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- Skjevik, Ann-Turi, et al.
(author)
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Utvärdering av växtplankton från Västerhavet
- 2011
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Reports (other academic/artistic)abstract
- SMHI har på uppdrag från Länsstyrelsen i Västra Götaland utvärderat all tillgängligväxtplanktondata från Västerhavet från perioden 1985-2010. Det utvärderade området sträcker sigfrån Riksgränsen (Figur 3) i norr vid norska gränsen till och med Öresund i söder och innefattar 4026 mättillfällen och 115 271 mätvärden.Syftet var att dels kvalitetssäkra och tillgängliggöra befintlig växtplanktondata och studera detomfattande datamaterial som finns från Västerhavet. Man ville undersöka om det finnsförändringar av växtplankton i tid och rum vad det gäller till exempel artsammansättning, giftigaarter, nytillkomna och försvunna arter och totala mängden växtplankton.Vad gäller säsongsvariation så visar sammanställningen av medelcelltätheten av alla data åren2005-2010 på en kort och intensiv vårblomning som domineras av kiselalger vid samtligastationer och typområden. De årliga vårblomningarna startar generellt tidigare i utsjöområdenaoch kommer igång senare närmre kusten och sist i Bohusläns fjordar. Förekomsten avväxtplanktonmaxima skiljer sig åt mellan stationer under resten av året men vanligt är en senvårellersommartopp och alltid en hösttopp i celltäthet av växtplankton.Figur 5 visar typområdena som är indelade enligt EU:s vattendirektiv. Generellt sett så ärartdiversiteten högre vid kusten än i utsjön. Antalet arter ökar i syd-nordlig riktning, med högstdiversitet i typområde 4 (N7 Nidingen) och 1s (Danafjord), båda i Kattegatt.Den stora variationen i storlek mellan växtplankton gör att biovolymsmaxima kan förekommautan motsvarande celltäthetsmaxima. Ett exempel på det är de höga totala cellbiovolymer undersommarmånaderna juni-juli som till stor del orsakas av stora kiselalger men inte finns ijämförelsevis lika höga cellantal.Tidsserier av all tillgänglig data per station av växtplankton testades statistiskt månadsvis ochstationsvis och resultaten visar på ett antal signifikanta trender. Både de totala cellantalen avväxtplankton och de totala antalen arter visar i många fall på en ökande trend.Djupintervallen 0-10 och 10-20 meter jämfördes och det visar sig att både artantal och cellantalhar liknande mönster säsongsmässigt och över tiden. Skillnaden är att celltätheter från 10-20meter ligger något lägre än de från 0-10 meter. Artsmässigt hittar man inte specifika arter unikt idjupprover, utan oftast hittas arterna också i ytprovet vid samma mättillfällen.Vårblomningsmaxima fångas sällan på grund av att det för lång tid mellan provtagningarna, mende upptäcks lika ofta i ytprover som i djupproverna.Antalet arter är generellt sett högre under hösten än under våren och säsongsvariationen är störst itypområde 3: Kosterfjorden, Stretudden och Åstol. Ur ett tidsperspektiv ökar antalet arter ochklasser vid samtliga stationer. En orsak kan vara förbättring av analysmetoder och utrustning, enannan att taxonomisk kunskap utvecklats med hjälp av interkalibreringar och expertgrupper. Ettantal arter har också tillkommit i floran, men de svarar inte för hela ökningen.Ett flertal nya arter, exempelvis kiselalgenCoscinodiscus wailesii och dinoflagellatenProrocentrum minimum, har spridits till Västerhavet på olika sätt. Kiselalgen Pseudosoleniacalcar-avis, som ansetts vara ny och höra hemma i varmare vatten än våra, visar sig finnas irapporter från 1800-talet. En annan ny alg som felaktigt identifierats tillChaetocerosconcavicornisoch sen lika felaktigt till C. convolutus är i själva verket en obeskriven art, härkalladChaetoceros sp.X. Gemensamt för de tre Chaetoceros-arterna är att de är skadliga för fiskpå grund av sina kraftiga spröt med hullingar som kan skada fiskens gälar.4Olika blomningar observeras årligen. Vissa är helt ofarliga som exempelvis vårblomningen avkiselalger och blomningar av kalkflagellatenEmiliania huxleyi. Andra är skadliga genom attorsaka syrebrist eller genom att den aktuella arten som uppträder i förhöjda cellantal är giftig förandra organismer i sin omgivning. Vissa arter är också skadliga i relativt låga cellantal på grundav förmågan att producera toxiner. Säsongsvariationen är artspecifik och en del giftiga arteråterkommer ofta över varningsgränsen under samma månad år efter år. Skadliga algblomningarförekommer relativt frekvent i Västerhavet. Stora blomningar förekommer inte varje år men oftamed något års mellanrum. Ett återkommande problem är dinoflagellater från släktetDinophysissom producerar diarrégifter vilka ansamlas i bl.a. musslor.I uppdraget ingick också att koppla växtplankton med fysikaliska och kemiskaomvärldsparametrar. Salthalt, syrehalt, temperatur och närsaltskoncentrationer togs med för att seom och hur någon eller några parametrar påverkar växtplanktonsamhället. AnalysverktygetPRIMER användes, och inga korrelationer mellan växtplankton och de fysikaliska och kemiskaparametrarna kunde påvisas.
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| 3. |
- Bäck, Tom, 1964, et al.
(author)
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The alpha-camera: a quantitative digital autoradiography technique using a charge-coupled device for ex vivo high-resolution bioimaging of alpha-particles.
- 2010
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In: Journal of nuclear medicine : official publication, Society of Nuclear Medicine. - : Society of Nuclear Medicine. - 1535-5667. ; 51:10, s. 1616-23
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Journal article (peer-reviewed)abstract
- Bioconjugates used in internal radiotherapy exhibit heterogeneous distributions in organs and tumors, implying a risk of nonuniform dose distribution in therapeutic applications using α-particle emitters. Tools are required that provide data on the activity distribution for estimation of absorbed dose on a suborgan level. The α-camera is a quantitative imaging technique developed to detect α-particles in tissues ex vivo. The aim of this study was to evaluate the characteristics of this imaging system and to exemplify its potential use in the development of α-radioimmunotherapy.
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| 5. |
- Cederkrantz, Elin, et al.
(author)
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Evaluation of Effects on the Peritoneum After Intraperitoneal α-Radioimmunotherapy with (211)At.
- 2012
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In: Cancer biotherapy & radiopharmaceuticals. - : Mary Ann Liebert Inc. - 1557-8852 .- 1084-9785. ; 27:6, s. 353-364
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Journal article (peer-reviewed)abstract
- Abstract The introduction of the short-lived α-emitter (211)At to intraperitoneal radioimmunotherapy has raised the issue of the tolerance dose of the peritoneum. The short range of the α-particles (70μm) and the short half-life (7.21h) of the nuclide yield a dose distribution in which the peritoneum is highly irradiated compared with other normal tissues. To address this issue, mice were injected with (211)At-trastuzumab to irradiate the peritoneum to absorbed doses ranging between 0 and 50 Gy and followed for up to 34 weeks. The peritoneum-to-plasma clearance of a small tracer, (51)Cr-ethylenediamine tetraacetic acid, was measured for evaluation of the small solute transport capacity of the peritoneal membrane. The macroscopic status of the peritoneum and the mesenteric windows was documented when the mice were sacrificed. Biopsies of the peritoneum were taken for morphology and immunohistochemical staining against plasminogen activator inhibitor-1 and calprotectin. Peritoneum-to-plasma clearance measurements indicated a dose-dependent decrease in peritoneal transport capacity in irradiated mice. However, macroscopic and microscopic evaluations of the peritoneal membrane showed no difference between irradiated mice versus controls. The results imply that the peritoneal membrane tolerates absorbed doses as high as 30-50 Gy from α-particle irradiation with limited response.
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| 6. |
- Chouin, Nicolas, et al.
(author)
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Ex Vivo Activity Quantification in Micrometastases at the Cellular Scale Using the α-Camera Technique.
- 2013
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In: Journal of nuclear medicine : official publication, Society of Nuclear Medicine. - : Society of Nuclear Medicine. - 1535-5667. ; 54:8, s. 1347-1353
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Journal article (peer-reviewed)abstract
- Targeted α-therapy (TAT) appears to be an ideal therapeutic technique for eliminating malignant circulating, minimal residual, or micrometastatic cells. These types of malignancies are typically infraclinical, complicating the evaluation of potential treatments. This study presents a method of ex vivo activity quantification with an α-camera device, allowing measurement of the activity taken up by tumor cells in biologic structures a few tens of microns. METHODS: We examined micrometastases from a murine model of ovarian carcinoma after injection of a radioimmunoconjugate labeled with (211)At for TAT. At different time points, biologic samples were excised and cryosectioned. The activity level and the number of tumor cells were determined by combined information from 2 adjacent sections: one exposed to the α-camera and the other stained with hematoxylin and eosin. The time-activity curves for tumor cell clusters, comprising fewer than 10 cells, were derived for 2 different injected activities (6 and 1 MBq). RESULTS: High uptake and good retention of the radioimmunoconjugate were observed at the surface of tumor cells. Dosimetric calculations based on the measured time-integrated activity indicated that for an injected activity of 1 MBq, isolated tumor cells received at least 12 Gy. In larger micrometastases (≤100 μm in diameter), the activity uptake per cell was lower, possibly because of hindered penetration of radiolabeled antibodies; however, the mean absorbed dose delivered to tumor cells was above 30 Gy, due to cross-fire irradiation. CONCLUSION: Using the α-camera, we developed a method of ex vivo activity quantification at the cellular scale, which was further applied to characterize the behavior of a radiolabeled antibody administered in vivo against ovarian carcinoma. This study demonstrated a reliable measurement of activity. This method of activity quantification, based on experimentally measured data, is expected to improve the relevance of small-scale dosimetry studies and thus to accelerate the optimization of TAT.
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| 8. |
- Frost, Sofia, 1981, et al.
(author)
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Comparison of (211)At-PRIT and (211)At-RIT of Ovarian Microtumors in a Nude Mouse Model.
- 2013
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In: Cancer biotherapy & radiopharmaceuticals. - : Mary Ann Liebert Inc. - 1557-8852 .- 1084-9785. ; 28:2, s. 108-14
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Journal article (peer-reviewed)abstract
- Abstract Purpose: Pretargeted radioimmunotherapy (PRIT) against intraperitoneal (i.p.) ovarian microtumors using avidin-conjugated monoclonal antibody MX35 (avidin-MX35) and (211)At-labeled, biotinylated, succinylated poly-l-lysine ((211)At-B-PL(suc)) was compared with conventional radioimmunotherapy (RIT) using (211)At-labeled MX35 in a nude mouse model. Methods: Mice were inoculated i.p. with 1×10(7) NIH:OVCAR-3 cells. After 3 weeks, they received PRIT (1.0 or 1.5MBq), RIT (0.9MBq), or no treatment. Concurrently, 10 additional animals were sacrificed and examined to determine disease progression at the start of therapy. Treated animals were analyzed with regard to presence of tumors and ascites (tumor-free fraction; TFF), 8 weeks after therapy. Results: Tumor status at baseline was advanced: 70% of sacrificed animals exhibited ascites. The TFFs were 0.35 (PRIT 1.0MBq), 0.45 (PRIT 1.5MBq), and 0.45 (RIT). The 1.5-MBq PRIT group exhibited lower incidence of ascites and fewer tumors >1mm than RIT-treated animals. Conclusions: PRIT was as effective as RIT with regard to TFF; however, the size distribution of tumors and presence of ascites indicated that 1.5-MBq PRIT was more efficient. Despite advanced disease in many animals at the time of treatment, PRIT demonstrated good potential to treat disseminated ovarian cancer.
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| 9. |
- Frost, Sofia, 1981, et al.
(author)
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In Vivo Distribution of Avidin-Conjugated MX35 and (211)At-Labeled, Biotinylated Poly-l-Lysine for Pretargeted Intraperitoneal ?-Radioimmunotherapy.
- 2011
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In: Cancer biotherapy & radiopharmaceuticals. - : Mary Ann Liebert Inc. - 1557-8852 .- 1084-9785. ; 26:6
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Journal article (peer-reviewed)abstract
- Abstract Purpose: Avidin-coupled monoclonal antibody MX35 (avidin-MX35) and astatine-211?labeled, biotinylated, succinylated poly-l-lysine ((211)At-B-PL(suc)) were administered in mice to assess potential efficacy as an intraperitoneal (i.p.) therapy for microscopic tumors. We aimed to establish a timeline for pretargeted radioimmunotherapy using these substances, and estimate the maximum tolerable activity. Methods: (125)I-avidin-MX35 and (211)At-B-PL(suc) were administered i.p. in nude mice. Tissue distributions were studied at various time points and mean absorbed doses were estimated from organ uptake of (211)At-B-PL(suc). Studies of myelotoxicity were performed after administration of different activities of (211)At-B-PL(suc). Results: We observed low blood content of both (125)I-avidin-MX35 and (211)At-B-PL(suc), indicating fast clearance. After sodium perchlorate blocking, the highest (211)At uptake was found in kidneys. Red bone marrow (RBM) accumulated some (211)At activity. Mean absorbed doses of special interest were 2.3 Gy/MBq for kidneys, 0.4 Gy/MBq for blood, and 0.9 Gy/MBq for RBM. An absorbed dose of 0.9 Gy to the RBM was found to be safe. These values suggested that RBM would be the key dose-limiting organ in the proposed pretargeting scheme, and that blood data alone was not sufficient for predicting its absorbed dose. Conclusions: To attain a favorable distribution of activity and avoid major toxicities, at least 1.0?MBq of (211)At-B-PL(suc) can be administered 24 hours after an i.p. injection of avidin-MX35. These results provide a basis for future i.p. therapy studies in mice of microscopic ovarian cancer.
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| 10. |
- Grosse, Julia, 1982-
(author)
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Kommer tid kommer tillit? : Unga vuxnas och medelålders erfarenheter
- 2012
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Doctoral thesis (other academic/artistic)abstract
- Even though Sweden is considered a high trust society, research on this topic is primarily based on a few standardized survey questions. It is also known that there is a robust pattern of less trustful young people compared to older ones. Still, a satisfactory explanation of this fact is lacking. Thus, the first aim of this dissertation is to map trust among young adults and middle-aged individuals. The second aim is to examine by which factors and in what way different dimensions of trust are determined, focusing on individuals’ life course and consequently experiences. Analytical principles from the life course tradition are used as a theoretical framework.Data is derived from a Swedish cross-sectional nationally representative postal survey on trust, and qualitative interviews using a mixed-methods approach.A multi-dimensional concept of trust is suggested. Participants report relatively high levels of trust in known and unknown people, confidence in institutions, normative notions of trust, security, and trustful behaviour. Trust also seems to be structured according to a closeness principle. Young adults display lower trust levels in general. However, in some respects the pattern is reversed, particularly regarding domains they are expected to be more familiar with.Contrary to the well-established idea of generalised trust derived from predispositions and primary socialization, and particularised trust originating from experiences in adulthood, the results of this study suggest that unique combinations of factors, both individual characteristics and experiences, might explain each of the different dimensions. Often there is a sphere-specific relationship between experiences and later trust, i.e. experiences from one sphere of life seem to exclusively affect trust within the same sphere. It is suggested that as people grow older they accumulate what is called experience capital, which might benefit trust and contribute to an explanation of the age differences.
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