Munin: Browsing by Title

Slåtsve, Arne Martin (Mastergradsoppgave; Master thesis, 15-Sep-2009)

[+]

Abstract:

ABC (ATP-binding cassette)-transportører er store, evolusjonsmessig høykonserverte membranproteiner som er påvist i alle arter fra prokaryoter til komplekse organismer. ABC-transportørene muliggjør energiavhengig transport av spesifikke substrater gjennom cellemembraner. Blant substratene vi kjenner er lipider, karbohydrater, peptider, vitaminer, steroidhormoner, xenobiotika og medikamenter. ABC-transportørene kjennetegnes av to karakteristiske ATP-bindende kassetter og to komplekse transmembrane domener. I de ATP-bindende kassettene genereres energi til substrattransporten ved ATP-hydrolyse. De transmembrane domenene forankrer ABC-transportørene i cellemembranen og danner transportveien gjennom denne. Det humane genom har 48 identifiserte ABC-transportørgener. Genene inndeles på bakgrunn av strukturlikhet i sju klasser (ABCA – ABCG). I løpet av de siste 30 årene har forskningen avdekket stadig mer om ABC-transportørenes fysiologiske betydning, deres rolle i patologien og farmakologien. I dag vet man at disse proteinene forhindrer fritt opptak av en rekke medikamenter fra GI-tractus, samt begrenser distribusjonen av medikamenter til blant annet hjernen, placenta, testes og hjertet. Transportørene er også sentrale i såkalt multimedikamentell resistens hos cancerceller og mikroorganismer. Man har utviklet flere måter å manipulere transportørene på - blant annet ved bruk av såkalte inhibitorer, for å bedre opptak og distribusjon av medikamenter. Mutasjoner i ABC-genene forårsaker en rekke sykdommer, og genene er gjenstand for til dels betydelige individuelle og etniske variasjoner. I denne litteraturstudien vil den mest sentrale kunnskapen om ABC-transportørene bli presentert. Innledningsvis vil historien om deres oppdagelse bli skissert, etterfulgt av generelle fakta om deres funksjon, struktur, regulering og evolusjonære opphav. Enkelte genetiske sykdommer vil også bli omtalt. Avslutningsvis vil ABC-transportørenes rolle i farmakokinetikken bli belyst.

URI:

http://hdl.handle.net/10037/2261

File(s) in this item: 1

thesis.pdf (281.8Kb)

Acculturation and self-rated health among Arctic indigenous peoples : a population-based cross-sectional study

Eliassen, Bent-Martin; Braaten, Tonje; Melhus, Marita; Hansen, Ketil Lenert; Broderstad, Ann Ragnhild (Journal article; Tidsskriftartikkel; Peer reviewed, 2012)

[+]

Abstract:

Acculturation is for indigenous peoples related to the process of colonisation over centuries as well as the on-going social transition experienced in the Arctic today. Changing living conditions and lifestyle affect health in numerous ways in Arctic indigenous populations. Self-rated health (SRH) is a relevant variable in primary health care and in general public health assessments and monitoring. Exploring the relationship between acculturation and SRH in indigenous populations having experienced great societal and cultural change is thus of great importance. The principal method in the Survey of Living Conditions in the Arctic (SLiCA) was standardised face-to-face interviews using a questionnaire. Very high overall participation rates of 83% were obtained in Greenland and Alaska, whilst a more conventional rate of 57% was achieved in Norway. Acculturation was conceptualised as certain traditional subsistence activities being of lesser importance for people’s ethnic identity, and poorer spoken indigenous language ability (SILA). Acculturation was included in six separate gender- and country-specific ordinal logistic regressions to assess qualitative effects on SRH. Multivariable analyses showed that acculturation significantly predicted poorer SRH in Greenland. An increased subsistence score gave an OR of 2.32 (P<0.001) for reporting poorer SRH among Greenlandic men, while an increased score for Greenlandic women generated an OR of 1.71 (P=0.01). Poorer SILA generated an OR of 1.59 in men (p=0.03). In Alaska, no evidence of acculturation effects was detected among Iñupiaq men. Among Iñupiaq women, an increased subsistence score represented an increased odds of 73% (p=0.026) for reporting poorer SRH. No significant effects of acculturation on SRH were detected in Norway. This study shows that aggregate acculturation is a strong risk factor for poorer SRH among the Kalaallit of Greenland and female Iñupiat of Alaska, but our cross-sectional study design does not allow any conclusion with regard to causality. Limitations with regard to wording, categorisations, assumed cultural differences in the conceptualisation of SRH, and confounding effects of health care use, SES and discrimination, make it difficult to appropriately assess how strong this effect is though.

URI:

http://hdl.handle.net/10037/4625

File(s) in this item: 1

article.pdf (250.3Kb)

Active loading of gemcitabine into liposomes

Møkleby, Tormund Aasjord (Master thesis; Mastergradsoppgave, May-2009)

[+]

Abstract:

Gemcitabine is a well established anticancer compound, and is in use today against several types of cancers. Gemcitabine has a short half life. Formulations of gemcitabine containing liposomes could extend it's half life, thereby maybe improving its effectiveness. Also, liposomes in the smaller size range have an advantage when it comes to treating cancer. They accumulate at the site of the tumor, and stay there for a longer time than it would have done in normal tissue(Massing and Fuxius 2000). Previous attempts to actively load gemcitabine into liposomes have used a pH gradient with acidic pH inside compared to more neutral pH on the outside of the liposomes, accomplished by an ammonium sulphate gradient. But this approach showed some difficulties; among other things that gemcitabine had a tendency to leak out in very short time. (Gravem 2006). In this thesis I have among other things investigated the possibility of loading gemcitabine into liposomes by precipitation. The hope was that this could give higher trapping efficiency and reduced leakage compared to the ammonium sulphate approach. Firstly, for comparable reasons and method development, an approach to load liposomes via an ammonium sulphate gradient was tried. Thought after encountering several problems the experiment was ended without any results indicating loading, most likely due to heavily diluted liposomes. Secondly I investigated if I could make gemcitabine precipitate. Firstly I tried a great range of different phosphate and sulphate salts, to test if any of them would cause a precipitation. Precipitation seemed to be independent of which salt used, but enhanced by factors such as high concentration of gemcitabine, alkaline conditions (pH ≥ 6), and low temperature. The two last conditions were the total opposites of loading via an ammonium sulphate gradient, and contained several contradictions as it meant that the outer pH had to be significantly lower to avoid precipitation and that a low temperature made it harder for gemcitabine to cross the membrane of the liposomes. An attempt to load gemcitabine into liposomes, using a pH 4 in the outer phase and pH 7 in the inner phase of the liposomes, with repeated cooling and freezing cycles, revealed poor loading. Thought optimizing conditions such as pHs, and time and temperatures in the cooling freezing cycles might enhance the loading a bit it is difficult to see this approach becoming a success.

URI:

http://hdl.handle.net/10037/2202

File(s) in this item: 1

thesis.pdf (1.114Mb)

Acute and long-term effects from petroleum discharges on temperate and Arctic Calanus species

Jensen, Louise Kiel (Doctoral thesis; Doktorgradsavhandling, 11-Nov-2011)

[+]

Abstract:	Summary Petroleum exploitation is emerging in the Arctic. In the Norwegian Arctic the southern Barents Sea is opened for development of oil and gas fields. This same area holds some of the world's largest and well managed commercial fish stocks such as Herring (Clupea harengus), Capelin (Mallotus villosus), Haddock (Melanogrammus aeglefinus), Atlantic Cod (Gadus morhua). For the interest of the fishing industry, as well as for maintaining a healthy ecosystem, petroleum related Environmental Risk Assessments (ERA) for the Barents Sea must be based on sound scientific knowledge of the special features of the Arctic ecosystem. In colder areas the physical behavior of oil is different compared to warmer areas. The lower temperature and lack of sun light during the Arctic winter slows down the natural physical weathering process of oil. In ERA in temperate areas the effects of exposure to the most volatile fraction of the oil are neglected due to short exposure time. However, in the Arctic the exposure to biota of this volatile fraction may be prolonged due to lower evaporation rates and the volatile fraction may be an important contributor to the overall adverse effect of an oil spill. Likewise, the exposure to the heavier oil fractions may be prolonged and knowledge on the long-term effects of exposure is essential. As an adaptation to the Arctic environment species found here have longer life spans, larger body sizes and higher lipid contents compared to temperate equivalent species. Thus Arctic species may accumulate contaminants over longer time and reach higher life time body levels. Meanwhile higher lipid content implies a higher affinity of lipophilic contaminants such as polycyclic aromatic hydrocarbons (PAHs). So, Arctic species may be exposed to oil compounds for a longer time because of the prolonged phycical presence and may, due to special adaptive features, be more efficient at accumulating oil contaminants. Today the knowledge of effects of oil contaminants on Arctic biota is limited, but growing. This thesis addresses a few of the research challenges in the field and provides knowledge on some effects of petroleum exposure to two copepod species; the sub-Arctic Calanus finmarchicus and the Arctic sibling species C. glacialis. First, Calanus was cultured for a generations under sub-Arctic conditions (Paper I). This work establishes that Calanus is suitable for ecological relevant long-term experiments. In an oil spill scenario, Arctic copepods and algae may be exposed to the more volatile fraction of the oil. Paper II provides data showing that the Arctic diatom species, Fragilariopsis oceanica, was the most sensitive species to exposure to the volatile hydrocarbon xylene. Further, the smaller, less lipid rich copepod species C. finmarchicus, was more sensitive compared to the true Arctic C. glacialis. Extrapolating these results to a spill situation, C. finmarchicus and C. glacialis populations would be affected by xylene exposure through both direct exposure (mortality) and indirectly through a decline in prey organisms (algae). Sub-lethal effects after long-term exposures to low concentrations of oil compounds may also be detected in C. finmarchicus and C. glacialis. Feeding was suppressed in C. finmarchicus after exposure to 7.0 µg PAHs l-1 for 11 days (Paper III). No significant effect on feeding was detected in C. glacialis exposed to 10.4 µg PAHs l-1 for 11 days. However, the hatching success of eggs laid by females exposed to 10.4 µg PAHs l-1 for two days was significantly reduced (Paper III). The long term effects of lipophilic PAHs in biota depend on the bioaccumulation capacity and internal concentrations of the various PAHs. Accumulation of lipophilic compounds is particularly important for the lipid rich Arctic species. Paper IV examines the uptake kinetics of two PAHs in C. finmarchicus and show that the accumulation of the lighter and less lipophilic compound, phenanthrene, is faster that the uptake of the heavier and more lipophilic benzo[a]pyrene (B[a]P). Equilibrium was reached for phenanthrene within 192 h exposure while no equilibrium was detected for B[a]P. The bioconcentration factor (BCF) was higher for B[a]P, reflecting the higher affinity for lipids of B[a]P compared to phenanthrene (Paper IV). So the heavier, more lipophilic PAH accumulates slower but to a higher concentration in C. finmarchicus. This thesis shows that not only acute but also long-term exposures may affect Arctic species. In addition, exposure duration may determine which compounds are accumulated by biota. Both indirect effects, such as decrease of food items, and direct effects, such as mortality, reduced feeding and reproduction failure may have implications for population development. These findings should be taken into consideration when developing ERA for the Barents Sea area.
Description:	Papers 1 and 2 of this thesis are not available in Munin: 1. Jensen, L.K., Carroll, JL., Pedersen, G., Hylland, K., Dahle, S. and Bakke, T.: 'A multigeneration Calanus finmarchicus culturing system for use in long-term oil exposure experiments', Journal of Experimental Marine Biology and Ecology (2006) 333: 71-78. Available at http://dx.doi.org/10.1016/j.jembe.2005.12.001 2. Jensen, L.K. and Carroll, JL.: 'Effects of the volatile petroleum component xylene on Arctic algae and zooplankton' (submitted manuscript to Marine Environmental Research).
URI:	http://hdl.handle.net/10037/3794

File(s) in this item: 3

paper_3.pdf (312.1Kb)

paper_4.pdf (161.7Kb)

thesis.pdf (1.551Mb)

Acute heart failure syndromes : treatment, outcomes and pathophysiological aspects of inflammation and vascular function

Hermansen, Stig Eggen (Doctoral thesis; Doktorgradsavhandling, 01-Nov-2012)

[+]

Abstract:	Akutt hjertesvikt, spesielt ved sirkulatorisk kollaps, er en dramatisk tilstand med høy dødelighet. Forekomsten av akutt hjertesvikt er økende og tilgjengelig kunnskap om sykdomsmekanismene samt medisinsk behandling er begrenset.De siste tiår har det vært en revolusjonerende utvikling i behandlingen av og overlevelsen ved iskemisk hjertesykdom og akutt hjerteinfarkt. Tilsvarende utvikling har det dessverre ikke vært i behandlingen av akutt hjertesvikt som er et økende problem assosiert med høy dødelighet. Formålet med dette prosjektet har vært å kartlegge epidemiologi, behandling og prognose ved forskjellige typer akutt hjertesvikt. For å øke den patofysiologiske forståelsen av sirkulasjonsregulering ved de mest alvorlige former for akutt hjertesvikt (kardiogent sjokk) har vi gjennomført observajonsstudier av biokjemiske responser og perifer karfunksjon i sykdomsforløpet. Prosjektet har vært todelt. Vi har først har sett på forekomsten av forskjellige typer akutt hjertesvikt og behandlingen som ble gitt ved medisinsk og kirurgisk intensiv avdeling ved UNN over en 2 års periode. Tross moderne behandling med bla tidlig revaskularisering døde ca 1/4 av pasientene under sykehusoppholdet. Dårligst prognose hadde de med kardiogent sjokk der nesten halvparten døde. De med lettere former for akutt hjertesvikt hadde meget dårlige leveutsikter i perioden etter utskrivelse og kun 50 % var i live etter to år. Mer utstrakt og tidlig bruk av mekanisk sirkulasjonsstøtte (hjertepumper) kan potensielt bedre overlevelsen hos de med mest alvorlig og behandlingsrefraktær hjertesvikt. Hos pasienter med kardiogent sjokk og alvorlig hjertesvikt etter hjertekirurgi er dårlig respons på konvensjonelle blodtrykksøkende medikamenter forbundet med spesielt dårlig prognose. For å kartlegge de underliggende mekanismene ved sirkulasjonssvikt spesielt mtp perifer sirkulasjonsregulering har vi målt perifer karfunksjon (endotelfunksjon), markører på systemisk inflammasjon og sirkulerende NO-blokkere (ADMA) under sykdomsforløpet. Tilstanden var karakterisert av en betydelig systemisk inflammasjon samt redusert perifer karfunksjon. Høye nivå av ADMA var assosiert med organsvikt og graden av hypoperfusjon.
Description:	The papers and the appendix of this thesis are not available in Munin: 1. Hermansen SE, Hansen M, Roaldsen M, Muller S, How OJ & Myrmel T.: 'Utilization and outcome of coronary revascularization and valve procedures in acute heart failure : an evaluation based on the classification from the European Society of Cardiology', Interactive CardioVascular and Thoracic Surgery (2008) vol.7, no.5:833-838. Available at http://dx.doi.org/10.1510/icvts.2008.175067 2. Hermansen SE, Hansen M, Roaldsen M, Muller S, How OJ & Myrmel T.: 'How many acute heart failure patients need a ventricular assist device?', Scandinavian Cardiovascular Journal (2008) vol.42, no.2:118-124. Available at http://dx.doi.org/10.1080/14017430701819113 3. Hermansen SE, Hansen M, Muller S, How OJ & Myrmel T.: 'Endothelial function during open heart surgery' (manuscript) 4. Hermansen SE, Kalstad T, How OJ & Myrmel T.: 'Inflammation and reduced endothelial function in the course of severe acute heart failure', Translational Research (2011) vol.157, no.3:117–127. Available at http://dx.doi.org/10.1016/j.trsl.2010.12.002 5. Hermansen SE, Lund T, Kalstad T, Ytrehus K & Myrmel T.: 'Adrenomedullin augments the angiogenic potential of late outgrowth endothelial progenitor cells', American Journal of Physiology Cell Physiology (2011) vol.300 no.4, C783-C791. Available at http://dx.doi.org/10.1152/ajpcell.00044.2010 Appendix: Hermansen SE, Naesheim T, How OJ & Myrmel T.: 'Circulatory assistance in acute heart failure : where do we go from here?', Scandinavian Cardiovascular Journal (2009) vol. 43, no.4:211-216. Available at http://dx.doi.org/10.1080/14017430802715962
URI:	http://hdl.handle.net/10037/4622

File(s) in this item: 1

thesis.pdf (1.140Mb)

Acute psychiatric admissions from an out-of-hours Casualty Clinic. How do referring doctors and admitting specialists agree?

Deraas, Trygve S.; Giæver, Anton; Hansen, Vidje; Olstad, Reidun (Journal article; Tidsskriftartikkel; Peer reviewed, 29-Mar-2006)

[+]

Abstract:

Background: Over the last decades there has been an increasing pressure on the acute psychiatric wards in Norway. The major contributor to psychiatric acute admissions at the University Hospital of North Norway in the city of Tromsø in 2001 was the GP-based Tromsø Casualty Clinic, only open out-of-hours. We explored all acute psychiatric referrals from Tromsø Casualty Clinic in 2001. The purpose of the study was to characterize the admissions and assess the agreement between the referring doctors and the hospital specialists according to the need for hospitalization, agreement on application of the law and the diagnostic evaluation to assess whether the admissions were appropriate. Methods: Retrospective, record based, descriptive study comprising 101 psychiatric acute referrals from the Tromsø Casualty Clinic to the psychiatric acute wards at the University Hospital of North Norway. Results: The specialists accepted all referrals except one, they mostly agreed upon the diagnoses suggested by the referring doctors and they mostly confirmed the application of the law. Seventy-five percent of the admissions took place during weekends, public holidays or nighttimes. Diagnoses of psychoses or suicidal attempts accounted for 76 % of the total referrals. Substance abuse was noted for 43 %, and in 22 % of all admissions the patients had stopped taking their psychopharmacological medication. The police assisted the referring doctors in one third of all admissions, and was the legal representative in 52 out of 59 involuntary admissions. Thirty percent of the admissions were first- time admissions. Thirty-two percent of the hospital stays lasted for three days or less. Median length of stay was 6.5 days. Conclusion: The casualty clinic physicians and the hospital specialists mostly agreed in their evaluation of patients indicating that most of the admissions were appropriate. The police was more often involved in the involuntary admissions than intended in the law. The proportion of patients with substance abuse was significant. Alternative treatment strategies should be developed for non-psychotic patients in need of short-term stays.

URI:

http://hdl.handle.net/10037/1118

File(s) in this item: 1

article.pdf (270.2Kb)

Browsing by Title

DSpace/Manakin Repository

Browsing by Title

Search Munin

Browse

All of Munin

Help

Abstract:	We find an invariant characterization of planar webs of maximum rank. For 4-webs, we prove that a planar 4-web is of maximum rank three if and only if it is linearizable and its curvature vanishes. This result leads to the direct web-theoretical proof of the Poincar´e’s theorem: a planar 4- web of maximum rank is linearizable. We also find an invariant intrinsic characterization of planar 4-webs of rank two and one and prove that in general such webs are not linearizable. This solves the Blaschke problem “to find invariant conditions for a planar 4-web to be of rank 1 or 2 or 3”. Finally, we find invariant characterization of planar 5-webs of maximum rank and prove than in general such webs are not linearizable.
Description:	Dette er forfatternes aksepterte versjon.
URI:	http://hdl.handle.net/10037/2049

Abstract:	Dedicated to the memory of Björn Roos (1937–2010), one of the fathers of modern multiconfigurational quantum chemistry, who also cared deeply about chemical applications, and a fun and inspiring friend to countless theoretically oriented chemists.
URI:	http://hdl.handle.net/10037/4086

Abstract:	An acquired loss of renal DNaseI has recently been shown to promote transformation of mild mesangial lupus nephritis into membrano-proliferative end-stage organ disease. In this study, we analyzed expression profiles of DNaseI in other organs of lupus-prone (NZBxNZW)F1 mice during disease progression to determine if silencing of the renal DNaseI gene is an organ specific feature or if loss of DNaseI reflects a systemic error in mice with sever lupus nephritis. Our results demonstrate normal or elevated levels of DNaseI mRNA and enzyme activity in liver, spleen and serum samples of (NZBxNZW)F1 mice throughout all stages of lupus nephritis. DNaseI activity was dramatically reduced only in kidneys of mice with sever nephritis and was the only nuclease that was down-regulated, while 6 other nucleases (DNaseIl1-3, caspase activated deoxyribonuclease, Dnase2a, and endonuclease G) were largely normally expressed in kidneys, liver and spleen. Loss of renal DNaseI was not accompanied by changes in serum DNaseI activity, suggesting an independent mechanism of DNaseI regulation in circulation and in kidneys, and an absence of compensatory upregulation of serum DNaseI activity in case of renal DNaseI deficiency. Thus, silencing of renal DNaseI is a unique renal feature in membrano-proliferative lupus nephritis. Determination of mechanism(s) responsible for DNaseI down-regulation is a future step in generation of new therapeutic targets to treat and prevent progressive lupus nephritis.
Description:	Accepted manuscript version, reprinted with permission (Elsevier). Published version available at http://dx.doi.org/10.1016/j.ajpath.2011.05.011 This article is part of Natalya Serdkina's doctoral thesis which is available in Munin at http://hdl.handle.net/10037/3563
URI:	http://hdl.handle.net/10037/3564

Abstract:	Purpose. Activity related pain may be a barrier to rehabilitation in patients with chronic musculoskeletal disorders. This study investigated patients’ reports of increased pain during activity, and the association between such pain and psychological factors and pain variables. Method. Questionnaires from 232 adults with chronic musculoskeletal pain measured pain intensity, spread of pain and pain duration. Pain during activity was assessed both on a 11 point Numeric Rating Scale (NRS), and operationalized as a dichotomous measure, where responders defined if they experienced pain during general activity and exercise. Psychological factors were measured by the Hopkins Symptom Check List 25, the Tampa Scale for Kinesiophobia and a subscale of the Arthritis Self – Efficacy Scale. Multiple and logistic regression was used to analyse associations between increased pain during activity and associated variables. Results. Increased pain during activity was reported by 69 % of participants. Fear of movement was a significant factor for reporting increased pain during activity, both general activity and exercise, also in a subsample with low psychological distress. Other significant factors were spread of pain and a low sense of self efficacy. Conclusion. Patients with high fear of movement, large spread of pain and low self efficacy were more likely to report increased pain during activity even in the absence of psychological distress.
Description:	Accepted manuscript version, reprinted with permission (Informa Helthcare). Published version available at http://dx.doi.org/10.3109/09638280903567877 This article is part of Elin Damsgård's doctoral thesis which is available in Munin at http://hdl.handle.net/10037/2500
URI:	http://hdl.handle.net/10037/3549

Browsing by Title

DSpace/Manakin Repository

Browsing by Title

File(s) in this item: 1

File(s) in this item: 1

File(s) in this item: 1

File(s) in this item: 1

File(s) in this item: 1

File(s) in this item: 1

File(s) in this item: 1

File(s) in this item: 1

File(s) in this item: 1

File(s) in this item: 1

File(s) in this item: 1

File(s) in this item: 1

File(s) in this item: 2

File(s) in this item: 1

File(s) in this item: 6

File(s) in this item: 1

File(s) in this item: 1

File(s) in this item: 3

File(s) in this item: 1

File(s) in this item: 1

Search Munin

Browse

All of Munin

Help