| 51. |
- Cornwallis, Charlie K, et al.
(författare)
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Single-cell adaptations shape evolutionary transitions to multicellularity in green algae
- 2023
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Ingår i: Nature Ecology and Evolution. - 2397-334X. ; 7:6, s. 889-902
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Tidskriftsartikel (refereegranskat)abstract
- The evolution of multicellular life has played a pivotal role in shaping biological diversity. However, we know surprisingly little about the natural environmental conditions that favour the formation of multicellular groups. Here we experimentally examine how key environmental factors (predation, nitrogen and water turbulence) combine to influence multicellular group formation in 35 wild unicellular green algae strains (19 Chlorophyta species). All environmental factors induced the formation of multicellular groups (more than four cells), but there was no evidence this was adaptive, as multicellularity (% cells in groups) was not related to population growth rate under any condition. Instead, population growth was related to extracellular matrix (ECM) around single cells and palmelloid formation, a unicellular life-cycle stage where two to four cells are retained within a mother-cell wall after mitosis. ECM production increased with nitrogen levels resulting in more cells being in palmelloids and higher rates of multicellular group formation. Examining the distribution of 332 algae species across 478 lakes monitored over 55 years, showed that ECM and nitrogen availability also predicted patterns of obligate multicellularity in nature. Our results highlight that adaptations of unicellular organisms to cope with environmental challenges may be key to understanding evolutionary routes to multicellular life.
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| 52. |
- Dimopoulos, Meletios A., et al.
(författare)
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All-oral ixazomib, cyclophosphamide, and dexamethasone for transplant-ineligible patients with newly diagnosed multiple myeloma
- 2019
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Ingår i: European Journal of Cancer. - : Elsevier BV. - 0959-8049 .- 1879-0852. ; 106, s. 89-98
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Tidskriftsartikel (refereegranskat)abstract
- Background: Novel efficacious treatments with long-term tolerability are needed for transplant-ineligible, newly diagnosed multiple myeloma (NDMM) patients. This phase 2 study evaluated the safety and efficacy of all-oral ixazomib-cyclophosphamide-dexamethasone (ICd) followed by single-agent ixazomib maintenance. Patients and methods: Patients were randomised (1:1) to receive 4.0 mg of ixazomib, 300 (Arm A) or 400 (Arm B) mg/m2 of cyclophosphamide (days 1, 8, and 15), and 40 mg of dexamethasone (days 1, 8, 15, and 22) as induction (up to 13 × 28-day cycles), followed by single-agent ixazomib maintenance (28-day cycles) until progressive disease, death, or unacceptable toxicity. Primary end-point was complete response (CR) + very good partial response (VGPR) rate for ICd induction. Results: Seventy patients were enrolled (n = 36 Arm A; n = 34 Arm B); median age was 73 years (range, 61–87). At data cut-off, 66% of patients had completed 13 induction cycles followed by ixazomib maintenance. Median overall treatment duration was 19 cycles (range, 1–29); 21% of patients discontinued treatment during induction and 3% during maintenance due to adverse events (AEs). During induction, among 67 response-evaluable patients, CR+VGPR rate was 25%, and overall response rate (ORR) was 73%. Including the maintenance phase, CR+VGPR rate was 33%, and ORR was 76%. Median progression-free survival was 23.5 months (median follow-up: 26.1 months). The most common all-grade AE was neutropenia (31%). Grade ≥3 AEs were reported by 73% of patients. Five on-study deaths occurred (not treatment-related). Conclusions: ICd treatment followed by ixazomib maintenance is tolerable and active in elderly, transplant-ineligible NDMM patients. Trial registration number: NCT02046070.
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| 53. |
- Dimopoulos, M A, et al.
(författare)
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Expert panel consensus statement on the optimal use of pomalidomide in relapsed and refractory multiple myeloma.
- 2014
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Ingår i: Leukemia. - : Springer Science and Business Media LLC. - 1476-5551 .- 0887-6924. ; 28:8, s. 1573-1585
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Forskningsöversikt (refereegranskat)abstract
- In this report, a panel of European myeloma experts discuss the role of pomalidomide in the treatment of relapsed and refractory multiple myeloma (RRMM). Based on the available evidence, the combination of pomalidomide and low-dose dexamethasone is a well-tolerated and effective treatment option for patients with RRMM who have exhausted treatment with lenalidomide and bortezomib. The optimal starting dose of pomalidomide is 4 mg given on days 1-21 of each 28-day cycle, while dexamethasone is administered at a dose of 40 mg weekly (reduced to 20 mg for patients aged >75 years). The treatment should continue until evidence of disease progression or unacceptable toxicity. Dose-modification schemes have been established for patients who develop neutropenia, thrombocytopenia and other grade 3-4 adverse events during pomalidomide therapy. Guidance on the prevention and management of infections and venous thromboembolism are provided, based on the available clinical evidence and the experience of panel members. The use of pomalidomide in special populations, such as patients with advanced age, renal impairment or unfavourable cytogenetic features, is also discussed.Leukemia accepted article preview online, 5 February 2014; doi:10.1038/leu.2014.60.
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| 54. |
- Dimopoulos, Meletios A., et al.
(författare)
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Safety and efficacy of pomalidomide plus low-dose dexamethasone in STRATUS (MM-010) : A phase 3b study in refractory multiple myeloma
- 2016
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 128:4, s. 497-503
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Tidskriftsartikel (refereegranskat)abstract
- Patients with relapsed and/or refractory multiple myeloma (RRMM) have poor prognosis. The STRATUS study assessed safety and efficacy of pomalidomide plus low-dose dexamethasone in the largest cohort to date of patients with RRMM. Patients who failed treatment with bortezomib and lenalidomide and had adequate prior alkylator therapy were eligible. Pomalidomide 4 mg was given on days 1-21 of 28-day cycles with low-dose dexamethasone 40 mg (20 mg for patients aged >75 years) on days 1, 8, 15, and 22 until progressive disease or unacceptable toxicity. Safety was the primary end point; secondary end points included overall response rate (ORR), duration of response (DOR), progression-free survival (PFS), and overall survival (OS). Among 682 patients enrolled, median age was 66 years, and median time since diagnosis was 5.3 years. Median number of prior regimens was 5. Most patients were refractory to both lenalidomide and bortezomib (80.2%). Median follow-up was 16.8 months; median duration of treatment was 4.9 months. Most frequent grade 3/4 treatment-emergent adverse events were hematologic (neutropenia [49.7%], anemia [33.0%], and thrombocytopenia [24.1%]). Most common grade 3/4 nonhematologic toxicities were pneumonia (10.9%) and fatigue (5.9%). Grade 3/4 venous thromboembolism and peripheral neuropathy were rare (1.6% each). The ORR was 32.6%, and the median DOR was 7.4 months. Median PFS and OS were 4.6 months and 11.9 months, respectively. We present the largest trial to date evaluating pomalidomide plus low-dose dexamethasone in patients with RRMM, further confirming that this regimen offers clinically meaningful benefit and is generally well tolerated. www.Clinicaltrials.gov identifier NCT01712789.
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| 55. |
- Domi, Esi, et al.
(författare)
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Genetic Deletion of Neuronal PPAR gamma Enhances the Emotional Response to Acute Stress and Exacerbates Anxiety: An Effect Reversed by Rescue of Amygdala PPAR gamma Function
- 2016
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Ingår i: JOURNAL OF NEUROSCIENCE. - : SOC NEUROSCIENCE. - 0270-6474. ; 36:50, s. 12611-12623
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Tidskriftsartikel (refereegranskat)abstract
- PPAR gamma is one of the three isoforms of the Peroxisome Proliferator-Activated Receptors (PPARs). PPAR gamma is activated by thiazolidinediones such as pioglitazone and is targeted to treat insulin resistance. PPAR gamma is densely expressed in brain areas involved in regulation of motivational and emotional processes. Here, we investigated the role of PPAR gamma in the brain and explored its role in anxiety and stress responses in mice. The results show that stimulation of PPAR gamma by pioglitazone did not affect basal anxiety, but fully prevented the anxiogenic effect of acute stress. Using mice with genetic ablation of neuronal PPAR gamma (PPAR gamma(NestinCre)), we demonstrated that a lack of receptors, specifically in neurons, exacerbated basal anxiety and enhanced stress sensitivity. The administration of GW9662, a selective PPAR gamma antagonist, elicited a marked anxiogenic response in PPAR gamma wild-type (WT), but not in PPAR gamma(NestinCre) knock-out (KO) mice. Using c-Fos immunohistochemistry, we observed that acute stress exposure resulted in a different pattern of neuronal activation in the amygdala (AMY) and the hippocampus (HIPP) of PPAR gamma(NestinCre) KO mice compared with WT mice. No differences were found between WT and KO mice in hypothalamic regions responsible for hormonal response to stress or in blood corticosterone levels. Microinjection of pioglitazone into the AMY, but not into the HIPP, abolished the anxiogenic response elicited by acute stress. Results also showed that, in both regions, PPAR gamma colocalizes with GABAergic cells. These findings demonstrate that neuronal PPAR gamma is involved the regulation of the stress response and that the AMY is a key substrate for the anxiolytic effect of PPAR gamma
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| 56. |
- Domi, Esi, et al.
(författare)
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Nicotine increases alcohol self-administration in male rats via a mu-opioid mechanism within the mesolimbic pathway
- 2020
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Ingår i: British Journal of Pharmacology. - : WILEY. - 0007-1188 .- 1476-5381. ; 177:19, s. 4516-4531
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Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose: Alcohol and nicotine use disorders are commonly comorbid. Both alcohol and nicotine can activate opioid systems in reward-related brain regions, leading to adaptive changes in opioid signalling upon chronic exposure. The potential role of these adaptations for comorbidity is presently unknown. Here, we examined the contribution of mu and kappa-opioid receptors to nicotine-induced escalation of alcohol self-administration in rats. Experimental Approach: Chronic nicotine was tested on alcohol self-administration and motivation to obtain alcohol. We then tested the effect of the kappa antagonist CERC-501 and the preferential mu receptor antagonist naltrexone on basal and nicotine-escalated alcohol self-administration. To probe mu or kappa receptor adaptations, receptor binding and G-protein coupling assays were performed in reward-related brain regions. Finally, dopaminergic activity in response to alcohol was examined, using phosphorylation of DARPP-32 in nucleus accumbens as a biomarker. Key Results: Nicotine robustly induced escalation of alcohol self-administration and motivation to obtain alcohol. This was blocked by naltrexone but not by CERC-501. Escalation of alcohol self-administration was associated with decreased DAMGO-stimulated mu receptor signalling in the ventral tegmental area (VTA) and decreased pDARPP-32 in the nucleus accumbens shell in response to alcohol. Conclusions and Implications: Collectively, these results suggest that nicotine contributes to escalate alcohol self-administration through a dysregulation of mu receptor activity in the VTA. These data imply that targeting mu rather than kappa receptors may be the preferred pharmacotherapeutic approach for the treatment of alcohol use disorder when nicotine use contributes to alcohol consumption.
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| 57. |
- Duran-Lozano, Laura, et al.
(författare)
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Germline variants at SOHLH2 influence multiple myeloma risk
- 2021
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Ingår i: Blood Cancer Journal. - : Springer Science and Business Media LLC. - 2044-5385. ; 11:4
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Tidskriftsartikel (refereegranskat)abstract
- Multiple myeloma (MM) is caused by the uncontrolled, clonal expansion of plasma cells. While there is epidemiological evidence for inherited susceptibility, the molecular basis remains incompletely understood. We report a genome-wide association study totalling 5,320 cases and 422,289 controls from four Nordic populations, and find a novel MM risk variant at SOHLH2 at 13q13.3 (risk allele frequency = 3.5%; odds ratio = 1.38; P = 2.2 × 10-14). This gene encodes a transcription factor involved in gametogenesis that is normally only weakly expressed in plasma cells. The association is represented by 14 variants in linkage disequilibrium. Among these, rs75712673 maps to a genomic region with open chromatin in plasma cells, and upregulates SOHLH2 in this cell type. Moreover, rs75712673 influences transcriptional activity in luciferase assays, and shows a chromatin looping interaction with the SOHLH2 promoter. Our work provides novel insight into MM susceptibility.
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| 58. |
- Ebrahim, Shimaa A M, et al.
(författare)
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Drosophila Avoids Parasitoids by Sensing Their Semiochemicals via a Dedicated Olfactory Circuit.
- 2015
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Ingår i: PLoS Biology. - : Public Library of Science (PLoS). - 1545-7885. ; 13:12
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Tidskriftsartikel (refereegranskat)abstract
- Detecting danger is one of the foremost tasks for a neural system. Larval parasitoids constitute clear danger to Drosophila, as up to 80% of fly larvae become parasitized in nature. We show that Drosophila melanogaster larvae and adults avoid sites smelling of the main parasitoid enemies, Leptopilina wasps. This avoidance is mediated via a highly specific olfactory sensory neuron (OSN) type. While the larval OSN expresses the olfactory receptor Or49a and is tuned to the Leptopilina odor iridomyrmecin, the adult expresses both Or49a and Or85f and in addition detects the wasp odors actinidine and nepetalactol. The information is transferred via projection neurons to a specific part of the lateral horn known to be involved in mediating avoidance. Drosophila has thus developed a dedicated circuit to detect a life-threatening enemy based on the smell of its semiochemicals. Such an enemy-detecting olfactory circuit has earlier only been characterized in mice and nematodes.
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| 59. |
- Eliasson, Kent, et al.
(författare)
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Do firms learn by exporting or learn to export? : Evidence from small and medium-sized enterprises
- 2012
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Ingår i: Small Business Economics. - : Springer. - 0921-898X .- 1573-0913. ; 39:2, s. 453-472
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Tidskriftsartikel (refereegranskat)abstract
- Using a matching approach, we compare the productivity trajectories of future export-entrants and matched nonentrants. Future exporters have higher productivity than do nonentrants before entry into international markets, which indicates self-selection into exports. More interestingly, we also observe a productivity increase among export-entrants relative to nonentrants before export entry. This might be explained by higher investments in physical capital prior to export entry. We find no evidence that the productivity gap between export-entrants and nonentrants continues to grow after export entry. Our results suggest that learning to export occurs but that learning by exporting does not. In contrast to previous studies on Swedish manufacturing, we focus particularly on small and medium-sized enterprises (SMEs).
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| 60. |
- Eliasson, Kent, et al.
(författare)
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Effects of foreign acquisitions on R&D and high-skill activities
- 2017
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Ingår i: Small Business Economics. - : Springer. - 0921-898X .- 1573-0913. ; 49:1, s. 163-187
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Tidskriftsartikel (refereegranskat)abstract
- Using Swedish microdata, we find no evidence for the concerns circulating in the public debate that foreign acquisitions lead to reductions in both R&D expenditures and high-skilled activities in targeted domestic firms for either MNEs or non-MNEs. Previous studies have only focused on larger firms. In this paper, we are able to study the impact on smaller firms (fewer than 50 employees), which is important because 90% of the firms acquired meet this criterion. For this group of firms, there is no information on R&D, but by using the register of educational attainment, we obtain data on the share of high skilled labor in all Swedish firms irrespective of size. Interestingly, we find that among smaller firms, foreign enterprises tend to acquire high-productive, skill-intensive firms (cherry-picking). After the acquisitions, skill upgrading appears in acquired smaller, non-MNE firms, particularly in the service sector.
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