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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Proliferation Signal Inhibitor associated proteinuria in a renal transplant recipient: Dysfunction of proximal tubular epithelial cells is a result of decreased cubilinand/or megalin expression? : Proliferation Signal Inhibitor associated Proteinuria

Komuraiah, Myakala January 2010 (has links)
Background The proliferation signal inhibitors (PSIs) sirolimus (SRL) and everolimus (ERL) are the potent immunosuppressive drugs using in organ transplantation and has been used successfully in renal transplant recipients (RTX) as well. PSIs are the key factors to overcome the allograft rejections after successful organ transplantation since the immune system starts to react against the graft. SRL and ERL prevents the action of immune system b inhibits the proliferation of T- and B-cells by inhibiting the intracellular signaling of interleukin-2. The presence of excess amount of serum proteins including albumin in the urine is considered as proteinuria, which reflects the loss of kidney function. The occurrence of proteinuria can be the result of abnormal glomerular filtration and/or impaired tubular endocytic function of renal proximal tubular epithelial cells (PTECs). Megalin and cubulin are two scavenger receptors present on epical surface of PTECs and involved in reabsorption of proteins after glomerular ultrafiltration process in the kidney. Proteinuria appears too high in renal transplanted patients during ongoing   treatment with PSIs. Aim Our study aimed to investigate and correlate the expression level of megalin and cubilin and albumin uptake in PTEC of renal transplanted patients before and after conversion to PSI. Methods To retrieve the maximal expression of our interest molecules in renal PTECs, we optimized antigen retrieval (AR) method and primary antibody dilution for each molecule separately. An optimization experiment was performed on 3 different normal patients renal biopsies were used. Later, human renal biopsy specimens originated from 4 different renal transplanted patients were used in this study. From all the 4 patients biopsy specimens were taken before and ongoing administration of PSIs (SRL, ERL). The expression of megalin, cubilin and albumin uptake in PTEC of renal transplant patients was determined by immunohistochemical staining. Results Based on the optimization experiments, we selected the AR method and primary antibody dilution for the expression of megalin, cubilin and albumin uptake. In 4 renal transplanted patients following administration of PSIs results in patients 1, 2, 3 expression of megalin, cubilin and albumin uptake during ongoing PSI treatment was not comparable or even more intense than before PSIs introduction. The expression of megalin, cubilin and albumin uptake was reduced in patient 4 during ongoing PSI treatment. Conclusion Our findings suggest that the renal transplant patient 4 developed proteinuria during PSI medication. The expression of megalin, cubilin and albumin uptake was markedly decreased during ongoing PSI treatment in patient 4. We concluded that there is a direct link between PSI medication and tubular dysfunction, which might cause proteinuria
32

Detection And Quantification Of Equine Type I Interferons

Wahlund, Casper January 2011 (has links)
Type I interferons (IFNs), perhaps the most important of cytokines in fighting viral infections, have been target for detailed research only the past few decades and much is yet to be investigated. Hidden in the mysteries of IFNs might be powerful anti-viral and anti-tumor therapies, alongside greatly increased understanding of vertebrate immunology. This project aims at investigating IFN expression of in vitro stimulated equine cell lines and studies of IFN expression in horses, both healthy and a number of horses diagnosed with inflammatory bowel disease (IBD). Amongst equine diseases, IBD is of increasing concern and scientific progressions within the project are, in several aspects, also applicable for human medicine.
33

In Vitro Study of Recruitment Ability of Macrophages and Trophoblasts in Early Human Pregnancy

Wendel, Caroline January 2010 (has links)
The tolerance towards the semi-allogenic foetus is obtained through both systemic and local changes in the maternal immune response. Locally, in the decidua, the cell composition differs from that found in the blood; natural killer (NK) cells and macrophages being the major cell types. Decidual macrophages (dMØ), which are alternatively activated, and trophoblasts, placental cells of foetal origin, are believed to participate in the foetal tolerance at the foetal-maternal interface. To test the recruitment ability of macrophages and trophoblasts, and to test if these cells are responsible for the special cell composition in the decidua, a migration assay was established. In this migration assay peripheral blood mononuclear cells (PBMC) were allowed to migrate through Matrigel-coated transwell inserts into lower wells containing a recruiting stimulus. After testing several conditions, a protocol was established for further use. The results showed that in vitro alternatively activated macrophages, which display many of the surface markers as dMØ, hold a recruiting ability and recruit monocytes. Further there was an indication that trophoblasts also hold a recruiting ability. Neither cell types were shown to recruit NK cells. In conclusion, this study presents a suitable protocol for assessing chemotactic factors and different cell type’s ability to recruit cells from blood. Although the experiments need to be repeated and extended and the recruitment ability of dMØ needs to be evaluated in detail before a final conclusion can be drawn, the preliminary data indicated that macrophages and trophoblasts can recruit monocytes.
34

Vårdpersonalens följsamhet till de basala rutinerna gällande handhygien. : - en litteraturstudie

Persson, Annelie, Zetterqvist, Åsa January 2009 (has links)
Handhygien är en grundläggande princip som förebygger, kontrollerar och reducerar vårdrelaterade infektioner och är ensam den mest effektiva metoden för att bryta en smittspridning. Syfte: att belysa vårdpersonalens följsamhet till de basala rutinerna gällande handhygien. Metod: Författarna gjorde en litteratursökning och granskning av vetenskapliga artiklar inom området. Resultat: Vårdpersonalens följsamhet till handhygienrutinerna visade sig ligga mellan 16,5%-70% och var större efter än före patientvård. Det fanns faktorer som gynnade och minskade följsamheten. Diskussion: Författarna fann stöd i sin teori om att vårdpersonalen skyddar sig i första hand själv och utför därför handhygienen i större grad än efter patientkontakt. Då det visade sig att kunskap leder till ökad följsamhet ansåg författarna att en årlig genomgång av handhygienrutinerna är lika viktigt som att repetera hjärt- och lungräddning.
35

Nested PCR for distinguishing Haemophilus haemolyticus from Haemophilus influenzae and Cloning and expression of fragmented Moraxella catarrhalis IgD-binding protein in E. coli

Bergström, Jennie January 2007 (has links)
ABSTRACT Nontypable Haemophilus influenzae is a common cause of otitis, sinusitis and conjunctivitis. It is the most common bacterial pathogen associated with chronic obstructive pulmonary disease (COPD). Studies have shown that nonpathogenic Haemophilus haemolyticus are often mistaken for Haemophilus influenzae due to an absent hemolytic reaction on blood agar. Distinguishing H. haemolyticus from H. influenzae is important to prevent unnecessary antibiotic use, and to understand the role of H. influenzae in clinical infections. In this study, PCR-primers for amplifying 16S rDNA sequences were used to set up a method for distinguishing H. haemolyticus from H. influenzae. The aim was to use the method for analyzing apparent H. influenzae strains, to investigate if some strains were in fact H. haemolyticus. However, because of problems with unspecific primerannealing,no conclusions could be drawn regarding misclassification of H. haemolyticus. Moraxella catarrhalis is the second most common bacterial pathogen associated with COPD. It also causes otitis and sinusitis. An important virulence factor of M. catarrhalis is the outer membrane protein Moraxella catarrhalis IgD-binding protein (MID). One part of the protein; MID764-913 , has been shown to function as an adhesin, and this part has been fragmented to further investigate its adhesive properties. The aim of this second, independent study, was to express some of these proteinfragments by cloning in E. coli. The time spent on this project was too short, and no proteins could be expressed duing this period.
36

Development and optimization of methods for detection of Chlamydophila pneumoniae

Kanberg, Josefine January 2008 (has links)
The purpose of the study was to set up a method for cultivation of C. pneumoniae from infected mouse tissue in Hep2 cells. We also evaluated a new reagent, Chlamatis, which is considered to increase the detection sensitivity of the bacterium with both PCR and cultivation. All 10 serum samples treated with Chlamatis were negative for C. pneumoniae in PCR. The cultivation of tissue was found to work without problems. The yield of the bacteria was highest at the speed of 30 Hz using homogenization with TissueLyser. Mice infected with C. pneumoniae were killed at days 4, 8, 20 and 40. The highest yields of C. pneumoniae were found at days 4 and 8 using PCR with all infected mice. The results obtained with PCR and cultivation confirmed each other to a large extent. For heart tissue, PCR positive mice were found only at days 4 and 8. The number of PCR positive lung samples confirmed to a large extent the number found by cultivation, except for mice killed after 4 days and 40 days where the results differed slightly. This indicated that the optimization of the cultivation method was successful
37

Detection and characterisation of Vibrio harveyi isolates

Themptander, Katarina January 2005 (has links)
Aim Because of the major problems that certain Vibrio specie, especially Vibrio harveyi, can cause the aquaculture industries a rapid method to identify Vibrio isolates is required. Early diagnosis of a V. harveyi infection could facilitate disease surveillance, treatment and prevention in cultured marine animals. Therefore, the use of PCR to aid in the identification of Vibrio is increasing and a way of extracting DNA in a cheap, fast and easy way is also of an important requirement to facilitate rapid diagnosis. Methods This report comprises biochemical profiling and PCR methods in the characterisation of four isolates of V. harveyi and single isolates of V. tubiashii, V. alginolyticus, V. anguillarum, V. splendidus, V. tapetis and V. parahaemolyticus. Strains were examined for adherence to a Hep-2 cell line. Four different DNA extraction methods were evaluated and compared. The detection limits and the analytical limits of two PCR methods for Vibrio were determined. Results The overall findings were that the use of a greater range of biochemical substrates than are in the API 20E is necessary to identify Vibrio strains, and that none of the strains tested adhered to Hep-2 cells. All extraction methods successfully produced DNA with the kit method giving the purest samples. RNA was a contaminant of the other techniques but this could be overcome by treating extracts with RNase. The rapid microwave extraction method gave appropriate PCR amplicons when tested. Conclusion PCR determination of the VH-sequence in combination with VHA and a distinguishable colonial morphology may be a good choice for the identifying of Vibrio harveyi.
38

Investigation of the effects of nanoparticle size on blood activation using a human wholeblood model

Heed, Elias January 2015 (has links)
Nanoparticles are used more and more extensively in today's society, especially in the industry sector. Humans get exposed to nanoparticles daily but the effect is a topic that has not been fully explored yet and its effect on humans is still unknown.The purpose of this project was to investigate whether the size of nanoparticles is a factor that influences their effect on humans, mainly the effect on blood activation. In order to study this, nanopaticles of polystyrene with three different sizes (75, 120 and 260 nm) were selected and incubated in a human whole blood model, the Chandler loop. The samples from the Chandler loop experiments were analysed with three different ELISA's: C3a, terminal complement complex (TCC, sC5b-9) and thrombin-antithrombincomplexes (TAT).The results in this study indicate that the smallest nanoparticle has a higher potential for activating the coagulation system than the larger ones. The complement system did not seem to be significantly activated from the nanoparticles. More experiments needs to be done in order to get a better statistic value but just as it is the results look promising and there is a tendency for a higher activation of the coagulation system with the 75 nm nanoparticles.
39

Birds and Borrelia

Olsen, Björn January 1995 (has links)
The Lyme disease causing spirochaete Borrelia burgdorferi sensu lato is transmitted by ticks within the genus Ixodes. These ticks are liberal host seekers and parasitise mammals, birds and reptiles. Prior to this study, the distribution of I. ricinus ticks and Lyme disease was thought to be restricted to the southern half of Sweden. On the island Norrbyskär, located in the Bothnian Gulf, there were reports of a high incidence of tick infestation on humans. To investigate the occurrence of B. burgdorferi s.l. in these ticks and to characterise presumptive isolates at the molecular level we sampled a number of I. ricinus ticks. Three different isolates were obtained from two different ticks, NBS16 from a nymph and NBS23a and NBS23b from an adult female tick. The seabird associated tick I. uriae is circumpolar distributed in both hemispheres. On the island Bonden, which house one of the largest seabird colonies in the Baltic Sea, I. uriae were collected and surveyed for spirochaetes. One isolate of B. burgdorferi s.l. was obtained. This B. burgdorferi s.l. isolate is identical to the Lyme disease Borrelia strain NBS16 isolated from Norrbyskär. To investigate the role of seabirds in the epidemiology of B. burgdorferi s.l., I. uriae were collected from seabird colonies in the southern and northern hemispheres. Borrelia DNA was extracted from the ticks and from cultured spirochaetes. Sequence analysis of the flagellin gene revealed that the DNA obtained was from B. garinii, regardless of the geographical origin of the sample. Identical fla gene fragments in ticks collected in both hemispheres indicate a transhemispheric exchange of B. garinii. A marine ecological niche and epidemiological route for Lyme disease Borrelia are proposed. The prevalence of B. burgdorferi s.l. infected ticks on migrating passerine birds was studied. A total of 22, 998 birds were caught and examined for ticks. The presence of spirochaetes in the 967 collected ticks was determined by DNA amplification by PCR on all ticks. To determine which B. burgdorferi s.l. species were present, classification was performed by DNA amplification using species-specific 16S rDNA primers and by DNA sequencing. Flagellin gene sequences of all species of B. burgdorferi s.l. previously recorded in Europe were found. B. garinii was the most prevalent. These data support the notion that passerine birds are at least partly responsible for the distribution of Lyme disease Borrelia spirochaetes in Europe. To elucidate the distribution of B. burgdorferi s.l. in subarctic regions, strains isolated from I. ricinus and I. uriae ticks found on islands in the northern Atlantic and Baltic Sea were characterised molecularly. All isolates were verified as B. garinii by 16S-rRNA gene analysis and immunoblotting using monoclonal antibodies specific for the outer surface proteins A and C. Three ribotypes (RT's) of B. garinii were found. The I. ricinus associated RT1 is phenotypically the most heterogeneous. RT2 is restricted to the islands in the northern Baltic Sea, whereas RT3 was also recovered from ticks found on islands in the North Atlantic. The heterogeneity of the B. garinii population in the Baltic Sea might be influenced by two geographically opposite directions, North Atlantic (RT3) and Euroasia (RT1). / digitalisering@umu.se
40

The Contribution of Innate Immunity to the Pathogenesis of ANCA-associated Vasculitis

Söderberg, Daniel January 2016 (has links)
Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) constitute a group of vasculitides characterized by neutrophil-rich necrotizing inflammation of small vessels and the presence of ANCA in the circulation. Dying neutrophils surrounding the walls of small vessels are a histological hallmark of AAV. Traditionally it has been assumed that these neutrophils die by necrosis, but neutrophil extracellular traps (NETs) have recently been visualized at the sites of vasculitic lesions. NETs were first described to be involved in capture and elimination of pathogens but dysregulated production and/or clearance of NETs are thought to contribute to vessel inflammation in AAV; directly by damaging endothelial cells and indirectly by acting as a link between the innate and adaptive immune system through the generation of pathogenic PR3-ANCA and MPO-ANCA that can activate neutrophils. ANCA can, however, be found in all individuals and are therefore suggested to belong to the repertoire of natural antibodies produced by innate-like B cells, implying that not all ANCA are pathogenic.  In paper I, we found neutrophils in patients to be more prone to undergo NETosis/necrosis spontaneously compared with neutrophils in healthy controls (HC), as well as that active patients possessed elevated levels of NETs in the circulation. Our results also suggest that ANCA during remission could contribute to the clearance of NETs as we observed an inverse relation between ANCA and NETs. In paper II, we observed neutrophils in patients to be more easily activated upon ANCA stimulation as they produced more ROS than neutrophils in HC. In paper III, we showed for the first time that cells of adaptive immunity (B and T cells) in addition to cells of innate immunity can release ET-like structures, in this case consisting of mitochondrial (mt) DNA. mtDNA can act as a damage-associated pattern molecule (DAMP) and promote inflammation, and increased levels of mtDNA has been observed in AAV. Our finding broadens our perspective of the possible roles of T and B cells in immunological responses, and should be further investigated in AAV. In paper IV, we observed reduced frequencies of MZ-like B cells, considered to be innate-like B cells that produce natural antibodies, and of the proposed regulatory B (Breg) cell populations CD24highCD27+ and CD25+CD27+ B cells in patients, particularly in those with active disease. We also observed the phenotypes of these different Breg cell populations to be different from the corresponding cells in HC. We hypothesize that the increased activation potential by neutrophils in AAV to produce ROS and undergo NETosis/necrosis contribute to the excessive inflammation as well as an increased antigen load of PR3 and MPO, and that this in combination with dysregulation of innate-like B cells and Breg cells could lead to break of tolerance to these antigens and production of pathogenic autoantibodies. ANCA can in turn activate neutrophils to release NETs, suggesting a vicious circle in disease development.

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