepatocarcinogenesis.
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Budge, Suzanne M. « Fatty acid biomarkers in a cold water marine environment ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0012/NQ52692.pdf.
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Neustein, Michelle Elizabeth Schauer Caroline L. Wheatley Margaret A. « Polymer thin film colorimetric gas sensor for lung cancer analytes / ». Philadelphia, Pa. : Drexel University, 2005. http://dspace.library.drexel.edu/handle/1860/488.
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