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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

Do the new signal transduction modulators have activity in vitro in tumor cells from ovarian carcinoma and lymphoma?

Lundin, Desiré January 2005 (has links)
<p>During the last decades, chemotherapy with cytotoxic drugs has played a significant role in cancer therapy. It’s important to develop new anticancer drugs, and drug sensitivity testing in vitro can be used to find the right diagnosis for the newly developed substances.</p><p>The aim of this study was to investigate the cytotoxic activity of the new signal transduction modulators bortezomib, gefitinib and PKC412. The well-established substances cisplatin, cytarabine, doxorubicin and vincristin were investigated for comparison.</p><p>The activity of the cytotoxic drugs was analysed in human tumor samples from patients with ovarian carcinoma (n=16) and lymphoma (n=15) by using the Fluorometric Microculture Cytotoxicity Assay (FMCA). The testing of cellular drug resistance by FMCA was accomplished successfully in 33 out of the 34 samples (97%).</p><p>The results of this study indicated that the activity of cytotoxic drugs in tumor cells obtained from patients with ovarian carcinoma and lymphoma may be detected by the FMCA. It also suggested that bortezomib and gefitinib could represent promising agents for treatment of ovarian carcinoma and that PKC412 might be of less use for patients with this diagnose.</p>
32

Do the new signal transduction modulators have activity in vitro in tumor cells from ovarian carcinoma and lymphoma?

Lundin, Desiré January 2005 (has links)
During the last decades, chemotherapy with cytotoxic drugs has played a significant role in cancer therapy. It’s important to develop new anticancer drugs, and drug sensitivity testing in vitro can be used to find the right diagnosis for the newly developed substances. The aim of this study was to investigate the cytotoxic activity of the new signal transduction modulators bortezomib, gefitinib and PKC412. The well-established substances cisplatin, cytarabine, doxorubicin and vincristin were investigated for comparison. The activity of the cytotoxic drugs was analysed in human tumor samples from patients with ovarian carcinoma (n=16) and lymphoma (n=15) by using the Fluorometric Microculture Cytotoxicity Assay (FMCA). The testing of cellular drug resistance by FMCA was accomplished successfully in 33 out of the 34 samples (97%). The results of this study indicated that the activity of cytotoxic drugs in tumor cells obtained from patients with ovarian carcinoma and lymphoma may be detected by the FMCA. It also suggested that bortezomib and gefitinib could represent promising agents for treatment of ovarian carcinoma and that PKC412 might be of less use for patients with this diagnose.
33

Microalbuminuria, blood pressure and cardiovascular risk factors in elderly males

Florvall, Gösta, Basu, Samar, Helmersson, Johanna, Larsson, Anders January 2005 (has links)
Objective - To correlate blood pressure and inflammatory markers with urine albumin analysed with a point-of-care testing (POCT) instrument, nephelometric determination of albumin and creatinine related urine albumin in elderly males. Methods and Results - The study population consisted of 103 diabetic and 603 nondiabetic males (age 77 years) in a cross-sectional study in central Sweden. We analyzed urine albumin with a HemoCue® Urine Albumin POCT instrument and a ProSpec® nephelometer and creatinine related urine albumin. There were strong correlation between both systolic and diastolic blood pressure and all three urine albumin methods (p&lt;0.0001). There were also significant correlations between the different urine albumin measurements and SAA, hsCRP and IL-6. Conclusions - Hypertension has a strong impact on hyperfiltration in diabetic and nondiabetic elderly males.
34

Misfolded superoxide dismutase-1 in amyotrophic lateral sclerosis / Felveckat superoxiddismutas-1 i amyotrofisk lateralskelros

Zetterström, Per January 2011 (has links)
Amyotrophic lateral sclerosis (ALS) is a disease in which the motor neurons die in a progressive manner, leading to paralysis and muscle wasting. ALS is always fatal, usually through respiratory failure when the disease reaches muscles needed for breathing. Most cases are sporadic, but approximately 5–10% are familial. The first gene to be linked to familial ALS encodes the antioxidant enzyme superoxide dismutase-1 (SOD1). Today, more than 160 different mutations in SOD1 have been found in ALS patients.  The mutant SOD1 proteins cause ALS by gain of a toxic property that should be common to all. Aggregates of SOD1 in motor neurons are hallmarks of ALS patients and transgenic models carrying mutant SOD1s, suggesting that misfolding, oligomerization, and aggregation of the protein may be involved in the pathogenesis. SOD1 is normally a very stable enzyme, but the structure has several components that make SOD1 sensitive to misfolding. The aim of the work in this thesis was to study misfolded SOD1 in vivo. Small amounts of soluble misfolded SOD1 were identified as a common denominator in transgenic ALS models expressing widely different forms of mutant SOD1, as well as wild-type SOD1. The highest levels of misfolded SOD1 were found in the vulnerable spinal cord. The amounts of misfolded SOD1 were similar in all the different models and showed a broad correlation with the lifespan of the different mouse strains. The misfolded SOD1 lacked the C57-C146 intrasubunit disulfide bond and the stabilizing zinc and copper ions, and was prinsipally monomeric. Forms with higher apparent molecular weights were also found, some of which might be oligomers. Misfolding-prone monomeric SOD1 appeared to be the principal source of misfolded SOD1 in the CNS. Misfolded SOD1 in the spinal cord was found to interact mainly with chaperones, with Hsc70 being the most important. Only a minor proportion of the Hsc70 was sequestered by SOD1, however, suggesting that chaperone depletion is not involved in ALS.  SOD1 is normally found in the cytoplasm but can be secreted. Extracellular mutant SOD1 has been found to be toxic to motor neurons and glial cells. Misfolded SOD1 in the extracellular space could be involved in the spread of the disease between different areas of the CNS and activate glial cells known to be important in ALS. The best way to study the interstitium of the CNS is through the cerebrospinal fluid (CSF), 30% of which is derived from the interstitial fluid. Antibodies specific for misfolded SOD1 were used to probe CSF from ALS patients and controls for misfolded SOD1. We did find misfolded SOD1 in CSF, but at very low levels, and there was no difference between ALS patients and controls. This argues against there being a direct toxic effect of extracellular SOD1 in ALS pathogenesis. In conclusion, soluble misfolded SOD1 is a common denominator for transgenic ALS model mice expressing widely different mutant SOD1 proteins. The misfolded SOD1 is mainly monomeric, but also bound to chaperones, and possibly exists in oligomeric forms also. Misfolded SOD1 in the interstitium might promote spread of aggregation and activate glial cells, but it is too scarce to directly cause cytotoxicity.
35

Hållbarhet av follikelstimulerande hormon, luteiniserande hormon, progesteron och sexualhormonbindande globulin samt jämförelse av serum och plasma på kemiinstrumentet Siemens ADVIA Centaur XPT. / Stability of follicle-stimulating hormone, luteinizing hormone, progesterone and sex hormone-binding globulin and comparison of serum and plasma on the Siemens ADVIA Centaur XPT chemistry instrument.

Ristić, Katarina January 2023 (has links)
Syftet med projektet var att utvärdera hållbarheten av analyterna follikelstimulerande hormon (FSH), luteiniserande hormon (LH), progesteron (PRGE) och sexualhormonbindande globulin (SHBG) i primärrör förvarade i kyl, i serum såväl som plasma, på ADVIA Centaur XPT (Siemens Healthineers). Samtliga analyter analyserades i serum respektive plasma vid tidpunkterna 0, 24, 48, 72, 96 samt 168 h efter insamling. Analyspåverkan av förvaringstid i kyl och korrelationen mellan analyser i serum och plasma utvärderades. FSH, LH och SHBG uppvisade acceptabla medelbias vid samtliga tidpunkter i båda matriserna. PRGE uppvisade låg medelbias, &lt;15 %, vid samtliga tidpunkter i serum men uppvisade medelbias &gt;15 % i plasma. Analys i plasma skiljde sig minimalt från serum för FSH, LH och SHBG. För PRGE var skillnaderna lite större. Utifrån resultatet bedömdes FSH, LH och SHBG vara hållbara i en vecka i kyl (168 h) i både serum och plasma. PRGE bedömdes vara hållbart i kyl i en vecka i serum men inte godtagbar i plasma. Laboratoriets riktlinjer kan utvidgas för FSH, LH och SHBG att också genomföras i plasma. PRGE fortsatt bör genomföras i serum. / The purpose of the project was to evaluate the stability of the analytes follicle-stimulating hormone (FSH), luteinizing hormone (LH), progesterone (PRGE) and sex hormone-binding globulin (SHBG) in primary collection tubes stored refrigerated, in serum and plasma, on ADVIA Centaur XPT (Siemens Healthineers). All analytes were analyzed in serum and plasma at 0, 24, 48, 72, 96 and 168 h after collection. The impact of storage time on the analysis results and the correlation between analyzes in serum and plasma were evaluated. FSH, LH and SHBG obtained a mean bias &lt;15 %, the threshold, at every moment in both matrices. PRGE showed a mean bias &lt;15 % at every moment in serum but showed a mean bias &gt;15 % in plasma. Analysis in plasma differed minimally from serum for FSH, LH and SHBG. For PRGE, the differences were slightly larger. This study considered FSH, LH and SHBG to be stable for one week (168 h) in both serum and plasma stored refrigerated. PRGE was considered to be stable for one week in serum stored refrigerated, and not acceptable in plasma. Analyzes of FSH, LH and SHBG can be carried out in plasma, while analyzes of PRGE should continue to be performed in serum.
36

Treatment of a mantle cell lymphoma cell line with cannabinoids and cytostatics : - effects on DNA synthesis and ceramide metabolism

Chabo, Ablahad January 2009 (has links)
<p>Mantle cell lymphoma (MCL) is an aggressive B-cell malignancy with bad prognosis, which predominates in males with advanced age. However, studies of the endocannabinoid system and how it affects tumour behaviour provides the basis for designing innovative therapeutic strategies that could open new opportunities for treatment of patient with MCL. It has earlier been shown that the cannabinoid receptor ligand (R)-(+)-methanandamide (R-MA) induce cell death in MCL by accumulation of ceramide. Ceramide has a pro-apoptotic effect on the cell but could be metabolized by the enzymes glucosylceramide synthase (GCS) and sphingosine kinase 1 (SphK1) to molecules with pro-proliferative effect. Therefore, treatments with R-MA on Jeko-1 MCL cell line were performed in this study to determine interference in the proliferative behaviour as well as in the gene expression of the enzymes GCS and SphK1. In addition, treatments with chemotherapeutic substances, such as doxorubicin or cytarabine (Ara-C), and combinations of R-MA and chemotherapeutic substance, were performed for the same reason. Results showed that the proliferation behaviour of Jeko cells remained unaffected when treated with R-MA, in contrast to the decreased proliferative effects shown when treated with cytostatics or combinations of R-MA and cytostatics. Furthermore, a tendency for up-regulation of GCS and SphK1 expression was recognized when cells were treated with cytostatics or combination of cytostatics and R-MA, in contrast to cells treated with R-MA alone. Although, R-MA alone had a tendency for a small down-regulation of GCS expression, it contributed to a potential elevation of GCS expression when combined with Ara-C or doxorubicin. It is believed that the effect from upregulated levels of the metabolizing enzymes GCS and SphK1 is balanced by, earlier observed, up-regulations of the ceramide synthesis enzymes.</p>
37

Sources of preanalytical error in primary health care : implications for patient safety

Söderberg, Johan January 2009 (has links)
Background Venous blood tests constitute an important part in the diagnosis and treatment of patients. However, test results are often viewed as objective values rather than the end result of a complex process. This has clinical importance since most errors arise before the sample reaches the laboratory. Such preanalytical errors affect patient safety and are often due to human mistakes in the collection and handling of the sample. The preanalytical performance of venous blood testing in primary health care, where the majority of the patients contact with care occurs, has not previously been reported. Aims To investigate venous blood sampling practices and the prevalence of haemolysed blood samples in primary health care. Methods A questionnaire investigated the collection and handling of venous blood samples in primary health care centres in two county councils and in two hospital clinical laboratories. Haemolysis index was used to evaluate the prevalence of haemolysed blood samples sent from primary health care centres, nursing homes and a hospital emergency department. Results and discussion The results indicate that recommended preanalytical procedures were not always followed in the surveyed primary health care centres. For example, only 54% reported to always use name and Swedish identification number, and 5% to use photo-ID, the two recommended means for patient identification. Only 12% reported to always label the test tubes prior to blood collection. This increases the possibility of sample mix-up. As few as 6% reported to always allow the patient to rest at least 15 minutes before blood collection, desirable for a correct test result. Only 31% reported to have filed an incident report regarding venous blood sampling, indicating underreporting of incidents in the preanalytical phase. Major differences in the prevalence of haemolysed blood samples were found. For example, samples collected in the primary health care centre with the highest prevalence of haemolysed samples were six times (95% CI 4.0 to 9.2) more often haemolysed compared to the centre with the lowest prevalence. The significant variation in haemolysed samples is likely to reflect varying preanalytical conditions. Conclusions This thesis indicates that the preanalytical procedure in primary health care is associated with an increased risk of errors with consequences for patient safety and care. Monitoring of haemolysis index could be a valuable tool for estimating preanalytical sample quality. Further studies and interventions aimed at the preanalytical phase in primary health care are clearly needed.
38

Some Characteristics of Human Prostasomes and Their Relationship to Prostate Cancer

Ronquist, Göran January 2009 (has links)
Background: The secretory epithelial cells of the prostate gland use sophisticated vehicles named prostasomes to relay important information to sperm cells in semen. This prostasome-forming and secretory ability of the epithelial cells is also preserved in poorly differentiated prostate cancer cells. Aim: The aim of this thesis was to examine different characteristics of prostasomes, especially those derived from malignant prostate cells, linked to their potential role in diagnosis and prognostication of prostate cancer. Results: Serum samples of prostate cancer patients contained autoantibodies against seminal prostasomes in a higher concentration than did control sera. These autoantibodies were most frequently directed against 25 prostasome-associated proteins, but no one was prostate specific. Clusterin was one of the most frequently occurring prostasomal proteins. Elevated titers were however seen in both patients´ and control sera. Clusterin turned out to be a major antigen of seminal prostasomes. No prostate specific or prostate cancer specific protein was discovered upon proteomic analysis of prostasomes deriving from malignant cells of vertebral metastases of prostate cancer patients. Human chromosomal DNA was identified in both seminal prostasomes and PC-3 cell prostasomes and strong evidence existed that the DNA was localized inside the prostasomes. Four out of 13 DNA clones of seminal prostasomes featured gene sequences (31%). The corresponding figures for PC-3 cell prostasomes were 4 out of 16 clones (25%). Conclusions: Prostasomes are immunogenic and give rise to serum autoantibodies. The most frequently occurring autoantibodies were directed against 25 prostasomal proteins but none of these was exclusively prostate specific. Thirty different proteins were identified in prostate cancer metastasis-derived prostasomes but none of these proteins was prostate cancer specific. Human chromosomal DNA was identified in prostasomes of both normal and malignant cell origin.
39

Cisplatin-resistance and cell death in malignant pleural mesothelioma cells

Janson, Veronica January 2008 (has links)
Malignant pleural mesothelioma (MPM) is an aggressive, treatment-resistant tumour. Cisplatin (cis-diamminedichloroplatinum (II)) is the best single-agent chemotherapy for MPM, but platinum-based combination therapies give the best overall response rates. However, cisplatin use is limited by resistance and severe side effects. This thesis has increased the knowledge concerning cisplatin-induced cell death in MPM by describing a novel potential therapeutic target, and three novel phenotypes of cisplatin-resistance in a human MPM cell line (P31) and its cisplatin-resistant sub-line (P31res1.2). The novel potential therapeutic target, and one of the novel phenotypes, was cisplatin-resistant pro-apoptotic BH3-only proteins. In the P31 cells, cisplatin transiently increased pro-apoptotic BH3-only proteins during 6 h of exposure. This response was almost completely abrogated in the P31res1.2 cells. De-regulated caspase activity and activation was the second novel phenotype identified. The P31res1.2 cells had earlier, possibly mitochondria-independent, caspase-3 activation, increased basal caspase-3 activity and increased basal cleavage of caspase-8 and -9. Despite these differences, 6-h equitoxic cisplatin exposures rendered 50-60% of the cells apoptotic in both cell lines. The third novel phenotype was abrogated Na+K+2Cl--cotransporter (NKCC1) activity. Although NKCC1 activity was dispensable for cisplatin-induced apoptosis, balanced potassium transport activity was essential for P31 cell survival. Finally, the survival signalling protein Protein Kinase B (PKB or Akt) isoforms α and γ were constitutively activated in a PI3K-independent manner in P31 cells. In the P31res1.2 cells, PKBα and γ activities were increased, and there was PI3K-dependent activation of PKBβ. However, this increase in PKB isoform activity was not strongly associated to the cisplatin-resistance of the P31res1.2 cells.
40

Bacterial toxins for cancer treatment

Johansson, David January 2008 (has links)
Even though anti‐cancer chemotherapy has been continuously improved during the last decades. problems with adverse effects and drug resistance still constitutes a considerable obstacle and sets a demand for new effective treatment options. Tissue homeostasis in multi‐cellular organisms is maintained through intrinsic cell death, apoptosis, which removes unwanted or damaged cells. Disrupted apoptosis is an important factor in tumorgenesis and drug resistance, therefore induction or restoration of apoptotic pathways is also important for the treatment of cancer. Several naturally occurring bacterial toxins have the ability to induce apoptosis and could thus be candidates to complement or improve the therapeutic effect of other anticancer drugs. The bacterial toxins, adenylate cyclase (AC) toxin from Bordetella pertussis, α‐toxin from Staphylococcus aureus and verotoxin‐1 (VT‐1) from Escherichia coli were investigated for their ability to induce apoptosis in different tumor cell lines. Toxin induction of cell death was investigated by cell viability assays, end‐stage apoptosis induction by DNA‐fregmentation (TUNEL) assay. Toxin receptor expression and signal transduction pathways to apoptosis were investigated by flow cytometry, caspase enzyme activity assays and western blot. Immunohistochemistry was used for identification of toxin receptor expression in tumor tissue samples. AC‐toxin was cytotoxic and induced apoptosis in cultured malignant plural mesothelioma (MPM) and small‐cell lung cancer (SCLC) cells. Low‐toxic concentrations of AC‐toxin enhanced cisplatin cytotoxicity and apoptosis in both cell lines. MPM‐cells with acquired cisplatin resistance were more sensitive to α‐toxin than the less resistant parental MPM cell line. A low‐toxic concentration of α‐toxin re‐sensitized resistant MPM cells to cisplatin cytotoxicity by apoptosis induced through the mitochondrial pathway without detectable activation of common up‐stream apoptosis signalling proteins. VT‐1 was highly cytotoxic and induced apoptosis in globotriosylceramide (Gb3) ‐expressing glioma, breast cancer and non‐small‐cell lung cancer (NSCLC) cells but was not cytotoxic to non‐Gb3‐expressing cells. PPMP, an inhibitor of glucosylceramide synthesis which makes exposed cells unable to synthesize Gb3 rendered Gb3‐expressing cells resistant to VT‐1. MPM cells with acquired‐cisplatin resistance expressed Gb3 in contrast to the absent of expression in the less resistant parental cell line. Gb3, could however be up‐regulated by cisplatin in Gb3‐negative MPM‐cells. Presence of a low‐toxic concentration of VT‐1 potentiated cisplatin‐induced cytotoxicity and apoptosis in the cisplatin‐resistance MPM cell line. VT‐1 was a potent inducer of apoptosis, probably via stress‐induced Mitogen‐activated protein kinase (MAPK)‐signaling involving c‐Jun N‐terminal kinase (JNK) and p38, leading to disruption of the mitochondrial membrane integrety, activation of caspase‐9 and ‐3, and ultimately DNA fragmentation and cell death. Gb3 expression was demonstrated in clinical specimens of glioblastoma and breast cancer making these tumor types interesting for further VT‐1 studies. We conclude that bacterial toxins may be used to induce apoptosis in several types of cancer cells. Low concentrations of verotoxin‐1 and α‐toxin may potentially be used to overcome acquired cisplatin‐resistance in cancer patients.

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