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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.
11

Profiling the approach to the investigation of viral infections in cases of Sudden Unexpected Death in Infancy (SUDI) in the Western Cape Province

Burger, Marilize Cornelle 03 1900 (has links)
Thesis (MScMedSc)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Sudden Unexpected Death in Infancy (SUDI) refers to any such sudden demise in a child. If the child dies while asleep within the first year of life, and if no conclusive cause of death can be ascertained by means of complete autopsy and investigation into the circumstances surrounding death, including visit of the death scene, such a case is classified as one of Sudden Infant Death Syndrome (SIDS). By South African law, a full medico-legal autopsy is mandated in cases where the cause of death is not evident – including cases of possible SIDS. There can be little doubt that viral infection can be a cause of death in cases of supposed SUDI. At the Tygerberg medico-legal (forensic) laboratory, the evaluation of lung tissue for the presence of fatal viral lung infections forms part of the institutional protocol for the examination of SUDI cases. Lung samples of these SUDI cases are routinely tested for the presence of Cytomegalovirus (CMV), adenovirus and respiratory syncytial virus (RSV) by means of shell vial cultures. In a retrospective pilot study of 366 SUDI case files from Tygerberg Hospital, Western Cape, from 2004 – 2006, it was evident that in only 13.9% of possible SIDS cases, positive results for one or more of the aforementioned viruses were obtained. We hypothesise that the current method of virus detection, together with other factors such as the interval between death and post mortem examination, transport time of the specimens to the laboratory etc. might not be optimal to give a realistic picture of death in infancy caused by viral pulmonary infection. As other test modalities exist for the diagnosis of pulmonary viral infections, these methods were compared in terms of positive yield and association with viral pneumonitis, keeping the cost and time needed for each assay in mind. A total of 82 samples were collected over an 8 month period and routine shell vial cultures were done, followed by real-time Polymerase Chain Reaction (PCR) and immunohistochemical (IHC) staining of the lung sections with consensus pathology opinion. As expected, the real-time PCR method was much more better suited for identifying positive samples than shell vials (35% vs. 3.7% respectively). IHC staining also aided the pathologist in diagnosing viral infections microscopically. We expect the findings to be instrumental in streamlining not only our institutional SIDS investigation protocol, but also the development of a standardised national SIDS investigation protocol. / AFRIKAANSE OPSOMMING: “Sudden Unexpected Death in Infancy” (SUDI) verwys na enige skielike sterfte van ‘n kind. Indien die kind sterf tydens sy/haar slaap periode en geen oortuigende oorsaak van dood bepaal kan word deur middel van ’n volledige nadoodse ondersoek en ondersoek na die omstandighede tydens die dood, insluitend ’n besoek aan die doodstoneel nie, word so ’n geval as Wiegiedood (SIDS) geklassifiseer. SuidAfrikaanse wetgewing vereis ’n volledige medies-geregtelike nadoodse ondersoek in gevalle waar die oorsaak van dood onbekend is – insluitend gevalle van moontlike Wiegiedood. Daar is min twyfel dat virusinfeksie ‘n oorsaak van, of bydraende faktor tot dood kan wees in gevalle van moontlike SUDI. By die Tygerberg forensiese laboratorium vorm die evaluasie van long weefsel vir die teenwoordigheid van dodelike virusinfeksies deel van die institusionele protokol vir die ondersoek van SUDI gevalle. Long monsters van hierdie SUDI gevalle ondergaan roetine toetse vir die teenwoordigheid van sitomegaalvirus, respiratoriese sinsitialevirus en adenovirus deur middel van selkulture (“shell vial cultures”). In ‘n retrospektiewe steekproef van 366 SUDI gevalle by Tygerberg Hospitaal, Wes-Kaap van 2004 – 2006, is bevind dat in slegs 13.9% van moontlike SUDI gevalle die teenwoordigheid van een of meer van bogenoemde virusse bevestig kon word. Ons hipotese is dat hierdie metode van virus deteksie, tesame met ander faktore soos die tydsinterval tussen dood en nadoodse ondersoek, tyd om monsters na die laboratorium te vervoer ens. moontlik nie optimaal is om ‘n realistiese beeld van dood in babas as gevolg van pulmonale virusinfeksie te gee nie. Aangesien ander toets modaliteite bestaan vir die diagnose van pulmonale virusinfeksies, is hierdie metodes vergelyk in terme van positiewe opbrengs en assosiasie met virale pneumonitis, teen ’n agtergrond van die koste en tyd benodig per toets. ’n Totaal van 82 monsters is oor ‘n 8 maande periode versamel en roetine selkulture is gedoen, gevolg deur “real-time” Polimerase Ketting Reaksie (PKR), asook immunohistochemiese (IHC) kleuring van long snitte met patologiese verslae. Soos vermoed, is gevind dat die real-time PKR metode baie meer akkuraat is om positiewe monsters te identifiseer as roetine selkulture (35% vs 3.7% onderskeidelik). IHC kleuring het ook mikroskopiese diagnose van virale infeksies deur die patoloog vergemaklik. Ons verwag dat hierdie bevindinge grootliks kan bydra in die vaartbelyning van ons institusionele SIDS ondersoek protokol, asook in die ontwikkeling van ’n gestandaardiseerde nasionale SIDS ondersoek protokol.
12

Staging Neurodegenerative Disorders: Structural, Regional, Biomarker, and Functional Progressions

Archer, Trevor, Kostrzewa, Richard M., Beninger, Richard J., Palomo, Tomas 01 February 2011 (has links)
The notion of staging in the neurodegenerative disorders is modulated by the constant and progressive loss of several aspects of brain structural integrity, circuitry, and neuronal processes. These destructive processes eventually remove individuals' abilities to perform at sufficient and necessary functional capacity at several levels of disease severity. The classification of (a) patients on the basis of diagnosis, risk prognosis, and intervention outcome, forms the basis of clinical staging, and (b) laboratory animals on the basis of animal model of brain disorder, extent of insult, and dysfunctional expression, provides the components for the clinical staging and preclinical staging, respectively, expressing associated epidemiological, biological, and genetic characteristics. The major focus of clinical staging in the present account stems from the fundamental notions of Braak staging as they describe the course and eventual prognosis for Alzheimer's disease, Lewy Body dementia, and Parkinson's disease. Mild cognitive impairment, which expresses the decline in episodic and semantic memory performance below the age-adjusted normal range without marked loss of global cognition or activities of daily living, and the applications of longitudinal magnetic resonance imaging, major instruments for the monitoring of either disease progression in dementia, present important challenges for staging concepts. Although Braak notions present the essential basis for further developments, current staging conceptualizations seem inadequate to comply with the massive influx of information dealing with neurodegenerative processes in brain, advanced both under clinical realities, and discoveries in the laboratory setting. The contributions of various biomarkers of disease progression, e.g., amyloid precursor protein, and neurotransmitter system imbalances, e.g., dopamine receptor supersensitivity and interactive propensities, await their incorporation into the existing staging models thereby underlining the ongoing, dynamic feature of the staging of brain disorders.
13

Olfactory Dysfunction in SARS-CoV-2 Infection: Benefits of Including Smell Tests in COVID-19 Patients

Caviness, Dalton, Jia, Cuihong, Rodriguez-Gil, Diego 07 April 2022 (has links)
Loss of olfactory function can readily be overlooked in a clinical setting. In most cases, symptomatic patients recover the sense of smell without any treatment due to the intrinsic neuroregenerative capacity in adult olfactory epithelium. The substantial prevalence of olfactory dysfunction following viral infection of the respiratory system leads many clinicians to consider this physical dysfunction as a subjective symptom rather than a diagnostic and pathologic sign amenable to analysis. Better understanding of the mechanisms behind olfactory dysfunction is expected to increase its clinical importance. Through analyzation of human and mouse specimens, one is able to gain insight into viral-induced olfactory dysfunction on a pathophysiologic level. These murine and human models provide a better understanding of mechanisms and reveal potential therapeutic targets. This is becoming increasingly useful considering the high prevalence of olfactory loss among COVID-19 patients. Here, we discuss the process of olfactory loss following viral infection, the possible mechanism of sudden olfactory dysfunction in COVID-19 infection, the possible benefits of clinical smell tests in COVID-19 patients, and a potentially overlooked consequence on olfactory function using dexamethasone in treating COVID-19 patients. We suggest that including smell tests in COVID-19 patients and studying the mechanism underlying olfactory dysfunction could provide potential strategy to prevent COVID-19 infection and spread and reveal potential therapeutic intervention to restore sense of smell. There are 18 sources used for this miniature literature review. All of our resources were chosen for up-to-date information regarding COVID-19 and it’s effect on the olfactory system. The sources were either found during a large PubMed search or recommendations sent from professors. This article just recently underwent a revision. After revision, our conclusions that smell tests would be beneficial in a clinical setting to prevent the spread and reveal therapeutic targets have been supported by the articles listed. This has been submitted and accepted by a peer-reviewed journal.
14

Topological DNA Damage, Telomere Attrition and T Cell Senescence During Chronic Viral Infections

Ji, Yingjie, Dang, Xindi, Nguyen, Lam Ngoc Thao, Nguyen, Lam Nhat, Zhao, Jaun, Cao, Dechao, Khanal, Sushant, Schank, Madison, Wu, Xiao Y., Morrison, Zheng D., Zou, Yue, El Gazzar, Mohamed, Ning, Shunbin, Wang, Ling, Moorman, Jonathan P., Yao, Zhi Q. 24 June 2019 (has links) (PDF)
Background: T cells play a key role in controlling viral infections; however, the underlying mechanisms regulating their functions during human viral infections remain incompletely understood. Here, we used CD4 T cells derived from individuals with chronic viral infections or healthy T cells treated with camptothecin (CPT) - a topoisomerase I (Top 1) inhibitor - as a model to investigate the role of DNA topology in reprogramming telomeric DNA damage responses (DDR) and remodeling T cell functions. Results: We demonstrated that Top 1 protein expression and enzyme activity were significantly inhibited, while the Top 1 cleavage complex (TOP1cc) was trapped in genomic DNA, in T cells derived from individuals with chronic viral (HCV, HBV, or HIV) infections. Top 1 inhibition by CPT treatment of healthy CD4 T cells caused topological DNA damage, telomere attrition, and T cell apoptosis or dysfunction via inducing Top1cc accumulation, PARP1 cleavage, and failure in DNA repair, thus recapitulating T cell dysregulation in the setting of chronic viral infections. Moreover, T cells from virally infected subjects with inhibited Top 1 activity were more vulnerable to CPT-induced topological DNA damage and cell apoptosis, indicating an important role for Top 1 in securing DNA integrity and cell survival. Conclusion: These findings provide novel insights into the molecular mechanisms for immunomodulation by chronic viral infections via disrupting DNA topology to induce telomeric DNA damage, T cell senescence, apoptosis and dysfunction. As such, restoring the impaired DNA topologic machinery may offer a new strategy for maintaining T cell function against human viral diseases.
15

Viral Hemorrhagic Conjunctivitis Outbreak in Rural Belize

Neighbor, Rebecca, Gleadhill, Claire, Denton, Kacie 12 April 2019 (has links)
ABSTRACT OBJECTIVES: The objectives of this project are to review current literature regarding conjunctivitis including the pathogens that cause conjunctivitis, how to diagnose and differentiate between viral and bacterial conjunctivitis, and the different modalities to treating the disease with limited resources in rural communities. Then examine an outbreak of viral hemorrhagic conjunctivitis in rural Belize in October of 2017. This includes examining data collected by ETSU Family Medicine Department during health outreach clinics regarding diagnosis made, treatment provided, and comparing this information to a survey collected about social determinants of health. Finally, discuss the importance of disseminating public health education regarding how to limit the spread of contagious infections to a rural population with limited health literacy and access to resources. METHODS: In October of 2017 East Tennessee State University (ETSU) Quillen College of Medicine medical students, primary care physicians, and residents traveled to rural Belize to provide free primary care. The clinics consisted of seeing patients at both an established clinic in Roaring Creek, Belize and at remote health clinics in even more rural locations. Many of the patients who presented to the clinics had similar complaints of itchy, red, and productive eyes. Quantitative data was recorded from patient charts regarding their presenting symptoms, diagnosis, and the treatment. The data was organized utilizing microsoft excel and evaluated using SPSS and measures of central tendency. Qualitative data was also collected from interactions with patients and newspaper articles published in Belize about the conjunctivitis outbreak. RESULTS: The results showed that a total of 431 patients received care and 52% of them were diagnosed with conjunctivitis. 46.9% of the patients were determined to have viral conjunctivitis, while 2.8% of them had bacterial conjunctivitis. It was discovered that many patients utilized one reusable cloth to wipe their children's eyes repeatedly thus spreading the disease across and throughout the rural communities. It was found through careful conversations with patients that they were putting urine and breast milk into their eyes in hopes that it would help their pink eye. The Belize Ministry of Health Reported that there were 5,343 cases of pink eye countrywide, with a viral strain being more predominant than bacterial. CONCLUSION: In conclusion, extremely contagious diseases like conjunctivitis are dangerous in rural developing countries because of lack of education about hygiene and limited resources necessary to contain such diseases. While medication is not effective for viral conjunctivitis, it can have devastating consequences (e.g blindness) if a superinfection is not caught early in the course. Education can be the best medicine especially in cases of viral diseases. Patients were also provided with resources to wash their hands often, sterilized water to flush their eyes, and single use towels. A lesson on conjunctivitis, its complications, and how to prevent the spread of the disease was aired on public television. This reports provides examples of both practice creative ways to spread health literacy in rural populations with limited access to resources.
16

Mask Adherence to Mask Mandate: College Campus Versus the Surrounding Community

Condra, Alex, Coston, Taylor, Jain, Monika, Manning, Seth, Wahlquist, Amy, Pettyjohn, Samuel 25 April 2023 (has links)
Adherence to masking recommendations and requirements continues to have a wide variety of impacts in terms of viral spread during the ongoing pandemic. As governments, schools, and private sector businesses formulate decisions around mask requirements, it is important to observe real-life adherence to policies and discern subsequent implications. The CDC MASCUP! observational study tracked mask-wearing habits of students on higher-education campuses across the country to collect stratified data about mask typologies, correct mask usage, and differences in behaviors at locations on a college campus and in the surrounding community. Our findings from a single institution include a significant adherence difference between on-campus (86%) and off-campus sites (72%) across the course of this study as well as a notable change in adherence at the on-campus sites with the expiration of a county-wide governmental mandate, despite continuance of a university-wide mandate. This study, completed on and around the campus of East Tennessee State University in Washington County TN, was able to pivotally extract information regarding increased adherence on campus versus the surrounding community. Changes were also seen when mask mandates were implemented and when they expired.
17

Involvement of the host RNA N6-adenosine methylation (m6A) pathway in the infection cycle of Alfalfa mosaic virus

Martínez Pérez, Mireya 27 November 2020 (has links)
[ES] Las modificaciones químicas post-transcripcionales implican un nuevo nivel de modulación de la expresión génica. Al comienzo de esta Tesis, algunos componentes del complejo de metilación del nitrógeno en posición 6 de la adenosina (m6A) habían sido caracterizados en plantas. Sin embargo, a diferencia de mamíferos y levadura, ninguno de los 13 homólogos de AlkB (atALKBH1-10B) - potenciales desmetilasas (o erasers) - y las 13 proteínas de la familia YTH (ECT1- 11, AT4G11970 y CPSF30) - potenciales proteínas de reconocimiento de m6A (o readers) - identificadas en el genoma de Arabidopsis se habían caracterizado funcionalmente. Además, varios estudios describen la presencia de m6A en RNAs de virus de mamíferos y las diferentes funciones que desempeña esta modificación en la regulación de esas infecciones. No obstante, no se ha estudiado la posible implicación de este mecanismo molecular en las infecciones virales de plantas. El descubrimiento de la interacción entre la CP del virus del mosaico de la alfalfa (AMV) y una proteína de Arabidopsis (atALKBH9B) con homología a una eraser humana fue el punto de partida de esta Tesis. En este trabajo se confirma esta interacción, y se demuestra que atALKBH9B también puede reconocer los RNAs virales. Los resultados revelan que atALKBH9B tiene la capacidad de desmetilar m6A a partir de moléculas de RNA monocatenario in vitro. Esta proteína se acumula en gránulos citoplasmáticos que se colocalizan con siRNA bodies y se asocian a P-bodies, lo que sugiere que su actividad podría estar relacionada con el silenciamiento y/o degradación de mRNA. Por otro lado, ensayos preliminares muestran que los RNAs del AMV, el virus del mosaico del pepino (CMV), el virus de la arruga del nabo (TCV) y el virus del mosaico de la coliflor (CaMV) se metilan durante la infección en Arabidopsis. Además, para AMV y CMV, los resultados fueron corroborados por UPLC-PDA-Tof-MS y los sitios m6A a lo largo de los RNAs del AMV fueron identificados mediante MeRIP-seq. Los resultados presentados confirman que la relación m6A/A a lo largo de los RNAs virales aumenta en plantas atalkbh9b en comparación con las silvestres, mientras que la traducción y/o replicación se ven afectadas y el movimiento sistémico a los tallos florales está prácticamente bloqueado. A diferencia de la CP de AMV, la de CMV no interacciona con atALKBH9B por Y2H y, como ocurre con el resto de virus analizados (CMV, TCV y CaMV), su ciclo de infección no se ve afectado en plantas atalkbh9b. Además, la secuenciación de mRNA realizada en este trabajo revela que la infección por AMV induce algunos genes de Arabidopsis pertenecientes a la maquinaria m6A, MTA, MTB, VIR y ECT5. De acuerdo con el efecto antiviral dependiente de m6A para el AMV y teniendo en cuenta que ECT2, ECT3 y ECT4 fueron recientemente caracterizadas como readers citoplasmáticas, la supresión del módulo ECT2/ECT3/ECT5 aumenta significativamente los títulos sistémicos de AMV y CMV. El efecto antiviral de ECT2 sobre AMV parece estar modulado por su unión directa a los residuos de m6A presentes en los RNAs virales, ya que un mutante de ECT2 defectuoso en el reconocimiento de m6A pierde la actividad antiviral que sí presenta la proteína original y no es capaz de arrastrar RNAs virales in vivo. Por otro lado, acorde a la localización previamente descrita para ECT2 y ECT4 y la capacidad de ECT2 para experimentar una fase similar al gel in vitro, la expresión transitoria de ECT5 muestra un patrón citoplasmático con formación de agregados. Se propone que, como se ha descrito para las proteínas YTH de mamíferos, la interacción entre las ECTs y el RNA polimetilado (en este caso, RNA viral) promovería la formación de gránulos de estrés y, en consecuencia, reduciría las tasas de traducción y replicación viral. En resumen, en este trabajo se caracteriza la primera m6A eraser de plantas, atALKBH9B, y, por primera vez, se describe la influencia del mecanismo de metilación m6A en las infecciones virales de plantas. / [EN] Post-transcriptional chemical modifications entail a new level of gene expression modulation. At the beginning of this Thesis, some components of the N6-adenosine methylation (m6A) complex had been characterized in plants, whereas 13 homologs of AlkB (atALKBH1-10B) - putative demethylases (or erasers) - and 13 proteins of the YTH family (ECT1-11, AT4G11970 and CPSF30) had been identified in the Arabidopsis genome. However, unlike mammals and yeast, no functional roles had been described for any of these proteins. Besides, several reports have brought to light the presence of m6A residues in viral RNAs from mammalian viruses and the critical roles that this modification plays regulating viral infections. However, the potential relevance of this molecular mechanism on plant viral infections remained fully unexplored. The discovery of the interaction between the AMV CP and an Arabidopsis protein (atALKBH9B) with similarity to a human eraser was the starting point of this Thesis. Here, this interaction is confirmed and it is demonstrated that atALKBH9B can also recognize the viral RNAs. Furthermore, the obtained results prove that atALKBH9B has the capability of demethylating m6A from single-stranded RNA molecules in vitro. This protein was observed to accumulate in cytoplasmic granules that colocalize with siRNA-bodies and associate to P-bodies, suggesting that atALKBH9B activity could be related to mRNA silencing and/or decay processes. On the other hand, preliminary assays show that viral RNAs of AMV, Cucumber mosaic virus (CMV), Turnip crinkle virus (TCV) and Cauliflower mosaic virus (CaMV) become methylated during infection in Arabidopsis. Besides, for AMV and CMV, the results were corroborated by UPLC-PDA-Tof-MS and m6A sites along the RNAs of AMV were identified through MeRIP-seq approach. The results presented here confirm that m6A/A ratio along viral RNAs is increased in atalkbh9b plants compared to wild type, whereas translation and/or replication are impaired and systemic movement to the floral stems is practically blocked. In contrast to AMV, CMV CP does not interact with atALKBH9B by Y2H and, as it occurs with the rest of the assayed viruses (CMV, TCV and CaMV), its infection cycle is not affected in atalkbh9b plants. Furthermore, the mRNA-seq analysis performed in this Thesis reveals that some Arabidopsis factors belonging to the m6A machinery, MTA, MTB, VIR and ECT5 genes, are upregulated upon AMV infection. Consistent with the m6A-dependent antiviral effect for AMV and considering that ECT2, ECT3 and ECT4 were recently characterized as cytoplasmic m6A readers, mutations of ECT2/ECT3/ECT5 Arabidopsis module significantly increase AMV and CMV systemic titers. The antiviral effect of ECT2 on AMV seems to be modulated via its direct binding to the m6A residues presented in the viral RNAs, since an ECT2 mutant defective in m6A recognition loses wild type antiviral activity and is not able to pull down viral RNAs in vivo. On the other hand, according to the previous subcellular localization described for ECT2 and ECT4 and the ability of ECT2 to undergo gel-like phase in vitro, the transitory expression of ECT5 displays a cytoplasmic pattern with the formation of some aggregates. As found for mammal YTH proteins, the interaction between ECTs and poly-methylated RNA (in this case viral RNA) is proposed to promote the formation of stress granules and, consequently, reduce viral translation and replication rates. In summary, in this work, atALKBH9B is reported as the first m6A eraser identified in plants and, for the first time, it is described the influence of m6A methylation mechanism in plant viral infections. / [CA] Les modificacions químiques post-transcripcionals impliquen un nou nivell de modulació de l'expressió gènica. Al començament d'esta Tesi, s'havien caracteritzat alguns components del complex de metilació del nitrogen en posició 6 de la adenosina (m6A) en plantes. No obstant això, a diferència de mamífers i llevat, cap dels 13 homòlegs d'AlkB (atALKBH1-10B) - potencials desmetilases (o erasers) - i les 13 proteïnes de la família YTH (ECT1- 11, AT4G11970 i CPSF30) - potencials proteïnes de reconeixement de m6A (o readers) - identificades en el genoma d'Arabidopsis s'havien caracteritzat funcionalment. A més, diversos estudis han descrit la presència de residus m6A en RNAs de virus de mamífers i les diferents funcions que exercix esta modificació en la regulació de les infeccions virals. No obstant això, no s'ha estudiat la possible implicació d'este mecanisme molecular en les infeccions virals de plantes. El descobriment de la interacció entre la CP del virus del mosaic de l'alfals (AMV) i una proteïna d'Arabidopsis (atALKBH9B) amb homologia a una eraser humana va ser el punt de partida d'esta Tesi. En este treball es confirma esta interacció, i es demostra que atALKBH9B també pot reconéixer els RNAs virals. Els resultats revelen que atALKBH9B té la capacitat de desmetilar m6A a partir de molècules de RNA monocatenari in vitro. Esta proteïna s'acumula en grànuls citoplasmàtics que es colocalitzen amb siRNA bodies i s'associen a P-bodies, la qual cosa suggerix que l'activitat atALKBH9B podria estar relacionada amb els processos de silenciament i/o degradació de mRNA. D'altra banda, assajos preliminars mostren que els RNAs virals de l'AMV, el virus del mosaic del cogombre (CMV), el virus de l'arruga del nap (TCV) i el virus del mosaic de la coliflor (CaMV) es metilen durant la infecció en Arabidopsis. A més, per AMV i CMV els resultats van ser confirmats per UPLC-PDA-Tof-MS i els llocs m6A al llarg dels RNAs d'AMV s'identificaren mitjançant MeRIP-seq. Els resultats presentats confirmen que la relació m6A/A al llarg dels RNAs virals augmenta en les plantes atalkbh9b en comparació amb les silvestres, mentre que la traducció i/o replicació es veuen afectades i el moviment sistèmic a les tiges florals està pràcticament bloquejat. A diferència de la CP d'AMV, la de CMV no interacciona amb atALKBH9B per Y2H i, com ocorre amb la resta dels virus analitzats (CMV, TCV i CaMV), el seu cicle d'infecció no es veu afectat en plantes atalkbh9b. A més, la seqüenciació de mRNA realitzada en este treball revela que la infecció per AMV indueix alguns gens d'Arabidopsis pertanyents a la maquinària m6A, MTA, MTB, VIR i ECT5. D'acord amb l'efecte antiviral dependent de m6A per a l'AMV i tenint en compte que ECT2, ECT3 i ECT4 van ser recentment caracteritzades com readers citoplasmàtiques, la supressió del mòdul ECT2/ECT3/ECT5 augmenta significativament els títols sistèmics d'AMV i CMV. L'efecte antiviral d'ECT2 sobre AMV sembla estar modulat a través de la seua unió directa als nucleòtids m6A presents en els RNAs virals, ja que un mutant de la proteïna ECT2 defectuós en el reconeixement de m6A perd l'activitat antiviral que sí que presenta la proteïna original i no és capaç d'arrossegar RNAs virals in vivo. D'altra banda, d'acord amb la localització subcel·lular descrita prèviament per a ECT2 i ECT4 i la capacitat d'ECT2 per a experimentar una fase similar al gel in vitro, l'expressió transitòria d'ECT5 mostra un patró citoplasmàtic amb la formació d'agregats. Es proposa que, com s'ha descrit per a les proteïnes YTH de mamífers, la interacció entre les ECTs i el RNA polimetilat (en aquest cas, RNA viral) promouria la formació de grànuls d'estrès i, en conseqüència, reduiria les taxes de traducció i replicació viral. En resum, en este treball es caracteritza la primera m6A eraser de plantes, atALKBH9B, i, per primera vegada, es descriu la influència de l'mecanisme de metilació M6A en les infeccions virals de plantes. / Martínez Pérez, M. (2020). Involvement of the host RNA N6-adenosine methylation (m6A) pathway in the infection cycle of Alfalfa mosaic virus [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/155976
18

Untersuchungen zur Immunitätslage junger Erwachsener gegen Masern, Mumps und Röteln / Study regarding the immune status of young adults against measles, mumps and rubella

Krieg, Jennifer, Jennifer Krieg, 14 April 2016 (has links) (PDF)
Einleitung: Masern, Mumps und Röteln sind weltweit verbreitete Kinderkrankheiten. Laut Zielvorgaben der World Health Organization (WHO) sollten bis 2015 die Masernviren eradiziert und die Inzidenzen für Mumps und Röteln deutlich vermindert sein. Trotz der beträchtlichen Senkung der Erkrankungszahlen nach der Einführung der jeweiligen Impfungen in den 1970 Jahren kommt es bis heute, sowohl national als auch international zu lokalen Ausbrüchen der Krankheiten. Dabei sind immer häufiger junge Erwachsene betroffen, deren Komplikationsrate bei allen drei Viruserkrankungen im Vergleich zu Kindern deutlich höher liegt. Dies erhöht die Brisanz im Falle eines Ausbruches und führt dazu, dass es auch heute noch in Deutschland vereinzelt zu Todesfällen im Fall von Masern kommt und auch dass nicht wenige Menschen an den Spätfolgen dieser drei impfpräventablen Erkrankungen leiden. Ziele der Untersuchungen: Die Zielstellung der vorliegenden Arbeit war es, die Immunitätslage von 18 bis 29 jährigen Angestellten des Universitätsklinikums Leipzig gegen diese drei viralen Erreger zu bestimmen und im Kontext mit dem Impfstatus der Probanden zu stellen. Zudem sollte untersucht werden, ob auch heute noch die historischen Veränderungen der Impfregime durch die Wiedervereinigung und die Unterschiede bei den untersuchten sogenannten „Wendekindern“ nachgewiesen werden können. Des Weiteren sollten die Verlässlichkeit der diagnostischen Parameter über die Beurteilung des Immunstatus bewertet werden. Materialien und Methoden: Es standen insgesamt über 500 Serumproben zur näheren Auswertung zur Verfügung. Mittels ELISA-Test wurde die jeweils spezifische IgG-Konzentration gegen Masern, Mumps und Röteln ermittelt. Zudem wurden die virusspezifischen Aviditäten von IgG-Antikörpern bestimmt und durch die Anfertigung von Neutralisationstesten (NT) auch deren neutralisierende Wirkung untersucht. Von 326 Probanden wurde die Impfanamnese ermittelt und analysiert. Ergebnisse: Bei keiner der drei Viruserkrankungen wurde in der untersuchten Altersgruppe der 18-29 Jährigen die Seroprävalenz von 95% erreicht, welche notwendig ist, um nachhaltig eine Eindämmung der viralen Erreger in einer Population erreichen zu können. Der Immunstatus der untersuchten Probandengruppe fiel gegen Masern (90,5% IgG-positiv) am besten aus, gefolgt von dem Röteln- (87,1% IgG-positiv) und dem Mumps-Immunstatus (81,6% IgG-positiv). Eine Abnahme der Antikörperkonzentrationen in dem zeitlichen Verlauf nach einer Impfung konnte in der vorliegenden Arbeit gezeigt werden. Bei den vor mehr als 10 Jahren gegen das jeweilige Virus Geimpften sank der Anteil an Seropositiven um 7,4% (Masern und Röteln) bzw. 8,1% (Mumps) im Gegensatz zu den Probanden, die ihre letzte Impfung vor weniger als 10 Jahren erhalten hatten. Die unterschiedlich durchgeführten Impfregime vor und nach der Wiedervereinigung waren in der untersuchten Probandengruppe noch gut zu erkennen. Bei den Geburtsjahrgängen vor 1990 waren die Impfquoten um durchschnittlich 15% niedriger als bei den Jahrgängen ab 1990. Aufgrund der erhöhten Wildviruszirkulation vor 20 Jahren zeigten die älteren Jahrgänge dennoch einen ähnlich hohen Antikörperstatus, wie die Jüngeren. Auch die Auswertung der Aviditätsindices und der NT-Titer im zeitlichen Abstand zu der zuletzt erhaltenen Impfung ergab einen Hinweis auf die Boosterung der Immunität gegen den jeweiligen viralen Erreger durch den Kontakt der Probanden mit Wildvirus. Die Korrelation zwischen den diagnostischen Parametern IgG-Konzentration, Avidität und Neutralisationstiter ließen sich am besten bei den Masern- und den Rötelnwerten erkennen. Die Zusammenhänge bei Mumps waren im Vergleich zu den anderen beiden viralen Erregern gering. Die Abhängigkeit von der Impfanamnese konnte bei allen drei viralen Erregern nur bei den IgG-Konzentrationen festgestellt werden. Ein Zusammenhang zwischen Impfstatus und Höhe der Aviditätsindices bzw. Neutralisationstiter lag nicht vor. Schlussfolgerungen: Sowohl der Immun- als auch der Impfstatus der untersuchten jungen Erwachsenen (18 29 Jahre) ist für eine nachhaltige Eindämmung des Masern-, Mumps- und des Rötelnvirus nicht ausreichend. Die Bestimmung der IgG-Konzentration als Routinediagnostikum für die Erhebung eines Immunstatus ist bei allen drei Viren nur mit Einschränkungen geeignet. Die Durchführung von Neutralisationstesten, insbesondere gegen Mumps, ist Goldstandard für die Bestimmung einer Immunitätslage. / Introduction: Measles, mumps and rubella are worldwide occurring childhood diseases. World Health Organization (WHO) declared the goal of measles eradication by 2015 and significant reduction of the incidence of mumps and rubella. Despite the substantial decrease after implementation of vaccination, there are still yearly outbreaks of the three infections on national and international level. At the same time, more often young adults are affected by all three viral diseases and their rate of complications is significantly higher than children. The explosive nature of the diseases leads to the fact that, even in Germany people die of measles. Further, more than a few people suffer from long-term effects of these diseases which could be prevented by vaccination. Aim of the research: The aim of the present project was to determine the immune status against the three viral diseases. Serum samples of 18 to 29 years-old employees of the Leipzig University Hospital were analyzed and connected with vaccination status. It was also determined if the historic changes of the vaccination politics in children of German reunification can still be demonstrated. Furthermore, the reliability of the diagnostic parameters, which is routinely taken for the evaluation of the immune status of a person, was considered. Material and Methods: More than 500 serum samples were available. The IgG concentration of mumps, measles and rubella was determined using routine ELISA assay. Furthermore, the specific antiviral IgG antibody avidity as well as their ability to neutralize viral infectivity (neutralization test) the vaccination history was recorded and analyzed. Results: The results show, that in none of the three diseases seroprevalence of >95% could be achieved which would be necessary for the sustainably containment of the viral pathogens in a population. In the examined cohort immunity against measles (90,5% IgG positive) was somewhat higher than against rubella (87,1% IgG positive) and mumps (81,6% IgG positive). A decrease in the antibody concentration could be demonstrated in the present paper when comparing the immune response in person with vaccination history of less than 10 years and those with last vaccination more than 10 years back. The seropositive rates decreased 7,4% (measles and rubella) or 8,1% (mumps). The different vaccination regimes before and after German reunification were still apparent. The vaccination rates from the birth cohort before 1990, was by an average of 15% lower than the cohorts from 1990. Due to the higher circulation of wild virus before 20 years ago, the older age groups had a similar status of antibodies than the younger group. Also, the analysis of the avidity and neutralization titer in the relationship of the period of time between the collection of data and the last obtained vaccination indicated booster of immunity by contact occult immunization (“stille Feiung”). The correlation between the diagnostic parameters, i.e. IgG concentration, avidity and neutralization assay, was best for measles and rubella. The relationships of mumps were lower than both the other viral pathogens. Only the IgG concentration from all three viruses correlated with the vaccination history. A relationship between the vaccination and the level of avidity or neutralization titers did not exist. Conclusion: The immune status and also the vaccination status from the investigated young adults (18 29 years) is not sufficient for the containment of measles, mumps and rubella. The determination of IgG concentration for surveillance of immunity all three viruses is of limited value. Particularly in case of mumps a neutralization assay appear indispensable.
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Relação bio-sociocomportamental na ocorrência do Diabetes Mellitus tipo1 / Bio-social behavior relation the occurrence of Diabetes Mellitus type 1

Maria Fatima Soares Guedes 04 March 2016 (has links)
O Diabetes Mellitus Tipo 1 (DM1) é uma doença caracterizada pela destruição das células beta do pâncreas levando à deficiência absoluta da produção de insulina, podendo ser autoimune ou idiopática. Diversos fatores ambientais podem influenciar o desenvolvimento desta patologia, dentre eles incluem-se fatores externos como a nutrição, infecções virais, peso ao nascer, idade materna, crescimento infantil aumentado, estresse e condições socioeconômicas. O objetivo do presente trabalho foi descrever as características bio-sociocomportamentais de indivíduos com Diabetes Mellitus Tipo 1 e a possíveis relações destas características com a ocorrência da patologia. Trata-se de um estudo observacional transversal com 399 indivíduos, sendo 202 com o diagnóstico de DM1 e 197 controles não diabéticos, pareados por sexo, idade e etnia, que responderam a um questionário com perguntas que versaram sobre informações bio-socioecomportamentais, nos intervalos das consultas médicas na Unidade Básica de Saúde Centro Dr. Alpheu de Vasconcelos Sampaio\" e Hospital Estadual de Bauru Dr. Arnaldo Curvêllo. Para análise dos dados utilizou-se o teste do qui-quadrado nas variáveis qualitativas nominais, o teste de Mann-Whitney nas variáveis qualitativas ordinais e o teste t nas variáveis quantitativas, o coeficiente de correlação de Spearman (variáveis qualitativas ordinais) e de Pearson (variáveis quantitativas) para verificar correlação entre variáveis. Adotou-se o nível de significância de 5% (p<0,05) em todos os testes estatístico. Os resultados mostraram que a renda familiar predominante é a de um a três salários mínimos, que o parto cesárea foi o mais evidente nos dois grupos. Com relação ao mês do diagnóstico, notou-se que ocorreu mais na estação de inverno, nos meses de junho e julho e evidenciou que a idade ao diagnóstico tem diminuído nos últimos anos. A infecção viral mais frequente foi a catapora. Quanto à doença periodontal, o estudo mostrou que a maioria desconhece que ela é uma das complicações do diabetes. Verificou-se que o parto normal ou vaginal contribuiram para o não desenvolvimento do DM1, e que o intervalo maior do que 5 anos entre os irmãos e a catapora estiveram associados ao DM1. / Diabetes mellitus type 1 (DM1) is a disease characterized by the destruction of pancreatic beta cells leading to absolute deficiency of insulin production, may be autoimmune or idiopathic. Several environmental factors may influence the development of this pathology among them include external factors such as nutrition, viral infections, birth weight, maternal age, increased infant growth, stress and socioeconomic conditions. The objective of this study was to describe the bio-socio-behavioral characteristics of individuals with Type 1 Diabetes Mellitus and the possible relationship of these characteristics with the occurrence of the disease. This is a cross-sectional observational study of 399 subjects, 202 diagnosed with type 1 diabetes and 197 nondiabetic controls matched for sex, age and ethnicity, who answered a questionnaire with questions that were about bio-socioecomportamentais information in ranges medical consultations in the Basic Health Unit Centre \"Dr. Alpheu Sampaio de Vasconcelos \"and Bauru State Hospital Dr. Arnaldo Curvello. Data analysis used the chi-square test in nominal qualitative variables, the Mann-Whitney test in the ordinal qualitative variables and the\" t \"in quantitative variables, Spearman\'s correlation coefficient (ordinal qualitative variables) and Pearson (quantitative variables) to check correlation between variables. We adopted the significance level of 5% (p <0.05) in all statistical tests. The results showed that the predominant family income is from one to three minimum wages, the cesarean delivery was most evident in both groups. Regarding the month of diagnosis, it was noticed that there was more in the winter season in the months of June and July and showed that the age at diagnosis has decreased in recent years. The most common viral infection was chickenpox. As for periodontal disease, the study showed that most are unaware that it is one of the complications of diabetes. It was found that normal vaginal delivery or contributed to the development of non-DM1, and that the greater range than five years between the brothers and chickenpox were associated with DM1.
20

Relação bio-sociocomportamental na ocorrência do Diabetes Mellitus tipo1 / Bio-social behavior relation the occurrence of Diabetes Mellitus type 1

Guedes, Maria Fatima Soares 04 March 2016 (has links)
O Diabetes Mellitus Tipo 1 (DM1) é uma doença caracterizada pela destruição das células beta do pâncreas levando à deficiência absoluta da produção de insulina, podendo ser autoimune ou idiopática. Diversos fatores ambientais podem influenciar o desenvolvimento desta patologia, dentre eles incluem-se fatores externos como a nutrição, infecções virais, peso ao nascer, idade materna, crescimento infantil aumentado, estresse e condições socioeconômicas. O objetivo do presente trabalho foi descrever as características bio-sociocomportamentais de indivíduos com Diabetes Mellitus Tipo 1 e a possíveis relações destas características com a ocorrência da patologia. Trata-se de um estudo observacional transversal com 399 indivíduos, sendo 202 com o diagnóstico de DM1 e 197 controles não diabéticos, pareados por sexo, idade e etnia, que responderam a um questionário com perguntas que versaram sobre informações bio-socioecomportamentais, nos intervalos das consultas médicas na Unidade Básica de Saúde Centro Dr. Alpheu de Vasconcelos Sampaio\" e Hospital Estadual de Bauru Dr. Arnaldo Curvêllo. Para análise dos dados utilizou-se o teste do qui-quadrado nas variáveis qualitativas nominais, o teste de Mann-Whitney nas variáveis qualitativas ordinais e o teste t nas variáveis quantitativas, o coeficiente de correlação de Spearman (variáveis qualitativas ordinais) e de Pearson (variáveis quantitativas) para verificar correlação entre variáveis. Adotou-se o nível de significância de 5% (p<0,05) em todos os testes estatístico. Os resultados mostraram que a renda familiar predominante é a de um a três salários mínimos, que o parto cesárea foi o mais evidente nos dois grupos. Com relação ao mês do diagnóstico, notou-se que ocorreu mais na estação de inverno, nos meses de junho e julho e evidenciou que a idade ao diagnóstico tem diminuído nos últimos anos. A infecção viral mais frequente foi a catapora. Quanto à doença periodontal, o estudo mostrou que a maioria desconhece que ela é uma das complicações do diabetes. Verificou-se que o parto normal ou vaginal contribuiram para o não desenvolvimento do DM1, e que o intervalo maior do que 5 anos entre os irmãos e a catapora estiveram associados ao DM1. / Diabetes mellitus type 1 (DM1) is a disease characterized by the destruction of pancreatic beta cells leading to absolute deficiency of insulin production, may be autoimmune or idiopathic. Several environmental factors may influence the development of this pathology among them include external factors such as nutrition, viral infections, birth weight, maternal age, increased infant growth, stress and socioeconomic conditions. The objective of this study was to describe the bio-socio-behavioral characteristics of individuals with Type 1 Diabetes Mellitus and the possible relationship of these characteristics with the occurrence of the disease. This is a cross-sectional observational study of 399 subjects, 202 diagnosed with type 1 diabetes and 197 nondiabetic controls matched for sex, age and ethnicity, who answered a questionnaire with questions that were about bio-socioecomportamentais information in ranges medical consultations in the Basic Health Unit Centre \"Dr. Alpheu Sampaio de Vasconcelos \"and Bauru State Hospital Dr. Arnaldo Curvello. Data analysis used the chi-square test in nominal qualitative variables, the Mann-Whitney test in the ordinal qualitative variables and the\" t \"in quantitative variables, Spearman\'s correlation coefficient (ordinal qualitative variables) and Pearson (quantitative variables) to check correlation between variables. We adopted the significance level of 5% (p <0.05) in all statistical tests. The results showed that the predominant family income is from one to three minimum wages, the cesarean delivery was most evident in both groups. Regarding the month of diagnosis, it was noticed that there was more in the winter season in the months of June and July and showed that the age at diagnosis has decreased in recent years. The most common viral infection was chickenpox. As for periodontal disease, the study showed that most are unaware that it is one of the complications of diabetes. It was found that normal vaginal delivery or contributed to the development of non-DM1, and that the greater range than five years between the brothers and chickenpox were associated with DM1.

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