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Ecology of the Brown Marmorated Stink Bug (Hemiptera: Pentitomidae): Oviposition on Different Trees, Nymphal Development on Various Vegetable Hosts, and Assessment of a Bacterial PathogenFormella, Adam John 07 January 2019 (has links)
The brown marmorated stink bug, Halyomorpha halys (Stål), is an invasive species that has spread throughout the United States and become a serious agricultural pest. Studies were conducted in Virginia on the survival of H. halys nymphs on different vegetable hosts and on the oviposition preference of H. halys on common tree hosts in southwestern Virginia. To determine the effects of vegetable host on H. halys survival, nymphs were placed on one of five vegetable host plants and their corresponding vegetable fruit. Survival was highest on sweet corn, followed by bell pepper and snap bean. Eggplant and tomato were poor compared to other vegetable hosts tested, potentially due to secondary compounds released by the plant to reduce feeding. Of six common host trees sampled, H. halys laid the most egg masses on catalpa, Catalpa bignonioides, while aggregation lure had no effect on the number of eggs laid. Across host trees, egg masses were more commonly found in trees with fruiting structures present. An additional study was conducted on a red-sternum phenotype of H. halys. Mortality was recorded by sternum phenotype for each sex. There was no difference in survival between groups at two time points. Biochemical tests were used to determine if the red-sternum was associated with the potentially pathogenic red bacteria Serratia marcescens. Only one stink bug's gut contents had a confirmed infection of S. marcescens. Results from these studies offer insight into H. halys development on vegetable hosts and oviposition preferences on different host trees. / MSLFS / The brown marmorated stink bug (BMSB), is an invasive insect that has spread throughout the United States and become a serious pest. Current research is focused on reducing their populations without increasing insecticide use. Studies were conducted to determine if vegetable host type influenced survival and development of this insect. Nymphs were placed on one of five vegetable plants with the corresponding vegetable fruit. Overall, survival was highest on sweet corn, followed by bell pepper and snap bean. Eggplant and tomato were poor hosts, potentially due to chemicals released by the plant to reduce insect feeding. Six common host trees of BMSB were sampled to determine where females lay the most egg masses and the effect of using an attraction lure. Catalpa trees had the most egg masses throughout the season. Use of a lure had no effect on the number of eggs laid on any tree. A red colored abdomen was observed in some adult insects throughout these studies. To determine if this was associated with higher mortality, male and female insects were observed for two weeks. There were no mortality differences at either seven or 14 days between any of the groups. Tests were used to determine if the red abdomen was caused by a red-colored bacterium. Of the insects sampled, there was only one stink bug with a confirmed infection. Results from these studies provides information that increases knowledge of this pest’s ecology in Virginia.
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Developing Disease-Targeted Photoacoustic Imaging Probes / HARNESSING THE SOUND OF LIGHT: DESIGN, SYNTHESIS & EVALUATION OF PHOTOACOUSTIC IMAGING PROBES FOR THE STUDY OF BONE DISEASE AND BACTERIAL INFECTIONSwann, Rowan January 2024 (has links)
To address the paucity of available molecularly targeted photoacoustic imaging probes (PIPs) and to generate meaningful data to support the ongoing effort to refine diagnostic photoacoustic imaging (PAI) applications, the work presented here focuses on the design, synthesis, and evaluation of novel PIPs. To this end, various light-absorbing small molecule dyes, targeting strategies, and disease-targeting molecules were evaluated.
First, a near-infrared photoacoustic probe was used to image bone in vivo through active and bioorthogonal pre-targeting strategies by utilizing a coupling between a tetrazine-derived cyanine dye and a trans-cyclooctene-modified bisphosphonate. In vitro hydroxyapatite binding and in vivo bone imaging studies showed significant localization of the agent to the target using both active and pre-targeting strategies.
The tetrazine-dye building block was then used to create a first-generation bacteria-targeting PIP, using a trans-cyclooctene-modified Zinc (II)-dipicolylamine (ZnDPA). The PIP demonstrated poor aqueous solubility and overlapping photoacoustic (PA) signal with deoxyhemoglobin. Therefore, a commercially available ZnDPA-derived fluorophore, PSVue794, was then repurposed for use as a PIP. PSVue794 demonstrated the ability to differentiate between bacterial infection, sterile inflammation, and healthy tissue in a mouse model, via PA imaging, which prompted its use in a series of proof-of-concept studies towards the generation of a model of implant infection. The feasibility of detecting the PIP in the presence of a PA signal-emitting metallic implant, which was deemed a significant hurdle due to the intensity of the PA signal of the metal, was verified. Although the work requires some follow-up evaluations to demonstrate the practical use of the model, ZnDPA-based PIPs have remained promising candidates for PAI of bacterial infection.
Finally, a novel general-purpose dye was designed to possess properties ideal for in vivo PAI. To evaluate the modifications made, the general-purpose dye was conjugated with ZnDPA, and was tested alongside the non-targeted counterpart and PSVue794. Through the studies conducted, it was evident that the rationale that contributed to the design of the general-purpose dye did lead to highly soluble PIP with promising PA properties, however, the PIP did not demonstrate target-specificity, in vivo. Therefore, investigations using the non-targeted PIP with higher affinity targeting vectors for PA-compatible diseases, such as surgical-site/implant infections and prostate cancer, is warranted. / Thesis / Doctor of Philosophy (PhD) / The work conducted within this thesis aims to outline the process of developing photoacoustic diagnostic agents for the detection of various diseases, including bone disease and bacterial infection. To this end, various small molecule, near-infrared absorbing dyes, disease-targeting molecules, and assembly methods were selected to generate several diagnostic agents. To demonstrate their utility, the diagnostic agents were each evaluated in a series of studies designed to assess their ability to generate detectable photoacoustic signal, interact specifically with disease-markers, and localize the sites of disease in living systems. Significant attention was placed on comprehensively evaluating the diagnostic agents through the development of methodology and generating a standard procedure for photoacoustic data production and reporting, which was practiced throughout the work.
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Economic Considerations of Aggressively Treating the Influenza Virus in EquinesHansen, Charlotte R 01 January 2016 (has links)
The equine influenza virus is a significant cause of respiratory disease in horses. Even though horses generally recover from this virus, sometimes horses with equine influenza develop secondary bacterial infections which can cause severe pneumonia, thereby increasing recovery times. Owners and managers are faced with the decision of whether to delay preventative treatment in hopes of the horse avoids contracting a secondary bacterial infection (“wait and see”) or aggressively treat the horse with an antibiotic in hopes of avoiding a serious infection (“treat now”). From a decision making standpoint, the economic considerations include explicit treatment costs as well as nonmonetary costs the owner or manager bear when caring for an ill horse.
This study investigating horse owner/manager preferences for treatment alternatives is approached in two parts. The first part of the study collects data from field practitioners to estimate the cost of treatment strategies under different scenarios. The second part consists of a questionnaire presented to horse owners and managers and includes four choices between alternative treatment strategies. Analyzing the data using a conjoint analysis approach, respondents’ willingness to pay for different elements of a treatment strategy are estimated. Based on treatment strategies and demographic interactions, a respondent was willing to pay to cover the cost of a horse who became ill with the equine influenza, but individual price sensitivities suggested horse owners and managers are willing to “treat now” versus “wait and see” in order to not see their horse feel poorly and miss training time.
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Vývoj experimentálního modelu pro testování žloutkových protilátek jako prostředku profylaxe bakteriálních infekcí / Development of an experimental model for yolk antibody prophylaxis of bacterial infectionsHadrabová, Jana January 2015 (has links)
Respiratory system of the cystic fibrosis patients is affected by the defect in gene coding for protein transporter for chloride ions - CFTR ("Cystic fibrosis transmembrane conductance regulator"). The main complication of this disease is airways chronic inflammation, in particular caused by bacterium Pseudomonas aeruginosa. Due to asialylation of the lung surfaces the bacterial adhesion is facilitated, for example via lectin PAIIL. The ability of the chicken yolk antibodies to protect lung epithelial cells against Pseudomonas aeruginosa adhesion has been already proven. Therefore this thesis has mainly focused on the influence of the yolk antibodies specific against PAIIL on the development of infection in lungs of experimental animals. The objective was the optimization of the experimental model on which it would be possible to observe the infection development caused by luminescent bacteria strain in vivo using the optical tomography. At first the experiments have been performed on Wistar rats. Since the bacteria colonies in the rat lungs were not detectable in vivo on the available equipment, the rat experimental model showed up as not suitable. Further on only the mouse models were used. Experiments for the inhalation of the antibodies and intratracheal instillation of the bacteria suspension...
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Avaliação da quantidade de bactérias e endotoxinas após o tratamento endodôntico de dentes com periodontite apical primária e a correlação com a indução de citocinas pró-inflamatórias em cultura de fibroblastos humanos / Evaluation of bacterial and endotoxin levels after root canal treatment with primary apical periodontitis teeth and its correlation with pro-inflammatory cytokines induction by human fibroblasts cultureNascimento, Laís Cunha Prado do 26 November 2018 (has links)
Este estudo clínico avaliou a quantidade de bactérias e endotoxinas, antes e após o tratamento endodôntico utilizando ativação ultrassônica de solução de hidróxido de cálcio e sua correlação com a indução de citocinas pró-inflamatórias por fibroblastos humanos. Vinte e três pacientes com dentes com periodontite apical primária foram submetidos ao tratamento endodôntico. O preparo químico-cirúrgico (PQC) foi realizado com instrumentos reciprocantes, utilizando NaOCl 2,5% durante o preparo e EDTA 17% para remoção do magma dentinário; complementado com a ativação ultrassônica de uma solução de hidróxido de cálcio. Os canais radiculares foram preenchidos com pasta de hidróxido de cálcio por 14 dias e obturados. Foram realizadas coletas microbiológicas dos canais antes (S1) e após o PQC (S2), após o protocolo de ativação ultrassônica (S3) e após a medicação intracanal (S4). As amostras foram analisadas por: PCR quantitativo (qPCR) utilizando iniciadores universais para quantificação de bactérias após extração de DNA; teste turbidimétrico de LAL para quantificação de endotoxinas; e ELISA para quantificação de citocinas (IL-1?, IL-6, CCL2) em cultura de fibroblastos humanos após indução com o conteúdo do canal radicular. Os dados foram analisados pelos seguintes testes estatísticos: teste de Wilcoxon e Q de Cochran para análise quantitativa de bactérias e endotoxinas; ANOVA e teste de Tukey, para quantificação dos níveis de citocinas; e teste de Pearson para correlação entre os níveis de endotoxinas e citocinas (todos com nível de significância de 5%). Bactérias e endotoxinas foram observadas em todas as amostras iniciais com uma mediana de 3,61 x 104 e 109 EU/ml, respectivamente. Após o preparo químico-cirúrgico, houve uma redução significativa (p <0,05) dos níveis de DNA bacteriano (mediana 7,84 x 103) e endotoxina (mediana 20,2 EU/ml). Entretanto, não houve redução de DNA bacteriano após as etapas seguintes. Com relação a endotoxina, houve redução significativa (p <0,05) após a medicação intracanal (9,58 EU/mL). Correlação positiva foi observado entre os níveis de endotoxina e a indução de citocinas pró-inflamatórias. Produção de IL-1?, IL-6, CCL2 foram observadas em todas as etapas do tratamento. Não houve diferença estatística dos níveis de IL-1 ? detectados nas diferentes amostras (p >0,05). Houve diminuição significativa de IL-6 e CCL-2 entre S1 e S2 (p <0,05). Entretanto, não houve redução dessas citocinas nas amostras S3 ou S4 em relação às amostras S2 (p >0,05). Conclui-se que o PQC foi eficaz na redução de bactérias e endotoxinas dos canais radiculares; enquanto a medicação intracanal influenciou apenas na redução de endotoxina. As amostras após o PQC induziram menores níveis de IL-6 e CCL-2 em fibroblastos humanos do que as amostras antes do tratamento endodôntico. Por outro lado, as demais etapas do tratamento não foram capazes de promover uma redução adicional dessas citocinas. / This clinical study analyzed bacteria and endotoxins levels before and after endodontic treatment using ultrasonic activation of a calcium hydroxide solution and an intracanal medication and its correlation with pro-inflammatory cytokines induction by human fibroblasts. Twenty-three patients with teeth with primary apical periodontitis were submitted to endodontic treatment. The root canal preparation of all the teeth was carried out with reciprocating files and 2.5% NaOCl during preparation; and 17% EDTA for smear layer removal, supplemented with the ultrasonic activation of a solution of calcium hydroxide. The root canals were medicated with calcium hydroxide for 14 days and then obturated. Microbiological sampling were performed before (S1) and after the root canal preparation (S2), after ultrasonic activation protocol (S3) and after intracanal medication (S4). The samples were analyzed by quantitative PCR (qPCR) using universal primers quantification of bacteria after DNA extraction; LAL turbidimetric test for detection and determination of endotoxin and ELISA for evaluate the cytokine production (IL-1?, IL-6, CCL2) by humam fibroblasts culture. Data was analyzed by Wilcoxon and Q cochran tests for the quantitative analysis of bacteria and endotoxins. ANOVA and tukey test, with significance level of 5%, were used for quantification of cytokine levels and Pearson\'s test for correlation between endotoxins and cytokine levels. Bacteria and endotoxins were observed in all initial samples with a median of 3.61 x 104 and 109 EU/ml respectively. After root canal preparation, there was a significant reduction (p<0,05) of bacterial DNA (median 7.84 x 103) and endotoxin (median 20.2 EU/ml). However, there was no reduction of bacterial DNA after following steps. Regarding endotoxin, there was a significant reduction (p <0.05) after intracanal medication (9.58 EU / mL), A positive correlation was observed between endotoxins and cytokine induction. Production of IL-1?, IL-6, CCL2 were observed in all stages of treatment.. There was no statistical difference between the presence of IL-1? in each step of the treatment (p >0.05). There was a significant decrease in the presence of the proinflammatory cytokine IL-6 and CCL-2 between the initial stage of endodontic treatment (S1) and the next step (S2) (p <0.05). However, in the following steps (S3 and S4) there was no reduction (p >0.05). It was concluded that the root canal preparation was effective in reducing bacteria and endotoxins, and intracanal medication only influenced in endotoxin reduction. Samples after the root canal preparation induced lower levels of IL-6 and CCL-2 in human fibroblasts than samples before endodontic treatment, whereas other stages of the endodontic treatment were not able to promote an additional reduction.
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Study of the metabolic aspects of resilience to intestinal infections in Drosophila melanogaster / Etude des aspects métaboliques de la résilience aux infections intestinales chez la DrosophileSocha, Catherine 27 November 2018 (has links)
Lors d’une infection microbienne, la défense de l’hôte comprend deux facettes complémentaires. Premièrement, le système immunitaire cible les pathogènes dans le but de les éliminer, une attaque correspondant à la résistance. Dans un second temps, l’organisme doit réparer les dégâts causés par le pathogène ou par la réponse immunitaire de l’hôte, un mécanisme appelé résilience. J’ai étudié les effets d’une infection intestinale par la bactérie Serratia marcescens chez la drosophile. Nous avons mis en évidence un processus de purge dans l’intestin, lors duquel les enterocytes -les cellules principales de l’intestin- se vident partiellement de leur contenu. L’épithélium intestinal devient alors très fin mais se régénère rapidement, protégeant ainsi la mouche des effets délétères de l’infection. J’ai identifié un transporteur d’acides aminés, CG1139, qui est nécessaire à la régénération de l’intestin. CG1139 est requis pour la mobilisation de certaines réserves métaboliques de la drosophile et pour le transport rétrograde de ces dernières vers l’intestin. / Upon microbial infections, host defenses comprise two complementary facets. First, immune effectors target and kill the invading pathogen, an attack referred to as resistance. Second, the infected host must repair the damages inflicted by microbes or by the immune response itself, a mechanism called resilience. I have studied the effects of an intestinal infection with the bacterium Serratia marcescens in Drosophila. We have discovered a purge mechanism in the intestine, where enterocytes -the main cell type in the gut- extrude some of their internal contents. The intestinal epithelium thus becomes very thin but rapidly recovers its shape, thereby protecting the fly against the deleterious effects of infection. I have identified an amino acid transporter, CG1139, which is required for the intestinal recovery. CG1139 is necessary to mobilize the fly’s internal metabolic reserves and to transport some these metabolic stores back to the gut, in a retrograde manner.
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Atividade antibacteriana dos óleos essenciais de Origanum vulgare L. e Cinnamomum zeylanicum B. contra bactérias multirresistentesCosta, Adalberto Coelho da 31 August 2009 (has links)
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Previous issue date: 2009-08-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / One of the largest world health problem is the bacteria resistance acquired to the
antimicrobials, and that increases more and makes difficult their treatment. The
nosocomial infections caused by these microorganisms difficultly will be eradicated
by routine therapeutic methods, and even so, the antibiotics are considered the main
therapeutic option. As alternative to treatment of those infections are considered the
research of antimicrobials obtained of vegetable origin. The aim of this work was to
determine the antibacterial activity of the essential oils obtained from Origanum
vulgare L. and Cinnamomum zeylanicum B. against multiresistant bacteria strains; to
identify the incidence of multiresistant pathogens as etiological agents of the
infectious processes in nosocomial patients; to determine "in vitro" the minimum
inhibitory concentration (MIC) of these referred oils against the bacteria whose
growth was inhibited in the preliminary tests with the respective oils; to confirm the
minimum bactericidal concentration (MBC) of the tested oils on the bacterial strains
after the detection of CIM and to evaluate the interference of the studied oils using
the bacterial kinetic curve. A preliminary "screening" was determined using the
diffusion agar technique. The CIM was determined by the microdilution method,
starting with solutions in the final concentrations of 8,0 up to 0,125%, obtaining the
following results: The cinnamomum essential oil inhibited the multiplication of the
bacteria in the following percentiles and concentrations: 95,83% - 8%; 91,66 - 2%
and 79,1% - 1%. The origanum essential oil inhibited the bacteria multiplication in the
respective percentile and concentrations of 75% - 0,125%; 83,33 - 0,25% and 100% -
0,5%. Based in the obtained data could be affirmed that in these studies the isolated
bacterial strains such as Enterococcus faecalis, Staphylococcus aureus, Escherichia
coli, Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa
were considered multiresistant to the tested antibiotics The C. zeylanicum B.
essential oil was effective as bacteriostatic agent on 92% of the bacterial strains in
with the CIM or 2%, and 4% of efficacy in CIM of 0,125%. The C. zeylanicum B.
essential oil didn't reveal bactericidal properties, when tested in the CBM's of the
considered microorganisms. The O. vulgare L essential oil demonstrated bactericidal
activity in about the totality of the Gram positive and Gram negative bacteria studied,
using a CBM of 0,5%. The bactericidal effect of the O. vulgare L. observed in the
study against multiresistant bacteria, it was a very important die, considering that the
found acquired values resemble each other with the drugs of last generation used in
the research. In the bacterial kinetics the essential oils of C. zeylanicum B. and O.
vulgare L. inhibited the microorganisms growth of the tested in the interval from 0,0 to
120 minutes. The antimicrobial values of the tested essential oils found in the
experiments conduct or indicate to the application of new methodologies, looking for
the way to a rational use of the same ones in the antibacterial therapeutics. / Um dos maiores problemas mundiais de saúde é a resistência que as bactérias vêm
adquirindo aos antimicrobianos, e que se acentua cada vez mais dificultando o seu
combate. As infeções hospitalares provocadas por esses microrganismos
dificilmente serão debeladas com terapêutica de rotina, mesmo assim, os
antibióticos permanecem a principal opção terapêutica. Como alternativa para o
tratamento dessas infecções destaca-se a pesquisa de antimicrobianos de origem
vegetal. Neste trabalho objetivou-se determinar a atividade antibacteriana dos óleos
essenciais de Origanum vulgare L. (orégano) e Cinnamomum zeylanicum B. (canela)
contra bactérias multirresistentes; Identificar a incidência de patógenos
multirresistentes como agentes etiológicos dos processos infecciosos em
pacientes atendidos em um nosocômio; determinar in vitro a concentração
inibitória mínima (CIM) dos referidos óleos sobre as bactérias cujo crescimento
foi inibido pelos respectivos óleos; confirmar a concentração bactericida mínima
(CBM) dos óleos testados sobre as cepas bacterianas após a detecção da CIM
e avaliar a interferência dos óleos estudados através da curva cinética
bacteriana. Foi realizado um screening preliminar, utilizando-se a técnica de
difusão em ágar. A CIM foi determinada pelo método de microdiluição, partindo-se
de soluções com as concentrações finais de 8,0 até 0,125%, obtendo-se os
seguintes resultados: O óleo essencial de C. zeylanicum inibiu a multiplicação das
bactérias nos seguintes percentuais e concentrações: 95,83% - 8%; 91,66 2% e
79,1% - 1%. O óleo essencial de O. vulgare inibiu a multiplicação das bactérias nos
percentuais e concentrações respectivos de 75% - 0,125%; 83,33 0,25% e 100 % -
0,5%. Com base nos dados obtidos pode-se afirmar que nesse estudo as amostras
bacterianas isoladas como Enterococcus faecalis, Staphylococcus aureus,
Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii e
Pseudomonas aeruginosa apresentaram-se multirresistentes aos antibióticos
testados. O óleo essencial de C. zeylanicum B. foi efetivo como bacteriostático
sobre 92% das cepas bacterianas na CIM de 2% e 4% na CIM de 0,125%. O
óleo essencial de C. zeylanicum B. não revelou propriedades bactericidas,
quando testado nas CBM s sobre os microrganismos testes. O óleo essencial de
O. vulgare L. apresentou atividade bactericida sobre a totalidade das bactérias
Gram positivas e Gram negativas estudadas, em uma CBM de 0,5%. O efeito
bactericida do O. vulgare L. sobre bactérias multirresistentes observado no
estudo, foi um dado muito importante, visto que, os valores encontrados
assemelham-se com as drogas de última geração utilizadas na pesquisa. Na
cinética bacteriana os óleos essenciais de C. zeylanicum B. e O. vulgare L.
inibiram o crescimento dos microrganismos testados no intervalo de 0,0 a 120
minutos. Os valores antimicrobianos dos óleos essenciais testados encontrados
nos ensaios conduzem à aplicação de novas metodologias, visando à utilização
de forma racional dos mesmos na terapêutica antibacteriana.
Palavras chave: Origanum vulgare, Cinnamomum zeylanicum, infecções
bacterianas, bactérias multirresistentes
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Epidemiology and recurrence rates of Clostridium difficile infections in Germany: a secondary data analysisLübbert, Christoph, Zimmermann, Lisa, Borchert, Julia, Hörner, Bernd, Mutters, Reinier, Rodloff, Arne C. January 2016 (has links)
Clostridium difficile infection (CDI) is the most common cause of health-care-associated infectious diarrhea. Recurrence rates are as high as 20–30% after standard treatment with metronidazole or vancomycin, and appear to be reduced for patients treated with fidaxomicin. According to the literature, the risk of CDI recurrence increases after the second relapse to 30–65%. Accurate data for Germany are not yet available. Methods: Based on the research database of arvato health analytics (Munich, Germany), a secondary data analysis for the incidence, treatment characteristics and course of CDI was performed. The database included high granular accounting information of about 1.46 million medically insured patients covering the period 2006–2013, being representative for Germany. The analysis was based on new-onset CDI in 2012 in patients which either received outpatient antibiotic therapy for CDI or were hospitalized. Results: The ICD-10 coded incidence of CDI in 2012 was 83 cases per 100,000 population.
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Cornichon Proteins: Unexpected Roles in Plant Pathogen Infection, ER Morphology Maintenance and Pollen DevelopmentLi, Jianhui 17 May 2017 (has links)
Cornichon (CNI) proteins are a conserved family of proteins among eukaryotes, from Erv14 in the yeast Saccharomyces cerevisiae to CNI homologs (CNIHs) in mammals and plants. Erv14 functions as a cargo receptor of coat protein complex II (COPII) for protein trafficking from the endoplasmic reticulum (ER) to the Golgi apparatus, en route to their final destinations. By interacting with specific cargo proteins, CNI proteins regulate key steps of embryo polarity in Drosophila, budding in yeast, and synaptic transmission in the mammalian brain. However, we have very limited understanding of plant CNIHs. Positive-strand RNA viruses assemble their viral replication complexes (VRCs) at specific host organelle membranes. With a better understanding of host factors involved in targeting viral replication proteins to the preferred organelles, we expect to block trafficking of viral replication proteins and thus, viral infection, by manipulating the required host proteins. Brome mosaic virus (BMV) is a model of positive-strand RNA viruses and its replication can be recapitulated in yeast. Importantly, BMV replication protein 1a is the only required viral protein to form VRCs at the perinuclear ER membrane in yeast. I demonstrate that Erv14 and COPII coat proteins are required for targeting BMV 1a to the perinuclear ER in yeast, suggesting a novel function of COPII vesicles in protein trafficking to the perinuclear ER membrane and in the BMV VRC formation. As for cellular functions, I show that plant CNIHs complement the defective distribution of BMV 1a in yeast mutant lacking Erv14. Taking advantage of Arabidopsis thaliana knockout mutants and knockdown of gene expression in Nicotiana benthamina, I also discover that CNIHs unexpectedly play crucial roles in pollen development, infection of a bacterial pathogen, and maintenance of ER tubules. I further confirm that CNI proteins are also required for maintaining ER tubules in yeast, suggesting a novel and conserved role in shaping ER morphology. Therefore, these findings indicate the functional diversity and redundancy of CNI proteins in key cellular processes and suggest a novel strategy to control plant pathogenic viruses and bacteria by manipulating plant CNIHs. / Ph. D. / Many cellular proteins play important roles in plant development but unfortunately are hijacked by plant viral, bacterial, and/or fungal pathogens for their infections. Cornichon (CNI) proteins are a conserved family of proteins and a great example that is involved in both plant development and plant pathogen infection. CNI protein was first described in a <i>Drosophila</i> mutant. Only 3% of mutant cells survived, but showed abnormal phenotype in abdominal segmentation with a similar shape of “pickle” during embryo development. Later on, this family of proteins was well studied in yeast and mammals but rarely studied in plants. Erv14, one of CNI proteins in yeast, is a cargo receptor of coat protein complex II (COPII) vesicles that participate in cellular early secretory pathway. COPII vesicles serve as cellular carriers to recruit cargo proteins from the endoplasmic reticulum (ER) membrane and depart for the Golgi apparatus, en route to their final destinations for proper cellular processes. In this dissertation, I have discovered that Erv14 and COPII components are unexpectedly involved in targeting a replication protein of a plant RNA virus to the perinuclear ER membrane, instead of the Golgi apparatus, suggesting a novel function of COPII in targeting proteins to the perinuclear ER. Erv14 has never been shown as involved in viral infection and thus, my work has identified a new host protein required for viral infection. I have further explored the cellular functions of CNI proteins in plants, and found that plant CNI proteins play significant roles in maintaining cellular ER network, supporting normal pollen development, and bacterial pathogen infection. Therefore, plant CNI proteins function similarly as Erv14 to recruit various cargo proteins into COPII vesicles en route to their final destinations for proper cellular processes. These cellullar processes may include, but are not limited to: ER morphology maintenance, pollen development, and plant immune response to pathogen infection. Furthermore, it is possible to develop a novel strategy to make plants resistant to plant viruses and/or bacteria by manipulating plant CNIHs.
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Efeito da ativação ultrassônica da pasta de hidróxido de cálcio na atividade metabólica de bactérias em canais radiculares: Estudo clínico randomizado / Effect of the ultrasonic activation of calcium hydroxide paste on the metabolic activity of bacteria in root canals: A randomized clinical trialCazares, Roberto Xavier Romero 13 December 2018 (has links)
Protocolos complementares de desinfecção estão sendo investigados com o objetivo de promover uma maior redução de bactérias viáveis após o preparo químico-cirúrgico dos canais radiculares. Este estudo clínico randomizado comparou o efeito da ativação ultrassônica da pasta de hidróxido de cálcio com o da pasta não ativada na redução da atividade metabólica de bactérias nos canais radiculares. Vinte pacientes com necrose pulpar e periodontite apical assintomática foram alocados de forma randomizada em dois grupos de acordo com o protocolo de medicação intracanal: Grupo UA - ativação ultrassônica da pasta de hidróxido de cálcio (n=10) e Grupo NA - não ativação da pasta (n=10). Amostras microbiológicas dos canais radiculares foram coletadas após os procedimentos de: cirurgia de acesso (S1), preparo químico-cirúrgico (S2), irrigação ultrassônica passiva (PUI) (S3) e medicação intracanal entre sessões com pasta de hidróxido de cálcio, com ou sem ativação ultrassônica (S4). As amostras endodônticas foram submetidas à extração de DNA e RNA. O RNA foi submetido à reação de transcrição reversa para confecção de DNA complementar (cDNA). O efeito dos procedimentos endodônticos na redução bacteriana foi determinado por qPCR baseada em rDNA, utilizando iniciadores universais para a região 16S rRNA do domínio Bacteria. A atividade metabólica das bactérias foi calculada pela razão rRNA/rDNA baseados nos dados dos ensaios de qPCR. Bactérias foram consideradas metabolicamente ativas quando a razão era maior ou igual a 1. A análise intragrupo foi realizada pelos testes de Wilcoxon e Q de Cochran; enquanto a análise entre os grupos foi realizada pelos testes de Mann-Whitney e Exato de Fisher (P < 0,05). As amostras S1 apresentaram uma mediana de 2,38 x 106 e 1,60 x 105 cópias de rDNA nos grupos UA e NA, respectivamente. Após o preparo químico-cirúrgico houve uma redução significativa de rDNA bacteriano nos dois grupos (UA: 2,14 x 103; NA: 7,48 x 103; P < 0,01 para ambos). Porém, 80% e 90% dos casos permaneceram com bactérias metabolicamente ativas após o preparo químico-cirúrgico nos grupos UA e NA, respectivamente. A PUI contribuiu para a redução do número de canais com bactérias ativas nos dois grupos (UA: 60%; NA: 50%). No grupo UA, esse número caiu para 30% após o protocolo da medicação intracanal com ativação ultrassônica, com uma diferença significativa entre S1 e S4 (P < 0,05). Por outro lado, no grupo NA, 60% dos canais continham bactérias metabolicamente ativas. A análise entre os grupos revelou uma diferença significativa entre os protocolos de medicação intracanal quanto ao metabolismo bacteriano em S4 (P < 0,05). Concluiu-se que a ativação ultrassônica da pasta de hidróxido de cálcio foi mais efetiva do que a pasta não ativada em reduzir o metabolismo bacteriano. / Complementary disinfection protocols have been investigated with the objective of promoting a greater reduction of viable bacteria after the chemical-surgical preparation of the root canals. This randomized clinical study compared the effect of the ultrasonic activation of the calcium hydroxide paste with an nonactivated paste in reducing the metabolic activity of bacteria in the root canals. Twenty patients with pulp necrosis and asymptomatic apical periodontitis were randomized into two groups according to the intracanal medication protocol: UA group - ultrasonic activation of calcium hydroxide paste (n = 10) and NA group - no activated paste (n = 10). Microbiological samples of the root canals were collected following the procedures of: access (S1), chemical-surgical preparation (S2), passive ultrasonic irrigation (PUI) (S3) and intracanal medication with calcium hydroxide paste, with or without activation (S4). The endodontic samples were submitted to DNA and RNA extraction. RNA was subjected to the reverse transcription reaction to make complementary DNA (cDNA). The effect of endodontic procedures on bacterial reduction was determined by rDNA-based qPCR using universal primers for the 16S rRNA region of the Bacteria domain. The metabolic activity of the bacteria was calculated by the rRNA/rDNA ratio based on qPCR assay data. Bacteria were considered to be metabolically active when the ratio was positive (greater than or equal to 1). Intragroup analysis was performed by the Wilcoxon and Cochran`s Q testes; while the analysis between the groups was performed by the Mann-Whitney test and Fisher\'s exact test (P <0.05). Samples S1 presented a median of 2.38 x 106 and 1.60 x 105 copies of rDNA in the UA and NA groups, respectively. After the chemical-surgical preparation, there was a significant reduction of bacterial rDNA in both groups (UA: 2.14 x 103, NA: 7.48 x 103, P <0.01 for both). However, 80% and 90% of the cases remained with metabolically active bacteria after the chemical-surgical preparation in the UA and NA groups, respectively. PUI contributed to the reduction of the number of canals with active bacteria in both groups (UA: 60%, NA: 50%). In the UA group, this number dropped to 30%, with a significant difference between S1 and S4 (P <0.05). Analysis between the groups revealed a significant difference between intracanal medication protocols for bacterial metabolism in S4 (P <0.05). It was concluded that the ultrasonic activation of the calcium hydroxide paste was more effective than the nonactivated paste in reducing the bacterial metabolism.
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