| 1. |
- Berglund, Erik, et al.
(författare)
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Intracellular concentration of the tyrosine kinase inhibitor imatinib in gastrointestinal stromal tumor cells.
- 2014
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Ingår i: Anti-Cancer Drugs. - 0959-4973 .- 1473-5741. ; 25:4, s. 415-22
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Tidskriftsartikel (refereegranskat)abstract
- Gastrointestinal stromal tumor (GIST) is the most common mesenchymal neoplasm in the gastrointestinal tract. In most GISTs, the underlying mechanism is a gain-of-function mutation in the KIT or the PDGFRA gene. Imatinib is a tyrosine kinase inhibitor that specifically blocks the intracellular ATP-binding sites of these receptors. A correlation exists between plasma levels of imatinib and progression-free survival, but it is not known whether the plasma concentration correlates with the intracellular drug concentration. We determined intracellular imatinib levels in two GIST cell lines: the imatinib-sensitive GIST882 and the imatinib-resistant GIST48. After exposing the GIST cells to imatinib, the intracellular concentrations were evaluated using LC-MS (TOF). The concentration of imatinib in clinical samples from three patients was also determined to assess the validity and reliability of the method in the clinical setting. Determination of imatinib uptake fits within detection levels and values are highly reproducible. The GIST48 cells showed significantly lower imatinib uptake compared with GIST882 in therapeutic doses, indicating a possible difference in uptake mechanisms. Furthermore, imatinib accumulated in the tumor tissues and showed intratumoral regional differences. These data show, for the first time, a feasible and reproducible technique to measure intracellular imatinib levels in experimental and clinical settings. The difference in the intracellular imatinib concentration between the cell lines and clinical samples indicates that drug transporters may contribute toward resistance mechanisms in GIST cells. This highlights the importance of further clinical studies to quantify drug transporter expression and measure intracellular imatinib levels in GIST patients.
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| 2. |
- Juhlin, Carl Christofer, et al.
(författare)
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Highly proliferative anal neuroendocrine carcinoma : molecular and clinical features of a rare, recurrent case in complete remission
- 2020
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Ingår i: BMC Gastroenterology. - : BMC. - 1471-230X .- 1471-230X. ; 20:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Poorly differentiated anal neuroendocrine carcinomas (ANECs) are rare lesions with poor prognosis, and the molecular etiology is only partially understood. Case presentation At our institution, we have treated and followed a patient with such a rare ANEC. He had primarily surgery followed by three rounds of repeated surgery for loco-regional recurrences. He also received three different combinations of chemotherapy and external beam radiation. At last follow-up 13 years since the primary diagnosis, the patient had been in complete remission for nine years. The patient's medical files were re-examined, including laboratory, radiology and clinical examinations. Histopathology was re-assessed, and expanded immunohistochemistry was performed from tissue specimens from the four surgical procedures. In addition, the molecular genetic status was evaluated through next-generation sequencing. The initial tumor was consistent with a 59 mm small cell neuroendocrine cancer with a Ki-67 index of 80%. Regional lymph node metastases were evident, and immunohistochemistry supported a neuroendocrine origin. A PCR screening detected human papilloma virus type 45 DNA (high-risk subtype), and focused next-generation sequencing found a missense mutation in thePhosphatidylinositol-4,5-Bisphosphate 3-Kinase Catalytic Subunit Alpha(PIK3CA) gene. In tissues representing subsequent recurrences, the Chromogranin A expression was lost, and the Ki-67 index increased to 90%. Conclusions For the first time, we report the detection of HPV45 in a case of ANEC. To our belief,PIK3CAmutations have also not been previously demonstrated in this tumor entity. In highly malignant ANECs, cure can in rare cases be achieved. Although speculative, expression of HPV45 and/or thePIK3CAmutation may have contributed to the favorable outcome.
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| 3. |
- Ahlén, Gustaf, et al.
(författare)
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Mannosylated mucin-type immunoglobulin fusion proteins enhance antigen-specific antibody and T lymphocyte responses
- 2012
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:10
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Tidskriftsartikel (refereegranskat)abstract
- Targeting antigens to antigen-presenting cells (APC) improve their immunogenicity and capacity to induce Th1 responses and cytotoxic T lymphocytes (CTL). We have generated a mucin-type immunoglobulin fusion protein (PSGL-1/mIgG2b), which upon expression in the yeast Pichia pastoris became multivalently substituted with O-linked oligomannose structures and bound the macrophage mannose receptor (MMR) and dendritic cell-specific intercellular adhesion molecule-3 grabbing non-integrin (DC-SIGN) with high affinity in vitro. Here, its effects on the humoral and cellular anti-ovalbumin (OVA) responses in C57BL/6 mice are presented.OVA antibody class and subclass responses were determined by ELISA, the generation of anti-OVA CTLs was assessed in 51Cr release assays using in vitro-stimulated immune spleen cells from the different groups of mice as effector cells and OVA peptide-fed RMA-S cells as targets, and evaluation of the type of Th cell response was done by IFN-γ, IL-2, IL-4 and IL-5 ELISpot assays.Immunizations with the OVA − mannosylated PSGL-1/mIgG2b conjugate, especially when combined with the AbISCO®-100 adjuvant, lead to faster, stronger and broader (with regard to IgG subclass) OVA IgG responses, a stronger OVA-specific CTL response and stronger Th1 and Th2 responses than if OVA was used alone or together with AbISCO®-100. Also non-covalent mixing of mannosylated PSGL-1/mIgG2b, OVA and AbISCO®-100 lead to relatively stronger humoral and cellular responses. The O-glycan oligomannoses were necessary because PSGL-1/mIgG2b with mono- and disialyl core 1 structures did not have this effect.Mannosylated mucin-type fusion proteins can be used as versatile APC-targeting molecules for vaccines and as such enhance both humoral and cellular immune responses.
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| 4. |
- Ahlén, Ingemar, et al.
(författare)
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Bats and offshore wind turbines studied in southern Scandinavia
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A pilot study 2002-2003 at turbines on land showed that certain locations in the landscape could explain some of the casualty risks and the main reasons for collisions were found. During the 2005 introductory studies and in the project 2006 on bats in offshore areas in Kalmarsund we could confirm earlier known flyways from coastal points and found an extensive activity of passing migrants but also of resident species coming from various directions to areas with an abundance of insects. Observations were made at Utgrunden and Yttre Stengrund in Kalmarsund in the Baltic Sea and in Öresund between Sweden and Denmark. The observers onboard the boats and at the coastal points where bats take off used ultrasound detectors, strong portable spotlights and at special times also thermal camera. Boxes for automatic recording of bats were used on land, were placed on the turbines, and on the boat's cap. These methods resulted in a total of 12 354 observations of bats, 3 830 over the sea and 8 524 on land. Bats fly over the sea in winds up to about 10 m/s, a major part of the activity took place at wind speeds less than 5 m/s. Bats of 10 species were observed on the open sea and all of them were foraging at suitable weather conditions, which means calm weather or light breeze. The bats did not avoid the turbines. On the contrary they stayed for shorter or longer periods hunting close to the windmills because of the accumulation of flying insects. Hunting close to the blades was observed, why the risk of colliding might be comparable to land-based turbines. Bats also used wind turbines for resting. Insects were collected at places and times when bats were observed feeding. Chironomids were dominating, but we also found many other flying species of other insect groups. Insects, but probably also crustaceans, were caught by bats in the water surface. Some terrestrial species occurred among the insects and spiders that were drifting in the air. At times we suppose that their origin was in the Baltic Republics or Russia. It was earlier completely unknown that many bat species, migratory and non-migratory, regularly use this food resource on the open sea far from the coasts in the late summer and early autumn. With radar on Utgrunden's lighthouse data on movements of the largest bat species, mainly Nyctalus noctula, could be studied. This gave data on flyways, directions, movement patterns when foraging, especially near the turbines. With the radar it was possible to measure altitude and the results showed that almost all activity took place below 40 m above sea level, while only a few cases of higher flight was recorded. Observations from boat showed that altitude was very variable according to the available insects. Bats were seen hunting from the water surface up to the upper part of the windmills. Need of further research and developing methods is discussed in the report. An updated risk assessment is presented. A standpoint today is that areas with concentrated flyways and foraging habitats with an abundance of flying insects must be very carefully examined if new windmills are planned. The collision risk at offshore wind power parks is impossible to study as long as there are no such parks. Investigations on bats needed for environmental impact assessments are suggested. To minimize the casualty risks at existing turbines further research is needed. Some measures to take have been discussed. In certain cases it is probably most effective to move a turbine a relative short distance because of the sometimes short edges of the flyways and also the insect rich habitats. Another method is to stop the turbine during periods of high risk. Because the accumulation of insects is the reason for bats hunting close to the blades methods to reduce the amount of flying insects at the turbines would be of interest. Methods to keep the bats away from the turbines do not exist and some such ideas might also have negative effects on other animals and also on humans.
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| 5. |
- Ahlén, Ingemar, et al.
(författare)
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Fladdermöss och havsbaserade vindkraftverk studerade i södra Skandinavien
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- En pilotundersökning 2002-2003 vid vindkraftverk på land i Sydsverige visade på lägen i landskapet där riskerna för kollisioner var förhöjda samt de viktigaste orsakerna till olyckorna. Under 2005 års förstudie och i projektet 2006 vid havsbaserade vindkraftverk kunde vi bekräfta tidigare utpekade utsträck över havet av fladdermöss i Kalmarsund och fann en omfattande aktivitet av passerande migranter men även av stationära arter som från olika håll flög ut till områden med mycket insekter. Observationer gjordes framför allt vid Utgrunden och Yttre Stengrund i Kalmarsund och i Öresund. Observatörerna på båtarna och på utsträcksplatser på land använde ultraljudsdetektorer, starka strålkastare och vid vissa tillfällen värmekamera. Automatiskt registrerande boxar användes på land, hängdes på vindkraftverken och placerades på båtens kapp. Metoderna resulterade i totalt 12 354 observationer av fladdermöss, varav 3 830 över havet och 8 524 på land. Fladdermöss flög över havet i vindstyrkor upp till ca 10 m/s, men en stor del av aktiviteten skedde vid vindstyrkor mindre än 5 m/s. Fladdermöss av 10 arter observerades ute till havs och alla sågs söka föda vid tjänlig väderlek, d.v.s. främst vid svaga vindar och blankvatten. Fladdermössen undvek inte vindkraftverken. Tvärtom stannade de ofta till för insektsjakt nära verken på grund den ansamling av insekter som förekom där. Jakt helt intill rotorbladen observerades, vilket innebär att kollisionsrisken kan vara jämförbar med landbaserade verk. Fladdermöss kan bevisligen också använda vindkraftverk som viloplats, vilket har skett i det mest insektsrika området vi undersökte.Insamling av insekter gjordes på de platser och vid de tillfällen då fladdermöss sågs jaga. Fjädermyggor dominerade, men många andra flygande arter av andra insektsgrupper var också företrädda. Insekter, och troligen även några kräftdjur, togs också i havsytan. Några arter av landlevande arter förekom bland de mängder av insekter och spindlar som drev omkring i luftmassorna. Vid vissa tillfällen antar vi att de har kommit från Balticum eller Ryssland. Det har inte tidigare varit känt att många fladdermusarter, stationära och migrerande, regelbundet utnyttjar denna födoresurs långt ute i havet under eftersommaren och tidiga hösten.Med radarn på Utgrundens fyr kunde data om de största arterna, troligen mest stor fladdermus, insamlas. Det gällde flygvägar, riktningar, rörelsemönster vid födosök, speciellt i närheten av vindkraftverken. Med radarn kunde fastställas att nästan all aktivitet skedde under 40 m höjd, endast enstaka fladdermöss flög högre vid sträckflykt. Direktobservationerna från båt visade att fladdermössen varierade höjd efter tillgången på insekter. Sålunda förekom flyghöjder från havsytan upp till verkens övre delar.Behov av fortsatt forskning och utvecklingsarbete diskuteras i rapporten. Vidare görs en uppdaterad riskbedömning. Ståndpunkten är nu att områden med koncentrerade flygvägar och insektsrika födosöksområden är de som måste granskas extra noga inför lokalisering av nya vindkraftverk. Risken för kollisioner vid ren passage genom stora vindkraftsparker kan inte bedömas, eftersom det ännu inte hunnit uppföras några parker. Förslag ges om vilka undersökningar som bör föregå lokaliseringsbesluten. Några krav på vad kontrollprogram vid utbyggnad bör innefatta diskuteras också. För att minska riskerna vid befintliga vindkraftverk krävs fortsatt forskning och metodutveckling. Några åtgärder som diskuterats hittills redovisas i rapporten. I svåra fall är sannolikt den effektivaste åtgärden att flytta vindkraftverket. Det kan troligen räcka med relativt korta avstånd på grund av att flygvägarna kan ha skarpa gränser och att de insektsrika födosöksbiotoperna också kan vara ganska väl avgränsade. En annan åtgärd kan vara att låta vindkraftverket stå stilla vid de tider då risken för kollisioner är stor. Eftersom ansamling av insekter kring vindkraftverken kan vara en viktig orsak till jakt nära rotorbladen kan man också tänka sig åtgärder för att minska mängden flygande insekter runt verken. Fungerande metoder som kan få fladdermöss att väja för vindkraftverk finns inte och idéer som förekommit kan ha negativa effekter i form av störningar eller skador på andra djurarter och för människor.
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| 6. |
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| 7. |
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| 8. |
- Ahlén, Niklas, 1970-
(författare)
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Carbothermal synthesis of transition metal carbide and carbonitride whiskers via a Vapour-Liquid-Solid (VLS) growth mechanism
- 1999
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A route for the synthesis of TiC, TiCyN1-y, TaxTi1-xC and TaxTi1-xCyN1-y whiskers via a carbothermal Vapour-Liquid-Solid (VLS) growth mechanism, yielding 70-90 vol.% whiskers, has been established. The whiskers were uniform in diameter (0.3-0.6mm), and had a length of about 10-30mm. The starting materials consisted of TiO2 and/or Ta2O5, C, a catalyst metal (Ni or Fe) and NaCl. Carbon was added to reduce the oxides, and NaCl to provide chlorine in the formation of TiClx(g) and TaOxCly(g) species. The overall chemical reaction is a straightforward carbothermal reduction process. The optimum synthesis temperature was found to be 1250°C for TiCyN1-y, TaxTi1-xC and TaxTi1-xCyN1-y whisker, and 1400°C for TiC. The growth direction of the whiskers was found to be <100> for TaC and TaxTi1-xC and either <100> or <111> for TiC. Nitridation of TiC whiskers yielded TiCyN1-y whiskers with morphology and chemical composition different from those obtained by the carbothermal VLS growth mechanism. From oxidation studies it was found that TiC had the lowest oxidation resistance (onset temperature Ton=390°C) and that TaC had the highest (Ton=550°C). The oxidation onset temperature was found to increase with increasing x-value for both TaxTi1-xC and TaxTi1-xCyN1-y whiskers. Microscopy studies (SEM and TEM) showed that whiskers with a native diameter exceeding 0.3 mm split into two halves along their length when oxidised. It was found that the TiO2 particle size of oxidised TaxTi1-xC whiskers are markedly smaller than that obtained from oxidation of TiC whiskers, whereas the Ta2O5 particle size was the same as that observed for oxidised TaC whiskers.
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| 9. |
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| 10. |
- Krishnan, Shuba, et al.
(författare)
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Metabolic Perturbation Associated With COVID-19 Disease Severity and SARS-CoV-2 Replication
- 2021
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Ingår i: Molecular & Cellular Proteomics. - : Elsevier BV. - 1535-9476 .- 1535-9484. ; 20
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Tidskriftsartikel (refereegranskat)abstract
- Viruses hijack host metabolic pathways for their replicative advantage. In this study, using patient-derived multiomics data and in vitro infection assays, we aimed to understand the role of key metabolic pathways that can regulate severe acute respiratory syndrome coronavirus-2 reproduction and their association with disease severity. We used multiomics platforms (targeted and untargeted proteomics and untargeted metabolomics) on patient samples and cell-line models along with immune phenotyping of metabolite transporters in patient blood cells to understand viral-induced metabolic modulations. We also modulated key metabolic pathways that were identified using multiomics data to regulate the viral reproduction in vitro. Coronavirus disease 2019 disease severity was characterized by increased plasma glucose and mannose levels. Immune phenotyping identified altered expression patterns of carbohydrate transporter, glucose transporter 1, in CD8+ T cells, intermediate and nonclassical monocytes, and amino acid transporter, xCT, in classical, intermediate, and nonclassical monocytes. In in vitro lung epithelial cell (Calu-3) infection model, we found that glycolysis and glutaminolysis are essential for virus replication, and blocking these metabolic pathways caused significant reduction in virus production. Taken together, we therefore hypothesized that severe acute respiratory syndrome coronavirus-2 utilizes and rewires pathways governing central carbon metabolism leading to the efflux of toxic metabolites and associated with disease severity. Thus, the host metabolic perturbation could be an attractive strategy to limit the viral replication and disease severity.
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