Dissertations / Theses on the topic 'HRV analysis'
To see the other types of publications on this topic, follow the link: HRV analysis.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'HRV analysis.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Padmanabhan, Sivasankar. "Drowsiness detection using HRV analysis." Thesis, California State University, Long Beach, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1596988.
Full textAbstract:
The field of drowsiness detection is gaining more attention these days. An estimate by National Highway Traffic Safety Administration states that the total number of people falling asleep on the wheel is increasing day by day. If there is an effective way to monitor this condition and alert the drivers, many fatal accidents can be prevented. This thesis work elaborates on one such simple, yet effective drowsiness detection algorithm, the HRV - Heart Rate Variability analysis. Many psychological researchers have found out that when a person becomes drowsy, there is a variation in their heart signal. Monitoring this physiological variation would be more efficient than monitoring their facial movements such as blinking, eye brow contraction, and yawning, which are said to happen after much longer time when compared to the immediate changes in the heart rate. Hence, an algorithm that detects drowsiness based on HRV analysis is developed and implemented by analyzing heart signals. Simple hardware setups were used to collect the ECG data, and digital filters were used to remove noise and extract the desired information for further analysis. The developed algorithm was implemented successfully and the results obtained were more precise and satisfactory. This approach of monitoring drowsiness is more reliable and accurate and when implemented with its necessary features, it can monitor drowsiness more effectively and save hundreds of lives every day.
2
Green, Jr Donald Lee. "ANALYSIS OF THE EFFECTS OF ATROPINE AND SALINE ON THE HRV OF RATS USING ENSEMBLE AVERAGING AND FREQUENCY ANALYSIS." MSSTATE, 2008. http://sun.library.msstate.edu/ETD-db/theses/available/etd-07102008-123307/.
Full textAbstract:
The aim of this study is to examine heart rate variability (HRV) alteration after the injection of atropine and saline and to determine if ensemble averaging affects the outcome of frequency domain analysis. The HRV data is pre-processed using ensemble averaging and then frequency domain and statistical analysis is done. The HRV readings originate from a previous study of four rats. Ensemble averaging reduces the mean drift effect in the data. The original and ensemble is then processed through an Fast Fourier Transform (FFT). The results show that the ensembled data allows frequency peaks and changes to be seen more clearly than the FFT of the original data set. Through statistical analysis it is also shown that the change in HRV from the atropine injection is much greater than the change in HRV from the saline injection.
3
Nytorpe, Piledahl Staffan, and Daniel Dahlberg. "Detektering av stress från biometrisk data i realtid." Thesis, Högskolan i Halmstad, Akademin för informationsteknologi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-31248.
Full textAbstract:
At the time of writing, stress and stress related disease have become the most common reasons for absence in the workplace in Sweden. The purpose of the work presented here is to identify and notify people managing unhealthy levels of stress. Since symptoms of mental stress manifest through functions of the Sympathetic Nervous System (SNS), they are best measured through monitoring of SNS changes and phenomena. In this study, changes in the sympathetic control of heart rate were recorded and analyzed using heart rate variability analysis and a simple runner’s heart rate sensor connected to a smartphone. Mental stress data was collected through stressful video gaming. This was compared to data from non-stressful activities, physical activity and extremely stressful activities such as public speaking events. By using the period between heartbeats and selecting features from the frequency domain, a simple machine learning algorithm could differentiate between the types of data and thus could effectively recognize mental stress. The study resulted in a collection of 100 data points, an algorithm to extract features and an application to continuously collect and classify sequences of heart periods. It also revealed an interesting relationship in the data between different subjects. The fact that continuous stress monitoring can be achieved using minimally intrusive sensors is the greatest benefit of these results, especially when connsidering its potential value in the identification and prevention of stress related disease.
4
Franěk, Pavel. "Analýza variability srdečního rytmu pomocí rekurentního diagramu." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-220048.
Full textAbstract:
The aim of this thesis is to describe the variability of cardiac rhythm and familiarity with the methods of the analysis, ie by monitoring changes in heart rhythm electrogram signal recording and using the methods in the time domain using recurrent diagram. The work describes the quantification of the methods and possibilities of quantifiers in the evaluation of heart rate variability analysis. It also describes the clinical significance of heart rate variability and diagnostic capabilities changes of heart rate variability caused by ischemic heart disease. The practical part describes how to create applications in Matlab to calculate the quantifiers analysis of heart rate variability in the time domain using recurrent diagram. The calculation was made of the positions R wave elektrogram signal isolated rabbit hearts. The calculated values of quantifiers both methods were statistically evaluated and discussed.
5
Macková, Pavlína. "EKG biofeedback." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-219742.
Full textAbstract:
The master’s thesis is focused on the possibilities of measuring heart rate of ECG signal and its use in therapeutic game of ECG biofeedback. This thesis describes the way of measuring ECG with acquisition unit Biopac and analyzes signal processing for measurement of heart rate – algorithms of QRS detection, HRV analysis. Realisation of therapeutic is designed for applications in Matlab.
6
Appelgren, Jörgen, and Fredrik Kjellström. "LCC-analys av FTX-system : En jämförelse av centralt- och lägenhetsplacerat." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-172562.
Full textAbstract:
This report is the result of a thesis conducted at the consulting firm Bjerking AB andis the final part of the Bachelor Programme in Construction Engineering at Universityof Uppsala. The work aims to investigate the costs and how the choice of ventilationsystem affects building projects during a long-term period. This report covers costssuch as investment, maintenance and energy but also how they affect residents andbuilders. Building regulations for energy consumption are expected to be tougher;therefore a comparison of two different heat recovery ventilation systems(HRV-system) was made. One system is based on a centrally placed unit that coversthe whole buildings ventilation through vertical shafts. The second system is based onapartment placed unit that only covers the individual apartment’s ventilation. The unitmakes it possible for the individual user to control the ventilation flow.The method used for comparison of the costs was Life Cycle Cost (LCC). It results inthe total cost during a selected calculation period of 20 years, where yearly basedcosts as energy and maintenance is included. Two housing projects in central Uppsalawere chosen as a reference. They were similar in design but with the two differentsystems of ventilation. A questionnaire was handed out to provide experience fromresidents with apartment units. The results were used in the analysis of the systemsand to determine its pros and cons.Information of costs was collected from different companies and resulted intocustomized spreadsheets to determine the cost per apartment. The result shows thatthe difference in investment is not significant between the systems but is big inmaintenance and energy. The biggest difference is maintenance where the apartmentsystems many service points is increasing the cost. Energy consumption for theapartment system leads to higher energy costs than with a central system, even if thecontrol function is used. The explanation is that a central systems fans have lowerpower usage and the heat recovery is more efficient then an apartment system.The conclusion is that a central system has a lower total cost compared to anapartment system during the calculation period. A reason for choosing the apartmentsystem would be if a need to maximize living space is a priority, and the developingphase of the project is well thought thru.Keywords: LCC-analysis, HRV-systems, Central unit, Apartment unit.
7
Heiss, Leah Rose Laurel, and leah heiss@rmit edu au. "Empathy and the space between: investigating the role of digitally enhanced apparel in promoting remote empathetic connection." RMIT University. Architecture and Design, 2006. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20070112.101632.
Full textAbstract:
This body of work is the culmination of a two year investigation into the role of electronically enhanced apparel and artefacts in providing empathetic linkage between people who do not share physical space. The research draws from the diverse fields of philosophy, communications theory, neuropsychology, presence technologies and technologically advanced textiles, and proposes that a nexus of these disciplines may provide significant opportunities for enhancing the user interactivity of garments and artefacts. Remote emotional connection is investigated through the creation of sensor embedded garments and artefacts that have been developed in collaboration with a fashion designer and an electronics engineer. The prototypes encourage remote empathetic connection through the real-time transference of heartbeat. The exegesis is structured into five chapters which consider remote presence, flexible consciousness, the architecture of empathy, plasticity in sense perception and the development of prototypes. The project chapter focuses in the development of and testing of a rnage of garments and artefacts thatt conduct presence information between remotely located people. The garments sense, process, transmit and receive the heartbeat signal (ECG). They are enabled with ECG sensors, signal processing equipment, small vibration motors and radio transceivers which allow users to 'feel' the heartbeat of a remote friend/lover/relative as vibration through their garment. The prototypes aim to enrich the remote communications experience through reintroducing an embodied, tactile dimension that is present in face-to-face communication. A range of user testing trials are discussed in the thesis which have been undertaken to assess the impact of the garments at a conscious and a non-conscious level. Conscious experiences were gauged through qualitative testing by way of interviews and unsolicited written reactions. Non-conscious physiological ractions were assessed by recording ECG throughout user-testing periods. This data has been processed by using HRV (heart rate variability) analysis software, running on MatLab.
8
Gunzenhauser, Jan. "Application of real-time HRV biofeedback in the scenario of meditation practice : Feasibility, usability and medical fidelity." Thesis, Linnéuniversitetet, Institutionen för medieteknik (ME), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-45420.
Full textAbstract:
Chronic stress is a prevalent and universally present hazard in modern society. It lowers the quality of life for individuals and significantly con- tributes to unsustainable health care costs. Therefore it is important to have natural and noninvasive ways of controlling stress. One such way is meditation, a technique which has been practiced for over five thousand years to improve stress regulation. Also, proceedings in sensing technologies lead to the discovery of biofeedback as another cost-effective technique for stress assessment and reduction. In continuation of research on real-time reflective human-computer-interfaces, this thesis combines these techniques by exploring the application of electrocardiography sensing technology in a heart rate variability (HRV) biofeedback system for the scenario of medita- tion practice. A proof-of-concept prototype was designed and implemented which quantifies stress and gives feedback on meditation effectiveness. For evaluation, a user study has been performed. Results were analysed in a systematic way to evaluate the feasibility and acceptance of the solution as well as the fidelity of HRV data that was measured during user tests. The prototype was found to be feasible in the context of technology acceptance while the fidelity of data, acquired by an algorithm for time and frequency domain analysis of HRV, was confirmed. A final conclusion is that the reflective aspect of the implemented real-time biofeedback system helps to improve regulatory capacity and thus lowers stress in individuals.
9
Thungtong, Anurak. "Synchronization, Variability, and Nonlinearity Analysis: Applications to Physiological Time Series." Case Western Reserve University School of Graduate Studies / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=case1364316597.
Full text
10
Huang, Lin. "Effects of aromatherapy on negative emotions and work and study performance: heart rate variability analysis to assess the balance of the autonomic nervous system." Doctoral thesis, Universitat Autònoma de Barcelona, 2017. http://hdl.handle.net/10803/402260.
Full textAbstract:
El
objetivo
general
de
esta
tesis
es
analizar
la
eficacia
de
la
aromaterapia
(AR)
para
reducir
las
emociones
negativas
e
incrementar
el
nivel
de
atención
y
rendimiento
en
el
situaciones
laborales
y
académicas.
Se
probará
esta
eficacia
con
cuestionarios
y
evaluando
el
equilibrio
del
Sistema
Nervioso
Autónomo
a
partir
del
análisis
HRV.
Para
llevar
a
cabo
este
objetivo
general,
se
realizarán
dos
estudios
principales.
Analizaremos
los
efectos
de
la
AR
sobre
la
variabilidad
de
la
frecuencia
cardíaca
(HRV)
como
un
marcador
del
equilibrio
simpático/parasimpático
desde
el
SNA.
El
objetivo
para
el
Estudio
1
fue
analizar
la
eficacia
de
la
AR
parea
reducir
la
ansiedad
y
mejorar
la
concentración
en
el
estudio
en
estudiantes
universitarios.
La
muestra
fue
de
12
estudiantes
(edad
entre
18
y
33
años).
Analizamos
los
efectos
del
aceite
esencial
de
albahaca
(Basil)
a
corto
término
(1
hora)
y
a
largo
término
(1
mes).
Encontramos
que
la
inhalación
del
aceite
esencial
de
albahaca
reduce
las
puntuaciones
de
ansiedad
y
mejora
la
variabilidad
cardíaca
(parámetros
SDRR
y
RMSSD).
La
AR
en
una
sesión
corta
o
con
una
botella
aromática
colgada
del
cuello
cada
día
durante
un
mes
produce
cambios
emocionales
y
de
HRV
en
los
participantes.
El
objetivo
del
Estudio
2
fue
analizar
la
eficacia
de
la
AR
para
mejorar
el
rendimiento
laboral
y
reducir
el
estrés
en
el
lugar
de
trabajo.
La
muestra
estaba
formada
por
42
trabajadores
universitarios
administrativos
(edad:
42.21
años,
SD=7.12;
género:
10
hombres
y
32
mujeres).
Todas
las
sesiones
fueron
realizadas
en
un
aula
universitaria
de
ordenadores
personales.
Los
participantes
fueron
asignados
al
azar
a
un
grupo
de
aromaterapia
(AG)
y
a
un
grupo
control
(CG),
y
fueron
invitados
a
participar
en
una
sesión
específica
solo
una
vez.
Se
sentaron
frente
a
un
ordenador.
Durante el período de intervención, se pusieron en marcha algunos
difusores de aceite y se mantuvieron funcionando a lo largo de la sesión con
aceite esencial de petit grain para las sesiones del grupo AG y un aceite
neutro (almendra) para las sesiones de CG. Al mismo tiempo, los
participantes completaron una tarea de ordenador en un sitio web específico
escribiendo con su teclado hasta que la terminaron. Los tiempos fueron
diferentes para todos los participantes y se registraron en el sitio web como
"Tiempo de ejecución". El grupo de aromaterapia realizó la tarea del sitio web
con el teclado 2, 28 min más rápido que la de CG (p = 0,05) y mostró una
mejor variabilidad cardíaca (parámetros HF, SDNN y RMSSD). La inhalación
de aceite esencial Petitgrain reduce el estrés y mejora el rendimiento en el
lugar de trabajo. La AR mejora el tiempo de rendimiento al escribir con el
teclado en una sesión simulada de trabajo de ordenador y produce algunos
cambios mejorando la HRV.
Conclusiones generales: Esta tesis doctoral confirma que la aromaterapia
(inhalar aceites esenciales) puede mejorar el rendimiento en el lugar de
trabajo, puede ayudar a manejar emociones negativas y puede incrementar el
nivel de atención en situaciones académicas y laborales. Nuestros resultados
confirman que la inhalación de aceites esenciales produce este efecto
equilibrando el sistema simpático / parasimpático del Sistema Nervioso
Autonómo. El análisis de HRV es un buen marcador de este efecto. Este
equilibrio del SNA puede explicarse por una acción combinada de los
componentes principales de los aceites esenciales Petitgrain y Basil. Algunos
de ellos tienen efectos sedantes, que pueden inducir cambios en la actividad
parasimpática, y otros componentes tienen efectos de activación, que
estimulan la actividad simpática. El efecto final puede ser una mejora de la
condición mental y emocional por una combinación de reducir el nivel de
estrés y aumentar el nivel de arousal de los participantes en términos de
atención y alerta. También podemos explicar nuestros resultados según la
Medicina Tradicional China (TCM). Los aceites esenciales pueden trabajar a
través de una terapia verdaderamente holística, teniendo en cuenta la mente,
el cuerpo y el espíritu de la persona. Los aceites esenciales pueden
conectarse con nuestro cuerpo y ayudarlo a encontrar la mejor manera de
resolver sus necesidades. Los efectos relajantes (actividad parasimpática)
pueden estar relacionados con el YIN y los efectos de activación (actividad
simpática) pueden estar relacionados con el YANG.The general aim of this thesis is to analyse the aromatherapy (AR) efficacy to reduce negative emotions and increase the attention level and performance in the workplace and in academic situations. Its efficacy will be tested through questionnaires and by checking the balance of the Autonomic Nervous System through HRV analysis. To carry out this general objective, we conducted two main studies. We will analyse the AR effects over the heart rate variability (HRV) as a marker of the sympathetic/parasympathetic balance from the ANS. The objective for Study 1 was to analyse the AR efficacy for reducing anxiety and improving study concentration in university students. The sample was composed by 12 students (age between 18 and 33 years old). We analysed the effects of basil essential oil inhalation at short-‐time (1 hour) and at long-‐time (1 month). We found that Inhalation of Basil essential oil reduces anxiety scoring and improves cardiac variability (SDRR and RMSSD parameters). AR in a short session or with an aromatic necklace every day during one month produces emotional and HRV changes on participants. The objective for Study 2 was to analyse the aromatherapy efficacy to improve the work performance and reduce the workplace stress. The sample was composed by 42 administrative university workers (age: 42.21 years, SD=7.12; gender: 10 men and 32 women). All sessions were performed in a university computer classroom. The participants were randomly assigned into an aromatherapy group (AG) and a control group (CG), and they were invited to participate in a specific session only once. They were seated in front of a computer. During the intervention period, some oil diffusers were launched and worked throughout the session with petit grain essential oil for AG sessions and a neutral oil (almond) for CG sessions. At the same time, participants completed a computer task in a specific website typing on their keyboard until they finished it. The single times were different for all participants and were recorded in the website as “Performance Time”. The aromatherapy group performed the website task with the keyboard 2, 28 min faster than CG typing (p=0.05) and showed better cardiac variability (HF, SDNN and RMSSD parameters). Inhalation of Petitgrain essential oil reduces stress and improves performance in the workplace. AR improves the performance time when typing with the keyboard in a simulated computer work session and produces some changes improving HRV. General Conclusions: This doctoral thesis confirms that aromatherapy (inhaling essential oils) can improve performance in the workplace, can help to manage negative emotions and can increment attention level in academic and workplace situations. Our results confirm that inhalation of essential oils produces this effect by balancing the sympathetic/parasympathetic system of the Autonomic Nervous System. HRV analysis is a good marker of this effect. This ANS balance can be explained by a combined action of the Petitgrain and Basil main components. Some of them have sedative effects, which can induce changes on the parasympathetic activity, and other components have activation effects, which stimulate the sympathetic activity. The final effect can be an improvement of the mental and emotional condition by a combination of reducing stress level and increasing arousal level of the participants in terms of attentiveness and alertness. We can also explain our results according to TCM. Essential oils can work through a truly holistic therapy, taking into account the mind, the body and the spirit of the person. Essential oils can connect with our body and help it to find the best way to solve its needs. The relaxing effects (parasympathetic activity) can be related to YIN and the activation effects (sympathetic activity) can be related to YANG.
11
Bock, Zannie. "A Discourse Analysis of Selected Truth and Reconciliation Commission Testimonies. : Appraisal and Genre. /." Thesis, University of Western Cape, 2007. http://etd.uwc.ac.za/usrfiles/modules/etd/docs/etd_gen8Srv25Nme4_2685_1260525552.pdf.
Full text
12
Thozhal, Rijo. "Automated ECG Analysis for Characteristics of Ischemia from Limb Lead MLIII Using the Discrete Hermite Transform." University of Akron / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=akron1434608401.
Full text
13
Alghoul, Karim. "Heart Rate Variability Extraction from Video Signals." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/33003.
Full textAbstract:
Heart Rate Variability (HRV) analysis has been garnering attention from researchers due to its wide range of applications. Medical researchers have always been interested in Heart Rate (HR) and HRV analysis, but nowadays, investigators from variety of other fields are also probing the subject. For instance, variation in HR and HRV is connected to emotional arousal. Therefore, knowledge from the fields of affective computing and psychology, can be employed to devise machines that understand the emotional states of humans. Recent advancements in non-contact HR and HRV measurement techniques will likely further boost interest in emotional estimation through . Such measurement methods involve the extraction of the photoplethysmography (PPG) signal from the human's face through a camera. The latest approaches apply Independent Component Analysis (ICA) on the color channels of video recordings to extract a PPG signal. Other investigated methods rely on Eulerian Video Magnification (EVM) to detect subtle changes in skin color associated with PPG.
The effectiveness of the EVM in HR estimation has well been established. However, to the best of our knowledge, EVM has not been successfully employed to extract HRV feature from a video of a human face. In contrast, ICA based methods have been successfully used for HRV analysis. As we demonstrate in this thesis, these two approaches for HRV feature extraction are highly sensitive to noise. Hence, when we evaluated them in indoor settings, we obtained mean absolute error in the range of 0.012 and 28.4.
Therefore, in this thesis, we present two approaches to minimize the error rate when estimating physiological measurements from recorded facial videos using a standard camera. In our first approach which is based on the EVM method, we succeeded in extracting HRV measurements but we could not get rid of high frequency noise, which resulted in a high error percentage for the result of the High frequency (HF) component. Our second proposed approach solved this issue by applying ICA on the red, green and blue (RGB) colors channels and we were able to achieve lower error rates and less noisy signal as compared to previous related works. This was done by using a Buterworth filter with the subject's specific HR range as its Cut-Off.
The methods were tested with 12 subjects from the DISCOVER lab at the University of Ottawa, using artificial lights as the only source of illumination. This made it a challenge for us because artificial light produces HF signals which can interfere with the PPG signal. The final results show that our proposed ICA based method has a mean absolute error (MAE) of 0.006, 0.005, 0.34, 0.57 and 0.419 for the mean HR, mean RR, LF, HF and LF/HF respectively. This approach also shows that these physiological parameters are highly correlated with the results taken from the electrocardiography (ECG).
14
Shi, Ping. "Photoplethysmography in noninvasive cardiovascular assessment." Thesis, Loughborough University, 2009. https://dspace.lboro.ac.uk/2134/5399.
Full textAbstract:
The electro-optic technique of measuring the cardiovascular pulse wave known as photoplethysmography (PPG) is clinically utilised for noninvasive characterisation of physiological components by dynamic monitoring of tissue optical absorption. There has been a resurgence of interest in this technique in recent years, driven by the demand for a low cost, compact, simple and portable technology for primary care and community-based clinical settings, and the advancement of computer-based pulse wave analysis techniques. PPG signal provides a means of determining cardiovascular properties during the cardiac cycle and changes with ageing and disease. This thesis focuses on the photoplethysmographic signal for cardiovascular assessment. The contour of the PPG pulse wave is influenced by vascular ageing. Contour analysis of the PPG pulse wave provides a rapid means of assessing vascular tone and arterial stiffness. In this thesis, the parameters extracted from the PPG pulse wave are examined in young adults. The results indicate that the contour parameters of the PPG pulse wave could provide a simple and noninvasive means to study the characteristic change relating to arterial stiffness. The pulsatile component of the PPG signal is due to the pumping action of the heart, and thus could reveal the circulation changes of a specific vascular bed. Heart rate variability (HRV) represents one of the most promising quantitative markers of cardiovascular control. Calculation of HRV from the peripheral pulse wave using PPG, called pulse rate variability (PRV), is investigated. The current work has confirmed that the PPG signal could provide basic information about heart rate (HR) and its variability, and highly suggests a good alternative to understanding dynamics pertaining to the autonomic nervous system (ANS) without the use of an electrocardiogram (ECG) device. Hence, PPG measurement has the potential to be readily accepted in ambulatory cardiac monitoring due to its simplicity and comfort. Noncontact PPG (NPPG) is introduced to overcome the current limitations of contact PPG. As a contactless device, NPPG is especially attractive for physiological monitoring in ambulatory units, NICUs, or trauma centres, where attaching electrodes is either inconvenient or unfeasible. In this research, a prototype for noncontact reflection PPG (NRPPG) with a vertical cavity surface emitting laser (VCSEL) as a light source and a high-speed PiN photodiode as a photodetector is developed. The results from physiological experiments suggest that NRPPG is reliable to extract clinically useful information about cardiac condition and function. In summary, recent evidence demonstrates that PPG as a simple noninvasive measurement offers a fruitful avenue for noninvasive cardiovascular monitoring. Key words: Photoplethysmography (PPG), Cardiovascular assessment, Pulse wave contour analysis, Arterial stiffness, Heart rate (HR), Heart rate variability (HRV), Pulse rate variability (PRV), Autonomic nervous system (ANS), Electrocardiogram (ECG).
15
Souza, Rafael Leme Cardoso. "Avaliação tecnológica do teste molecular (NAT) para HIV, HCV e HBV na triagem de sangue no Brasil." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/99/99131/tde-09102018-090250/.
Full textAbstract:
Após anos de debates, o teste de detecção de ácidos nucleicos (NAT) para HIV e HCV na triagem de sangue foi implementado de forma obrigatória no Brasil em 2013, e HBV, em 2016. Um dos motivos citados sobre o atraso em sua implementação foi o custo elevado que seria adicionado à sorologia e, até o momento, uma ampla avaliação econômica em saúde (AES) a respeito de sua eficiência no país não está disponível. Diversos artigos já demonstraram que a razão incremental de custo-utilidade (ICUR) do NAT em relação à sorologia varia de 0,21 a 8,84 milhões de dólares americanos (US$) para cada QALY ganho. Esta grande variação dá-se, principalmente, por diferenças entre a idade média dos receptores de sangue (RS), incidência/prevalência dos vírus entre os doadores de sangue (DS), custo dos testes e tratamentos médicos, cobertura da vacina contra o HBV e sensibilidade do teste utilizado. Assim, faz-se necessária uma avaliação abrangente desta tecnologia e sua efetividade para o cenário brasileiro. Objetivos: Realizar uma revisão sistemática (RevS) de estudos econômicos completos sobre o uso do NAT para HIV, HCV e/ou HBV no mundo; realizar a AES sobre o NAT sob a perspectiva pública brasileira; caracterizar as doações de sangue em janela imunológica no país. Métodos: Metodologia Cochrane de RevS das bases de dados Medline, Embase, LILACS, CRD, BVS ECO, Google Scholar e IDEAS; questionário aplicado aos bancos de sangue e modelo econômico on-line da International Society of Blood Transfusion (ISBT) para cálculo da ICUR do \"NAT em mini-pool de seis amostras individuais\" (MP6) versus \"testes sorológicos\" (SR) no Brasil. Resultados: Quatorze estudos de dezesseis diferentes países foram avaliados. O NAT apresentou a maior relevância nos países de baixa renda, onde há as maiores prevalências e incidências virais, menores taxas de doadores de repetição (DR) e RS mais jovens. A maioria dos estudos concluiu que o NAT, independente do vírus analisado, não é custo-efetivo. As principais diferenças entre as características dos estudos foram relacionadas aos custos médicos e idade dos RS. O maior desvio dos padrões de uma RevS foram: não incluir o racional para definição dos desfechos e o modelo utilizado e não ter claro o conflito de interesse dos autores; para esta AES, o MP6 versus SR apresentou um ICUR de US$ 231.630,00/QALY, ou seja, 26,2 vezes o PIB per capita nacional) e um ICER de US$ 330.790,00/Ano de vida ganho (AVG). A análise de sensibilidade univariada do modelo demonstrou que somente a taxa de desconto, idade do RS, custo do NAT e epidemiologia dos vírus alteraram de forma significativa o ICUR obtido, variando desde US$ 76.957,00/QALY a US$ 933.311,00/QALY; a maioria dos casos de janela imunológica no Brasil são jovens, média de 29 anos, do sexo masculino, com pelo menos o ensino médio completo e mesmo com a obrigatoriedade do Anti-HBc no Brasil, o NAT-HBV é o que apresentou o maior rendimento. Conclusões: Os jovens, principalmente, ainda buscam os bancos de sangue como locais de testagem após comportamento de risco e é de extrema importância a revisão do custo real e completo do teste NAT no Brasil para ampla abordagem da tecnologia nacional incorporada e, se necessário, revisar a forma e modelo de reembolso da mesma e permitir a defesa do bem-estar da população e do bem público.After years of discussion, nucleic acid (NAT) testing in the blood screening for HIV and HCV was implemented in Brazil in 2013 and HBV in 2016. One of the reasons cited for the delay in its implementation was the high cost that would be added to serology screening and a comprehensive economic assessment of its efficiency in the country is not yet available. Several articles have already shown that the incremental cost-utility ratio (ICUR) of NAT versus serology ranges from 0.21 to 8.84 million American dollars (US$) for each QALY gained. This large variation is mainly due to differences between the mean age of the blood recipient, viruses\' incidence / prevalence among donor population, cost of medical tests and treatments, HBV vaccine coverage, and sensitivity of the test used. Thus, a comprehensive evaluation of this technology and its effectiveness under the perspective of the Brazilian public health system (SUS) is needed. Objectives: Development of a systematic review (RevS) of complete economic studies about the use of NAT for HIV, HCV and / or HBV in the world. Conduct an economic evaluation of NAT under SUS perspective; characterize Brazilian blood donations in the serology \"window period\". Methods: Cochrane RevS Methodology of the Medline, Embase, LILACS, CRD, CRD ECO, Google Scholar and IDEAS databases; Questionnaire applied to blood banks and online economic model from the International Society of Blood Transfusion (ISBT) to calculate the ICUR for \"NAT in mini-pool of six individual samples\" (MP6) versus \"Serology Tests\" (SR) in Brazil. Results: Fourteen studies from sixteen different countries were assessed. NAT was most relevant in low-income countries, where there are the highest prevalences and viral incidences, lower rates of repeat donors and younger recipients of blood (RS). Most of the studies concluded that NAT, regardless of the virus evaluated, is not cost-effective. Differences in the characteristics of the studies were related to the costs and age of RS. The major deviations from RevS standards were: not including the rationale for selecting the outcomes and the model used and not being clear about the authors\' conflict of interest; MP6 vs SR showed an ICUR of US$ 231.630,00/QALY, 26,2 times Brazilian GND per capita) and an ICER of US$ 330.790,00/Life year gained (AVG). The univariate sensitivity analysis of the model demonstrated that only changes on discount rate, NAT cost, RS age and viruses\' epidemiology significantly altered the ICUR in a range between US$ 76.957,00/QALY and US$ 933.311,00/QALY; Most RS window period cases in Brazil are young, average of 29 years old, male, with at least high school education completed and even with the requirement of Anti-HBc in Brazil, NAT-HBV is the one that presented the highest yield. Conclusions: Young people, mainly, still seek blood banks as testing sites, especially after a risk behavior. It is extremely important to reveal the real and complete cost of the Brazilian NAT to fully evaluate its efficiency and, if needed, reassess its current reimbursement model, allowing the wellbeing defense of the population and public interest.
16
Jež, Radek. "Software pro ruční rozměření signálů EKG." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-219251.
Full textAbstract:
This thesis deals with evaluation EKG in terms of classification rhythm and analysis HRV. In theoretic part of work are described basics of heart physiology and its usual pathology, basics of electrocardiography, evaluation EKG and standard methods of HRV evaluation. In practical part are described algorithms used in created application. Mainly describes technique of rhythm evaluation, ectopic rhythms and delineation error elimination, data preparing for HRV evaluation, drift removal from DES and HRV evaluation methods. Created program was tested on CSE and MIT- BIH database records. For lack of suitable data and absence of tested data, it wasn’t possible to test all the classification rules of used algorithms. Tested part of program appears reliable and functional.
17
Alemayehu, Amare Eshetu. "Analysis of HCV Coinfections among Newly Diagnosed HIV Cases in Germany." Doctoral thesis, Humboldt-Universität zu Berlin, 2021. http://dx.doi.org/10.18452/22502.
Full textAbstract:
In Anbetracht der enormen Verbesserung der HCV-Therapie durch die Entwicklung hochwirksamer und direkt wirkender Virostatika (DAA) dient diese Studie der Analyse von HCV-Koinfektionen unter den gemeldeten HIV-Neudiagnosen in Deutschland. Zunächst wurde die Eignung zweier kommerzieller HCV Ag/Ab ELISAs, dem Murex (Abbott) und dem Monolisa (Bio-Rad), zum Nachweis von HCV in getrockneten Serumspots (DSS) verglichen. Der Murex-ELISA zeigte sich sensitiver bei Antigen-positiven Plasma-HCV-Serokonversionsproben während der Monolisa eine höhere Sensitivität bei HCV-Antikörper-positiven DSS-Eluaten. Des Weiteren wurde ein Aviditätstest zur Unterscheidung von neuen und bereits länger bestehenden Infektionen bei einem Aviditätsindex Cut-off von 40% und einem Zeitraum von 364 Tagen etabliert. Von den insgesamt 6.097 untersuchten Proben der Jahre 2015-2017 waren 396 HCV-ELISA-reaktiv (6,5%). Von diesen wurden 256 (64,6%) als aktive und 140 (35,4%) als ausgeheilte Infektionen identifiziert. Ein hoher Anteil der HCV-Koinfektionen wurde bei intra-venösen Drogenkonsumenten (77,8%, n=168/216), in der Altersgruppe der 30-39 Jährigen (9%, n=179/1.978) und bei Menschen osteuropäischer Herkunft (38,3%, n=124/324) beobachtet. Im Vergleich zum Jahr 2016 hat sich der Anteil der ausgeheilten Infektionen im Jahr 2017 bei der Gesamtzahl der Patienten (p<0,01) sowie insbesondere bei Personen ausländischer (p<0,01) und osteuropäischer (p<0,05) Herkunft erhöht. Die HCV Subtypen (St)-1a, St-3a und St-1b waren mit 33,9% (n=79/233), 33,5% (n=78/233) und 23,3% (n=52/233) vorherrschend. Der Anteil der St-1a- und St-1b-Proben, deren HCV-Sequenz gegen DAAs resistent ist, war in allen untersuchten Jahren hoch (25%-42,9%). Der beobachtete Anstieg des Anteils der ausgeheilten HCV-Koinfektionen kann auf die DAA-Therapie zurückgeführt werden. Es sind jedoch weitere Anstrengungen erforderlich, damit Gruppen mit weiterhin hoher HCV-Prävalenz von dieser Behandlung profitieren.In light of the major shift in HCV therapy resulting from the availability of highly potent direct acting antivirals (DAA), this study performed a surveillance of HCV coinfections among reported HIV new diagnoses in Germany. First the suitability of two HCV Ag/Ab ELISAs, Murex (Abbott) and Monolisa (Bio-Rad) for dried serum spots (DSS) was compared. The Murex was more sensitive in antigen positive plasma HCV seroconversion samples while the Monolisa showed a higher sensitivity in HCV antibody positive DSS eluates. Furthermore, an avidity test was established to distinguish between new and already longer existing infections at an avidity index cut-off of 40% and a period of 364 days. Of the total of 6,097 samples examined for the years 2015-2017, 396 were HCV ELISA reactive (6.5%). Of these, 256 (64.6%) were identified as active and 140 (35.4%) as resolved infections. A high proportion of HCV coinfections were observed in intravenous drug users (77.8%, n=168/216), in the age group 30-39 years (9%, n=179/1,978) and in people of Eastern European origin (38.3%, n=124/324). Compared to 2016, the proportion of resolved infections in 2017 has increased in the total number of patients (p<0.01) and especially in people of foreign (p<0.01) and Eastern European (p<0.05) origin. HCV subtypes (St)-1a, St-3a, and St-1b were predominant with 33.9% (n=79/233), 33.5% (n=78/233) and 23.3% (n=52/233), respectively. The proportion of St-1a and St-1b samples whose HCV sequence has resistance to DAAs was high in all diagnoses years (25%-42.9%). The observed increase in the proportion of resolved HCV coinfections can be attributed to DAA therapy. However, further efforts are needed to ensure that groups with continued high HCV prevalence benefit from this treatment.
18
Hawkins, Anna Elizabeth. "The detection and analysis of hepatitis B virus genome variation and its use in clinical studies." Thesis, University College London (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243553.
Full text
19
Alemayehu, Amare Eshetu [Verfasser]. "Analysis of HCV Coinfections among Newly Diagnosed HIV Cases in Germany / Amare Eshetu Alemayehu." Berlin : Humboldt-Universität zu Berlin, 2021. http://d-nb.info/1228858470/34.
Full text
20
Albinsson, Sofie. "Automation of manual Hepatitis E (HEV) and Hepatitis A (HAV) PCR analysis to Tecan FreedomEVO 150." Thesis, KTH, Skolan för bioteknologi (BIO), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-215310.
Full text
21
Zhang, Xinjian. "HIV/AIDS relative survival analysis." unrestricted, 2007. http://etd.gsu.edu/theses/available/etd-07262007-123251/.
Full textAbstract:
Thesis (M.S.)--Georgia State University, 2007.Title from file title page. Gengsheng (Jeff) Qin, committee chair; Ruiguang (Rick) Song, Xu Zhang, Yu-Sheng Hsu, committee members. Electronic text (79 p. : col. ill.) : digital, PDF file. Description based on contents viewed Sept. 16, 2008. Includes bibliographical references (p. 38-42).
22
Heap, Caroline J. "Analysis of HIV-1 neutralisation." Thesis, University of Warwick, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.409953.
Full text
23
Alencar, Wong Kuen. "Análise de sobrevida de pacientes coinfectados HIV/HCV de um centro de referência em DST/AIDS no município de São Paulo." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/6/6132/tde-30092011-133057/.
Full textAbstract:
Introdução: A estimativa de sobrevida de pacientes com HIV/aids aumentou após a terapia antirretroviral de alta potência: no entanto, a mortalidade por doenças hepáticas também cresceu. Objetivos: Estimar a probabilidade acumulada de sobrevida após o diagnóstico de aids entre pacientes coinfectados HIV/HCV e realizar análise exploratória para investigar fatores relacionados à sobrevida desses pacientes. Metodologia: Estudo de coorte não concorrente, utilizando sistemas de Informações: o de Agravos de Notificação, o de informação laboratorial e o de informação da vigilância epidemiológica do Centro de Referência e Treinamento DST/AIDS-SP, de pacientes com aids maiores de 13 anos, acompanhados no ambulatório geral. As variáveis estudadas foram: hepatite C, hepatite B, categoria de exposição, contagem de células T CD4+, faixa etária, escolaridade, cor, sexo e períodos de diagnóstico de aids: 1986 a 1993, 1994 a 1996, 1997 a 2002 e 2003 a 2010. Foi utilizado o estimador de Kaplan-Meier, o modelo de Cox e as estimativas das hazard ratio (HR) com os respectivos intervalos de confiança (IC 95 por cento ). Resultados: De um total de 2.864 pessoas incluídas, com idade mediana de 35 anos, 219 foram a óbito (7,5 por cento ). De 358 (12,5 por cento ) coinfectados, 159 (45,1 por cento ) eram usuários de drogas injetáveis (UDI) e de 2.506 não coinfectados, 96 (3,9 por cento ) eram UDI. A probabilidade acumulada de sobrevida entre coinfectados, a partir do diagnóstico de aids, foi 100 por cento aos 60 meses no período de 1986 a 1993; 27,8 por cento aos 168 meses no período de 1994 a 1996; 76,3 por cento aos 168 meses no período de 1997 a 2002 e 92,8 por cento aos 96 meses no período de 2003 a 2010. As curvas de sobrevida foram diferentes entre coinfectados e não coinfectados no período de 1994 a 1996 (log rank = 19,8; p < 0,001) e no período de 1997 a 2002 (log rank = 38,8; p < 0,001). No modelo de Cox multivariado, mostraram-se preditores de óbito, independentemente das outras variáveis: ter hepatite C (HR = 2,9; IC 2,1-3,9), ter hepatite B (HR = 2,5; IC 1,7-3,6), ter até 3 anos de estudo (HR = 2,3; IC 1,5-3,6), ter 50 anos ou mais de idade (HR = 2,1; IC 1,3-3,2). Ter diagnóstico de aids no período entre 1997 a 2002 mostrou-se fator de proteção ao óbito (HR = 0,4; IC 0,3-0,5). Conclusões: Coinfectados HIV/HCV apresentaram menor sobrevida quando comparado com não coinfectados nos períodos de diagnóstico de aids 1994 a 1996 e 1997 a 2002. A partir do período 1994 a 1996, observou-se aumento significativo na probabilidade acumulada de sobrevida entre coinfectados, sendo que no período 2003 a 2010, essa probabilidade foi semelhante entre coinfectados e não coinfectados, refletindo possível impacto do tratamento da hepatite CIntroduction: The estimated survival of patients with HIV/AIDS has increased after highly active antiretroviral therapy; mortality due to liver diseases, however, has also increased. Objectives: To estimate the accumulated probability of survival after AIDS diagnosis among HIV/HCV co-infected individuals and to perform an exploratory analysis to investigate factors related to the survival of these patients. Method: Non-concurrent cohort study, using data from the National Disease Reporting Information System, the laboratory and epidemiological surveillance information systems of the SP-STD Reference and Training Center-CRT, of patients over 13 years of age, followed at the general outpatient clinic. The following variables were studied: hepatitis C, hepatitis B, exposure category, T CD4+ cell count, age group, schooling, color, sex, and AIDS diagnostic periods: 1986 to 1993, 1994 to 1996, 1997 to 2002 and 2003 to 2010. Survival analysis was performed using the Kaplan-Meier estimator and the Cox model, with estimates of the hazard ratio (HR) and respective confidence intervals (95 per cent CI). Results: Of a total of 2,864 individuals included, with a median age of 35 years, 219 died (7.5 per cent ). Of the 358 (12.5 per cent ) HIV/HCV co-infected individuals, 159 (45.1 per cent ) were injecting drug users (IDU), and of the non-co-infected 2,506, 96 (3.9 per cent ) were IDU. The accumulated probability of survival among HIV/HCV co-infected individuals at 60, 168, 168 and 96 months as of AIDS diagnosis, was 100 per cent in the 1986 -1993 period; 27,8 per cent in the 1994-1996 period; 76,3 per cent in the 1997-2002 period; and 92,8 per cent in the 2003-2010 period. The survival curves were different between co-infected and non-co-infected individuals in the 1994-1996 (log rank = 19,8; p < 0,001) and in the 1997-2002 (log rank = 38,8; p < 0,001). In the multivariate model, regardless of other variables, the following were predictors of death: having hepatitis C (HR = 2.9; CI 2.1-3.9); having hepatitis B (HR = 2.5; CI 1.7-3.6); being 50 years old or over (HR = 2.1; CI 1.3-3.2) and having up to 3 years of schooling (HR = 2.3; CI 1.5-3.6). AIDS diagnosis between 1997 and 2010 was shown to be a protective factor for death (HR = 0.4; CI 0.3-0.5). Conclusions: HIV/HCV co-infected individuals had shorter survival, when compared to non-co-infected individuals in the 1994-1996 and in the 1997-2002 AIDS diagnostic periods. As of the 1994-1996 period, a significant increase in the accumulated probability of survival among HIV/HCV co-infected individuals was observed. In the 2003-2010 period, the probability was similar between co-infected and non-coinfected individuals, showing the possible impact of hepatitis treatment
24
Martin, Quigley Christina M. "Characterization of Occult Hepatitis B Virus Infection in HIV-Positive Individuals." University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1307441402.
Full text
25
Rogers, Joy Michelle. "Changepoint Analysis of HIV Marker Responses." Digital Archive @ GSU, 2006. http://digitalarchive.gsu.edu/math_theses/16.
Full textAbstract:
We will propose a random changepoint model for the analysis of longitudinal CD4 and CD8 T-cell counts, as well as viral RNA loads, for HIV infected subjects following highly active antiretroviral treatment. The data was taken from two studies, one of the Aids Clinical Group Trial 398 and one performed by the Terry Beirn Community Programs for Clinical Research on AIDS. Models were created with the changepoint following both exponential and truncated normal distributions. The estimation of the changepoints was performed in a Bayesian analysis, with implementation in the WinBUGS software using Markov Chain Monte Carlo methods. For model selection, we used the deviance information criterion (DIC), a two term measure of model adequacy and complexity. DIC indicates that the data support a random changepoint model with the changepoint following an exponential distribution. Visual analyses of the posterior densities of the parameters also support these conclusions.
26
Shire, Norah J. "Boosting, Bagging, and Classification Analysis to Improve Noninvasive Liver Fibrosis Prediction in HCV/HIV Coinfected Subjects: An Analysis of the AIDS Clinical Trials Group (ACTG) 5178." Cincinnati, Ohio : University of Cincinnati, 2007. http://rave.ohiolink.edu/etdc/view.cgi?acc_num=ucin1172860066.
Full textAbstract:
Thesis (Ph.D.)--University of Cincinnati, 2007.Advisor: Charles Ralph Buncher. Title from electronic thesis title page (viewed April 23, 2009). Keywords: Coinfection; Boosting and bagging; Classification analysis; HIV; Viral hepatitis. Includes abstract. Includes bibliographical references.
27
Post, Frank A. "Survival of South-African HIV infected patients." Master's thesis, University of Cape Town, 1998. http://hdl.handle.net/11427/26573.
Full textAbstract:
In sub-Saharan Africa, resource-limitation results in scarce availability of HIV prognostic tools such as CD4+ T-Lymphocyte (CD4) count and HIV viral load. To facilitate counselling and clinical decisions in this setting, widely available and inexpensive markers of prognosis are required. Chapter one gives an overview of the epidemiology and pathophysiology of HIV infection (with particular reference to sub-Saharan Africa), and its clinical manifestations. Staging systems for HIV infection and aspects of management in resource-poor environments are briefly discussed. Chapter two describes the epidemiological, pathophysiological and clinical aspects of tuberculosis (TB) in HIV infected patients, the commonest opportunistic infection in sub-Saharan Africa. It further provides HIV and TB prevalence data from the Western Cape, South Africa. In chapter three a study is presented demonstrating the usefulness of the total lymphocyte count (TLC) in combination with the World Health Organisation (WHO) clinical staging system to predict outcome in 831 HIV positive patients. A TLC of 1250/μL was found to be the equivalent of a CD4 count of 200/μL. Patients with early HIV disease (WHO stage 1&2) had low annual rates of progression to AIDS : 3-4% if the TLC was above 1250/μL, 12-14% if the TLC was below 1250/μL. Annual progression to AIDS increased to 25% and 46% in patients with clinical stage 3 and a TLC above or below 1250/μL respectively. Patients with AIDS had 30-55% one-year mortality rates depending on the TLC. Chapter four illustrates that pulmonary tuberculosis (PTB) in HIV infected patients presents with a radiographic spectrum reflecting the degree of HIV induced immune suppression. Chest radiographs and pre-treatment total lymphocyte counts provide prognostic information. Upper zone cavitatory infiltrates typical of reactivation PTB were associated with a preserved CD4 count (mean 389/μL) and predicted a 100% two-year survival. Pleural effusions were associated with a mean CD4 count of 184/μL and predicted 65% two-year survival. Patients with atypical radiographic presentation, including lower and mid-zone infiltrates, hilar and mediastinal adenopathy or interstitial patterns, had low CD4 counts (mean 105/μL) and a 36% survival at two years. Rather than classifying every patient with pleura-pulmonary tuberculosis as WHO stage 3, incorporation of the prognostic value of the chest radiograph into the clinical staging system, such that typical reactivation PTB becomes stage 2, tuberculous pleural effusion stage 3 and atypical PTB stage 4, would enhance the prognostic accuracy of HIV related tuberculosis. Chapter five demonstrates that patients with AIDS could be categorized accord ing to one of three survival patterns, relating to the type of opportunistic illness. One-year survival rates were highest for extra-pulmonary tuberculosis and herpes simplex virus infection (70% ); intermediate for oesophageal candidiasis, cryptococcal meningitis, kaposi sarcoma and pneumocystis carinii pneumonia (45%) ; and poorest for the HIV wasting syndrome, AIDS-dementia complex and performance status 4 (20%). Despite the overall poor prognosis associated with the acquired immunodeficiency syndrome, a substantial proportion of patients survive, even in the absence of anti-retroviral therapy, for a number of years. Chapter six concludes by proposing how the data presented in this thesis could be used in the clinical management of patients with HIV infection in a resource limited environment.
28
Deuchert, Eva. "HIV in sub saharan Africa an econometric analysis of HIV risk factors /." [S.l. : s.n.], 2007. http://nbn-resolving.de/urn:nbn:de:bsz:25-opus-39681.
Full text
29
Msimanga, Wela Patrick. "Phylogenetic analysis of HIV-1 in Mpumalanga." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80344.
Full textAbstract:
Thesis (MScMedSc)--Stellenbosch University, 2013.The diversity of HIV-1 sequences derived from patients in Bushbuckridge, Mpumalanga, was investigated. The gag p24, pol p10 and p66/p51, pol p31 and env gp41 gene fragments from 51 patients were amplified and sequenced. Quality control on the sequences was carried out using the LANL QC online tool. HIV-1 subtype was assigned using the LANL QC (RIP), REGA and jpHMM online tools. Subtype for the pol gene fragment was further designated using the SCUEAL online tool. Most of the sequences, that is 89%, belonged to HIV-1 subtype C. LANL QC (RIP), REGA, jpHMM also detected recombinants in 11% of the sequences. One of the isolates could only have the env gp41 gene fragment amplified and sequenced, which was determined to be HIV-1 subtype B. Phylogenetic analysis using the Neighbor-Joining and Maximum Likelihood methods from MEGA v 5 showed that, except for the env gp41 designated as a subtype B, all sequences in the study clustered with HIV-1 subtype C. Significantly, phylogenetic analysis showed that not only are the Bushbuckridge, Mpumalanga sequences related to HIV-1 subtype C sequences from southern Africa, India, Ethiopia and Brazil, but it is possible there has been multiple introductions of HIV-1 in the province. SDRMs were observed in two samples.
30
Simmons, Alison. "Molecular and mechanistic analysis of HIV Nef." Thesis, Open University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.412404.
Full text
31
De, la Harpe Alana. "A comparative analysis of mathematical models for HIV epidemiology." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/96983.
Full textAbstract:
Thesis (MSc)--Stellenbosch University, 2015.ENGLISH ABSTRACT: HIV infection is one of the world’s biggest health problems, with millions of people infected worldwide. HIV infects cells in the immune system, where it primarily targets CD4+ T helper cells and without treatment, the disease leads to the collapse of the host immune system and ultimately death. Mathematical models have been used extensively to study the epidemiology of HIV/AIDS. They have proven to be effective tools in studying the transmission dynamics of HIV. These models provide predictions that can help better our understanding of the epidemiological patterns of HIV, especially the mechanism associated with the spread of the disease. In this thesis we made a functional comparison between existing epidemiological models for HIV, with the focus of the comparison on the force of infection (FOI). The spread of infection is a crucial part of any infectious disease, as the dynamics of the disease depends greatly on the rate of transmission from an infectious individual to a susceptible individual. First, a review was done to see what deterministic epidemiological models exist. We found that many manuscripts do not provide the necessary information to recreate the authors’ results and only a small amount of the models could be simulated. The reason for this is mainly due to a lack of information or due to mistakes in the article. The models were divided into four categories for the analysis. On the basis of the FOI, we distinguished between frequency- or density-dependent transmission, and as a second criterion we distinguished models on the sexual activity of the AIDS group. Subsequently, the models were compared in terms of their FOI, within and between these classes. We showed that for larger populations, frequency-dependent transmission should be used. This is the case for HIV, where the disease is mainly spread through sexual contact. Inclusion of AIDS patients in the group of infectious individuals is important for the accuracy of transmission dynamics. More than half of the studies that were selected in the review assumed that AIDS patients are too sick to engage in risky sexual behaviour. We see that including AIDS patients in the infectious individuals class has a significant effect on the FOI when the value for the probability of transmission for an individual with AIDS is bigger than that of the other classes. The analysis shows that the FOI can vary depending on the parameter values and the assumptions made. Many models compress various parameter values into one, most often the transmission probability. Not showing the parameter values separately makes it difficult to understand how the FOI works, since there are unknown factors that have an influence. Improving the accuracy of the FOI can help us to better understand what factors influence it, and also produce more realistic results. Writing the probability of transmission as a function of the viral load can help to make the FOI more accurate and also help in the understanding of the effects that viral dynamics have on the population transmission dynamics.
AFRIKAANSE OPSOMMING: MIV-infeksie is een van die wêreld se grootste gesondheidsprobleme, met miljoene mense wat wêreldwyd geïnfekteer is. MIV infekteer selle in die immuunstelsel, waar dit hoofsaaklik CD4+ T-helperselle teiken. Sonder behandeling lei die siekte tot die ineenstorting van die gasheer se immuunstelsel en uiteindelik sy dood. Wiskundige modelle word breedvoerig gebruik om die epidemiologie van MIV/vigs te bestudeer. Die modelle is doeltreffende instrumente in die studie van die oordrag-dinamika van MIV. Hulle lewer voorspellings wat kan help om ons begrip van epidemiologiese patrone van MIV, veral die meganisme wat verband hou met die verspreiding van die siekte, te verbeter. In hierdie tesis het ons ‘n funksionele vergelyking tussen bestaande epidemiologiese modelle vir MIV gedoen, met die fokus van die vergelyking op die tempo van infeksie (TVI). Die verspreiding van infeksie is ‘n belangrike deel van enige aansteeklike siekte, aangesien die dinamika van die siekte grootliks afhang van die tempo van oordrag van ‘n aansteeklike persoon na ‘n vatbare persoon. ‘n Oorsig is gedoen om te sien watter kompartementele epidemiologiese modelle alreeds bestaan. Ons het gevind dat baie van die manuskripte nie die nodige inligting voorsien wat nodig is om die resultate van die skrywers te repliseer nie, en slegs ‘n klein hoeveelheid van die modelle kon gesimuleer word. Die rede hiervoor is hoofsaaklik as gevolg van ‘n gebrek aan inligting of van foute in die artikel. Die modelle is in vier kategorieë vir die analise verdeel. Op grond van die TVI het ons tussen frekwensie- of digtheidsafhanklike oordrag onderskei, en as ‘n tweede kriterium het ons die modelle op die seksuele aktiwiteit van die vigs-groep onderskei. Daarna is die modelle binne en tussen die klasse vergelyk in terme van hul TVIs. Daar is gewys dat frekwensie-afhanklike oordrag gebruik moet word vir groter bevolkings. Dit is die geval van MIV, waar die siekte hoofsaaklik versprei word deur seksuele kontak. Die insluiting van die vigs-pasiënte in die groep van aansteeklike individue is belangrik vir die akkuraatheid van die oordrag-dinamika van MIV. Meer as helfte van die uitgesoekte studies aanvaar dat vigs-pasiënte te siek is om betrokke te raak by riskante seksuele gedrag. Ons sien dat die insluiting van vigs-pasiënte in die groep van aansteeklike individue ‘n beduidende uitwerking op die TVI het wanneer die waarde van die waarskynlikheid van oordrag van ‘n individu met vigs groter is as dié van die ander klasse. Die analise toon dat die TVI kan wissel afhangende van die parameter waardes en die aannames wat gemaak is. Baie modelle voeg verskeie parameter waardes bymekaar vir die waarskynlikheid van oordrag. Wanneer die parameter waardes nie apart gewys word nie, is dit moeilik om die werking van die TVI te verstaan, want daar is onbekende faktore wat ‘n invloed op die TVI het. Die verbetering van die akkuraatheid van die TVI kan ons help om die faktore wat dit beïnvloed beter te verstaan, en dit kan ook help om meer realistiese resultate te produseer. Om die waarskynlikheid van oordrag as ‘n funksie van die viruslading te skryf kan help om die TVI meer akkuraat te maak en dit kan ook help om die effek wat virale dinamika op die bevolkingsoordrag-dinamika het, beter te verstaan.
32
Truong, Hong-Ha Manh. "Molecular epidemiology of HIV-1 transmission : a case study of source partners of individuals with acute retroviral syndrome /." Thesis, Connect to this title online; UW restricted, 2000. http://hdl.handle.net/1773/9282.
Full text
33
Labeodan, Moremi Morire OreOluwapo. "Stochastic analysis of AIDS epidemiology." Thesis, Pretoria : [s.l.], 2009. http://upetd.up.ac.za/thesis/available/etd-10172009-112824.
Full text
34
Ngui, Siew Lin. "Molecular analysis of hepatitis B virus transmission events." Thesis, University College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299915.
Full text
35
Davis, Katie L. "Analysis of HIV-1 variable loop 3-specific neutralizing antibody responses by HIV-2/HIV-1 envelope chimeras." Thesis, Birmingham, Ala. : University of Alabama at Birmingham, 2008. https://www.mhsl.uab.edu/dt/2009r/davis.pdf.
Full text
36
Gonzalez-Rabade, N. "Immunological analysis of chloroplast-derived HIV-1 antigens." Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.599489.
Full textAbstract:
The aim of this project was to assess the expression, purification and immunogenicity in mice of two important HIV antigens, the core protein p24 and the regulatory protein Nef, produced in transplastomic Nicotiana tabacum plants. A comparison of p24-expressing tobacco Petite Havana transplastomic plants, containing gene constructs with different 5’ untranslated regions (UTRs), demonstrated the importance of regulatory and stabilizing elements. Plants containing a p24 construct with a bacteriophage T7 gene 10 (T7g10) 5’ UTR and generating a protein with 5 extra amino acids at the N-terminus, accumulated almost twice as much protein as plants containing other constructs. Analysis of p24 accumulation in leaves of the high biomass tobacco variety Maryland Mammoth revealed a dramatic difference between a transplastomic line containing a codon-optimized construct encoding five extra N-terminal amino acids, which accumulated p24 in all leaves of the plant, and a transplastomic line containing a native p24 construct which accumulated p24 only in young leaves. To assess the subcutaneous and nasal immunogenicity of plant-derived p24, the protein was purified to ~95% homogeneity from Maryland Mammoth transplastomic plants. After immunization of experimental mice, ELISAs for p24-specific IgG and T-cell proliferation assays showed that chloroplast p24 could elicit a strong humoral response following subcutaneous administration and a cellular response following intranasal administration. Oral administration of partially purified tobacco p24-Nef as a booster, after subcutaneous priming with either p24 or Nef, elicited strong humoral and cellular responses, with both IgG1 and IgG2 subtypes found in sera. In addition, tobacco BiP was found to be as good an adjuvant as Vibrio cholerae toxin B and Mycobacterium tuberculosis Hsp70 for enhancing the immune response to p24.
37
Long, Elisa Frances. "Economic analysis of preventive and therapeutic HIV interventions /." May be available electronically:, 2008. http://proquest.umi.com/login?COPT=REJTPTU1MTUmSU5UPTAmVkVSPTI=&clientId=12498.
Full text
38
Searle, Alexandra. "African legislatures and HIV/AIDS : an exploratory analysis." Master's thesis, University of Cape Town, 2011. http://hdl.handle.net/11427/12442.
Full textAbstract:
Includes bibliographical references.Since 1981 AIDS has killed more than 25 million people world-wide, the majority of whom lived within developing countries. The worst affected region, Sub Saharan Africa, currently has 3.5% of the world’s population yet 37% of the world’s people living with HIV. In light of the magnitude of the pandemic in the region it has been increasingly acknowledged that not only are HIV and AIDS health issues but also pervasive development issues due to the impact they have on national socioeconomic development. Unsurprisingly a disease of ‘sex and drugs’4 is a highly controversial and politicized issue. An effective response represents a serious challenge for national governance institutions, particularly within the unique and complex socio political environments of the region. The need for ‘democratic governance’ and a ‘multi-sectoral’ approach within the HIV & AIDS response highlights the critical role of national legislatures. Due to the severity and scope of the pandemic there is an assumption that elected representatives would be in the forefront of the response. Effective legislatures are the sine qua non of a representative democracy, and arguably an important vehicle through which to drive the HIV national response. Legislatures represent a cross section of society and play a central role in the coordination and implementation of national responses. Further understanding and explanation of legislative responses around HIV & AIDS speak to issues of democratic governance and the need to improve overall accountability and transparency within these institutions.
39
Lalonde, Matthew Scott. "HIV Drug Resistance Polymorphism Analysis Using Ligase Discrimination." Case Western Reserve University School of Graduate Studies / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=case1244059520.
Full text
40
Pappa, Sara T. "A Content Analysis of Online HPV Immunization Information." University of Cincinnati / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1479819905816751.
Full text
41
Hussaini, Nafiu. "Mathematical modelling and analysis of HIV transmission dynamics." Thesis, Brunel University, 2010. http://bura.brunel.ac.uk/handle/2438/5672.
Full textAbstract:
This thesis firstly presents a nonlinear extended deterministic Susceptible-Infected (SI) model for assessing the impact of public health education campaign on curtailing the spread of the HIV pandemic in a population. Rigorous qualitative analysis of the model reveals that, in contrast to the model without education, the full model with education exhibits the phenomenon of backward bifurcation (BB), where a stable disease-free equilibrium coexists with a stable endemic equilibrium when a certain threshold quantity, known as the effective reproduction number (Reff ), is less than unity. Furthermore, an explicit threshold value is derived above which such an education campaign could lead to detrimental outcome (increase disease burden), and below which it would have positive population-level impact (reduce disease burden in the community). It is shown that the BB phenomenon is caused by imperfect efficacy of the public health education program. The model is used to assess the potential impact of some targeted public health education campaigns using data from numerous countries. The second problem considered is a Susceptible-Infected-Removed (SIR) model with two types of nonlinear treatment rates: (i) piecewise linear treatment rate with saturation effect, (ii) piecewise constant treatment rate with a jump (Heaviside function). For Case (i), we construct travelling front solutions whose profiles are heteroclinic orbits which connect either the disease-free state to an infected state or two endemic states with each other. For Case (ii), it is shown that the profile has the following properties: the number of susceptible individuals is monotone increasing and the number of infectives approaches zero, while their product converges to a constant. Numerical simulations are shown which confirm these analytical results. Abnormal behavior like travelling waves with non-monotone profile or oscillations are observed.
42
Myburgh, Rene. "The criminalization of HIV/AIDS : a comparative analysis." Thesis, Nelson Mandela Metropolitan University, 2013. http://hdl.handle.net/10948/d1020754.
Full textAbstract:
The Human Immunodeficiency Virus (HIV)1 and the Acquired Immunodeficiency Syndrome (AIDS)2 have become a global epidemic. With an average of 35.3 million people infected with the virus worldwide, countries are desperate to curb HIV infections.3 Most HIV positive men, women and children are found in Sub-Saharan Africa.4 In an attempt to fight HIV/AIDS, some countries have opted for an approach of criminalization, where it is a crime to infect or expose another person to the virus.5 Other countries, such as South Africa, have chosen to avoid the criminalization approach, and to focus rather on public health schemes that can assist in the prevention of transmission. The United Nations (UN) has stated that overly broad application of criminal law to HIV raises serious human rights and public health concerns.7 Because of these concerns, the Joint United Nations Programme on HIV/AIDS (UNAIDS) has urged states to limit application of criminal law to HIV-related cases.8 Furthermore, UNAIDS has urged states to rather employ scientifically proven methods to prevent HIV transmission. This treatise will set out the laws adopted by Canada, Zimbabwe, the United Kingdom, New Zealand and South Africa. Out of all five countries, South Africa is the only country that does not criminalize HIV transmission or exposure.10 In setting out the common law, statute law, case law as well as academic considerations, this treatise will attempt to identify trends in the current criminalization of HIV climate. In addition to setting out the law in the five countries, this treatise seeks to show that South Africa is one of the few countries with a developed legal system to shy away from criminalization. This treatise also seeks to establish whether South Africa’s approach is a suitable option for the country, considering it boasts the highest HIV infection rate in the world.
43
Wade, Christopher Mark. "Analysis of HIV-1 and foraminiferal molecular evolution." Thesis, University of Edinburgh, 1997. http://hdl.handle.net/1842/14622.
Full textAbstract:
In section A, five papers are presented which examine the evolution of HIV-1 both within and between patients. The first paper presented examines the molecular epidemiology of HIV-1 within Scotland, Northern England, and Ireland (paper I), with attention focused on identifying risk group associated differences within the cohort. This work also provides important background information for the interpretation of molecular data from transmission clusters. The main focus of the work on HIV-1 evolution has been on the transmission of HIV-1, with particular emphasis placed on mother-child transmission. Four papers are presented which examine evolutionary aspects of HIV-1 transmission. The first of these (paper II) examines the viral variants transmitted from mother to child in four mother-child transmission pairs. The second (paper III) analyses similar data from five mother-child transmission pairs, focusing predominantly on viral evolution within the child over the first year of life. The final two papers investigating HIV-1 transmission examine viral variation within two transmission sets. Paper IV examines the vertical transmission of HIV-1 to two infected children born to the same mother at an approximately two year interval, while paper V examines the heterosexual transmission of HIV-1 from a male index to two female contacts and the subsequent vertical transmission of HIV-1 to their two children. The phylogenetic placement of these transmission sets within the Edinburgh cohort is also assessed. In section B, four papers are presented which examine aspects of foraminiferal evolution. The first paper (paper I) focuses on the problems inherent in the amplification of foraminiferal DNA due to the association of large numbers of symbionts, commensals and food particles with each foraminifer. The amplification of foraminiferal sequences for the small subunit ribosomal RNA gene is then described, and the phylogenetic placement of the foraminifera within eukaryote evolution examined (papers II and III). Finally, the phylogenetic relationships within the foraminifera are described (paper V).
44
Giese, S. "Cellular analysis of HIV transmission from primary macrophages." Thesis, University College London (University of London), 2014. http://discovery.ucl.ac.uk/1426714/.
Full textAbstract:
In human monocyte-derived macrophages (MDM), the human immunodeficiency virus type 1 (HIV-1) assembles on deeply invaginated domains of the plasma membrane, or Intracellular Plasma Membrane-Connected Compartments (IPMC). Some of the membranes forming the IPMCs are decorated with thick, electron-dense, cytoplasmic coats. A range of proteins typically found in focal adhesion complexes (FAC) cluster at these coat structures. I show that the FAC protein CD18 co-localises with IPMCs in MDMs and primary alveolar macrophages. Upregulation of CD18 during macrophage differentiation coincides with the appearance of IPMCs, and downregulation of CD18 by RNAi perturbs the integrity of IPMCs in uninfected and HIV-infected MDMs. These observations suggest that CD18 and FACs are necessary to form, or maintain, IPMCs in MDMs. Bst-2/Tetherin inhibits the release of HIV by physically linking budding virions to the plasma membrane of host cells. The HIV-1 protein Vpu counteracts Tetherin, thus permitting HIV propagation. I show that type 1 interferons induce Tetherin expression in primary MDMs by around one order of magnitude. Tetherin localises to the cell surface, the trans-Golgi network, and IPMCs. Vpu downregulates Tetherin from the plasma membrane, and, in the absence of Vpu, HIV is retained in IPMCs. My data indicate that so-called virological synapses play a major role in the direct cell-cell transmission of HIV from macrophages to CD4+ T cells, and that Tetherin inhibits this intercellular spread. Thus, I show that Tetherin restricts HIV propagation from primary human macrophages regardless of the mode of transmission. Overall this study identifies structural components crucial for the integrity of the HIV assembly compartment, and characterises the Tetherin-mediated restriction of HIV in macrophages.
45
Mackay, Hayley. "Critical analysis of employer’s workplace policies towards HIV positive employees." Diss., University of Pretoria, 2013. http://hdl.handle.net/2263/27261.
Full textAbstract:
The courts approach to HIV positive employees will be studied as they give a rough This dissertation takes its focus from the plight of millions of South Africans living with HIV/AIDS. HIV sufferers count for 11.2 percent of our entire population. It has furthermore been predicted that in the next 10 years to come, 40 to 50 percent of the current workforce will be lost to HIV/AIDS.1 Only certain people qualify for free government issued anti-retrovirals (HIV/AIDS medication), this leaves a large portion of people unable to afford their much needed medication. This ultimately leads to them becoming very ill and often unable to work. These statistics do not leave the South African employment situation with great confidence. Much legislation has been promulgated that prohibits the discrimination of those suffering from the disease and this legislation and its impact will be analyzed to see if it does meet the current needs of those suffering from HIV/AIDS. What will be discussed is how this legislation does not make available for the mechanism for employers to provide either the treatment or the access to a medical aid for their employees suffering from HIV. The cost of such a provision of treatment will be a great expense to any employer, especially those of a smaller nature. What will be dealt with is ways in which to encourage employers to implement such a scheme, through tax rebates and seeing the financial benefits of implementing such an arrangement. The provision of treatment encourages a better working relationship and reduces, amongst other things, the cost of staff replacement. The Labour Relations Act2 does offer employer’s guidelines as to how HIV positive employees should be handled at the workplace. However these are just guidelines. What will be examined is how such a policy can be implemented in any workplace, the contents of such a policy and benefits of it being a compulsory workplace addition. Successful workplace policies and legislative guidelines will be used to create an ideal HIV workplace policy model. The courts approach to HIV positive employees will be studied as they give a rough indication of whether HIV positive person’s rights are being affected at the workplace. This will dictate to us whether there is a need for improvement and to what extent. What will be seen is that there are large gaps in the South African employment arena. HIV positive employees are falling through these gaps with no protection and no one willing to take on the challenge of helping to improve their lives.Dissertation (LLM)--University of Pretoria, 2013.
Public Law
unrestricted
46
Samaniego, Walter Numas. "Discorhabdin C 3-aza analogs and other potential anticancer and anti-HIV agents : synthesis, characterization and biological evaluation." Diss., Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/30899.
Full text
47
Tuthill, Tobias J. "Construction expression and preliminary biological analysis of HCV and HCV-dengue chimeric virus genomes." Thesis, Imperial College London, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368893.
Full text
48
Barankanira, Emmanuel. "Analyses spatiales de problèmes de santé publique en Afrique subsaharienne : exemples du VIH/SIDA et de la malnutrition." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT048/document.
Full textAbstract:
Cette thèse porte sur l’analyse spatiale de problèmes de santé publique rencontrés en Afrique subsaharienne. Dans une première étude, nous avons analysé les variations spatiales de la prévalence du VIH au Burundi et les déterminants socio-comportementaux chez les personnes âgées de 15 à 49 ans à partir des données de l’Enquête Démographique et de Santé (EDS) de 2010. Dans une deuxième étude, nous avons analysé l’évolution de la répartition spatiale de la prévalence du retard de croissance chez les enfants âgés de moins de 3 ans en Côte d’Ivoire à partir des données des EDS de 1994, 1998-1999 et 2011-2012. Pour ces deux études, nous avons tout d’abord prédit en des points non échantillonnés les niveaux de prévalence du problème étudié, soit par la méthode des noyaux, soit par la méthode du krigeage ordinaire. Nous avons ensuite procédé à la détection des agrégats spatiaux ou clusters par la méthode de Kulldorff puis à l’identification de zones de différents risques par la méthode du partitionnement oblique du territoire. Finalement, nous avons utilisé la modélisation spatiale pour identifier les facteurs associés. Ces techniques d’analyse spatiale présentent de nombreux avantages mais également de nombreuses limites que nous soulignonsThis thesis is about the spatial analysis of public health issues in sub-Saharan Africa. In a first study, we analysed the spatial variations of HIV prevalence and the socio-behavioral determinants among people aged 15 to 49 in Burundi using 2010 Demographic and Health Survey (DHS) data. In a second study, we analysed the evolution of the spatial distribution of stunting prevalence among under-three children in Côte d’Ivoire using 1994, 1998-1999 and 2011-2012 DHS data. For both studies, we first predicted the prevalence levels of the public health issue under study in unsampled points by the kernel method or ordinary kriging. We then identified clusters using the Kulldorff’s method and zones of different risks using the oblique partitioning method of the study area. Finally, we used spatial modeling to identify associated risk factors. These spatial analysis techniques have not only many advantages but also many limitations that we emphasize
49
Pedergnana, Vincent. "Contrôle génétique de la réponse à l’infection par des virus oncogènes en population endémique." Thesis, Paris 5, 2013. http://www.theses.fr/2013PA05S022.
Full textAbstract:
La recherche de facteurs génétiques de susceptibilité aux infections virale dans des populations générales exhaustives endémiques est une approche originale en épidémiologie génétique. Nos travaux de thèse nous ont permis d’établir, dans une population endémique pour deux virus oncogènes MCPyV et HHV-8 au Cameroun et dans une population endémique pour le VHC en Egypte, plusieurs arguments forts en faveur d’une susceptibilité génétique aux infections par les virus oncogènes humains définies par la séropositivité/ séronégativité vis-à-vis du virus impliqué. Concernant l’infection par le MCPyV, dont les modes de transmission sont peu connus, nous avons mis en évidence l’existence de fortes corrélations familiales mère-enfant et entre enfants pour la séropositivité au virus, en faveur d’une transmission virale par contacts proches. Ces résultats sont similaires à ceux observés pour l’HHV-8, dans la même population, virus pour lequel la transmission par voie salivaire est l’hypothèse la plus forte. Concernant l’infection par l’HHV-8, nous avons identifié un locus majeur de prédisposition à l’infection par une analyse de ségrégation mettant un gène majeur mendélien autosomique récessif prédisposant à l’infection, suivie d’une analyse de liaison paramétrique utilisant le modèle de l’analyse de ségrégation. Concernant l’infection par le VHC, nous avons identifié par une analyse de liaison génétique un locus majeur de prédisposition à l’infection. Nous avons ensuite identifié, par une analyse d’association en génome entier sur une grande cohorte de plus de 6500 individus, trois signaux associés avec l’infection par le VHC. Par ailleurs, nous avons également réalisé une étude fine des variants du locus du gène IL28B, associés à la clairance du VHC, cohérente avec les résultats publiés au cours de nos travaux. L’identification de facteurs génétiques impliqués dans la susceptibilité aux infections virales oncogènes et aux cancers associés permettra de mieux comprendre la physiopathologie de la réponse à ces infections et les mécanismes intervenant depuis l’exposition virale jusqu’au développement de cancersThe identification of genetic variants predisposing to viral infection in highly endemic general populations is an original approach in genetic epidemiology. Our work suggests a genetic control of the susceptibility to human oncogenic viruses infection, in a population in Cameroon in which MCPyV and HHV-8 are highly endemic and in an Egyptian population in which HCV is endemic. MCPyV is thought to be the etiological agent of Merkel cell carcinoma, but little is known about its distribution and modes of transmission. We provided evidence for familial aggregation of MCPyV infection status suggesting that MCPyV infection is acquired through close contact, possibly involving saliva and/or the skin, especially between young siblings and between mothers and their children. Infection with HHV-8 has been shown to display strong familial aggregation, in countries in which HHV-8 infection is endemic. Our segregation analysis provided strong evidence for a recessive major gene conferring predisposition to HHV-8 infection. The following linkage analysis identified a single region on chromosome 3p22 significantly linked to HHV-8 infection. This study provides the first evidence that HHV-8 infection in children in endemic areas has a strong genetic basis. Concerning HCV infection, we performed a linkage analysis that mapped a major locus predisposing to HCV infection in an Egyptian cohort. We then performed a genome-wide association study in more than 6500 individuals, identifying three signals associated with HCV infection. Finally we investigated the role of several IL28B SNPs in HCV spontaneous clearance in an Egyptian population. The results confirm the major role of IL28B variants in the spontaneous clearance of HCV genotype 4 infection in an Egyptian population. The identification of genetic variants predisposing to viral infection should greatly improve our understanding of the molecular mechanisms involved in the response to these infections and may also unravel new pathways for investigation in viruses-associated diseases, such as cancer
50
Gong, Bo. "Raman spectroscopic studies of the hepatitis delta virus (HDV) ribozyme." Cleveland, Ohio : Case Western Reserve University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=case1228319219.
Full text