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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Relation of dietary inorganic arsenic to serum matrix metalloproteinase-9 (MMP-9) at different threshold concentrations of tap water arsenic.

Kurzius-Spencer, Margaret, Harris, Robin B, Hartz, Vern, Roberge, Jason, Hsu, Chiu-Hsieh, O'Rourke, Mary Kay, Burgess, Jefferey L 10 1900 (has links)
Arsenic (As) exposure is associated with cancer, lung and cardiovascular disease, yet the mechanisms involved are not clearly understood. Elevated matrix metalloproteinase-9 (MMP-9) levels are also associated with these diseases, as well as with exposure to water As. Our objective was to evaluate the effects of dietary components of inorganic As (iAs) intake on serum MMP-9 concentration at differing levels of tap water As. In a cross-sectional study of 214 adults, dietary iAs intake was estimated from 24-h dietary recall interviews using published iAs residue data; drinking and cooking water As intake from water samples and consumption data. Aggregate iAs intake (food plus water) was associated with elevated serum MMP-9 in mixed model regression, with and without adjustment for covariates. In models stratified by tap water As, aggregate intake was a significant positive predictor of serum MMP-9 in subjects exposed to water As≤10 μg/l. Inorganic As from food alone was associated with serum MMP-9 in subjects exposed to tap water As≤3 μg/l. Exposure to iAs from food and water combined, in areas where tap water As concentration is ≤10 μg/l, may contribute to As-induced changes in a biomarker associated with toxicity.
92

Evaluation of methotrexate polyglutamates as a biomarker for optimizing methotrexate treatment in Crohn’s disease

Mohan, Ashray 24 November 2021 (has links)
Methotrexate (MTX) is an antagonist of folic acid metabolism that was initially designed to treat malignancies, including childhood leukemia. After its anti-inflammatory properties were discovered, use of MTX became widespread in the treatment algorithms for several autoimmune illnesses, including the inflammatory bowel diseases (IBD), Crohn’s disease (CD) and ulcerative colitis (UC). The specific cause(s) of IBD in general, and CD in specific, have not yet been fully elucidated. However, most investigators agree that the pathogenesis is likely due to a combination of genetic vulnerability and precipitating environmental exposures. Some of these identifiable modifiers include adherence to a low fiber diet, vitamin D deficiency, smoking, and an alteration in the diversity of the gut microbiome in response to viral or bacterial illness or antibiotic medications. Disease activity in patients with CD, particularly during clinical trials, is assessed using composite indices, including the Crohn’s Disease Activity Index (CDAI), Crohn’s Disease Endoscopic Index of Severity (CDEIS), and the Short Inflammatory Bowel Disease Questionnaire (SIBDQ). A wide range of medications is used to induce and maintain long-term remission in patients with active CD. These include corticosteroids, immunosuppressive agents (thiopurines and MTX) and several classes of biologics such as TNF-inhibitors, anti-IL-12/23 and anti-adhesion molecules. TNF-inhibitors are often used as first-line biologic therapies in patients with IBD because they have been in widespread use for over two decades and therefore afford the clinician a more data-driven consideration of risk to benefit ratio when discussing treatment options with their patients. However, there is a relatively high rate of primary non-response and acquired secondary loss of response to TNF-inhibitors. A secondary loss of response often results from the production of neutralizing antibodies, referred to as Antibodies to Infliximab (ATI). In response, concomitant low-dose oral MTX therapy has been employed by clinicians to reduce the immunogenicity of biologic therapy. In addition, previous studies have also demonstrated the efficacy of MTX monotherapy in maintaining clinical remission in patients with CD when delivered at relatively higher doses. However, there is no consensus on the proper dosing or route of administration (oral or parenteral) of MTX. This knowledge gap has resulted in inconsistent clinical practice across physicians and institutions. Pharmacologic studies have identified the metabolic pathways underpinning the mechanism of action of MTX. It is generally understood that MTX in its native form is free to move across cell membranes in a bidirectional manner. It is only after MTX has been glutamated (MTX-PG) that it is “caged” within the cell and can exert its effects. MTX can be glutamated on up to five discrete sites, each contributing to its stereospecificity and membrane permeability. A better understanding of this process may inform the development of rational dosing and pharmacokinetic-based treatment algorithms that provide patients with a sufficient MTX (and subsequently MTX-PG) level required to achieve anticipated clinical efficacy but not so high as to contribute undo morbidity to treated patients. Therefore, optimizing MTX/MTX-PG dosing can significantly advance the utility of this immunomodulatory pathway to treat IBD and other autoimmune disorders. MTX can be administered orally or parenterally, the latter being delivered by either subcutaneous or intramuscular injection. Previous studies have demonstrated increased bioavailability of the drug at higher doses when delivered via the parenteral route. The native form of MTX has a short half-life and is eliminated from the body within 24 hours. Instead, it is the active metabolites of MTX which are retained for more extended periods of time and are ultimately responsible for the anti-inflammatory effects in the body. A MTX molecule can have anywhere from 1 and 5 glutamyl groups attached to it, denoted as MTX-PG1, MTX-PG 2, MTX-PG3, MTX-PG 4, and MTX-PG 5. The mechanism(s) by which MTX-PG moieties contribute anti-inflammatory activity is not fully understood but remains an area of active research. Several studies have explored the association between disease activity and erythrocyte MTX-PG levels. While initial results were mixed, more recent prospective cohort studies in patients with Rheumatoid Arthritis (RA) found an inverse relationship between intracellular levels of longer-chain MTX-PG (MTX-PG3, MTX-PG4, and MTX-PG5) and disease activity. This finding has raised the possibility that monitoring MTX-PG levels could be used as a clinical tool to optimize MTX therapy for patients. However, several key issues persist, including high interpatient variability in MTX-PG levels. Similar studies in patients with CD have thus far been scarce. More prospective studies are needed to explore the utility of MTX-PG pharmacokinetics as a useful biomarker and clinical tool to develop an individualized approach to managing patients with Crohn’s disease.
93

Serum brain-derived neurotrophic factor (BDNF) concentrations in pregnant women with post-traumatic stress disorder and comorbid depression

Yang, Na, Gelaye, Bizu, Rondón, Marta B., Sanchez, Sixto E., Williams, Michelle A., Zhong, Qiu-Yue 19 May 2016 (has links)
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / There is accumulating evidence for the role of brain-derived neurotrophic factor (BDNF) in the pathophysiology of depression. However, the role of BDNF in the pathophysiology of post-traumatic stress disorder (PTSD) remains controversial, and no study has assessed BDNF concentrations among pregnant women with PTSD. We examined early-pregnancy BDNF concentrations among women with PTSD with and without depression. A total of 2928 women attending prenatal care clinics in Lima, Peru, were recruited. Antepartum PTSD and depression were evaluated using PTSD Checklist—Civilian Version (PCL-C) and Patient Health Questionnaire-9 (PHQ-9) scales, respectively. BDNF concentrations were measured in a subset of the cohort (N = 944) using a competitive enzyme-linked immunosorbent assay (ELISA). Logistic regression procedures were used to estimate odds ratios (OR) and 95 % confidence intervals (95 % CI). Antepartum PTSD (37.4 %) and depression (27.6 %) were prevalent in this cohort of low-income pregnant Peruvian women. Approximately 19.9 % of participants had comorbid PTSD-depression. Median serum BDNF concentrations were lower among women with comorbid PTSD-depression as compared with women without either condition (median [interquartile range], 20.44 [16.97–24.30] vs. 21.35 [17.33–26.01] ng/ml; P = 0.06). Compared to the referent group (those without PTSD and depression), women with comorbid PTSD-depression were 1.52-fold more likely to have low (<25.38 ng/ml) BDNF concentrations (OR = 1.52; 95 % CI 1.00–2.31). We observed no evidence of reduced BDNF concentrations among women with isolated PTSD. BDNF concentrations in early pregnancy were only minimally and non-significantly reduced among women with antepartum PTSD. Reductions in BDNF concentrations were more pronounced among women with comorbid PTSD-depression. / Revisión por pares
94

Using gene and microRNA expression in the human airway for lung cancer diagnosis

Gerrein, Joseph 22 January 2016 (has links)
Lung cancer surpasses all other causes of cancer-related deaths worldwide. Gene-expression microarrays have shown that differences in the cytologically normal bronchial airway can distinguish between patients with and without lung cancer. In research reported here, we have used microRNA expression in bronchial epithelium and gene expression in nasal epithelium to advance biological understanding of the lung-cancer "field of injury" and develop new biomarkers for lung cancer diagnosis. MicroRNAs are known to mediate the airway response to tobacco smoke exposure but their role in the lung-cancer-associated field of injury was previously unknown. Microarrays can measure microRNA expression; however, they are probe-based and limited to detecting annotated microRNAs. MicroRNA sequencing, on the other hand, allows the identification of novel microRNAs that may play important biological roles. We have used microRNA sequencing to discover novel microRNAs in the bronchial epithelium. One of the predicted microRNAs, now known as miR-4423, is associated with lung cancer and airway development. This finding demonstrates for the first time a microRNA expression change associated with the lung-cancer field of injury and microRNA mediation of gene expression changes within that field. The National Lung Screening Trial showed that screening high-risk smokers using CT scans decreases lung-cancer-associated mortality. Nodules were detected in over 20% of participants; however, the overwhelming majority of screening-detected nodules were non-malignant. We therefore need biomarkers to determine which screening-detected nodules are benign and do not require further invasive testing. Given that the lung-cancer-associated field of injury extends to the bronchial epithelium, our group hypothesized that the field of injury may extend farther up in the airway. Using gene expression microarrays, we have identified a nasal epithelium gene-expression signature associated with lung cancer. Using samples from the bronchial epithelium and the nasal epithelium, we have established that there is a common lung-cancer-associated gene-expression signature throughout the airway. In addition, we have developed a nasal epithelium gene-expression biomarker for lung cancer together with a clinico-genomic classifier that includes both clinical factors and gene expression. Our data suggests that gene expression profiling in nasal epithelium might serve as a non-invasive approach for lung cancer diagnosis and screening
95

Plasma microRNAs Are Potential Biomarkers of Acute Rejection After Hindlimb Transplantation in Rats / 血漿中マイクロRNAはラット後肢移植モデルの急性拒絶反応のバイオマーカーとなりえる

Oda, Hiroki 26 March 2018 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第20969号 / 医博第4315号 / 新制||医||1026(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 戸口田 淳也, 教授 濵﨑 洋子, 教授 三森 経世 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DGAM
96

The Effects of Well-Rounded Exercise Program on Systemic Biomarkers Related to Cartilage Metabolism / 包括的な運動療法が関節軟骨代謝に関する全身性バイオマーカーに与える効果について

Azukizawa, Masayuki 25 March 2019 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第21672号 / 医博第4478号 / 新制||医||1035(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 川上 浩司, 教授 古川 壽亮, 教授 上杉 志成 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
97

Point of use sensing of human performance biomarkers in body fluids

Ray, Prajokta January 2018 (has links)
No description available.
98

The Role of CLCA2 in Anoikis Resistance of HNSCC ——Potential Biomarker for Prediction of Sensitivity to EGFR Inhibitors

Yin, Yufang 01 May 2019 (has links) (PDF)
Head and neck squamous cell carcinoma (HNSCC) develops in mucous membranes that line the mouth, throat and sinuses. It is the sixth most common cancer worldwide with more than 600,000 new cases diagnosed every year. The 5 year survival of HNSCC patients is less than 50% after initial diagnosis, while median survival after relapse or metastasis is less than one year. Unfortunately, the prognosis of HNSCC has not changed in the last two decades, mostly due to the poor understanding of the mechanism of this disease. New therapeutic targets and agents are in urgent need.
99

Identification Methods and Chemometric Analysis of Mammalian Volatile Biomarkers

Dissanayake, Shamitha Asoka 15 August 2014 (has links)
The ultimate goal of this research is to provide a low cost, efficient, reproducible, quantitative, non-invasive screening method to diagnose diseases at an early stage through identification of volatile biomarkers of disease. Progress has been made in the areas towards development of an analytical system that can provide a rapid and specific assay for above mentioned Volatile Organic Compounds (VOCs). (i) Methods have been designed for the collection, concentration, identification and quantification of volatile biomarkers. (ii) Advanced signal processing evaluation of data has tentatively identified key VOCs patterns with breath and body odor. (iii) Novel absorbent coatings have been studied for use with miniature chemical sensors that one day may be part of a portable analytical system. Both breath and body odor contain a complex mixture of chemicals, which are influenced by many internal and external factors. Breath and skin odor samples were collected with minimum external contaminations using traditional SPME and active SPME GCMS techniques. Body odor from 65 human subjects was tested with and without selected scent removal products. Breath samples were collected from 21 canine subjects. The VOCs profiles of these samples were determined and then statistically treated with principal component analysis, discriminant analysis, and tree regression techniques to simplify and interpret the complex mixtures. While much of our work has utilized large bench-top equipment, our over-arching goal is to provide a portable device that can diagnose diseases at an early stage. Concurrent work was done to enhance the performance of a miniaturized detector for the detection of potential biomarkers. Two organic polymers mixed with conductive carbon nanoparticles were deposited between the microcapacitor plates of microsensors using ink-jet technology. Microsensors were also fabricated using conducting ionic liquids. The performances of the individual chemicapacitive sensors were characterized through exposure to different concentrations of varied volatile organic compounds with different functional groups in a climate-controlled vapor delivery system.
100

Dermal α-synuclein oligomers and aggregates in Parkinson’s disease / Nachweis von Alpha-Synuclein-Oligomeren und -Aggregaten in Hautbiopsien von Parkinson-Patienten

Kuzkina, Anastasia January 2020 (has links) (PDF)
Lewy bodies and Lewy neurites are neuropathological hallmarks of Parkinson’s disease (PD). These depositions in the brain mostly consist of aggregated α-synuclein (α-syn) phosphorylated at Ser129. A number of studies reported detection of phosphorylated α-syn (p-α-syn) in the dermal nerve fibers in Parkinson’s disease. The objective of this study was to investigate whether pathological α-syn accumulations detected in the skin represent aggregated protein. A number of methods aimed at detecting α-syn oligomers and aggregates were first tested and optimized on the brain samples in PD and normal control. These methods included proximity ligation assay (PLA), PET-blot, immunohistochemical (IHC) stains with α-syn aggregate (5G4) or oligomer specific (ASyO5) antibodies and a stain against native α-syn (syn211) after proteinase K (PK) digestion. Subsequently, the most specific methods (stains with 5G4, ASyO5 and syn211 after PK digestion) were studied in two separate patient and control cohorts. Anti-p-α-syn stain was performed in parallel. Single sections from at least 2 biopsy sites from 44 patients and 22 controls (cohort 1) as well as serial sections of 4 biopsy sites from 27 patients and 5 controls (cohort 2) were systematically studied for presence of aggregated and oligomeric α-syn. In total, 5G4 positive deposits were found in 24% (cohort 1) and 37% (cohort 2), ASyO5 positive lesions in 17,7% (cohort 1) and 33% (cohort 2), syn211 positive lesions after PK digestion in 38,7% (cohort 1) and 48% (cohort 2) of cases. There was a major overlap among positivity for a particular staining on the patient level and in most cases, the same nerve fiber was found to be positive for all 4 markers in neighboring sections. Among the skin biopsies which contained p-α-syn accumulation, 59% were also PK resistant, 41% were 5G4 positive and 45% were ASyO5 positive. The samples belonging to normal controls did not show any positive signal in either of the newly established stainings or in the anti-p-α-syn staining. Using 3 distinct IHC methods, α-syn oligomers and aggregates were detectable in the majority of p-α-syn positive skin biopsies. This finding supports the hypothesis that α-syn aggregation occurs in the peripheral (i.e. dermal) nerves and can be specifically detected using skin biopsy. / Die neuropathologischen Kennzeichen des Morbus Parkinson sind Lewy-Körperchen und Lewy-Neuriten. Diese Ablagerungen im Gehirn bestehen hauptsächlich aus aggregiertem α-Synuclein (α-Syn), das am Ser129 phosphoryliert ist. Mehrere Studien konnten zeigen, dass phosphoryliertes α-Syn (p-α-Syn) auch in Nervenfasern der Haut von Parkinsonpatienten nachweisbar ist. Das Ziel dieser Arbeit war, zu untersuchen, ob es sich bei den pathologischen Ablagerungen von p-α-Syn in der Haut wie im Gehirn um Aggregate handelt. Mehrere Methoden, die dem Nachweis von α-Syn-Oligomere und Aggregate dienen, wurden zuerst an Gehirnen von einem Parkinsonpatienten und Normalkontrolle getestet und optimiert, darunter: Proximity Ligation Assay (PLA), PET-Blot, immunhistochemische Färbungen mit α-Syn-Aggregat- (5G4) oder Oligomer-spezifischen Antikörper (ASyO5) und eine Färbung mit einem Antikörper gegen natives α-Syn (syn211) nach Verdau mit Proteinase K (PK). Danach wurden die spezifischsten Methoden (Färbung mit 5G4, ASyO5 und syn211 nach PK-Verdau) an den Hautstanzbiopsien von zwei Patienten- und Normalkontrollkohorten untersucht. Parallel wurde in den Biopsien das p-α-Syn angefärbt. Einzelschnitte von je mind. 2 Biopsiestellen von 44 Patienten und 22 Kontrollen (Kohorte 1) sowie Serienschnitte von je 4 Biopsiestellen von 27 Patienten und 5 Kontrollen (Kohorte 2) wurden systematisch nach Vorliegen von aggregierten und oligomerischen α-Syn untersucht. Zusammenfassend, wurden 5G4-positive Ablagerungen in 24% (Kohorte 1) und 37% (2. Kohorte), ASyO5-positive Läsionen in 17,7% (Kohorte 1) und 33% (Kohorte 2), syn211-positive Läsionen nach PK-Verdau in 38,7% (Kohorte 1) und 48% (Kohorte 2) der Fälle gefunden. Das p-α-Syn wurde entsprechend in 43,6% und 48% der Fälle detektiert. Es zeigte sich die Tendenz, dass Patienten, bei denen p-α-Syn nachweisbar war, auch für mehrere der neuen Marker positiv waren; auch häufig waren für alle 4 Marker positive Nervenfasern in naheliegenden Schnitte zu sehen, was für eine Kolokalisation spricht. Unter den Hautbiopsien, in den p-α-Syn-Ablagerungen zu sehen waren, hatten 59% gleichzeitig PK-resistente, 41% 5G4- und 45% ASyO5-positive Ablagerungen. Bei Kontrollen waren Ablagerungen weder mit den neu eingeführten Methoden noch mit anti-p-α-Syn-Färbung detektierbar. Mit Hilfe von drei unterschiedlichen immunhistochemischen Methoden waren Oligomere und Aggregate vom α-Syn im Großteil der p-α-Syn-positiven Hautbiopsien nachweisbar. Dieser Befund unterstützt die Hypothese, dass die Ablagerung von α-Syn-Aggregaten auch in peripheren (v.a. dermalen) Nerven vorkommt und spezifisch nachgewiesen werden kann.

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