<p>Renal artery stenosis (RAS) is a potentially curable cause of hypertension and azotemia. Besides intra-arterial renal angiography there are several non-invasive techniques utilized to diagnose patients with suspicion of renal artery stenosis. Removing the stenosis by revascularization to restore unobstructed blood flow to the kidney is known to improve and even cure hypertension/azotemia, but is associated with a significant complication rate. </p><p>To visualize renal arteries with x-ray techniques a contrast medium must be used. In a randomized, prospective study the complications of two types of contrast media (CO₂ and ioxaglate) were compared. CO₂ was not associated with acute nephropathy, but induced nausea and had lower attenuation differences compared to Ioxaglate. Acute nephropathy was related to the ioxaglate dose and the risk was evident even at very low doses if the patients were azotemic with creatinine clearance <40 ml/min. </p><p>Evaluating patients for clinically relevant renal artery stenosis can be done utilizing several non-invasive techniques. MRA was retrospectively evaluated and shown to be accurate in detecting hemodynamically significant RAS. In a prospective study of 58 patients, evaluated with four methods for renal artery stenosis, it was shown that MRA and CTA were significantly better than ultrasonography and captopril renography in detecting hemodynamically significant RAS. The standard of reference was trans-stenotic pressure gradient measurement, defining a stenosis as significant at a gradient of ≥15 mmHg. The discrepancies were mainly found in the presence of borderline stenosis.</p><p>The outcome of percutaneous revascularization procedures showed a technical success rate of 95%, clinical benefit in 63% of treated patients, 30-day mortality 1.5% and major complication rate of 13%. The major complication rate for patients with baseline serum creatinine >300µmol/l was 32%. Our results compare favorably with published studies and guidelines.</p>

The purpose of this work was to improve the diagnosis of intracranial hemorrhage with MRI, using, among others, T2*-w GE sequences. Various sequences were tested in rabbits at two magnetic field strengths. Then, the most effective technique was applied to stroke patients. Experimental studies: The MR detectability of small experimental haematomas in the brain and of blood in the cerebrospinal fluid (CSF) spaces of 30 rabbits was evaluated. MRI examinations were performed at determined intervals. The last MR images were compared to formalin fixed brain sections and, in 16 rabbits, also to the histological findings. T2*-weighted GE sequences revealed all the intraparenchymal haematomas at 1.5 T, appearing strongly hypointense. Their signal patterns remained unchanged during the follow-up. Blood in the CSF spaces was best detected at 1.5T with T2*-weighted GE sequences during the first 2 days. FLAIR and SE sequences were rather insensitive. Clinical studies: MR examinations were performed at 1.5T, including T1- and T2-w SE, FLAIR and T2*-w GE sequences. In the first clinical study, 66 intraparenchymal hematomas (IPH) of different sizes and ages were examined. T2*-w GE sequence was the most sensitive. On all the sequences, we found a big variety of signal patterns, without a clear relationship to the age of the hematomas. In a second clinical study, MR examinations were performed to 83 patients with acute stroke: 43 presented acute IPH and 40 were used as controls. Old microhemorrhages (OMHs) were found in 60% of the patients with IPH, and in 15% of the controls. Conclusion: T2*-weighted GE sequences are capable of revealing very small intraparenchymal hemorrhages at any stage, and blood in CSF spaces during at least the first 2 days. The age of IPHs cannot reliably be estimated with MRI. We have found a correlation between the presence of OMHs and acute intraparenchymal hematomas.

The tumor vasculature is poor and heterogeneous which may result in inadequate oxygenation and changed energy status. In addition the balance between cell proliferation and the rate of cell death is disturbed, which results in tumor growth. The aims of this study were 1) to gain more insight into the relation between tumor vascularity, hypoxia, and proliferation in solid tumors, and 2) to study the changes and dynamics of tumor oxygenation in relation to the vascular architecture within individual tumors. For this purpose a double hypoxic marker method was developed, which was subsequently used to 3) determine the turnover rate of hypoxic cells in three different tumor models and 4) to study the effect of cytotoxic drugs on tumor hypoxia and cell death. Solid tumor models grown in mice were used. The tumor microenvironment was investigated with exogenous cell markers for hypoxia (pimonidazole and CCI-103F), cell proliferation (BrdUrd) and blood perfusion (Hoechst 33342). The vasculature and the exogenous cell markers were visualized with immunohistochemical techniques. The tumor sections were scanned and quantified with an image analysis systemconsisting of a fluorescence microscope, CCD camera and image analysis software. The spatial organization of hypoxia, proliferation, and tumor vasculature was analyzed in several xenograft lines. The study revealed two main hypoxic patterns that seemed to be the consequence of complex relations between vasculature, oxygen delivery, proliferation, and cell loss. The novel double hypoxic cell marker method, with sequential injection of two hypoxic markers, was developed to study dynamic changes of the tumor oxygenation. Based on varying injection intervals between the markers the hypoxic cell half-life was determined in three tumor lines, and ranged from 17 to 49 hours. Intra-tumoral changes in oxygenation status upon oxygen modifying treatments were measured with the double hypoxic marker method. Both decreased levels of tumor hypoxia after carbogen breathing (95%O2 and 5% CO2) and increased levels of tumor hypoxia, as a result of reduced tumor perfusion after hydralazine treatment was detected. Finally the double hypoxic marker assay was used to analyze the effects of the hypoxic cytotoxin tirapazamine in relation to the hypoxic cell population, which caused a reversible decrease of the hypoxic fraction. The results presented in this thesis now form the basis for further studies to identify subpopulations of cells that represent specific targets for therapy, and to investigate the effects of different treatment modalities.

Whereas the effect of size and coating material on the pharmacokinetics and biodistribution of iron oxide based contrast agents are well documented, the effect of these parameters on liver metabolism has never been investigated. The primary purpose of this work was to evaluate the effect of iron oxide particle size and coating on the rate of liver clearance and particle degradation using a rat model. The magnetic and relaxation properties of five different iron oxide contrast agents were determined prior to the onset of the animal studies. The R2* values and the T1-enhancing efficacy of the agents were also evaluated in blood using phantom models. The results of these studies indicated that the efficacy of these agents was matrix and frequency dependent. Correlations between the R2* values and the magnetic properties of the agents were established and a new parameter, Msat/r1, was created to enable better estimations of contrast agent T1-enhancing efficacy in blood. The bio-distribution of one of the agents was also evaluated to assess the importance of sub-cellular particle distribution, using an isolated rat liver cell model. Phantom models were also used to verify that materials with magnetic properties similar to the particle breakdown products (ferritin/hemosiderin) may induce signal reduction when compartmentalized in a liver cell suspension. The results revealed that the cellular distribution of the agent did not influence the rate of particle degradation. This finding conflicted with current theory. Additionally, the study indicated that the compartmentalization of magnetic materials similar to ferritin may induce significant signal loss. Methods enabling the accurate determination of contrast agent concentration in the liver were developed and validated using one of the agents. From these measurements the liver half-life of the agent was estimated and compared to the rate of liver clearance, as determined from the evolution of the effective transverse relaxation rate (R2*) in rat liver. The results indicate that the liver R2* enhancement persisted at time points when the concentration of contrast agent present in the liver was below method detection limits. The prolonged R2* enhancement was believed to be a result of the compartmentalisation of the particle breakdown products within the liver cells. Finally, the liver clearance and degradation rates of the five different iron oxide particles in rat liver were evaluated. The results revealed that for materials with similar iron oxide cores and particle sizes, the rate of liver clearance was affected by the coating material present. Materials with similar coating, but different sizes, exhibited similar rates of liver clearance. In conclusion, the results of this work strongly suggest that coating material of the iron oxide particles may contribute significantly to the rate of iron oxide particle clearance and degradation in rat liver cells.

Three-dimensional rotational angiography (3D-RA) is an established method within the field of interventional neuroradiology. The method has also a great potential in other areas with a complicated arterial anatomy. The purpose of this study was firstly to develop an investigative protocol for 3D-RA in renal transplanted patients with threatening allograft failure in diagnosing stenosis in the transplanted renal artery; secondly the protocol was evaluated and compared with a modified protocol including reduced contrast medium load. Furthermore, the advantages of the 3D reconstructions compared to the angiographic images were evaluated, likewise if an extended angle of rotation reduced the artifacts in the 3D reconstructions. The two protocols were compared with regard to image quality and acute nephrotoxicity. The accuracy of Doppler ultrasonography and the result of percutaneous transluminal angioplasty (PTA) were also assessed. 3D-RA was consecutively performed in 57 renal transplanted patients with suspicion of renal artery stenosis. A significant stenosis was found in 49% of the patients. The 3D reconstructions profiled 43% of the transplant renal artery stenoses better than the angiographic images. An extended angle of rotation reduced the artifacts. There was no statistical difference regarding image quality between the two protocols, and the renal function was equally affected in both protocols. Doppler ultrasonography sensitivity was 100%; specificity was 48% and positive predictive value 67%. PTA had a technical success rate of 92% and a clinical success rate of 75% after 3 months. 3D-RA is a helpful supplement in cases with complicated vascular anatomy, especially when PTA may be indicated. The 3D reconstructions profile the course of the artery more frequently than the angiographic images and support PTA. The 3D reconstructions are degraded of artifacts. Sampling artifacts can be diminished by increased C-arm rotation and increased number of projections. The distortions caused by beam hardening remain to be solved.

Renal artery stenosis (RAS) is a potentially curable cause of hypertension and azotemia. Besides intra-arterial renal angiography there are several non-invasive techniques utilized to diagnose patients with suspicion of renal artery stenosis. Removing the stenosis by revascularization to restore unobstructed blood flow to the kidney is known to improve and even cure hypertension/azotemia, but is associated with a significant complication rate. To visualize renal arteries with x-ray techniques a contrast medium must be used. In a randomized, prospective study the complications of two types of contrast media (CO2 and ioxaglate) were compared. CO2 was not associated with acute nephropathy, but induced nausea and had lower attenuation differences compared to Ioxaglate. Acute nephropathy was related to the ioxaglate dose and the risk was evident even at very low doses if the patients were azotemic with creatinine clearance &lt;40 ml/min. Evaluating patients for clinically relevant renal artery stenosis can be done utilizing several non-invasive techniques. MRA was retrospectively evaluated and shown to be accurate in detecting hemodynamically significant RAS. In a prospective study of 58 patients, evaluated with four methods for renal artery stenosis, it was shown that MRA and CTA were significantly better than ultrasonography and captopril renography in detecting hemodynamically significant RAS. The standard of reference was trans-stenotic pressure gradient measurement, defining a stenosis as significant at a gradient of ≥15 mmHg. The discrepancies were mainly found in the presence of borderline stenosis. The outcome of percutaneous revascularization procedures showed a technical success rate of 95%, clinical benefit in 63% of treated patients, 30-day mortality 1.5% and major complication rate of 13%. The major complication rate for patients with baseline serum creatinine &gt;300µmol/l was 32%. Our results compare favorably with published studies and guidelines.

In this two years master’s thesis I examine the library’s representation of research and its influence upon the relationship between the library practice and the research practice. I also intend to find out what controls the representation and if it is possible to see changes in the representation over time. My source material has been texts published in the Swedish library journal – and social domain – Biblioteksbladet during the last decennium (2001–2011). The method I have used is Norman Fairclough’s critical discourse analysis (CDA) with its three-dimensional, analytical frame-work that focuses on the text, the discursive practice and the social practice. On the level of the social practice I also have included Antonio Gramsci’s theory of hegemony. The results show that the research-image is mainly influenced by pragmatism and marketization and that these two discourses are reflected in the library’s relationship to the research community. An increase in the speech about research may also be noted. At the same time, a similar speech about education and life-long learning is prominent. The explanation I suggest is the hegemonization or naturalization of the ideology of human capital, which is shaping all of the educational institutions. It is principally in this ideological context, and on the basis of real economic demands, the representation of research and the research-connection must be seen.

<p>This study deals with knowledge organization of feminist research, in bibliographic catalogues and in a Swedish context. The thesis develops a definition of feminist discourse which incorporates but is not limited to feminist research. Feminist research, in turn, is understood as articulating a critical approach aimed at critiquing and changing inequitable gender relations. The thesis analyzes the meaning of a range of feminist perspectives through a close text analysis of feminist PhD-dissertations. Two universal knowledge organization systems: Svenska ämnesord and Klassifikationssystem för svenska bibliotek; and one subject-specific system: Kvinnohistoriska samlingarnas ämnesord, are studied in order to discuss the extent to which they are able to articulate feminist perspectives, as well as how they actually articulate such perspectives in practice. The two universal systems studied tend to marginalize feminist perspectives as forms of knowledge. This thesis interprets this marginalization in the light of these systems’ putative objectivistic and universalistic epistemology and ontology. It is suggested that they privilege disciplinary knowledge over interdisciplinary knowledge forms, and substantive topics over conceptual perspectives. Guidelines for knowledge organizatory practice tend to encourage indexers and classifiers to search for central substantive themes. In this schema, feminism is understood as a field relating to socio-political women’s issues. Feminist knowledge qua knowledge is marginalized by the systems studied, and is at times given a plain wrong classifycation. further, this thesis suggests that the subject-specific knowledge organization system studied: Kvinnohistoriska samlingarnas ämnesord, is only able to deal with feminist research in an incomplete and inadequate way. Although this index is designed to classify texts within the broad subject field of: women’s studies, masculinity studies and gender research, as well as other material relevant to the field, the structure of the index is too simple and does not allow for associative relationships between terms; nor does it define feminist discourse. The premises and guidelines for knowledge organization practice are also under-developed or not well defined. Successful organization of feminist knowledge needs instead to be based on a particular understanding of knowledge and knowledge organization as contextually shaped (and shaping). Feminist literature is first and foremost about expressing feminist discourse qua theme, perspective, and part of the feminist tradition (such as critical, women-centring, and reflexive feminisms) – an observation that needs to be reflected in the knowledge organization.</p>

<p>The aims of this work were to image and analyze the needle behavior at automated core biopsy, to investigate the clinical utility of an alternative core biopsy technique using a semiautomated gun in breast and axillary lesions, and also to compare core biopsy with surgical specimens in malignant breast lesions regarding histologic features and hormone receptor expression.</p><p>In two experimental studies, using butter and silicon phantoms, respectively, the needle pass was imaged and its dynamic behavior studied. It was shown that the needle took a curved course in phantoms. It deviated to the same side as where the tip lay, and the degree of the curvature increased with increasing hardness of the phantoms. Our experimental methods can be applied for imaging of needle behavior and thereby improvement of needle configuration.</p><p>In two clinical studies, a semiautomated gun was used for large needle core biopsy of breast and axillary lesions in two series of 145 and 21 patients, respectively. The sensitivity of the method for diagnosis of malignancy was 87% (108/124), and in 37% (31/83) of cases the full length of the needle notch was filled with specimen. No injury to the neurovascular structures of the axillary area was observed. It was concluded that the semiautomated gun can be used as an alternative to the automated gun when the size and location of the lesion render use of the automatic device uncertain or dangerous, e.g., in small breast lesions or lesions located in the axilla.</p><p>In a series of 129 cases of breast cancer, comparison of core biopsy and surgical specimens showed that core biopsy provided enough information on the histologic type and grade of the lesions. Also, there was moderate to high concordance between the two methods for assessment of progesterone receptors and estrogen receptors (Spearman`s kappa 0.67 and 0.89, respectively).</p>

The aims of this work were to image and analyze the needle behavior at automated core biopsy, to investigate the clinical utility of an alternative core biopsy technique using a semiautomated gun in breast and axillary lesions, and also to compare core biopsy with surgical specimens in malignant breast lesions regarding histologic features and hormone receptor expression. In two experimental studies, using butter and silicon phantoms, respectively, the needle pass was imaged and its dynamic behavior studied. It was shown that the needle took a curved course in phantoms. It deviated to the same side as where the tip lay, and the degree of the curvature increased with increasing hardness of the phantoms. Our experimental methods can be applied for imaging of needle behavior and thereby improvement of needle configuration. In two clinical studies, a semiautomated gun was used for large needle core biopsy of breast and axillary lesions in two series of 145 and 21 patients, respectively. The sensitivity of the method for diagnosis of malignancy was 87% (108/124), and in 37% (31/83) of cases the full length of the needle notch was filled with specimen. No injury to the neurovascular structures of the axillary area was observed. It was concluded that the semiautomated gun can be used as an alternative to the automated gun when the size and location of the lesion render use of the automatic device uncertain or dangerous, e.g., in small breast lesions or lesions located in the axilla. In a series of 129 cases of breast cancer, comparison of core biopsy and surgical specimens showed that core biopsy provided enough information on the histologic type and grade of the lesions. Also, there was moderate to high concordance between the two methods for assessment of progesterone receptors and estrogen receptors (Spearman`s kappa 0.67 and 0.89, respectively).