Dissertations / Theses on the topic 'Β-defensin'
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1
Selim, Erik. "Solid-phase synthesis of Avian β-Defensin 8." Thesis, Linnéuniversitetet, Institutionen för kemi och biomedicin (KOB), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-32076.
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Differences in the expression of antimicrobial peptides in vivo have been proposed as underlying factors influencing susceptibility to infection. In this context, the role of avian b-defensins in inhibiting avian influenza infections is a study object in an ongoing collaboration with the Zoonotic Ecology and Epidemiology group at Lnu. In this report, an attempt to synthesize two variants of the peptide Anas Platyrhynchos AvBD-8, using Fmoc-based SPPS, is described. The length of AvBD-8 (43 aa) necessitated peptide synthesis in two segments to subsequently be ligated using native chemical ligation. The first component of a 19 aa segment was thus a Dbz-linker, which would allow to ligate this end with a second segment (24 aa). Halfway through the synthesis of this larger segment the batch was split into two pots, allowing the synthesis of two segments differing by one single amino acid (R for W). The composition of these segments were: Dbz-HDTSCTGGAQKCQVANNPA (Dbz-segment), SVVTRCCPIGQKCWGFARTNPPPC(boc) (W-segment), and SVVTRCCPIGQKCRGFARTNPPPC(boc) (R-segment). Crude product yields were 284,5 mg; 67,6% (Dbz-segment), 137,6 mg; 52,3% (W-segment), and 166,3 mg; 64,2%. Preliminary mass spectrometric analysis on the crude products did not indicate the presence of the desired segments in major mass peaks. Further product purification is necessary in order to allow definite conclusions, but it appears as if the synthesis has not worked. Possible explanations are either impure or degraded reactant(-s), folding or shielding effects of the growing peptide chain at some point inhibiting synthesis, or experimental errors during one or more of the many steps involved in the synthesis.
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Abujaber, Razan. "Phenotypic consequences of β-defensin copy number variation in humans." Thesis, University of Leicester, 2016. http://hdl.handle.net/2381/38814.
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Beta defensins (DEFB) at the 8p23.1 genomic location are multifunctional secreted short peptides that have antibacterial and antiviral action in many species and possess immune cell signal activity, constituting a link between innate and adaptive immunity. In humans, the β-defensin region is known to be copy number variable (CNV) and contains seven genes repeated as a block, with a diploid copy number between 1 and 12. This thesis shall explore the structural variability of the β-defensin CNV region; compare and contrast the different methods used for calling DEFB CNVs and investigate the role of CNVs of DEFB in various diseases. One of its aims is to also develop a model system to investigate if DEFB expression levels differ with CN in response to treatment with Pneumolysin by using Normal Human Bronchial Epithelial (NHBE) cells. Results from this thesis confirm that the DEFB CNV region is 322kb in length, with a polymorphic inversion that occurs at a prevalence of 30% at the 8p23.1 genomic location that is independent of the DEFB CN. Paralogue Ratio Test (PRT) proved to be the best method of genotyping DEFB CNV especially in larger cohorts. In addition, work from this thesis also founded the basis of developing an in vitro model system to investigate whether DEFB expression levels differ with CN in response to treatment with pneumolysin by using Normal Human Bronchial Epithelial (NHBE) cells. As far as case/control and cohort studies are concerned, results from this thesis show that DEFB CN is not associated with lung function in the general population and has no effect on patients with COPD and Asthma, nor does it support previous results that present an association between HIV viral load and DEFB CN. DEFB CN was also found not to be associated with recurrent UTIs in VUR patients, nor with hypertension. Data suggested that DEFB CN might be associated with BMI but this has not been reproduced in a smaller cohort.
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Ottolini, Barbara. "Evolution of copy number variation in the rhesus macaque β-defensin region." Thesis, University of Leicester, 2014. http://hdl.handle.net/2381/28961.
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Beta defensins are multifunctional secreted short peptides rapidly evolving in mammals. They present antibacterial and antiviral action in many species and possess immune cell signal activity, constituting a link between innate and adaptive immunity. In humans the β-defensin region is known to be copy number variable (CNV) and contains seven genes repeated as a block, with a diploid copy number between 1 and 12 and an approximate repeat length of 240kb but the extent and nature of CNV in other mammals remains poorly known. The rhesus macaque (Macaca mulatta) is the most widespread non-human primate, hence constituting a good model to study adaptation and its divergence time from the human lineage (~25MYA) presents enough sequence diversity to investigate mechanisms of copy number variation and evolution. Its genome has been sequenced, although there is poor assembly quality in repeated segments such as the β-defensin region. This thesis studied the genomic architecture of the rhesus macaque β-defensin region using a variety of methods (aCGH, PCR-based methods, BAC library screening and cytogenetic approaches) with the aim of overcoming the limitations of the assembly and of determining the copy number distribution for this region. Evidences are here provided that only the region containing DEFB2L gene (orthologue to human DEFB4) is CNV, with a diploid copy number between 2 and 11, with a repeat size of 20kb, while the rest of the cluster shows no variation. This could represent a case where the same area prone to copy number variation evolved to present a different copy number unit structure in two different lineages, still converging in the same copy number distribution for the possible effect of similar functional constraints. Also, evidences of non-synonymous variations are shown for the DEFB2L gene, suggestive of the different evolutionary pattern followed by the rhesus macaque β-defensin region.
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Meisch, Jeffrey P. "Human β-defensin 3 peptide is increased and redistributed in Crohn’s ileitis." Case Western Reserve University School of Graduate Studies / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=case1270735950.
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Zhang, Ke, and 张科. "Evaluation of anti-human respiratory syncytial virus effects of short interfering RNAs and β-defensin-4." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/209570.
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The human respiratory syncytial virus (hRSV) infection is a global public health burden in children aged under 2 years and immunocompromised or elderly adults. The choice for prophylaxis and therapy of hRSV infection was constrained to Palivizumab and Ribavirin. Therefore, this study aimed to develop effective anti-hRSV infection agents, such as short interfering RNA (siRNA) and β-defensin-4 (β-D-4).
Since there still is no compatible animal model to evaluate antiviral effect of anti-hRSV agents, we first attempted to establish suitable animal model. A clinical isolate of hRSV (KI-RSV-W) was adapted in BALB/c mice by serial passages. Old male mice (age > 8 months) were used for establishment of hRSV infection model, because the more efficient viral infection in lungs of the old male mice than that old female mice and young mice (age < 3 weeks). After the virus was propagated in old male mice for 20 passages, a virus variant KI-RSV-P70-4 exhibited more efficient infection/replication in the mice. Its viral load was about 100-fold higher than that of wild type strain KI-RSV-W. The infection of KI-RSV-P70-4 also caused more severe histopathological changes in lung tissues. Although KI-RSV-P70-4 could not result in death of the infected mice, both viral load and pathological change in lungs may be good indicators for evaluating antiviral effect. The mouse model and adapted hRSV strain solidly laid the foundation for evaluation of anti-hRSV agents.
We then designed and evaluated anti-hRSV effect of siRNAs. A total of 25 siRNAs targeting 4 viral genes (M2-1, NS2, N and F) were designed and their anti-hRSV effect was assessed in vitro. The results showed that 6 siRNAs respectively targeting M2-1, N and F genes exhibited higher anti-hRSV effect than that of the positive control, whereas those targeting NS2 gene did not show significant antiviral effect. The 50% inhibitory concentrations (IC50) of three most potent siRNAs (M2-1-361, N889 and F-1143) were 0.51, 2.14 and 0.64 nM, respectively.
Antiviral activity of β-D-4 against hRSV infection was evaluated in vitro and in vivo. In vitro experiments showed supreme antiviral effect with IC50 around 3.4 μg/ml when the virus was pretreated with β-D-4, but no significant inhibitory effect was observed when the cells were pretreated with β-D-4 or β-D-4 was maintained in the culture medium after viral infection. These results indicated that the inhibitory effect of β-D-4 was associated with direct interaction with the virus itself and blocked virus entry of the cells. Furthermore, a single dose (13.6 μg) of β-D-4 intratracheal (i.t.) administration in old male mice after the viral infection resulted in about 0.7 log reduce of viral load in lung tissues, while inoculation of premixed β-D-4 and the virus caused about 3 logs decrease of viral load in lungs. These results have demonstrated that β-D-4 may be an effective anti-hRSV agent.
Taken together, old male BALB/c mice might be used to establish hRSV infection model. Three siRNAs and the β-D-4 were validated as the potent anti-hRSV agents, respectively.published_or_final_version
Microbiology
Doctoral
Doctor of Philosophy
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Telford, Erica. "Dual role of three natural molecules in regulating the expression of β-defensin-3 and pro-inflammatory mediators." Thesis, Sorbonne Paris Cité, 2018. http://www.theses.fr/2018USPCC273.
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Les peptides antimicrobiens (PAMs) sont des effecteurs de la réponse innée produits et sécrétés par les cellules épithéliales intestinales. A l’interface entre l’épithélium et les microbes, ils représentent un élément important de la barrière muqueuse. Certains PAMs, tels que la bêta-défensine humaine 1 (BDH-1), sont exprimés de manière constitutive, tandis que d'autres PAMs, dont la BDH-2 et la BDH-3, sont induits par des signaux dérivés des microbes et de l'hôte. Les PAMs contrôlent la densité des bactéries commensales dans la lumière intestinale ainsi que la capacité invasive des agents pathogènes. En effet, les PAMs jouent un rôle majeur dans l’induction des réponses immunitaires innée et adaptative. Ainsi, outre leurs effets antimicrobiens et immunorégulateurs, les PAMs ont également une fonction angiogénique et anti-tumorale, entre autres. Il y a peu d’études sur la régulation des PAMs. Cependant, leur dérégulation a été associée à plusieurs pathologies humaines, notamment aux maladies inflammatoires chronique de l’intestin, ce qui souligne leur rôle majeur dans le maintien de l'homéostasie. Grâce à leurs effets multiples, les PAMs constituent une cible thérapeutique intéressante pour développer des solutions alternatives ou complémentaires aux antibiotiques afin de mieux faire face à l'émergence de maladies infectieuses et à la résistance aux antibiotiques. Enfin, les PAMs pourraient aider à rétablir l'homéostasie dans les maladies inflammatoires.À la suite d’un criblage d’une banque de molécules naturelles, notre équipe a identifié trois cibles prometteuses, l'andrographolide (AND), l'isoliquiritigénine (ISL) et l'oridonine (ORD), qui augmentent l'expression de BDH-3 sans induire celle de gènes pro-inflammatoires. Au cours de ce projet, nous avons étudié précisément l'effet de l'AND, de l'ISL et de l'ORD sur l'induction de l'expression de BDH-3 dans un modèle in vitro de cellules épithéliales intestinales. Ces molécules ont un effet inducteur non seulement individuellement mais également de manière synergique puisque la combinaison de ces molécules augmente fortement l’expression de BDH-3. En outre, AND, ISL et ORD ont réduit l'expression des gènes pro-inflammatoires IL-1β, IL-6, IL-8 et TNF-α lorsque celle-ci était induite par des stimuli inflammatoires endogènes ou bactériens. D’autres études menées par le groupe ont pour but de définir in vitro et ex vivo l’activité de ces composés et de déterminer leurs mécanismes d’actions en étudiant les voies intracellulaires impliquées.En conclusion, l’AND, l’ISL et l’ORD représentent des outils prometteurs pour étudier la régulation des PAMs et pourraient devenir des candidats thérapeutiques pour les pathologies nécessitant un renforcement de la barrière muqueuse tout en réduisant l'inflammationAntimicrobial peptides (AMPs) are innate immune effectors produced and secreted by intestinal epithelial cells at the microbe-epithelium interface, where they represent an important component of the mucosal barrier. Some AMPs, such as human beta defensin (HBD)-1, are constitutively expressed, while others, including HBD-2 and HBD-3, are induced by a broad range of microbial- and host-derived signals. AMPs control the density of luminal commensal bacteria and invasive capacities of pathogens and have a role in perpetuating the innate immune response and inducing the adaptive response. Indeed, they present antimicrobial, immunoregulatory, angiogenic and anti-tumor effects, among the others. Little is known about regulation of AMP expression, but its deregulation has been associated with several human pathologies, including inflammatory bowel diseases, highlighting their crucial role in maintaining the homeostasis. Due to their multifaceted activities, AMPs represent an appealing therapeutic target for developing novel or complementary solutions to antibiotics, to face the emergence of infectious diseases in public health and the crisis of antimicrobial resistance, and to help re-establishing homeostasis in inflammatory diseases.By screening a bank of natural molecules, our team identified three promising targets, andrographolide (AND), isoliquiritigenin (ISL) and oridonin (ORD), which increase the expression of HBD-3 without inducing pro-inflammatory genes. This project thoroughly studied the effect of AND, ISL and ORD on inducing expression of HBD-3 in an in vitro model of intestinal epithelial cells. These molecules not only produced this effect when used alone, but also acted synergistically, highly inducing the expression of HBD-3 when used in combination. Moreover, AND, ISL and ORD hindered the expression of the pro-inflammatory genes IL-1β, IL-6, IL-8 and TNF-α upon stimulation of cells with endogenous or bacterial inflammatory stimuli. Further studies conducted by the group aimed at characterizing the activity of the compounds in vitro and ex vivo and unravelling their mechanisms of action by studying the intracellular pathways involved.In conclusion, AND, ISL and ORD represent useful tools to study the regulatory network controlling expression of AMPs and might develop to be candidate drugs for pathologic conditions in which strengthening the mucosal barrier, while reducing inflammation, is needed
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Steiner, Tamara Alice [Verfasser]. "Die Bedeutung des humanen β-Defensin-3 für die Infektion von humanem respiratorischem Epithel mit Moraxella catarrhalis / Tamara Alice Steiner." Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2014. http://d-nb.info/1052221475/34.
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Pahl, René [Verfasser]. "Rolle von IL-1β und ADAM17 in der Regulation der β-Defensin-Antwort im Rahmen der Candida-Ösophagitis / René Pahl." Kiel : Universitätsbibliothek Kiel, 2013. http://d-nb.info/1041255527/34.
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Reynolds, Natalie Louise. "Functional studies of vertebrate β-defensins." Thesis, University of Edinburgh, 2011. http://hdl.handle.net/1842/27262.
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The β-defensins are a family of small, cationic antimicrobial peptides. They are conserved in a variety of species ranging from lower vertebrates to mammals and plants, and were first identified for their broad-spectrum antimicrobial activity. Since their initial discovery, this role has broadened to include a number of diverse additional functions including the chemotaxis of immune cells (immature dendritic cells, macrophages and CD4+ T cells), the determination of coat colour in dogs and seed maturation in tomatoes. The aim of this thesis is to investigate the function of vertebrate beta-defensins. I address this question by assessing how mouse β-defensin structure affects its bactericidal activity and also by carrying out β-defensin knockdown studies in zebrafish. In this work, I address the question of how β-defensin structure affects its bactericidal activity by examining the effects of sequentially removing amino acids from the N-terminal of murine Defbl4. I show that these deletions reduce bactericidal activity however the effects are much more striking in gram positive species than gram negative. Through the comparison of monomeric and dimeric species as well as analysis of peptide charge and hydrophobicity, this work indicates that a combination of primary sequence and structure is responsible for the bactericidal properties of this peptide. In addition, this thesis describes the characterisation of three β-defensin-like peptides (Defbll, Defbl2 and Defbl3) previously described in zebrafish. I utilise antimicrobial assays to determine the bactericidal properties of synthetic Defbl2 and Defbl3 against a panel of microbes and also show that Defbll is antimicrobially inactive. Furthermore, this work identifies the expression of defbl1 during zebrafish gastrulation and utilises a combination of wholemount in situ hybridisation, morpholino knockdown and rescue and microarray analysis to ascertain a novel essential role for this peptide in early development. This work is the first report of a β-defensin being involved in vertebrate development and presents a further widening of the influence of the defensin family.
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Rolfe, Mark J. "The antibacterial and chemoattractant activities of murine β-defensins." Thesis, University of Edinburgh, 2003. http://hdl.handle.net/1842/27300.
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Antimicrobial peptides form an important aspect of the innate immune response of mammals. They function to kill invading microorganisms and in many cases activate other aspects of the innate and adaptive immune systems. One of the largest families of antimicrobial peptides is the defensins. In vertebrates, there are three subfamilies of defensins, termed α, β and θ based on the connectivity of the six conserved cysteines. The β-defensins, which are produced mainly by epithelial tissues and keratinocytes, came to wider interest when it was proposed that their loss of function might play a role in the pathogenesis of cystic fibrosis (CF) lung disease. Previous work has suggested that the airway surface liquid (ASL) of primary cultures of human airway epithelial cells possess salt-sensitive antibacterial activity and that this is impaired in CF individuals by elevated levels of sodium chloride. Further work has also suggested that the β-defensins secreted by the airway epithelia might comprise an important component of this salt-sensitive defence system. The aim of this project was 1) to characterise the salt-sensitive antibacterial activity of members of the human and murine β-defensin subfamily, 2) to analyse their activity as chemoattractants, 3) to establish a cell culture-based system for the production of β-defensins to allow for greater analysis of their range of activities and 4) to verify the validity of novel human β-defensins identified by bioinformatics techniques. In this thesis describes the characterisation of the salt-sensitive activities of synthetic human β-defensin 2 (DEFB2), mouse β-defensin2 (Defb2), and a novel β-defensin related 1, Defrl, which lacks the first of the canonical six cysteines are described against a range of CF-related pathogens. This work has concluded that a) DEFB2, Defb2 and Defrl display, to varying degrees, salt-sensitive antibacterial activity, b) The differences observed between the activities of the peptides may represent the evolution of species-specific profiles of antibacterial activity for specific defensins. c) That the loss of in Defrl of the first canonical cysteine does not result in loss of antibacterial activity and, most interestingly, Defrl also demonstrates activity against B. cenocepacia - a pathogen normally resistant to the activity of antimicrobials. Data presented in this thesis also suggests that synthetic Defb2 and Defrl show chemotactic activity to CD4+ T-lymphocytes and to immature dendritic cells. This work concludes that, like human β-defensins 1 and 2, the murine β-defensins, Defb2 and Defrl, can act as a bridge between the innate and adaptive immune systems. In this thesis, expression pattern of five novel human β-defensins in a range of human tissues is also analysed. Evidence is presented that they are all expressed at high levels in the testis and that two of these genes are expressed at much lower levels a variety of other tissues. These data suggest that the β-defensins are an expanding, and potentially quite large, subfamily of genes, many of which are yet to be characterised in terms of their expression profile and the antimicrobial and chemotactic activities.
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Syed, Mobin. "Role of human β-defensins in human burn wounds." Thesis, University of Westminster, 2009. https://westminsterresearch.westminster.ac.uk/item/90zx8/role-of-human-defensins-in-human-burn-wounds.
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Background - Burns is a complex condition requiring assessment and addressing of both the wound and the patient in a holistic way. In spite of tremendous improvements in burn care, infection continues to remain an important cause of morbidity and mortality. Human Β Defensins (HBD) are a group of recently discovered antimicrobial peptides. The main subtypes include HBD1, 2 and 3 and are individually known to have other functions apart from being anti-microbial. Some of these are inherently expressed while others are induced in response to microbial challenge. Aims - The aim of the current PhD was to understand the pattern of expression of HBDs in acute burns, their source of expression, and factors influencing the expression, with a view to use these peptides as therapeutic agents in future. Methods - The expression of HBD1, 2 & 3 was determined at mRNA and protein levels in acute burn wounds of different burn durations, using real time rt-PCR and immunohistochemistry, respectively. The influence of type and quantity of bacteria, contribution from blood cells and the influence of stress on HBD expression was determined in separate clinical situations similar to those seen in major burns. Results - The results show that HBD1, 2 and 3 mRNA is highly expressed in both early and late burns, but a parallel increase is not reciprocated at protein levels. The bacteria isolated from the burn wounds showed a trend changing from colonising organisms to more resistant forms in time, however no significant correlation with HBD was established. Peripheral blood cells produced HBD in response to inflammatory mediator’s in-vivo, thus suggesting to a possible contribution of HBD 1, 2 and 3 from blood cells in granulating burn wounds. There was no down regulation of HBD1, 2 and 3 in the presence of increased cortisol levels – a reflection of heightened stress as seen in burns. HBD1 and 3 mRNA expressions showed an early up-regulation, followed by elevation in HBD2 mRNA levels. There was no HBD2 mRNA and protein expression in keloid tissue specimens from various parts of the body. The absence of HBD2 – a unique intrinsic peptide with an ability to trigger the anti-fibrotic cytokines suggests to the possibility that HBD’s are implicated in the pathogenesis of keloids, which are usually associated with burn scars. Conclusion - The studies suggest a possible role of HBD in the pathogenesis of burn wounds and the potential to use these as therapeutic peptides to prevent infections and scarring associated with burns.
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De, Cecco Martin. "Biophysical studies to elucidate structure-activity relationships in β-defensins." Thesis, University of Edinburgh, 2011. http://hdl.handle.net/1842/4931.
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β-defensins are a class of mammalian defence peptides with therapeutic potential because of their ability to kill bacteria and attract host immune cells. In order to realise this potential, it is necessary to understand how the functions of these peptides are related to their structures. This thesis presents biophysical analysis of β- defensins and related peptides in conjunction with biological assays. These studies provide new insights into the structure-activity relationships of β-defensins. Ion mobility-mass spectrometry (IM-MS) is used throughout this thesis to probe the tertiary structure of peptides in vacuo and, by inference, make conclusions about their conformations in solution prior to ionisation. Where appropriate, IM-MS is complemented by other techniques, including high performance liquid chromatography and circular dichroism spectroscopy. First, the importance of a C-terminal cysteine residue within the murine β-defensin Defb14 is investigated. The functional and structural implications of chemically modifying the cysteine residue are examined. Second, the N-terminal region of Defb14 is modified by the substitution and deletion of amino acids. Again, the effects on biological activity and structure are discussed. Finally, the functional and structural overlap of β-defensins with another family of proteins – the chemokines – is considered. The oligomerisation of β-defensins and their interaction with glycosaminoglycans is of particular interest: structural data for human β-defensins 2 and 3 in the absence and presence of polysaccharides are presented.
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ALMEIDA, Felipe Rodrigues de. "Associação dos polimorfismos da β-defensina 1 em pacientes com periodontite crônica." Universidade Federal de Pernambuco, 2017. https://repositorio.ufpe.br/handle/123456789/25457.
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Variações genéticas do gene que codifica as β-defensinas podem influenciar a susceptibilidade às infecções, inclusive à periodontite crônica. Este estudo teve como objetivo, verificar a associação de polimorfismos genéticos da β-defensina 1 (-52; -44; -20) em pacientes portadores de periodontite crônica comparados à periodontalmente saudáveis. Nesta análise clínico-laboratorial, participaram pacientes provenientes das clínicas integrais do curso de Odontologia da Universidade Federal de Pernambuco (UFPE) e dos ambulatórios do Hospital Agamenon Magalhães (HAM), no período de novembro de 2015 a outubro de 2016, os quais obedeceram os critérios de inclusão e exclusão adotados. Os participantes foram divididos em 02 grupos: portadores de periodontite crônica (GP=95) e periodontalmente saudáveis (GC=69). Inicialmente foram coletados dados sóciodemográficos (nome, idade, gênero, estado civil, renda salarial, escolaridade) e clínicos dos pacientes (profunidade de sondagem (PS), nível de inserção clínica (NIC) e índice de sangramento à sondagem (ISS)). Além disso, foram coletadas amostras de saliva total espontânea, as quais foram submetidas à isolamento e purificação do ADN e genotipagem por reação em cadeia da polimerase em tempo real (RCP-TR), para verificação da presença de polimorfismos de única base (SNPs) da β-defensina 1(-52; -44; -20). O teste exato de Fisher foi utilizado para verificar associações entre os dados de PS, NIC e ISS e os genótipos investigados. O nível de significância adotado foi de 5% e intervalo de confiança de 95%. Ambos os polimorfismos da β-defensina 1 (-52, -44 e -20) foram observados em pacientes com periodontite crônica, contudo, apenas o SNP (-20) apresentou diferença estatística entre os grupos GP e GC (p<0,05). Para o SNP (-20), o alelo A apresentou-se em mais da metade do GP (p<0,000) e o genótipo AA foi mais frequente neste grupo (p<0,000). Verificou-se que a razão de chances de um paciente com periodontite crônica apresentar o genótipo AA foi 14,15 vezes maior do que em periodontalmente saudáveis. Quanto à freqüência haplotípica, a maior freqüência foi de GCA (p<0,000), seguido de ACA no grupo GP (p<0,000). Apenas o genótipo GG do SNP (-44) apresentou resultado significativo para a variável NIC (p<0,017). Portanto, o estudo sugere que o SNP (-20) parece influenciar na predisposição da periodontite crônica, sendo o genótipo AA mais presente nos indivíduos com periodontite crônica, assimo como, os haplótipos GCA e ACA estão mais presentes em pacientes com periodontite crônica comparados a periodontalmente saudáveis.
Genetic variations of gene that encoding β-defensins may influence the susceptibility to infections, including chronic periodontitis. This study aimed to verify the association of genetic polymorphisms of β-defensin 1 (-52; -44; -20) in patients with chronic periodontitis compared to periodontally healthy. In this clinical-laboratorial analysis participated in the study patients from dental clinics of Federal University of Pernambuco (FUPE) and outpatient clinics of Agamenon Magalhães Hospital (AMH), from november 2015 to october 2016, which obeyed the inclusion and exclusion criteria adopted. Participants were divided into 2 groups: patients with chronic periodontitis (PG = 95) and periodontally healthy (CG = 69). Initially, were collected socio-demographic data (name, age, gender, marital status, salary income, schooling) and clinical status of the patients (depth of probing (DP), clinical insertion level (CIL) and bleeding probing index (BPI)). In addition, samples of spontaneous total saliva were collected, which were submitted to DNA isolation and purification and genotyping by real-time polymerase chain reaction (RT-PCR) to verify the presence of single-base polymorphisms (SNPs) of β-defensin 1 (-52; -44; -20). The Fisher´s exact test was used to verify associations between DP, CIL and BPI data and the investigated genotypes. The significance level was 5% and 95% confidence interval. Both polymorphisms of β-defensin 1 (-52; -44; -20) were observed in patients with chronic periodontitis; however, only SNP (-20) presented statistical difference between PG and CG groups (p <0.05 ). For SNP (-20), “A” allele was present in more than half of PG (p <0,000) and “AA” genotype was more frequent in this group (p <0.000). It was verified that the odds ratio of a patient with chronic periodontitis presenting “AA” genotype was 14.15 times higher than periodontally healthy subjects. As to the haplotype frequency, the highest frequency was “GCA” (p <0.000), followed by “ACA” in PG group (p <0.000). Only “GG” genotype of SNP (-44) presented a significant result for CIL variable (p <0.017). Therefore, the study suggests that SNP (-20) seems to influence the predisposition of chronic periodontitis, with “AA” genotype being more present in individuals with chronic periodontitis, as “GCA” and “ACA” haplotypes are more present in patients with chronic periodontitis compared to periodontally healthy.
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Anhuef, Ole [Verfasser]. "Antimikrobielle Wirkung des humanen β-Defensins 2 gegen Escherichia coli / Ole Anhuef." Tübingen : Universitätsbibliothek Tübingen, 2021. http://d-nb.info/1237684323/34.
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DIAS, Rayanne Soraia Aguiar de Melo. "Análise dos polimorfismos da β-defensina-1 em diabéticos tipo 2 com periodontite crônica." Universidade Federal de Pernambuco, 2017. https://repositorio.ufpe.br/handle/123456789/25650.
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A íntima relação entre Diabetes Mellitus (DM) e Periodontite Crônica (PC) é foco de várias investigações na literatura. Alguns mecanismos fisiopatológicos explicam essa relação; porém, o papel de variações genéticas em genes relacionados a resposta imune inata, neste contexto, ainda não é claro e se mostra como um caminho para trazer novas informações. Considerando a importância do gene da β-defensina-1 na imunidade inata, primeira linha de defesa do organismo contra infecções, e supondo que polimorfismos de única base (SNPs) neste podem influenciar a susceptibilidade às infecções, o presente trabalho teve como objetivo avaliar a distribuição de SNPs funcionais do gene DEFB1 em indivíduos com diabetes mellitus tipo 2 (DM2) com PC e indivíduos saudáveis (controles), além da sua possível associação com o desenvolvimento de PC em portadores de DM2. Ao todo, 185 indivíduos participaram do estudo, sendo 116 com DM2 e PC e 69 indivíduos saudáveis para essas duas condições (grupo controle). Três SNPs funcionais (-52 G>A [rs1799946], -44 C>G [rs1800972] e -20 G>A [rs11362]) foram genotipados pela técnica de Reação em Cadeia da Polimerase (PCR) em tempo real, usando sondas alelo específicas (TaqMan®). As distribuições dos genótipos nos SNPs de DEFB1 estavam condizentes com o Equilíbrio de Hardy-Weinberg, exceto para o SNP rs1800972 nos indivíduos controles. Os resultados mostraram uma associação significativa para o SNP na posição -20 G>A de DEFB1. O alelo G e os genótipos GA e GG foram significativamente (p<0.05) mais frequentes entre indivíduos DM2 com PC (59,5%, 50% e 34,5%, respectivamente) que indivíduos saudáveis (26,8%, 36,2% e 8,7%, respectivamente). Quanto aos haplótipos, observou-se que as combinações GCG e ACG (-52,-44,-20) também foram mais frequentes entre os indíviduos DM2 com PC (28% e 23,3%, respectivamente) que em indivíduos controles (15,2% e 6,5%, respectivamente). Adicionalmente, também verificou-se associações significativas da distribuição dos genótipos do SNP na posição -20 em relação a severidade (p=0.021) e a classificação da PC (0.046). Diante disso, sugere-se que o alelo G, os genótipos GA e GG no SNP -20 G>A e os haplótipos GCG e ACG podem estar associados com uma maior susceptibilidade para o desenvolvimento de PC em diabéticos tipo 2 em uma população do nordeste do Brasil.
The close relation between Diabetes Mellitus (DM) and Chronic Periodontitis (CP) is the focus of several investigations in the literature. Some pathophysiological mechanisms explain this relation; nevertheless, the role of genetic variations in genes related to innate the immune response, in this context, is still not clear and has shown to be a way to bring new information. Considering the importance of the β-defensin-1 gene in the innate immunity, the first line of defence against infections, and assuming that single base polymorphisms (SNPs) in this gene could influence on the susceptibility to infections, the current study aimed evaluate the distribution of functional SNPs of DEFB1 gene in DM type 2 individuals with CP and healthy individuals (controls) and their possible association with the development of CP in type 2 DM carriers. Altogether, 185 individuals participated in this study, of which 116 were type 2 DM and CP carriers, and 69 were healthy individuals in what regards both conditions studied (control group). Three functional SNPs (-52 G>A [rs1799946], -44 C>G [rs1800972] e -20 G>A [rs11362]) were genotyped by the real-time polymerase reaction (PCR) technique using specific allele probes (TaqMan®). The distributions of the genotypes in the DEFB1 SNPs were consistent with the Hardy-Weinberg Equilibrium, except for the SNP rs1800972 in the control individuals. Results showed a significant association for the SNP at the -20 G>A position of DEFB1. The G allele and GA and GG genotypes were significantly (p<0.05) more frequent among DM2 individuals with CP (59.5%, 50% and 34.5%, respectively) than healthy individuals (26.8%, 36.2% and 8.7%, respectively). Regarding the haplotypes, it was observed that the GCG and ACG combinations (-52, -44, -20) were also more frequent among PC type 2 DM patients with PC (28% and 23.3%, respectively) than in controls (15.2% and 6.5%, respectively). In addition, we also found significant associations of the distribution of the SNP genotypes at position -20 in relation to severity alone (p=0.021) and PC severity / extension (p=0.046). Therefore, it is suggested that the G allele, the GA and GG genotypes in the -20 G>A SNP and the GCG and ACG haplotypes may be associated with a greater susceptibility to the development of PC in type 2 diabetics in a population in the northeast of Brazil.
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Luya, Estrada Leys Anita [Verfasser]. "Die Expression von β-Defensinen in menschlichen Haarfollikeln / Leys Anita Luya Estrada." Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2017. http://d-nb.info/1133492797/34.
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Noda, Nathália Mayumi [UNESP]. "β Defensinas em membranas corioamnióticas de gestações complicadas por prematuridade: expressão gênica e imunolocalização." Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/95862.
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000750044.pdf: 1066568 bytes, checksum: b9c9827836a3a05f6103e4c726fd72d6 (MD5)Eventos inflamatórios na interface mateno-fetal estão pronunciados em gestações complicadas por prematuridade e a corioamnionite é reconhecida como a principal causa de morbimortalidade perinatal. As membranas corioamnióticas desempenham papel fundamental na imunidade inata local e inibem o crescimento de micro-organismos, em parte, pela expressão de β defensinas humanas (HBDs). Essas moléculas são antimicrobianos naturais que apresentam atividade antibatcteriana, antifúngica e antiviral e são produzidas por células epiteliais. Quantificar a expressão gênica e avaliar a imunolocalização de HBD-1, HBD-2 e HBD-3 em membranas corioamnióticas de gestações complicadas por prematuridade. Trata-se de um estudo prospectivo e transversal. Fragmentos das membranas corioamnióticas foram coletadas de gestantes atendidas no Serviço de Obstetrícia do Hospital das Clínicas da Faculdade de Medicina de Botucatu, UNESP, Botucatu, São Paulo, Brasil. O grupo estudo foi constituído por 25 membranas corioamnióticas de gestantes em Trabalho de Parto Prematuro na presença ou não de Rotura Prematura de Membranas Pré-Termo que tiveram parto prematuro como desfecho gestacional. Como grupo controle, 27 membranas corioamnióticas de gestações de termo em trabalho de parto foram analisadas. Fragmentos das membranas corioamnióticas foram fixadas em formalina a 10%, embebidas em parafina e seccionadas para análise da imunolocalização de HBD-1, HBD-2 e HBD-3 pela técnica de imunoistoquímica. Outros fragmentos das membranas corioamnióticas foram congelados em nitrogênio líquido e submetidos à extração do RNA total para posterior quantificação da expressão de RNAm de HBD-1, HBD-2 e HBD-3 empregando-se a técnica de PCR em tempo real utilizando o sistema TaqMan Gene Expression Assays (Applied Biosystems). Os resultados obtidos no estudo foram submetidos aos testes z e de Mann Whitney. O software empregado...
Inflammatory events can be pronounced in the maternal-fetal interface in pregnancies complicated by prematurity and chorioamnionitis is a major cause of perinatal morbidity and mortality. The chorioamniotic membranes play fundamental role in the local innate immunity and inhibit the microorganisms growth, partly by the expression of human β defensins (HBDs). These molecules are natural antimicrobials that present antibacterial, antifungal and antiviral activities and are produced by epithelial cells. To quantify the expression and to evaluate the immunolocalization of HBD-1, HBD-2 and HBD-3 in chorioamniotic membranes from pregnancies complicated by prematurity. This was a prospective controlled study. Fragments of chorioamniotic membranes were collected from pregnant women admitted at the Obstetrics Unit of the Clinical Hospital of the Botucatu Medical School, São Paulo State University, Botucatu, São Paulo, Brazil. The study group consisted of 25 chorioamniotic membranes samples from pregnant women with preterm labor, in the presence or not of Preterm Premature Rupture of Membranes (PPROM), who delivery prematurely. In the control group, 27 chorioamniotic membranes from pregnancies at term in the presence at labor were analysed. Samples of the chorioamniotic membranes were fixed in 10% formalin, embedded in paraffin and sectioned for immunolocalization of HBD-1, HBD-2 and HBD-3 by immunohistochemistry technique. Other chorioamniotic membranes samples were collected in liquid nitrogen and total RNA was extracted to quantify mRNA expression of HBD-1, HBD-2 and HBD-3 using real time quantitative PCR employing the TaqMan Gene Expression Assays (Applied Biosystems). Statistical analyses were performed using z and Mann Whitney tests in SigmaStat Software and the level of significance adopted was of 5%. In relation to demographic and obstetrics data no statistically significant difference concerning maternal ...
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Noda, Nathália Mayumi. "β Defensinas em membranas corioamnióticas de gestações complicadas por prematuridade : expressão gênica e imunolocalização /." Botucatu, 2013. http://hdl.handle.net/11449/95862.
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Orientador: Márcia Guimarães da SilvaBanca: Rosane Ribeiro Figueiredo Alves
Banca: Luciane Alarcão Dias Melício
Resumo: Eventos inflamatórios na interface mateno-fetal estão pronunciados em gestações complicadas por prematuridade e a corioamnionite é reconhecida como a principal causa de morbimortalidade perinatal. As membranas corioamnióticas desempenham papel fundamental na imunidade inata local e inibem o crescimento de micro-organismos, em parte, pela expressão de β defensinas humanas (HBDs). Essas moléculas são antimicrobianos naturais que apresentam atividade antibatcteriana, antifúngica e antiviral e são produzidas por células epiteliais. Quantificar a expressão gênica e avaliar a imunolocalização de HBD-1, HBD-2 e HBD-3 em membranas corioamnióticas de gestações complicadas por prematuridade. Trata-se de um estudo prospectivo e transversal. Fragmentos das membranas corioamnióticas foram coletadas de gestantes atendidas no Serviço de Obstetrícia do Hospital das Clínicas da Faculdade de Medicina de Botucatu, UNESP, Botucatu, São Paulo, Brasil. O grupo estudo foi constituído por 25 membranas corioamnióticas de gestantes em Trabalho de Parto Prematuro na presença ou não de Rotura Prematura de Membranas Pré-Termo que tiveram parto prematuro como desfecho gestacional. Como grupo controle, 27 membranas corioamnióticas de gestações de termo em trabalho de parto foram analisadas. Fragmentos das membranas corioamnióticas foram fixadas em formalina a 10%, embebidas em parafina e seccionadas para análise da imunolocalização de HBD-1, HBD-2 e HBD-3 pela técnica de imunoistoquímica. Outros fragmentos das membranas corioamnióticas foram congelados em nitrogênio líquido e submetidos à extração do RNA total para posterior quantificação da expressão de RNAm de HBD-1, HBD-2 e HBD-3 empregando-se a técnica de PCR em tempo real utilizando o sistema TaqMan Gene Expression Assays (Applied Biosystems). Os resultados obtidos no estudo foram submetidos aos testes z e de Mann Whitney. O software empregado ...
Abstract: Inflammatory events can be pronounced in the maternal-fetal interface in pregnancies complicated by prematurity and chorioamnionitis is a major cause of perinatal morbidity and mortality. The chorioamniotic membranes play fundamental role in the local innate immunity and inhibit the microorganisms growth, partly by the expression of human β defensins (HBDs). These molecules are natural antimicrobials that present antibacterial, antifungal and antiviral activities and are produced by epithelial cells. To quantify the expression and to evaluate the immunolocalization of HBD-1, HBD-2 and HBD-3 in chorioamniotic membranes from pregnancies complicated by prematurity. This was a prospective controlled study. Fragments of chorioamniotic membranes were collected from pregnant women admitted at the Obstetrics Unit of the Clinical Hospital of the Botucatu Medical School, São Paulo State University, Botucatu, São Paulo, Brazil. The study group consisted of 25 chorioamniotic membranes samples from pregnant women with preterm labor, in the presence or not of Preterm Premature Rupture of Membranes (PPROM), who delivery prematurely. In the control group, 27 chorioamniotic membranes from pregnancies at term in the presence at labor were analysed. Samples of the chorioamniotic membranes were fixed in 10% formalin, embedded in paraffin and sectioned for immunolocalization of HBD-1, HBD-2 and HBD-3 by immunohistochemistry technique. Other chorioamniotic membranes samples were collected in liquid nitrogen and total RNA was extracted to quantify mRNA expression of HBD-1, HBD-2 and HBD-3 using real time quantitative PCR employing the TaqMan Gene Expression Assays (Applied Biosystems). Statistical analyses were performed using z and Mann Whitney tests in SigmaStat Software and the level of significance adopted was of 5%. In relation to demographic and obstetrics data no statistically significant difference concerning maternal ...
Mestre
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Weber, Augusto. "Maturação espermática no epidídimo suíno: análise proteômica do espermatozoide e regulação hormonal da expressão de β-defensinas." reponame:Repositório Institucional da UNIVATES, 2016. http://hdl.handle.net/10737/1580.
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A maturação espermática, que ocorre no epidídimo, é etapa essencial para a aquisição de características necessárias a fertilização in vivo. Durante o transito epididimário o espermatozoide sofre uma série de alterações que transformam uma célula imatura, com pouca capacidade fertilizante, em uma célula matura, apto a fertilizar. O conhecimento das proteínas presentes no espermatozoide de suínos obtidos da cauda do epidídimo e a relação de β-defensinas, proteínas relacionadas com imunidade e reprodução, em testículo e epidídimo de suínos imunizados contra o GnRH, pode esclarecer os mecanismos envolvidos na maturação epididimária. O presente trabalho foi subdivido em dois experimentos, sendo o primeiro relacionado com a proteômica do espermatozoide suíno retirado da cauda do epidídimo, com objetivo de identificar e descrever as proteínas, bem como a relação destas proteínas em vias metabólicas. Foram identificadas 1681 proteínas, através da ferramenta MudPIT, sendo realizadas análises de bioinformática para a descrição dos processos biológicos, componentes celulares e função molecular, bem como foram agrupadas as proteínas em mapas metabólicos. A identificação destas 1681 proteínas permite a formação de um banco de dados para posteriores pesquisas aplicadas. O segundo experimento, que trata da expressão das β-defensinas em epidídimo de suínos imunizados contra o GnRH, objetiva compreender a expressão gênica de β-defensinas em modelo animal de depleção androgênica. Os dados obtidos indicam que a expressão das β-defensinas é maior nos animais imunizados contra o GnRH, sugerindo assim que as β-defensinas sejam andrógeno dependentes. Estes resultados podem ser utilizados no desenvolvimento de biotecnologias aplicadas a reprodução animal, auxiliando assim na melhoria dos índices produtivos e reprodutivos.
Sperm maturation, which occurs on epididymis, is essential to the acquisition of needed characteristics for in vivo fertilization. During the epididymal transit, spermatozoa undergo a series of alterations that transform an immature cell with few fertilizing ability, in a mature cell, with fertilization capacity. The knowledge of proteins presents on boar spermatozoa taken from epididymis cauda and the relationship of β-defensins, proteins related to immunity and reproduction, on testis and epididymis of boars immunized against GnRH, can explain the mechanisms involved on epididymal maturation. The present work was subdivided in two experiments, being the first related with proteomics of boar spermatozoa taken from epididymis cauda, which aim to identify and describe the proteins, besides your relationship with metabolic routes. Were identified 1681 proteins, through MudPIT technology, carried out analyzes of biological process, cellular component and molecular function, grouping this proteins in metabolic routes. The identification of 1681 proteins allow a formation of databank for applied future researches. The second experiment, expression of β-defensins in testis and epididymis of boars immunized against GnRH, aim to understand the genic expression of β-defensins in animal model of androgen depletion. This data indicate that expression of β-defensins is higher on immunized boars, suggesting that porcine β-defensins are dependent of androgens. This results can be utilized to development animal reproductive applied biotechnologies, helping to improve productive and reproductive indices.
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Böhling, Arne [Verfasser]. "Biophysikalische Untersuchungen an bakteriellen Modellmembranen bezüglich ihrer lateralen Organisation und der Interaktion mit humanen β-Defensinen / Arne Böhling." Kiel : Universitätsbibliothek Kiel, 2008. http://d-nb.info/1019670266/34.
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Hinrichsen, Kerstin [Verfasser]. "In-vitro- und In-vivo-Untersuchungen zur Bedeutung der β-Defensine 3 und 14 in der kutanen Erregerabwehr der Maus / Kerstin Hinrichsen." Kiel : Universitätsbibliothek Kiel, 2009. http://d-nb.info/1019811145/34.
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NUNES, Maria Julliana Galvão. "Análise da expressão do TNF-α, β-Defensinas 2 e 3 e proteína p16 na mucosa anal de pacientes infectados pelo Papilomavírus humano." Universidade Federal de Pernambuco, 2017. https://repositorio.ufpe.br/handle/123456789/25395.
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A incidência de carcinoma anal e lesões precursoras relacionadas tem aumentado no mundo, em homens e mulheres e a infecção persistente pelo Papilomavírus humano (HPV) desempenha um papel fundamental na carcinogênese anal. Os fatores de risco para o desenvolvimento de câncer anal incluem intercurso anal, múltiplos parceiros e infecção cervical pelo HPV. Desta forma, o objetivo deste estudo foi avaliar a infecção simultânea pelo HPV na mucosa cervical e anal e elucidar a associação entre a expressão local da proteína p16, β-defensina-2 e 3 e TNF-α (fator de necrose tumoral alfa) na mucosa anal e o grau de lesões anais associadas ao HPV. O grupo de estudo foi constituído por mulheres sexualmente ativas, com idade entre 18 e 60 anos. A coleta de células foi realizada a partir da mucosa cervical e anal com escova ginecológica, seguida de exame de colposcopia e anuscopia. O DNA foi extraído de amostras de células anais e cervicais e a PCR convencional foi realizada para detectar presença de HPV (tipos: 6, 16, 18, 31 e 33). A PCR em tempo real foi realizada utilizando primers específicos para a β-defensina 2, 3 e TNF-α. Os fragmentos de biopsia foram submetidos a coloração hematoxilina-eosina de rotina para a avaliação histológica e reação imunohistoquímica utilizando anticorpo anti-p16. Neste estudo, a positividade para p16 foi associada ao grupo com neoplasia, estatisticamente significativo (p = 0,0002) e padrão contínuo foi predominante. Cerca de 75% dos pacientes com neoplasia foram positivos para HPV e p16. Verificou-se alta taxa de infecção por HPV nas mucosas anal (70,52%), cervical (74,73%) e infecção simultânea cervical e anal (54,73%). A infecção simultânea (mucosa anal e cervical) pelo mesmo tipo de HPV foi observada em 17,30% dos pacientes. Entre os tipos de HPV identificados, o genótipo predominante nas amostras anal e cervical foi HPV6 (26,38%) e (19,71%), respectivamente. Nossos resultados também mostraram uma diminuição da expressão de TNF-α em lesões anais de alto grau em comparação com o normal HPV-positivo (p <0,0001), enquanto que os níveis de expressão de β-defensina 3 aumentaram em pacientes de alto grau (p = 0,0009). A aquisição de infecção simultânea anal e cervical pode ocorrer por diferentes meios, mostrando que o canal anal é uma fonte de infecção.
The incidence of anal carcinoma and related precursor lesions have been increasing worldwide for both men and women. The human papillomaviruses (HPVs) play a fundamental role in anal carcinogenesis, through persistent infection. Women with cervical cancer and history anal intercourse have an increased risk of anal cancer. The aim of this study was to evaluate simultaneous HPV infection in cervical and anal mucosa and to elucidate the association between p16 protein, β-defensin-2, 3 and TNF-α (tumor necrosis factor alpha) expression local in the anal mucosa and the degree of HPV-associated anal lesions. Study group was composed of sexually active immunocompetent women. Cells collection was performed from cervical and anal mucosa with a brush, followed by anuscopy and colposcopy exam. DNA was extracted from anal and cervical cell samples and PCR was performed to detect HPV presence (types: 6, 16, 18, 31 and 33). Real-time PCR was performed using specific primers to β-defensin 2, 3 and TNF-α. Biopsy fragments were subjected to routine hematoxylin-eosin staining for the histological assessment and immunohistochemistry reaction using anti-p16 antibody. In our study, positivity for p16 was frequently associated with group with neoplasia, statistically significant (P = 0.0002) and continuous pattern was predominant. About 75% of patients with neoplasia were positive for HPV and p16. A high rate of HPV infection in anal (70.52%), cervical (74.73%) and simultaneous cervical and anal mucosa (54.73%) was found. Simultaneous infection (anal and cervical mucosa) by the same type HPV was observed in 17.30% of the patients. Among all HPV types identified, the predominant genotype in anal and cervical samples was HPV6 (26.38%) and (19.71%), respectively. Our findings also showed a decreased TNF-α expression in high-grade anal lesion compared to normal HPV-positive (p < 0.0001), whereas expression levels of β-defensin 3 were increased in high-grade patients (p = 0.0009). The acquisition of simultaneous infection anal and cervical may occur by different means, showing that the anal canal is also a source of infection.
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Krause, Alexander [Verfasser]. "Charakterisierung neuer humaner antimikrobieller Peptide : LEAP-1, LEAP2 und humanes β-Defensin 4 / von Alexander Krause." 2001. http://d-nb.info/964221667/34.
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Chang, Ya-Wen, and 張雅雯. "Role of β-defensin 2 in advanced glycation end products- induced effects in NRK-49F cells." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/02662455101675995471.
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碩士高雄醫學大學
生物化學研究所碩士班
94
Advanced glycation end-product (AGE) is important in the pathogenesis of diabetic nephropathy which is characterized by cellular hypertrophy / hyperplasia leading to renal fibrosis. However, the biological effects of AGE on renal cells remain poorly understood. Our previous study suggesting that AGE induces mitogenesis in NRK-49F cells, which may result in interstitial renal fibrosis. To further investigate the mechanism by which AGE induces mitogenesis, NRK-49F cells were treated with AGE for various time periods. We found that AGE induced the β-defensin 2 mRNA expression at 48 hours. β-defensin 2 has been described as antimicrobial peptides which exhibited chemotactic activity to recruit dendric cells and T lymphocytes. In recent years, β-defensin 2 was also reported to have growth factor-like mitogenic effects on different cell types. AGE-induced β-defensin 2 mRNA expression was attenuated by pretreatment of calphostin C (PKC inhibitor)、LY294002 (PI3K inhibitor)、PD98059 (ERK inhibitor)、SB203580 (p38 MAPK inhibitor) and SP600125 (JNK inhibitor). To reveal the involvement of β-defensin 2 in mitogenesis of NRK-49F cells, we examined the effects of β-defensin 2 on cell proliferation and cell cycle progression by [3H]-thymidine incorporation assay and Western blotting, respectively. Interestingly, β-defensin 2 induced cell proliferation and promoted cell cycle progression in NRK-49F cells by increased cyclin E、cyclin D1 and cdk4. Together, these results suggested the possibility that AGE may induce renal fibroblasts mitogenesis through activation of β-defensin 2.
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Chen, Tzu-Yu, and 陳姿伃. "Impacts of Salmonella enterica serovar Typhimurium and antibiotics on human β-defensin expression in human intestinal epithelium." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/jfz2n4.
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碩士國立臺北科技大學
生物科技研究所
100
Salmonella enterica serovar Typhimurium (Salmonella Typhimurium) is an important pathogen which causes morbidity and mortality worldwide. So far, the early immune responses in human intestinal epithelial cells after Salmonella Typhimurium infection are little known. In this study, we have established an in vitro model to observe IL-8、β-defensin 1、2 and 3 gene and protein expression in human intestinal epithelial cells after Salmonella Typhimurium wild-type strain SL1344 or SPI-1 mutant strain △ spaS infection by RT-PCR and ELISA assay . Furthermore, the effect of Ceftriaxone treatment after infection on gene and protein expression of human IL-8、 β-defensin 1、2 and 3 were investigated. Our results shown the mRNA level of IL-8、β-defensin 1、2 and 3 were increased after wild-type strain and mutant strain infection. However, the ability of wild-type strain is higher than mutant strain. The mRNA level of IL-8 after infection was reduced by Ceftriaxone treatment. However, Ceftriaxone did not affect the mRNA expression of β-defensin-1. On the contrary, the mRNA level of β-defensin 2 and 3 were increased. Furthermore, the level of the protein expression affected by Ceftriaxone treatment was not significant. The results of this study indicated that the intestinal cells encounting typhimurium Salmonella infection may increase the antimicrobial gene expression to resist infection, and treatment of Salmonella typhimurium infection with Ceftriaxone may not interfere with this antibacterial mechanism.
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Lee, Po-Hui, and 李柏輝. "Delivery of Parathyroid Hormone or Human β-defensin 2 via Gene Therapy Strategy for Treatment of Craniofacial Bone Defects." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/s5x4n5.
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博士國立陽明大學
口腔生物研究所
106
Craniofacial bone defects are common dental conditions. It is still challenging clinically to obtain predictable bone regeneration in large or bacteria-contaminated bone defects. The purpose of this study was to explore the effect of novel regenerative strategies, such as tissue engineering and gene therapy, in difficult-to-treat craniofacial bone defects. The first part of the study was focus on treating large size craniofacial bone defects. Gene activated matrix (GAM) is a nonviral gene therapy technique based on the principles of tissue engineering. A GAM is formed by plasmid DNA (pDNA), encoding gene of growth factor, entrapped in resorbable matrix. GAM composed of pDNA containing gene of parathyroid hormone (PTH) and collagen matrix can effectively promote bone regeneration in bone defects of long bones. Demineralized freeze-dried bone allograft (DFDBA) is one of the bone grafts widely used in dentistry. We aimed to explore the bone regenerative effects of PTH-GAM, with collagen matrix or DFDBA/collagen matrix, in the treatment of rat critical-sized calvarial bone defect. Rat calvarial bone defected were implanted with DFDBA/collagen composite scaffold (D/C), PTH-GAM with collagen matrix (PTH-C-GAM), or PTH-GAM with D/C matrix (PTH-D/C-GAM). The defects without implantation were used as control (Sham). New bone formation was evaluated by performing radiography, dual energy X-ray absorptiometry (DEXA), microcomputed tomography (μCT), and histological examination. The results indicated that the new bone formation in the calvarial bone defects, from more to less, was in the order of PTH-D/C-GAM, PTH-C-GAM, D/C, and Sham groups. We concluded that PTH-GAM with collagen matrix can promote bone regeneration in large craniofacial bone defects in rats. Moreover, the change of the collagen matrix with the D/C matrix improves the osteogenic effects of PTH-GAM. The second part of the study was focus on treating bacteria-contaminated large size craniofacial bone defects. Human β-defensin 2 (hBD2), an antimicrobial peptide of innate immune system, possesses excellent antimicrobial activities and rare drug resistance. The application of hBD2 in bone regenerative therapies is still unexplored. We aimed to determine the effects of hBD2 gene-modified bone marrow mesenchymal stem cell (BMSC) in the treatment of Staphylococcus aureus (S.a.)-contaminated calvarial bone defect in rats. The results indicated that BMSC overexpressing hBD2, generated via adenoviral infection method, can reduce the viable S.a. numbers both in vitro and in vivo. We established a bacteria-contaminated rat calvarial bone defect model and found that bacterial contamination severely compromises the bone regenerative effects of BMSCs. Furthermore, the hBD2 gene-modified BMSCs can dramatically reduce the viable S.a. numbers in the bone defects, mitigate the negative effects of bacterial contamination, and effectively promote bone healing. We hope that with advancement of the novel regenerative techniques, as we used in this study, the current difficult-to-treated bone defects in dental clinical practice can be effectively treated in the future.
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Alase, Adewonuola A., J. Seltmann, T. Werfel, and Miriam Wittmann. "Interleukin-33 modulates the expression of human β-defensin 2 in human primary keratinocytes and may influence the susceptibility to bacterial superinfection in acute atopic dermatitis." 2012. http://hdl.handle.net/10454/7432.
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noBackground Interleukin (IL)-33 is a member of the IL-1 family and has been implicated in Th2-driven allergic diseases such as atopic dermatitis (AD) and asthma. The principal Th2 cytokine IL-4, found highly expressed in acute allergic eczema, is known to downregulate human β-defensin 2 (hBD2) expression in human keratinocytes and this is associated with superinfection in patients with AD. Objectives To investigate the effect of IL-33 on the expression of hBD2 in human keratinocytes. Methods hBD2 production by stimulated keratinocytes was measured by enzyme-linked immunosorbent assay. Results Our results showed that serum is a very potent inducer of hBD2 and 2·5% human serum was much more potent in inducing hBD2 than 20 ng mL−1 of tumour necrosis factor-α. Interestingly, serum from patients with AD showed an impaired ability to induce hBD2 in normal keratinocytes. IL-33 significantly downregulated serum-induced hBD2. The downregulatory capacity of IL-33 was found to be 1·5- to 2-fold weaker compared with IL-4. Conclusions Our data suggest that IL-33 can significantly contribute to the decreased expression of hBD2 in acute eczematous reaction clinically characterized by spongiosis and oozing – thus indicative for contact of the epidermis with serum components.
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"PEPTIDE ENGINEERING FOR DEVELOPMENT OF ANTIMICROBIALS AGAINST Mannheimia haemolytica." Thesis, 2013. http://hdl.handle.net/10388/ETD-2013-10-1332.
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Mannheimia haemolytica (M. haemolytica)-induced bovine respiratory disease causes millions of dollars in economic losses to Canadian cattle industry. Contemporary management strategies built around the use of antimicrobials are proving to be increasingly unavailing and lead to drug residues in meat which may contribute to the development of multi drug resistant bacteria. Many M. haemolytica vaccines are effective in stimulating antibody responses but studies of vaccina-tion in young calves and the cattle exposed to M. haemolytica (high-risk cattle) have shown poor vaccine efficacy. Antimicrobial peptides (AMPs) may help in the management of respiratory disease caused by M. haemolytica while minimizing the risk of drug residues in animal-derived food products.
AMPs are positively charged molecules that can kill bacteria primarily through the electrostatic interactions with the anionic bacterial lipid bilayer. Since the primary target of AMPs is the bac-terial surface charge, which is evolutionarily conserved, the development of resistance towards AMPs seems less likely. These peptides hold potential to replace or reduce the use of antibiotics.
Human β-Defensin 3 (HBD3) and Microcin J25 (MccJ25) are cationic peptides that have shown good activity against many Gram-negative bacteria. Five peptides, namely native HBD3, three synthetic HBD3 analogues (28 amino acid, 20AA, and 10AA), and MccJ25 were selected for microbicidal activity against M. haemolytica. Three C-terminal analogues of HBD3 with all cysteines replaced with valines were manually synthesized using solid phase peptide synthesis (SPPS).
In all the three analogue, replacement of cysteine with valine rendered them linear and increased their antibacterial activity. Minimum Bactericidal concentration (MBC) assays were performed with the final inoculum size of 1-5x105 cells/ml, with the exception of the 10AA analogue which was incubated with 104 cells/ml final inoculum size. The antimicrobial assay showed that M. haemolytica was intermediately sensitive to HBD3, 28AA and 20AA analogue with an MBC of 50 µg/ml. MccJ25 had limited effect with an MBC greater than 100 µg/ml. The MBC value of 6.3 µg/ml achieved with the 10AA analogue is likely a result of lower final inoculum size.
AMPs have several immunomodulatory functions, and these peptides can act as chemoattractant, induce cytokine release that in turn leads to chemotaxis of monocytes and neutrophils. Since neutrophils play an important role in the pathogenesis of BRD, the chemotactic effect of HBD3, 20AA and 28AA peptides on bovine neutrophils was studied using Boyden chamber. Peripheral blood neutrophils isolated from normal healthy cattle showed chemotaxis towards HBD3 and 20AA peptides (P<0.05) but not towards 28AA analogue. Co-incubation of neutrophils with any of the peptides did not affect their chemotaxis towards N-formyl-L-methionyl-L-leucyl-phenylalanine (fMLP).
Based on these data, it can be concluded that HBD3 and its analogues showed antimicrobial ef-fects against M. haemolytica but MccJ25 had limited microbicidal activity against M. haemolytica. While HBD3 and 20AA analogue were chemotactic for bovine peripheral blood neutrophils, none of the peptides inhibited fMLP-induced migration of neutrophils. These peptides hold potential for further in vivo testing to develop them for use to manage M. haemolytica-induced respiratory disease in cattle.
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Jübner, Martin [Verfasser]. "Immunologische und immunhistochemische Charakterisierung des neuen humanen β-Defensins [Beta-Defensins] hBD17 / von Martin Jübner." 2004. http://d-nb.info/97226373X/34.
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Saß, Vera [Verfasser]. "Die molekulare Wirkung des humanen β-Defensins [Beta-Defensins] hBD3 auf Staphylococcus aureus / vorgelegt von Vera Saß." 2008. http://d-nb.info/990974677/34.
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Rodríguez, Jiménez Francisco Javier [Verfasser]. "Identification and characterization of three new human β-defensins [beta-defensins]: hBD23, hBD27, and hBD29 / von Francisco Javier Rodríguez Jiménez." 2003. http://d-nb.info/969277040/34.
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Mintcheva, Mariana E. [Verfasser]. "Genexpression humaner β-defensine [beta-defensive] (HBD-1, -2), Interleukine(IL-6, -8) und von Cyclooxygenase-2 in odontoblasten-ähnlichen Zellen und Gingivaepithelzellen nach bakterieller Stimulation / Mariana Emilova Mintcheva." 2008. http://d-nb.info/989777871/34.
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Schulz-Maronde, Sandra [Verfasser]. "Identifizierung und funktionelle Charakterisierung von hBD3, einem neuen antimikrobiellen Peptid aus der Gruppe der humanen β-Defensine [Beta-Defensine] / von Sandra Schulz-Maronde." 2003. http://d-nb.info/969247044/34.
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Trabert, Susanne [Verfasser]. "Vergleichende Untersuchung zur Expression antimikrobieller Peptide (humaner β-Defensine [Beta-Defensine] 1-3) bei der bisphosphonat-assoziierten Knochennekrose und der Osteoradionekrose / vorgelegt von Susanne Trabert." 2010. http://d-nb.info/100204832X/34.
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Luley, Kim Barbara [Verfasser]. "Expressionsanalyse von Calprotektin und humanen α- [Alpha-] und β-Defensinen [Beta-Defensinen] in der kolorektalen Karzinogenese / vorgelegt von Kim Barbara Luley." 2005. http://d-nb.info/978695380/34.
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Petzl, Nadine [Verfasser]. "Peripartale Expression von Toll-like-Rezeptoren und β-Defensinen [Beta-Defensinen]im Endometrium des Rindes / vorgelegt von Nadine Petzl (geb. Ritter)." 2007. http://d-nb.info/985348151/34.
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Hsiao, Hsien-Chieh, and 蕭獻謙. "Differential Expression of β-defensins in The Canine Endometrium during Estrus Cycle and with Cystic Endometrial Hyperplasia." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/66520205011373073983.
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碩士國立嘉義大學
獸醫學系研究所
99
β-defensins (BD) are a family of small cationic proteins that have been shown to be associated in defense against pathogenic organisms. The endometrial epithelium is the first defensive line against pathogenic microbes. To date, the expression of β- defensins in epithelial surfaces have been reported in respiratory tract, gastrointestinal tract, skin, and reproductive tract. However, little is known about β-defensins ex- pression in bitches during estrus cycle and with pyometra. The aim of this study is to extend our knowledge on expression and action of β-defensins in the canine endometrium. We studied canine β-defensins (cBDs) expression between healthy uteri and pyometra samples obtained from bitches presented for ovariohysterectomy. The results of this study demonstrated that the expression of cBD1 were upregulated during pregnancy in uteri under semi-quantitative RT-PCR analysis. And cBD1 expression was markedly increased in hydrometra, mucometra, and pyometra compared with healthy uteri group. The expression of cBD1 upregulated may correlate with abundant glands, thickness in the endometrium. On the other hand, the β-defensins were not regulated by TLR2 and TLR4. In conclusion, the CBDs expression may play an essential role in the innate immune defense of the canine endometrium.
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Overgahr, Willebrand Charlotte [Verfasser]. "Die Rolle des humanen β-Defensins-2 [Beta-Defensins-2] in der Regulation der Genexpression von Genen der Immunabwehr in odontoblasten-ähnlichen Zellen / vorgelegt von: Charlotte Overgahr gen. Willebrand." 2007. http://d-nb.info/985185198/34.
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