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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.
1

Detection of miRNA by SMART technology

Sailis, Fiammetta January 2017 (has links)
Aberrant expression of short non-coding micro RNAs (miRNA) in many human diseases, along with remarkable stability in physiological media, has made them attractive clinical biomarkers. In particular, miRNA-122 is substantially elevated in plasma of patients with established drug-induced liver injury and can also be used to identify early liver injury when current markers, such as alanine aminotransferase (ALT), still show normal levels. The development of a rapid test for miRNA-122 e.g. in drug poisoning would allow earlier and more sensitive clinical diagnosis of liver injury. Nucleic acids are traditionally analysed by polymerase chain reaction (PCR), which has a high degree of sensitivity but suffers from high cost and is prone to sample contamination. The aim of this project is to develop a PCR free method to directly detect miRNA- 122 in biological samples using SMART technology. The SMART technology takes advantage of dynamic chemistry for sequence specific recognition of nucleic acids using aldehyde-modified nucleobases (SMART nucleobases), and target-complementary peptide nucleic acid (PNA) probe containing an “abasic” position (so called modified PNA probe). In this study, this unique detection method was used in a fluorescent detection with the use of light up probes, which are probes with an environmental dye as nucleobase; a FRET system was also designed to allow the discrimination between perfect match target and mismatched one. The SMART technology was also transferred onto magnetic beads to develop an ELISA like assay allowing sensitive and rapid detection of single stranded DNA mimic of the miRNA-122. With its potential PCR free approach, this easily adapted platform promises to transform and expand routine clinical diagnostic testing and screening for circulating miRNAs.
2

False negative results for blood tested in the presence of chemical interferents

Gheevarghese, Reshma Mariam 09 February 2022 (has links)
Blood is considered one of the most widely tested biological matrices. The first step in blood identification involves visual examination followed by presumptive testing. Once a positive presumptive result is observed, confirmatory tests are performed to determine that a stain is human blood, thus reducing the time and resources spent on forensically irrelevant samples. When interfering agents are present, this general workflow is hindered as presumptive tests can render false-negative results. General awareness of these interfering agents can help analysts to recognize forensically relevant evidence that may have otherwise been deemed immaterial. The main objective of this study was to understand various interfering agents and their effects on presumptive blood tests such as Kastle Meyer (KM) and Orthotolidine (O-tol) reagents and confirmatory tests such as HemaTrace® and Rapid Stain Identification (RSID™) Blood. Additional experiments explored the effects on downstream DNA analysis. In the first part of the study, bloodstains in varying concentrations were exposed to ten chemical interferents over a period of time to understand how blood dilution, age of the stain, and the chemical nature of the interferent affect presumptive blood test results. Antioxidants, active oxygen, and tannins are known to interrupt the mechanism of presumptive tests. Thus, ten interfering agents (ascorbic acid, chlorogenic acid, catechin, sodium percarbonate, hydrogen peroxide, oxalic acid, proanthocyanidins, quebracho extract, chestnut extract, and theaflavin) were selected based on these characteristics. Six blood dilutions (neat, 1:10, 1:50, 1:100, 1:500, and 1:1000) were exposed to the interferents, and presumptive tests for blood were conducted on six days (day 1, 8, 22, 43, 71, and 106). The second part of the study examined bloodstains deposited on real-world samples (wines, citrus fruit juices, teas, coffee, cleaning agents, and leather products) containing chemical interferents. In addition, confirmatory testing for human blood was conducted with HemaTrace® and RSID™-Blood on day 106 using the 1:500 dilution. Finally, DNA analysis of 1:10 dilution stains was performed on day 150 to study whether downstream DNA analysis was compromised due to the presence of the interferents. The results showed that as blood concentration reduced, more false-negative results were observed when chemical interferents were present. Further, chemical interferents produced frequent atypical color changes in tests with KM and O-tol reagents, while only some atypical color changes were observed with the household products tested. Immunochromatographic assay results indicated both HemaTrace® and RSID™-Blood could detect the presence of blood when interfering agents are present, although the positive result bands with RSID™-Blood were faint and sometimes difficult to visualize. Poor DNA results from the untreated blood sample limited any interpretation of the DNA results obtained from bloodstains deposited on household products. Overall, the data indicates that valuable blood evidence may be overlooked due to faint or false-negative results when these interferents are present. Future studies should focus on how these interferents may affect downstream DNA analysis.
3

Colorectal cancer in the Australian population : prospects for prevention through screening / David Weller.

Weller, David P. January 1994 (has links)
Includes bibliographical references. / xiii, 260 leaves ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Examins Fecal Occult Blood Test (FOBT) screening as a possible means of reducing mortality from colorectal cancer in Australia. Consists of an evaluation of a FOBT screening program in South Australia (in terms of numbers of cancers detected, accuracy of the test used, costs of the program and characteristics of participants) and surveys of the general population and of South Australian general practitioners, providing information on knowledge, attitudes and practices in relation to colorectal cancer and its prevention. / Thesis (Ph.D.)--University of Adelaide, Dept. of Community Medicine, 1995?
4

Colorectal cancer cost-effectiveness of screening and chemoprevention in average risk males /

Coffindaffer, Jarrett W. January 2006 (has links)
Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains ix, 98 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 92-98).
5

Development and external validation of an automated computer-aided risk score for predicting sepsis in emergency medical admissions using the patient's first electronically recorded vital signs and blood test results

Faisal, Muhammad, Scally, Andy J., Richardson, D., Beatson, K., Howes, R., Speed, K., Mohammed, Mohammed A. 24 January 2018 (has links)
Yes / Objectives: To develop a logistic regression model to predict the risk of sepsis following emergency medical admission using the patient’s first, routinely collected, electronically recorded vital signs and blood test results and to validate this novel computer-aided risk of sepsis model, using data from another hospital. Design: Cross-sectional model development and external validation study reporting the C-statistic based on a validated optimized algorithm to identify sepsis and severe sepsis (including septic shock) from administrative hospital databases using International Classification of Diseases, 10th Edition, codes. Setting: Two acute hospitals (York Hospital - development data; Northern Lincolnshire and Goole Hospital - external validation data). Patients: Adult emergency medical admissions discharged over a 24-month period with vital signs and blood test results recorded at admission. Interventions: None. Main Results: The prevalence of sepsis and severe sepsis was lower in York Hospital (18.5% = 4,861/2,6247; 5.3% = 1,387/2,6247) than Northern Lincolnshire and Goole Hospital (25.1% = 7,773/30,996; 9.2% = 2,864/30,996). The mortality for sepsis (York Hospital: 14.5% = 704/4,861; Northern Lincolnshire and Goole Hospital: 11.6% = 899/7,773) was lower than the mortality for severe sepsis (York Hospital: 29.0% = 402/1,387; Northern Lincolnshire and Goole Hospital: 21.4% = 612/2,864). The C-statistic for computer-aided risk of sepsis in York Hospital (all sepsis 0.78; sepsis: 0.73; severe sepsis: 0.80) was similar in an external hospital setting (Northern Lincolnshire and Goole Hospital: all sepsis 0.79; sepsis: 0.70; severe sepsis: 0.81). A cutoff value of 0.2 gives reasonable performance. Conclusions: We have developed a novel, externally validated computer-aided risk of sepsis, with reasonably good performance for estimating the risk of sepsis for emergency medical admissions using the patient’s first, electronically recorded, vital signs and blood tests results. Since computer-aided risk of sepsis places no additional data collection burden on clinicians and is automated, it may now be carefully introduced and evaluated in hospitals with sufficient informatics infrastructure. / Health Foundation
6

Leishmaniose Visceral: raça canina e perfil lipídico / Visceral leishmaniasis: canine breeds and lipid profile

Fonseca, Andre Luis Soares da 05 December 2013 (has links)
A leishmaniose visceral, causada no Brasil por protozoários da espécie Leishmania (L.) infantum, apresenta-se nos canídeos com manifestações similares à doença humana. Diversos trabalhos tem investigado a relação entre raças caninas e suscetibilidade/resistência à doença sendo as alterações lipídicas consideradas também nessa avaliação. Para avaliar o grau de comprometimento conforme a raça e as alternações lipídicas nos cães portadores de leishmaniose visceral, analisamos alterações hematológicas e bioquímicas frente à manifestação da doença em diferentes raças ou grupos raciais. Para tanto, incluímos 162 cães de área endêmica, sem histórico de outras patologias ou de vacinação contra leishmaniose, organizados em grupos de cães naturalmente infectados segundo a raça, quais sejam, Boxer, Labrador, Pit Bull, Sem Raça Definida (SRD) e Outras Raças, e grupo controle não infectados. Na avaliação das manifestações clínicas, dividimos os animais, dentro de cada grupo de cães infectados em assintomáticos (sem nenhum sinal clínico), oligossintomáticos (de 1 a 3 sinais clínicos) e polissintomáticos (acima de 3 sinais clínicos). As raças/grupos formadas pelo total de cães infectados (assintomáticos + oligossintomáticos + polissintomáticos) também foram avaliados segundo o escore de gravidade da infecção. Para analisar as possíveis alterações laboratoriais decorrentes da infecção de cães por Leishmania (L.) infantum foram realizados hemograma, leucograma, dosagens de albumina, globulinas, proteínas plasmáticas totais, creatinina, ureia, alanino aminotransferase (ALT), Fosfatase Alcalina (FA), colesterol total, lipoproteínas de alta densidade (high density lipoproteins, HDL), lipoproteínas de baixa densidade (low density lipoproteins, LDL), lipoproteínas de densidade muito baixa (very low density lipoproteins, VLDL) e triglicérides. Analisados em conjunto, observamos que os animais assintomáticos, independentemente de raça/grupo, apresentaram parâmetros bioquímicos e hematológicos similares aos valores descritos para o grupo controle não infectado. Não observamos diferença na gravidade das manifestações da doença entre as raças ou grupos raciais para o desenvolvimento da Leishmaniose Visceral Canina. As diversas raças e grupos raciais apresentaram alterações nos parâmetros pesquisados, porém os quadros de hipoalbuminemia, hiperglobulinemia e anemia foram identificados com maior frequência, sendo correlacionados à gravidade na raça Labrador e nos grupos SRD e Outras Raças. O quadro de anemia foi mais importante na raça Pit Bull. O grupo Outras Raças apresentou o maior número de alterações correlacionadas à gravidade. A raça Labrador apresentou concentração de HDL diminuída em relação às demais raças. As alterações lipídicas, principalmente em HDL, VLDL e triglicérides foram correlacionadas à gravidade no grupo Outras Raças. / Visceral leishmaniasis caused in Brazil by protozoa Leishmania (L.) infantum, presents in dogs similar manifestations as human disease. Some work has investigated the relationship between dog breeds and susceptibility/resistance to disease and lipid changes has been also considered in this evaluation. To assess the degree of commitment according breed and lipid changes in dogs with visceral leishmaniasis, we analyzed hematological and biochemical parameters and the manifestation of the disease in different breeds or groups. Therefore, we included 162 dogs from an endemic area of Brazil with no history of other diseases or vaccination against leishmaniasis, organized in groups of dogs naturally infected by breed, namely Boxer, Labrador, Pit Bull, Mogrel dogs, Other Breeds and uninfected control group. In the evaluation of the clinical manifestations, we divided the animals in infected asymptomatic (no clinical signs), oligosymptomatic (1-3 clinical signs) and polisymptomatic dogs (above 3 clinical signs). Breeds/groups formed by the total of infected dogs (asymptomatic+oligosymptomatic+polisymptomatic) were also assessed according to the severity of the infection. To analyze the possible laboratory changes resulting from infection of dogs by Leishmania (L.) infantum were performed red blood cell count, white blood cell count, evaluation of albumin, globulin, total plasma protein (TPP), creatinine, urea, alanine aminotransferase (ALT), alkaline phosphatase (ALP), total cholesterol, high density lipoproteins (HDL), low density lipoproteins (LDL), very low density lipoprotein (VLDL) and triglycerides. Taken together, we observed that asymptomatic animals, regardless of breeds/group, showed biochemical and hematological parameters similar to values reported for the uninfected control group. There were no differences in severity of disease manifestations among breed or racial groups for the development of Canine Visceral Leishmaniasis. The different breeds and racial groups showed changes in the parameters studied, but hypoalbuminemia, hypergammaglobulinemia and anemia were identified more frequently being correlated to the severity in Labrador, mongrel and Other Breeds groups. The anemia was most important in Pit Bull. The group Other Breeds had the largest number of changes correlated to the severity. The Labrador showed decreased HDL levels compared to other breeds. Lipid changes, especially in HDL, VLDL and triglycerides were correlated to the severity in the Other Breeds group.
7

POINT-OF-CARE CLINICAL DIAGNOSIS USING MASS SPECTROMETRY SYSTEM

Ran Zou (5930504) 16 January 2019 (has links)
<p>Point of care (POC) diagnosis is essential in personalized treatment to obtain effective clinical outcomes when the patient is on site. And Mass spectrometry (MS) system promotes the applications of rapid sampling ionization, which could be a tool for fast disease determination. In this thesis, a miniature MS system was firstly developed for POC tissue analysis. Lipid profile in rat organs were demonstrated. By coupling with online Paternò–Büchi (PB) reaction, fast determination of lipid C=C bond location isomers was realized. The system was applied to quantitatively analyze the change of lipid C=C location isomers between mouse normal and cancerous samples. The intensity ratio of fatty acid 18:1 (D9) and 18:1 (D11) in wild type breast tissue was calculated to be 2.881, while the ratio in tumor breast tissue was 0.667. The direct sampling-based miniature MS system is potential for POC analysis of lipid profiles and lipid biomarkers discovery.</p> <p>Secondly, an integration of paper-capillary spray and MS make it possible to analyze dried blood samples instantly in clinical laboratory and hospital. Quantitation of ratio between deuterate Phenylalanine and deuterate Tyrosine was achieved by using paper spray and paper-capillary spray MS directly, without any pretreatment of blood samples. Furthermore, these methods could generate calibration curves which enable the calculation of Phenylalanine concentration in whole human blood within 60 seconds. This disposable design is a promising application for point-of-care (POC) PKU analysis in newborn screening. </p> <p>At last, an increased in free fatty acids (FFAs) of cereals was observed during storage, and a simple and direct rice quality assessment was performed using nanoESI (Nano-Electrospray Ionization) mass spectrometry method. Six fatty acids including palmitic, oleic, and linoleic acids were compared between different rice species, growth regions and harvest years. 2D and 3D linear discriminant analysis (LDA) methods were deployed and a good sample separation was achieved. This direct sampling method of extracting FAs from rice surface combined with MS is suitable for industrial use in rapid identification for large number of samples.</p>
8

Leishmaniose Visceral: raça canina e perfil lipídico / Visceral leishmaniasis: canine breeds and lipid profile

Andre Luis Soares da Fonseca 05 December 2013 (has links)
A leishmaniose visceral, causada no Brasil por protozoários da espécie Leishmania (L.) infantum, apresenta-se nos canídeos com manifestações similares à doença humana. Diversos trabalhos tem investigado a relação entre raças caninas e suscetibilidade/resistência à doença sendo as alterações lipídicas consideradas também nessa avaliação. Para avaliar o grau de comprometimento conforme a raça e as alternações lipídicas nos cães portadores de leishmaniose visceral, analisamos alterações hematológicas e bioquímicas frente à manifestação da doença em diferentes raças ou grupos raciais. Para tanto, incluímos 162 cães de área endêmica, sem histórico de outras patologias ou de vacinação contra leishmaniose, organizados em grupos de cães naturalmente infectados segundo a raça, quais sejam, Boxer, Labrador, Pit Bull, Sem Raça Definida (SRD) e Outras Raças, e grupo controle não infectados. Na avaliação das manifestações clínicas, dividimos os animais, dentro de cada grupo de cães infectados em assintomáticos (sem nenhum sinal clínico), oligossintomáticos (de 1 a 3 sinais clínicos) e polissintomáticos (acima de 3 sinais clínicos). As raças/grupos formadas pelo total de cães infectados (assintomáticos + oligossintomáticos + polissintomáticos) também foram avaliados segundo o escore de gravidade da infecção. Para analisar as possíveis alterações laboratoriais decorrentes da infecção de cães por Leishmania (L.) infantum foram realizados hemograma, leucograma, dosagens de albumina, globulinas, proteínas plasmáticas totais, creatinina, ureia, alanino aminotransferase (ALT), Fosfatase Alcalina (FA), colesterol total, lipoproteínas de alta densidade (high density lipoproteins, HDL), lipoproteínas de baixa densidade (low density lipoproteins, LDL), lipoproteínas de densidade muito baixa (very low density lipoproteins, VLDL) e triglicérides. Analisados em conjunto, observamos que os animais assintomáticos, independentemente de raça/grupo, apresentaram parâmetros bioquímicos e hematológicos similares aos valores descritos para o grupo controle não infectado. Não observamos diferença na gravidade das manifestações da doença entre as raças ou grupos raciais para o desenvolvimento da Leishmaniose Visceral Canina. As diversas raças e grupos raciais apresentaram alterações nos parâmetros pesquisados, porém os quadros de hipoalbuminemia, hiperglobulinemia e anemia foram identificados com maior frequência, sendo correlacionados à gravidade na raça Labrador e nos grupos SRD e Outras Raças. O quadro de anemia foi mais importante na raça Pit Bull. O grupo Outras Raças apresentou o maior número de alterações correlacionadas à gravidade. A raça Labrador apresentou concentração de HDL diminuída em relação às demais raças. As alterações lipídicas, principalmente em HDL, VLDL e triglicérides foram correlacionadas à gravidade no grupo Outras Raças. / Visceral leishmaniasis caused in Brazil by protozoa Leishmania (L.) infantum, presents in dogs similar manifestations as human disease. Some work has investigated the relationship between dog breeds and susceptibility/resistance to disease and lipid changes has been also considered in this evaluation. To assess the degree of commitment according breed and lipid changes in dogs with visceral leishmaniasis, we analyzed hematological and biochemical parameters and the manifestation of the disease in different breeds or groups. Therefore, we included 162 dogs from an endemic area of Brazil with no history of other diseases or vaccination against leishmaniasis, organized in groups of dogs naturally infected by breed, namely Boxer, Labrador, Pit Bull, Mogrel dogs, Other Breeds and uninfected control group. In the evaluation of the clinical manifestations, we divided the animals in infected asymptomatic (no clinical signs), oligosymptomatic (1-3 clinical signs) and polisymptomatic dogs (above 3 clinical signs). Breeds/groups formed by the total of infected dogs (asymptomatic+oligosymptomatic+polisymptomatic) were also assessed according to the severity of the infection. To analyze the possible laboratory changes resulting from infection of dogs by Leishmania (L.) infantum were performed red blood cell count, white blood cell count, evaluation of albumin, globulin, total plasma protein (TPP), creatinine, urea, alanine aminotransferase (ALT), alkaline phosphatase (ALP), total cholesterol, high density lipoproteins (HDL), low density lipoproteins (LDL), very low density lipoprotein (VLDL) and triglycerides. Taken together, we observed that asymptomatic animals, regardless of breeds/group, showed biochemical and hematological parameters similar to values reported for the uninfected control group. There were no differences in severity of disease manifestations among breed or racial groups for the development of Canine Visceral Leishmaniasis. The different breeds and racial groups showed changes in the parameters studied, but hypoalbuminemia, hypergammaglobulinemia and anemia were identified more frequently being correlated to the severity in Labrador, mongrel and Other Breeds groups. The anemia was most important in Pit Bull. The group Other Breeds had the largest number of changes correlated to the severity. The Labrador showed decreased HDL levels compared to other breeds. Lipid changes, especially in HDL, VLDL and triglycerides were correlated to the severity in the Other Breeds group.
9

Error detection in blood work : Acomparison of self-supervised deep learning-based models / Felupptäckning i blodprov : En jämförelse av självbevakade djupinlärningsmodeller

Vinell, Paul January 2022 (has links)
Errors in medical testing may cause serious problems that has the potential to severely hurt patients. There are many machine learning methods to discover such errors. However, due to the rarity of errors, it is difficult to collect enough examples to learn from them. It is therefore important to focus on methods that do not require human labeling. This study presents a comparison of neural network-based models for the detection of analytical errors in blood tests containing five markers of cardiovascular health. The results show that error detection in blood tests using deep learning is a promising preventative mechanism. It is also shown that it is beneficial to take a multivariate approach to error detection so that the model examines several blood tests at once. There may also be benefits to looking at multiple health markers simultaneously, although this benefit is more pronounced when looking at individual blood tests. The comparison shows that a supervised approach significantly outperforms outlier detection methods on error detection. Given the effectiveness of the supervised model, there is reason to further study and potentially employ deep learning-based error detection to reduce the risk of errors. / Fel i medicinska tester kan orsaka allvarliga problem som har potential att allvarligt skada patienter. Det finns många maskininlärningsmetoder för att upptäcka sådana fel. Men på grund av att felen är sällsynta så är det svårt att samla in tillräckligt många exempel för att lära av dem. Det är därför viktigt att fokusera på metoder som inte kräver mänsklig märkning. Denna studie presenterar en jämförelse av neurala nätverksbaserade modeller för detektering av analytiska fel i blodprov som innehåller fem markörer för kardiovaskulär hälsa. Resultaten visar att feldetektering i blodprov med hjälp av djupinlärning är en lovande förebyggande mekanism. Det har också visat sig att det är fördelaktigt att använda ett multivariat tillvägagångssätt för feldetektering så att modellen undersöker flera blodprov samtidigt. Det kan också finnas fördelar med att titta på flera hälsomarkörer samtidigt, även om denna fördel är tydligare när modellen tittar på individuella blodprov. Jämförelsen visar att ett övervakat tillvägagångssätt avsevärt överträffar metoder för detektering av extremvärden vid feldetektering. Med tanke på effektiviteten av den övervakade modellen finns det anledning att studera tillvägagångssättet vidare och eventuellt använda djupinlärningsbaserad feldetektering för att minska risken för fel.

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