| 6151. |
- Sulniute, Rima, et al.
(författare)
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Plasmin is essential in preventing periodontitis in mice
- 2011
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Ingår i: American Journal of Pathology. - : Elsevier BV. - 0002-9440 .- 1525-2191. ; 179:2, s. 819-828
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Tidskriftsartikel (refereegranskat)abstract
- Periodontitis involves bacterial infection, inflammation of the periodontium, degradation of gum tissue, and alveolar bone resorption, which eventually leads to loss of teeth. To study the role of the broad-spectrum protease plasmin in periodontitis, we examined the oral health of plasminogen (Plg)-deficient mice. In wild-type mice, the periodontium was unaffected at all time points studied; in Plg-deficient mice, periodontitis progressed rapidly, within 20 weeks. Morphological study results of Plg-deficient mice revealed detachment of gingival tissue, resorption of the cementum layer, formation of necrotic tissue, and severe alveolar bone degradation. IHC staining showed massive infiltration of neutrophils in the periodontal tissues. Interestingly, doubly deficient mice, lacking both tissue- and urokinase-type plasminogen activators, developed periodontal disease similar to that in Pig-deficient mice; however, mice lacking only tissue- or urokinase-type plasminogen activator remained healthy. Supplementation by injection of Pig-deficient mice with human plasminogen for 10 days led to necrotic tissue absorption, inflammation subsidence, and full regeneration of gum tissues. Notably, there was also partial regrowth of degraded alveolar bone. Taken together, our results show that plasminogen is essential for the maintenance of a healthy periodontium and plays an important role in combating the spontaneous development of chronic periodontitis. Moreover, reversal to healthy status after supplementation of Pig-deficient mice with plasminogen suggests the possibility of using plasminogen for therapy of periodontal diseases. (Am J Pathol 2011, 179:819-828; DOI: 10.1016/j.ajpath.2011.05.003)
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| 6152. |
- Sun, Aijun, 1973-
(författare)
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Radiolabeled acetate PET in oncology imaging : studies on head and neck cancer, prostate cancer and normal distribution
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The use of positron emission tomography (PET) for imaging in oncology has grown rapidly in recent years. 2-[18F]-fluorodeoxyglucose (FDG) is the most common tracer of PET, although drawbacks exist. Radiolabeled 1-[11C]-acetate (C-AC) is a simple probe for evaluation of perfusion, anabolism (lipogenesis) and catabolism (oxidative metabolism) in all living tissues. This study explored the potential of AC PET in head and neck cancer, benign and malignant lymph nodes in prostate cancer and normal distribution. In head and neck cancer, C-AC PET detected more primaries and lymph node metastases than FDG PET. The mean primary tumor volumes delineated by C-AC was 51% larger than that of FDG before radiotherapy (RT). Both FDG and C-AC PET tumor volumes must be carefully validated before used in clinical routine. Baseline tumor clearance rate (kmono) was higher in complete responders (CR) than that in partial responders (PR). kmono tended to correlate inversely with FDG SUV at baseline. Radiosensitive tumors might rely predominantly on oxidative metabolism for their biogenetic needs. kmono increased in PR during RT. The potential reversibility of impaired kmono in radioresistant tumors imply that treatment targeting the intermediary metabolism might improve the outcome. Tumor relative perfusion index (rF) and kmono were coupled in CR throughout the RT, but not in PR. Dynamic C-AC PET provides a new non-invasive method to simultaneously evaluate the tumor oxidative metabolism and perfusion which link the RT response in patients by a single tracer injection. In prostate cancer, elevated C-AC accumulation is common in benign inguinal lymph nodes, probably due to increased lipogenesis rather than lymphatic drainage. CT Hounsfield unit of benign nodes was lower than that of metastases, suggesting that density measurement using CT might improve the specificity of nodal staging of prostate cancer. A novel tracer 2-[18F]-fluoroacetate (F-AC) was synthesized and used for dynamic PET-CT imaging in animals. Compared with C-AC PET-CT, F-AC showed prolonged blood retention, no detectable trapping in myocardium and salivary glands, rapid excretion from liver to bile and urine and de-fluorination resulting in intensive skeletal activity. F-AC does not mimic the normal physiologic path of C-AC and appears to be of little use for assessment of perfusion, intermediary metabolism or lipogenesis.
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| 6153. |
- Sun, Jing, et al.
(författare)
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Development and characterization of 10 microsatellite loci in paeonia lactiflora (paeoniaceae)
- 2011
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Ingår i: American Journal of Botany. - Lancaster, Pa. : Published in cooperation with the Botanical Society of America by the Brooklyn Botanic Gardens. - 0002-9122 .- 1537-2197. ; 98:9, s. E242-E243
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Tidskriftsartikel (refereegranskat)abstract
- Premise of the study: Microsatellite primers were developed in Paeonia lactiflora for further population genetic studies. Methods and Results: Ten dinucleotide microsatellite markers were developed using an enriched genomic library. They were identified in 58 individuals, and nine markers were also amplified in its cultivars. The number of alleles per locus ranged from three to 11, with a mean of six. The observed and expected heterozygosities ranged from 0.1662 to 0.9140 and from 0.0841 to 0.8157, respectively. Conclusions: These microsatellite markers will facilitate further studies on population genetics variation and genetic structure of P. lactiflora.
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| 6154. |
- Sun, M, et al.
(författare)
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In vitro and in vivo testing of novel ultrathin PCL and PCL/PLA blend films as peripheral nerve conduit
- 2010
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Ingår i: Journal of Biomedical Materials Research. Part A. - : Wiley. - 1549-3296 .- 1552-4965. ; 93:4, s. 1470-1481
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Tidskriftsartikel (refereegranskat)abstract
- In an attempt to obviate the drawbacks of nerve autograft, ultrathin microporous biodegradable PCL and PCL/PLA films were tested for their compatibility with motor neuron-like NG108-15 cells and primary Schwann cells. Data obtained from MTS colorimetric and DNA fluorimetric assays showed that both cell lines readily attached and proliferated on these materials. Images taken using scanning electron microscope and fluorescence microscope confirmed these observations. Enhanced cell-surface interaction was achieved by pretreating the films in NaOH solution. Importantly, NG108-15 cells could be induced into differentiated phenotype with long, un-branched neurites growing across the surface of the materials. The bipolar spindle-shaped phenotype of Schwann cells was also retained on these scaffolds. Positive immunochemical staining using antibodies against neurofilament for NG108-15 cells and S100 for Schwann cells indicated the expression of these marker proteins. In a small-scaled pilot testing, the performance of PCL conduits in bridging up a 10 mm gap in rat sciatic nerve model was assessed. Immunohistochemical staining showed that regenerated nerve tissue and penetrated Schwann cells have the potential to span the whole length of the conduit in 2 weeks.
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| 6155. |
- Sun, Mingzhu, et al.
(författare)
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Novel thin-walled nerve conduit with microgrooved surface patterns for enhanced peripheral nerve repair
- 2010
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Ingår i: Journal of materials science. Materials in medicine. - : Springer. - 0957-4530 .- 1573-4838. ; 21:10, s. 2765-2774
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Tidskriftsartikel (refereegranskat)abstract
- Randomly aligned nerve cells in vitro on conventional culture substrata do not represent the complex neuronal network in vivo and neurites growing in uncontrolled manner may form neuroma. It is of great importance to mimic the organised growth pattern of nerve cells in the study of peripheral nerve repair. The aim of this work was to modify and optimize the photolithographic technique in creating a reusable template in the form of a silicon wafer that could be used to produce contact guidance on biodegradable polymer surface for the orientated growth of nerve cells. Micro-grooves (approximately 3 μm in depth) were etched into the silicon template using KOH at increased temperature. The originality of this work lies in the low cost and high efficiency method in producing microgrooves on the surface of biodegradable ultra-thin polymer substrates (50-100 μm), which can be readily rolled up to form clinically implantable nerve conduits. The design of a pattern with small ridge width (i.e., 5 μm) and bigger groove width (i.e., 20 μm) favored the alignment of cells along the grooves rather than on the ridges of the patterns, which minimized the effect of cross growing of neurites between adjacent grooves. Effectively, enhanced nerve regeneration could be anticipated from these patterned conduits.
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| 6156. |
- Sund, Malin, 1972-, et al.
(författare)
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Endogenous matrix-derived inhibitors of angiogenesis
- 2010
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Ingår i: Pharmaceuticals. - : MDPI AG. - 1424-8247. ; 3, s. 3021-3039
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Tidskriftsartikel (refereegranskat)abstract
- Endogenous inhibitors of angiogenesis are proteins or fragments of proteins that are formed in the body, which can inhibit the angiogenic process. These molecules can be found both in the circulation and sequestered in the extracellular matrix (ECM) surrounding cells. Many matrix-derived inhibitors of angiogenesis, such as endostatin, tumstatin, canstatin and arresten, are bioactive fragments of larger ECM molecules. These substances become released upon proteolysis of the ECM and the vascular basement membrane (VBM) by enzymes of the tumor microenvironment. Although the role of matrix-derived angiogenesis inhibitors is well studied in animal models of cancer, their role in human cancers is less established. In this review we discuss the current knowledge about these molecules and their potential use as cancer therapeutics and biomarkers.
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| 6157. |
- Sundberg, Bodil, 1966-, et al.
(författare)
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The Development of Pre-school Student Teachers´ Attitudes Towards Science and Science Teaching During Their University Studies
- 2010
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Ingår i: Contemporary science education research. - Istanbul : Ankara Pegem Akademi. - 9786053640325 ; , s. 157-166, s. 157-166
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Konferensbidrag (refereegranskat)abstract
- Considerable concern has been raised in Sweden about decreasing interest in science among young people. One key to improving attitudes towards science is an early positive contact with science. Numerous studies have however shown that elementary and pre-school teacher generally have negative attitudes towards science and science teaching, as well as poor science content knowledge. As a consequence, science teaching in pre-schools often is fragmented. A pre-school teacher education that prepares student teachers for teaching science with confidence has therefore been put forward as a way of increasing quality science teaching in pre-schools. In this longitudinal study, attitudes towards science and science teaching of students enrolled in a science and art oriented pre-school teacher programme were followed during their first years of university studies.The results show that the socialization process into the scientific discourse takes time, and that one full year of exposure to activities with scientific content was needed for skeptical attitudes towards science to change. The results also indicate that dominant attitudes, norms and behaviors of the pre-school professional culture may clash with developing science teaching skills. Pre-school teacher education therefore also needs to communicate about these contradicting cultures.
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| 6158. |
- Sundberg, Bodil, 1966-, et al.
(författare)
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What are the voices of becoming practitioners telling us about science in pre-school? : Pre-school student teachers´ attitudes towards science and science teaching - a longitudinal study.
- 2010
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Ingår i: 20th EECERA ANNUAL CONFERENCE. KNOWLEDGE AND VOICE IN EARLY CHILDHOOD. ; , s. 216-216
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Konferensbidrag (refereegranskat)abstract
- The aim of this study is to investigate the relationship between the developing professional identity and attitudes towards science teaching among student pre-school teachers. We see professional identity as a dynamic equilibrium between the professional self-image and the variety of roles (pre-school) teachers feel they have to play. Accordingly, professional identity can change over time through relevant others, events and experiences. In this longitudinal study, 65 students enrolled in an art and science dominated teacher programme have been followed since the start in august 2008. Results are presented from 4 consecutive questionnaires and an individual interview of 8 students. The results show that sceptical attitudes towards science decreased significantly after one year of science studies. On the contrary hesitance towards holding structured scientific activities persisted throughout the year. Results from the individual interviews confirm these findings. Here, the descriptions of perceived relevant roles of their profession are dominated by themes of caring and supporting, not teaching. The reluctance towards science teaching in early years thus appear to be more connected to student teachers’ view of the professional preschool teacher role, where structured teaching not is a pronounced part, than to negative attitudes towards science itself. These findings thereby contradict the general idea that the ambiguity about teaching science in pre-school among student teachers is connected to negative attitudes toward science as a subject. This new perspective suggests a need to integrate a discussion of the pre-school teacher role and professional identity into science courses for becoming pre-school teachers.
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| 6159. |
- Sundberg, Erik, 1979-, et al.
(författare)
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Evidence of disseminated intravascular coagulation in a hemorrhagic fever with renal syndrome-scoring models and severe illness
- 2011
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Ingår i: PLOS ONE. - San Francisco, CA : Public Library of Science. - 1932-6203. ; 6:6, s. e21134-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Viral hemorrhagic fevers (VHF) are considered to be a serious threat to public health worldwide with up to 100 million cases annually. The general hypothesis is that disseminated intravascular coagulation (DIC) is an important part of the pathogenesis. The study objectives were to study the variability of DIC in consecutive patients with acute hemorrhagic fever with renal syndrome (HFRS), and to evaluate if different established DIC-scores can be used as a prognostic marker for a more severe illness. Method and Findings: In a prospective study 2006–2008, data from 106 patients with confirmed HFRS were analyzed and scored for the presence of DIC according to six different templates based on criteria from the International Society on Thrombosis and Haemostasis (ISTH). The DIC-scoring templates with a fibrinogen/CRP-ratio were most predictive, with predictions for moderate/severe illness (p<0.01) and bleeding of moderate/major importance (p<0.05). With these templates, 18.9–28.3% of the patients were diagnosed with DIC. Conclusions: DIC was found in about one fourth of the patients and correlated with a more severe disease. This supports that DIC is an important part of the pathogenesis in HFRS. ISTH-scores including fibrinogen/CRP-ratio outperform models without. The high negative predictive value could be a valuable tool for the clinician. We also believe that our findings could be relevant for other VHFs.
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| 6160. |
- Sundberg, Kay K., et al.
(författare)
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Long-term survivors of childhood cancer report quality of life and health status in parity with a comparison group
- 2010
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Ingår i: Pediatric Blood & Cancer. - : Wiley. - 1545-5009 .- 1545-5017. ; 19, s. 78-78
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: There is a need for more knowledge about how survivors of childhood cancer perceive their lives and what influence current health status has on their quality of life. The purpose was to describe this among a group of long-term survivors and among a comparison group. PROCEDURE: Telephone interviews were performed with a cohort of 246 long-term survivors and 296 randomly selected from the general population using the Schedule for the Evaluation of Individual Quality of Life-Direct Weighting (SEIQoL-DW). The participants nominated the areas they considered to be most important in life and rated the current status of each area on a seven-point category scale. An overall individual index score was calculated as a measure of quality of life. Self-reported health status was assessed using the Short Form Health Survey (SF-36). RESULTS: Long-term survivors rated their overall quality of life and self-reported health status almost in parity with the comparison group. In both groups, family life, relations to other people, work and career, interests and leisure activities were the areas most frequently reported to influence quality of life. The survivors only differed from the comparison group on one of eight SF-36 scales reflecting problems with daily activities owing to physical health. CONCLUSIONS: Health status was not shown to have a major impact on overall quality of life, indicating that health and quality of life should be evaluated distinctively as different constructs. This should be taken in consideration in clinical care of children with childhood cancer and long-term survivors.
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