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- Malmström, Annika, 1957-
(författare)
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Studies for Better Treatment of Patients with Glioma
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In Sweden annually over 500 people will be diagnosed with the malignant brain tumor glioma. They are graded from I-IV. The majority are glioblastoma (grade IV) (GBM), these being the most aggressive type. Median survival for those treated with standard of care is expected to be around 15 months. This tumor will mainly affect those 60 years or older.The studies in this thesis focus on treatment of patients with malignant gliomas grade III and IV. The aim of the studies is to improve the care of glioma patients. Papers I and II explored different therapeutic options in randomized trials, to facilitate individualized treatment recommendations. Findings from studies I and II, together with additional trials, demonstrated the importance of analyzing the tumor marker O6-methylguanine DNA methyltransferase (MGMT) methylation status for survival of GBM patients treated with Temozolomide (TMZ). The third paper investigated how the analysis of this marker is implemented internationally.The first study (paper I, Nordic trial) investigated treatment options for patients 60 years or older with GBM. The trial compared standard radiotherapy (SRT) over 6 weeks versus hypofractionated radiotherapy (HRT) over 2 weeks versus single agent TMZ administered in up to six 4 weekly cycles. In all, 342 patients were included in the trial. This study demonstrated that those randomized to TMZ had superior survival as compared to SRT. In addition, quality of life (QoL) data also suggested a better QoL for TMZ treatment than for radiotherapy. The benefit of TMZ treatment seemed to be limited to those with the tumor molecular marker MGMT methylated (inactivated).The second trial (paper II, Neoadjuvant trial) studied whether integrating TMZ treatment with SRT for patients younger than 60 years with GBM (grade IV) and astrocytoma grade III would confer a survival benefit, if administered postoperatively, before the start of SRT (neoadjuvant). TMZ was provided for 2-3 four weekly cycles followed by SRT to patients randomized to neoadjuvant treatment and was compared to postoperative SRT alone. Although this trial could not illustrate any advantage of delaying the start of SRT while administering TMZ for the study cohort in general, for those included as astrocytoma grade III the median survival was found to be superior by 5 years when randomized to neoadjuvant TMZ. This trial also confirmed the importance of MGMT promoter methylation for the efficacy of TMZ.The third study (paper III) investigated international practices for analyzing tumor MGMT promoter methylation status. MGMT analysis can be conducted by various laboratory methods, which in some cases can provide opposing results regarding the MGMT methylation status of the patient´s tumor. This can lead to incorrect treatment recommendations. To establish which methods and cut-offs that are regularly used to determine tumor MGMT status in the clinic, an international survey was provided to those working in the field. We also inquired about opinions regarding an international consensus on how MGMT should be tested. The 152 respondents reported several methodologies and different cut-off levels also for the same method. A majority of respondents warrant international guidelines.In conclusion, the results of the 2 randomized trials contribute to individualized treatment recommendations for patients affected by GBM or astrocytoma grade III. The results of the survey regarding analyses of MGMT clarify the current problematic situation. The request of the respondents regarding international guidelines might contribute to their future development, so that personalized treatment recommendations can be improved.
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| 2. |
- Karlsson, Iulia
(författare)
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Cytokines as diagnostic biomarkers in canine pyometra and sepsis
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Sepsis is a syndrome with high morbidity, mortality and astronomical health care costs and it is challenging to diagnose both in humans and animals due to the lack of suitable diagnostic biomarkers. Although several types of proteins have been suggested as diagnostic biomarkers of sepsis, none of them were shown to be reliable for routine use in the clinical practice. Dogs with uterine bacterial infection called pyometra often develop sepsis and have been suggested as a natural model of sepsis. To investigate whether there is a pattern of biomarkers that can be useful to diagnose bacterial sepsis on early stages in addition to existing clinical criteria, we measured both local gene expression and serum levels of cytokines in dogs with pyometra and compared these levels with known inflammatory markers and blood clotting parameters. Serum concentrations of keratinocyte-derived chemokine (KC)-like protein and the global clot strength were significantly increased both in dogs with pyometra compared to healthy dogs and in dogs with sepsis compared to dogs without sepsis in pyometra. Moreover, the expression levels of the chemokines interleukin (IL)-8 and C-X-C motif ligand 5 (CXCL5) mRNA were significantly higher in uteri from dogs with pyometra compared to healthy dogs and in cultured stromal endometrial cells derived from uteri of healthy dogs and cocultured with LPS or pathogenic Escherichia coli compared to unstimulated cells. Although serum concentrations of IL-8, high-mobility group box 1 (HMGB1), prostaglandin F2α, IL-2, IL-15, IL-18, interferon (IFN)-γ and monocyte-macrophage colony stimulating factor (MG-CSF) were not different between dogs with or without sepsis in the presence of pyometra, some of these cytokines correlated significantly with clinical parameters such as total white blood cell count (correlated with HMGB1) and KC-like (correlated with IL-8). Measurements of serum IL-10, CXCL10, tumor necrosis factor (TNF)-α, IL-6 and IL-4 will require a more sensitive method in dogs with pyometra. Our findings suggest that KC-like, CXCL5 and IL-8 may be useful as early diagnostic biomarkers of sepsis in dogs with pyometra. Further investigation of these chemokines in sepsis may help to improve routines in sepsis diagnosis in dogs and possibly also humans.
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| 3. |
- Bergman, Daniel, et al.
(författare)
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Investigation of interference from canine anti-mouse antibodies in hormone immunoassays
- 2019
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Ingår i: Veterinary clinical pathology. - : Wiley. - 0275-6382 .- 1939-165X. ; 48:S1, s. 59-69
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Canine anti-mouse antibodies are a potential source of immunoassay interference, but erroneous immunoassay results are not always easily identifiable. Anti-Müllerian hormone (AMH) is a marker for the presence of gonads in dogs, but elevated AMH concentrations in neutered dogs could also be caused by antibody interference. For other assays, a discrepant result obtained after antibody precipitation might indicate antibody interference.OBJECTIVES: We aimed to evaluate if canine anti-mouse antibodies are a source of erroneous results in the AMH assay and if antibody precipitation with polyethylene glycol (PEG) is a useful tool for detecting antibody interference in a variety of immunoassays used in the veterinary clinical laboratory.METHODS: Twenty-nine positive and 25 negative samples for anti-mouse antibodies were analyzed for AMH, canine total thyroxine (TT4), canine thyroid-stimulating hormone (TSH) and progesterone before and after treatment with PEG. Results that differed by more than four SDs from the intra-assay coefficients of variation were considered discrepant. Elevated AMH concentrations in neutered dogs with anti-mouse antibodies and no visible gonads present were considered evidence of interference.RESULTS: Evidence of antibody interference was found in two samples analyzed for AMH. The presence of anti-mouse antibodies did not lead to a higher proportion of discrepant results after PEG treatment for any of the immunoassays. The overall incidence of discrepant results for healthy controls was very high (73%).CONCLUSIONS: Canine anti-mouse antibodies are a source of erroneous AMH results. Antibody precipitation with PEG is not a useful tool for detecting interference caused by such antibodies.
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| 4. |
- Hillström, Anna
(författare)
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Canine C-reactive protein : validation of two automated canine-specific C-reactive protein assays and studies on clinical and research applications
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- C-reactive protein (CRP) is a sensitive and specific marker of systemic inflammation in dogs, valuable for diagnosing and monitoring inflammatory diseases. The use of CRP in canine medicine has however been hampered by the lack of automated assays optimized for measuring CRP in this species. The need for improved CRP assays was the reason for initiating the current project, with the goal to generate automated, canine-specific CRP tests that could reliably measure serum CRP over the whole concentration range expected to occur in dogs. Two different assays were developed for this purpose. One was designed for routine diagnostic testing, and one was a high-sensitivity CRP test intended for research. Method validation studies were performed, demonstrating that both tests met the predefined quality criteria. Using the two novel CRP tests, it was possible to reliably measure serum CRP concentrations in the range of 0.5-1200 mg/l. After successful termination of the validation studies, the CRP assays were used in clinical research studies. C-reactive protein concentrations were measured in dogs with pyometra undergoing ovariohysterectomy, to evaluate how surgical treatment affected degree of systemic inflammation in these patients. Two other studies were performed to evaluate the usefulness of CRP as a diagnostic test. C-reactive protein concentration was found to discriminate well between dogs with suppurative arthritis and dogs with osteoarthritis, whereas measurement of CRP was not efficient for diagnosing late post-operative bacterial infections after orthopaedic surgery because these infections often did not elicit a systemic inflammatory response. In conclusion, two novel automated canine-specific CRP assays were developed and validated with satisfactory results. The tests showed high practicability for measuring CRP in samples from clinical research studies. Availability of these assays will facilitate the use of CRP as a routine diagnostic test in veterinary medicine, and can improve quality in research on canine inflammatory diseases.
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| 5. |
- Rising, Anna, et al.
(författare)
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Systemic AA amyloidosis in the red fox (Vulpes vulpes)
- 2017
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Ingår i: Protein Science. - : WILEY. - 0961-8368 .- 1469-896X. ; 26:11, s. 2312-2318
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Tidskriftsartikel (refereegranskat)abstract
- Amyloid A (AA) amyloidosis occurs spontaneously in many mammals and birds, but the prevalence varies considerably among different species, and even among subgroups of the same species. The Blue fox and the Gray fox seem to be resistant to the development of AA amyloidosis, while Island foxes have a high prevalence of the disease. Herein, we report on the identification of AA amyloidosis in the Red fox (Vulpes vulpes). Edman degradation and tandem MS analysis of proteolyzed amyloid protein revealed that the amyloid partly was composed of full-length SAA. Its amino acid sequence was determined and found to consist of 111 amino acid residues. Based on inter-species sequence comparisons we found four residue exchanges (Ser31, Lys63, Leu71, Lys72) between the Red and Blue fox SAAs. Lys63 seems unique to the Red fox SAA. We found no obvious explanation to how these exchanges might correlate with the reported differences in SAA amyloidogenicity. Furthermore, in contrast to fibrils from many other mammalian species, the isolated amyloid fibrils from Red fox did not seed AA amyloidosis in a mouse model.
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