Diss. (sammanfattning) Uppsala : Univ., 2003. / Härtill 4 uppsatser.

Diss. (sammanfattning) Umeå : Univ., 2004. / Härtill 5 uppsatser.

Thesis (doctoral)--Lund University, 1994. / Added t.p. with thesis statement inserted.

Thesis (doctoral)--Lund University, 1994. / Added t.p. with thesis statement inserted.

Statement of the problem The primary objective of this thesis was to determine the best study design to evaluate the safety and effectiveness of an intermediate dose of low molecular weight heparin for secondary prevention of pregnancy associated VTE (PAVTE). An RCT was deemed unfeasible,so the use of a single arm study with prior evaluation of feasibility with a pilot study is proposed. // Methods - A systematic review was conducted to evaluate the efficacy of current strategies used for secondary prevention of PAVTE.A survey was used to elicit the non-inferiority margin. // Results - The pooled proportion of recurrent VTE in patients treated with full dose LMWH was 0.012(95% CI 0.006 to 0.02) and the rate of major bleeding was 0.025(95% CI=0.01 to 0.041). The non-inferiority margin was elicited at 2.5%. // Conclusions - Although a randomized controlled trial should be conducted whenever possible, in certain scenarios they are unfeasible. Therefore, an alternative study design should perhaps be used to evaluate the safety and efficacy of therapeutic strategies.

No description available.

Heparin is a complex mixture of sulfated polysaccharides derived from animals and one of the oldest drugs in use. While an efficacious anticoagulant, heparin is beset by side effects and pharmacokinetic difficulties. Low molecular weight heparins (LMWH) are made by depolymerizing unfractionated heparin (UFH) and present improvements in these areas. However, they still retain a phenomenally high level of complexity due to their polydispersity and the introduction of non-native structural features. This makes the structural characterization LMWHs a daunting task. This work details the development of a novel capillary electrophoretic (CE) method for fingerprinting LMWHs. Since their complexity normally results in a nearly featureless electropherogram, polyalkylamines were used as a resolving agents to yield highly resolved and reproducible fingerprints characteristic of the LMWH being investigated. Linear polyamines of resolved LMWH in a manner dependent on chain length and charge density, while cyclic polyamines were incapable of resolution. Longer length glycosaminoglycans such as UFH and chondroitin sulfate were not successfully fingerprinted as they lacked run to run consistency. Further investigation into the mode of polyamine binding showed that they bound to LMWH via a two site binding model, indicating the presence of specific sites on LMWH that tightly bind polyamines. Upon the saturation of these sites, the polyamines continue to interact via general electrostatic binding. Pentaethylenehexamine was also able to separate the known contaminant oversulfated chondroitin sulfate from UFH. In July of 2010, the US food and drug administration approved a generic for the widely used LMWH enoxaparin, a questionable move due to the difficulties of proving the equivalence of such a complex mixture. A comparison of the brand and generic batches of enoxaparin using the fingerprinting method revealed striking similarities, bolstering the generic’s claim of equivalency and providing a protocol for the evaluation of other biosimilar LMWHs. This is the first work utilizing CE in developing high resolution fingerprints of LMWH. It presents a noteworthy method for quality assessment of LMWH and provides the basis for designing other small molecule probes for the analysis of complex glycosaminoglycans.

Low molecular weight gelators (LMWGs) are small molecules that are capable of entrapping solvents to form a gel in organic solvents or aqueous solution. These compounds rely solely on noncovalent forces to form the fibrous networks necessary to entrap a variety of solvents. The organogels and hydrogels thus formed could have applications in a variety of fields from environmental to biological to medicinal. Carbohydrates are ideal starting materials to synthesize LMWGs, because of their natural abundance, dense chirality, and biocompatibility. D-Glucose is the most common monosaccharide and D-glucosamine is isolated from natural sources, such as crab shells. Several series of compounds were synthesized using compounds 1-3 as the starting materials. These include esters, carbamates, amides, and ureas. The structure and gelation relationship was analyzed to obtain guidelines for designing new LMWGs. Compound 1 is a simple derivative of D-glucose and its terminal alkynyl esters and saturated carbamates are effective gelators. Compound 2 is a simple derivative of D-glucosamine and its amide and urea derivatives are also effective gelators. Compound 3 is formed from the deoxygenation of D-glucose. 1OOHOOCH3OHOPh2OOHOOCH3NH2OPh3OOHOOHOPh The design, synthesis and gelation properties of several classes of sugar based low molecular organo/hydrogelators will be discussed in this thesis in chapters 2, 3, and 4. After obtaining highly effective organo/hydrogelators, potential applications of these novel molecular systems can be explored. Some preliminary study on using one of the gelator in enzyme assay has shown that it is possible to utilize the hydrogels to immobilize enzymes. However, future research can explore further on the applications of these gelators.

Despite the recognized advances in the treatment of breast cancer, it still accounts for 15% of all cancer-related deaths. 90% of breast cancer deaths are due to unpredicted metastasis. There is neither successful treatment for metastatic patients nor a specific test to predict or detect secondary lesions. Patients with primary tumor will be either over-treated with cytotoxic side effects or under-treated and risk recurrence. This necessitates the need for personalized treatment, which is hard to offer for such heterogeneous disease. Obstacles in treating breast cancer metastasis are mainly due to the gaps exist in the understanding of the molecular mechanism of metastasis. The linear model of metastasis is supported by several observations that reflect an early crosstalk between the primary and secondary tumor, which in turn makes the secondary microenvironment fertile for the growth of disseminated cells. This communication occurs through circulation and utilizes molecules which have not been identified to date. Identifying such molecules may help in detecting initial stages of tumor colonization and predict the target organ of metastasis. Furthermore, these molecules may help to provide a personalized therapy that aims to tailor treatment according to the biology of the individual tumor. Advances in proteomics allows for more reproducible and sensitive biomarker discovery. Proteomic biomarkers are often more translatable to the clinic compared to biomarkers identified using other omics approaches. Further, protein biomarkers can be found in biological fluids making them a non-invasive way to treat or investigate cancer patients. We present in this manuscript our study of the use of a proteomic approach on blood serum samples of metastatic and non-metastatic patients using LC-MS/MS quantitative analysis machine to identify molecules that could be associated with different stages of breast cancer metastasis. We focused on the deferential expression of low molecular weight biomolecules known to reflect disease-specific signatures. We manually analyzed 2500 individual small biomolecules in each serum sample of total of 51 samples. Comparisons between different sample types (from stage I and III Breast Cancer patients in this case) allows for the detection of unique short peptide biomarkers present in one sample type. We built a multi-biomarker model with more sensitivity and specificity to identify the stage of the tumor and applied them on blinded set of samples to validate prediction power. We hope that our study will provide insights for future work on the collection, analysis, and understanding of role of molecules in metastatic breast cancer.

The low-molecular weight proteome is of great interest due to the vast number of smaller proteins and peptides present within it, some of which are likely to be disease-related and may provide insights into disease mechanisms or even prediction and diagnosis. Serum is often the most preferred specimen for disease prediction or diagnosis, as it can be obtained less-invasively and its collection is fairly routine in a clinical setting. Although serum samples are one of the most preferred specimens for disease studies, additional disease information may also be obtained using other specimens, such as tissue. The study of tissue specimens can be extremely valuable in disease studies as it likely contains the highest concentration of potential markers for tissue related diseases. Therefore, despite the difficulty of sample collection, as compared to serum specimens, tissue specimens can be invaluable in studying tissue-related diseases. Tissue proteomics approaches for studying the low-molecular weight proteome of tissue have been infrequently described in the literature, which suggests the need to develop new methods or improve upon current proteomics approaches to better study this subset of the proteome in tissue. In this dissertation, I first report on a low-molecular weight tissue proteomics approach that we have developed based on a previously reported serum approach. As reported here, we conclude that this tissue proteomics approach cannot only distinguish the low-molecular weight proteome of different tissue types, but it also appears to be within the reproducibility range of other currently used proteomic approaches. Additionally, we also report on the use of a serum proteomics approach for biomarker discovery and identification in preeclampsia and endometriosis. These studies reveal many candidate biomarkers for preeclampsia prediction and endometriosis diagnosis. In the preeclampsia study we discovered several candidate biomarkers early in pregnancies (12-14 weeks gestation) that were able to predict preeclampsia later in pregnancy with statistical significance. In the endometriosis study, several candidate biomarkers were discovered that were statistically significant in diagnosing endometriosis. Further, for both preeclampsia and endometriosis, combinations of 3 or 4 biomarkers yielded an improved sensitivity and specificity in disease prediction and diagnosis with combined area under the curves of greater than 0.8. Thus, the low-molecular weight proteome of both tissue and serum could potentially provide important information regarding disease physiology, prediction, and diagnosis that may supplement our current understanding of these processes.