| 1. |
- Borgos, S., et al.
(författare)
-
Mapping global effects of the anti-sigma factor MucA in Pseudomonas fluorescens SBW25 through genome-scale metabolic modeling
- 2013
-
Ingår i: BMC Systems Biology. - : Springer Science and Business Media LLC. - 1752-0509. ; 7
-
Tidskriftsartikel (refereegranskat)abstract
- BackgroundAlginate is an industrially important polysaccharide, currently produced commercially by harvesting of marine brown sea-weeds. The polymer is also synthesized as an exo-polysaccharide by bacteria belonging to the genera Pseudomonas and Azotobacter, and these organisms may represent an alternative alginate source in the future. The current work describes an attempt to rationally develop a biological system tuned for very high levels of alginate production, based on a fundamental understanding of the system through metabolic modeling supported by transcriptomics studies and carefully controlled fermentations.ResultsAlginate biosynthesis in Pseudomonas fluorescens was studied in a genomics perspective, using an alginate over-producing strain carrying a mutation in the anti-sigma factor gene mucA. Cells were cultivated in chemostats under nitrogen limitation on fructose or glycerol as carbon sources, and cell mass, growth rate, sugar uptake, alginate and CO2 production were monitored. In addition a genome scale metabolic model was constructed and samples were collected for transcriptome analyses. The analyses show that polymer production operates in a close to optimal way with respect to stoichiometric utilization of the carbon source and that the cells increase the uptake of carbon source to compensate for the additional needs following from alginate synthesis. The transcriptome studies show that in the presence of the mucA mutation, the alg operon is upregulated together with genes involved in energy generation, genes on both sides of the succinate node of the TCA cycle and genes encoding ribosomal and other translation-related proteins. Strains expressing a functional MucA protein (no alginate production) synthesize cellular biomass in an inefficient way, apparently due to a cycle that involves oxidation of NADPH without ATP production. The results of this study indicate that the most efficient way of using a mucA mutant as a cell factory for alginate production would be to use non-growing conditions and nitrogen deprivation.ConclusionsThe insights gained in this study should be very useful for a future efficient production of microbial alginates.
|
|
| 2. |
- Ellingsen, Jens, 1979-
(författare)
-
Chronic obstructive pulmonary disease: exacerbations and mortality : Prognostic value of biomarkers and comorbidities
- 2024
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality. COPD is associated with systemic inflammation, and comorbidities are common. A characteristic feature is acute exacerbations (AECOPDs), i.e., episodes of worsening symptoms. AECOPDs are associated with increased mortality.Aim: To find prognostic risk factors for COPD mortality and AECOPDs, focusing on comorbidities and inflammatory biomarkers.Methods: In Paper I, associations between comorbidities, pharmacological treatment, and mortality were analysed in a real-world cohort of almost 18,000 primary care COPD patients. Data from medical records and national registers were analysed in Cox proportional hazards regressions.Papers II–IV were based on the Tools Identifying Exacerbations (TIE) cohort study of 572 COPD patients recruited from primary and secondary care in three Swedish regions. Participants were invited to three yearly visits, including phlebotomy, spirometry, and health questionnaires.In Paper II, the ability of blood neutrophil-to-lymphocyte ratio (NLR) and eosinophils (B-Eos) to predict AECOPDs was analysed with mixed-effects logistic regressions.In Paper III, the ability of C-reactive protein (CRP), fibrinogen, blood leukocytes (B-Leu), and four blood cell indices to predict AECOPDs was analysed with ordinal logistic regressions.In Paper IV, an algorithm for clinical phenotyping previously developed to predict mortality was studied. The algorithm’s ability to predict AECOPDs and mortality was analysed with Cox proportional hazards regressions; additionally, the identified phenotypes were analysed concerning differences in blood-based inflammatory biomarkers.Results: Several comorbidities, including heart diseases, were associated with increased mortality risk. Some pharmacological treatments were associated with increased or decreased mortality risk (Paper I). NLR, B-Eos, CRP, fibrinogen, and B-Leu (Papers II–III) predicted AECOPDs after adjustment for confounders, whereas other blood cell indices were of limited value (Paper III). The clinical phenotyping algorithm predicted AECOPDs and mortality, and the phenotypes had different patterns of inflammatory biomarkers (Paper IV).Conclusions: Comorbidities, particularly heart diseases, are substantial risk factors for mortality in COPD and should be an integral part of management of COPD patients. NLR, B-Eos, CRP, fibrinogen, and B-Leu are independent predictors of AECOPDs and should be further investigated as parts of, e.g., risk prediction tools. A previously developed algorithm for clinical phenotyping predicts mortality and AECOPDs.
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
- Ellingsen, Jens, 1979-, et al.
(författare)
-
CRP, Fibrinogen, White Blood Cells, and Blood Cell Indices as Prognostic Biomarkers of Future COPD Exacerbation Frequency : The TIE Cohort Study
- 2024
-
Ingår i: Journal of Clinical Medicine. - : MDPI. - 2077-0383. ; 13:13
-
Tidskriftsartikel (refereegranskat)abstract
- Background/Objective: Systemic inflammation is common in chronic obstructive pulmonary disease (COPD), and evidence suggests that inflammatory biomarkers can predict acute exacerbations (AECOPDs). The aim of this study was to analyse whether C-reactive protein (CRP), fibrinogen, white blood cell count (WBC), or the blood cell indices PLR (platelet-to-lymphocyte ratio), SII (systemic immune inflammation index), SIRI (systemic inflammation response index), and AISI (aggregate index of systemic inflammation) can predict future AECOPDs.Methods: In the Tools Identifying Exacerbations (TIE) cohort study, participants with spirometry-confirmed COPD were recruited from primary and secondary care in three Swedish regions and assessed during a stable phase of COPD. AECOPD frequency during the three-year follow-up was reviewed in medical records. Associations were analysed via ordinal logistic regressions.Results: Of the 571 participants, 46% had >= 1 AECOPD during follow-up, and the mean +/- SD AECOPD frequency was 0.63 +/- 1.2/year. In unadjusted analyses, high levels of CRP (odds ratio 1.86, 95% CI 1.29-2.67), fibrinogen (2.09, 1.38-3.16), WBCs (2.18, 1.52-3.13), SII (1.52, 1.05-2.19), SIRI (1.76, 1.23-2.52), and AISI (1.99, 1.38-2.87) were associated with a higher AECOPD frequency. After adjustment for AECOPD history, age, sex, smoking, body mass index, COPD Assessment Test score, lung function, and inhaled corticosteroid use, associations remained for high levels of CRP (adjusted odds ratio of 1.64; 95% CI of 1.08-2.49), fibrinogen (1.55; 1.07-2.24), and WBC (1.65; 1.10-2.47).Conclusions: CRP, fibrinogen, and WBC, assessed during stable-phase COPD, enhanced AECOPD prediction, whereas PLR, SII, SIRI, and AISI did not.
|
|
| 6. |
- Ellingsen, Jens, et al.
(författare)
-
Impact of Comorbidities and Commonly Used Drugs on Mortality in COPD - Real-World Data from a Primary Care Setting
- 2020
-
Ingår i: The International Journal of Chronic Obstructive Pulmonary Disease. - : DOVE MEDICAL PRESS LTD. - 1176-9106 .- 1178-2005. ; 15, s. 235-245
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Life expectancy is significantly shorter for patients with chronic obstructive pulmonary disease (COPD) than the general population. Concurrent diseases are known to infer an increased mortality risk in those with COPD, but the effects of pharmacological treatments on survival are less established. This study aimed to examine any associations between commonly used drugs, comorbidities and mortality in Swedish real-world primary care COPD patients.Methods: Patients with physician-diagnosed COPD from a large primary care population were observed retrospectively, utilizing primary care records and mandatory Swedish national registers. The time to all-cause death was assessed in a stepwise multiple Cox proportional hazards regression model including demography, socioeconomic factors, exacerbations, comorbidities and medication.Results: During the observation period (1999-2009) 5776 (32.5%) of 17,745 included COPD patients died. Heart failure (hazard ratio [HR]: 1.88, 95% confidence interval [CI]: 1.74-2.04), stroke (HR: 1.52, 95% CI: 1.40-1.64) and myocardial infarction (HR: 1.40, 95% CI: 1.24-1.58) were associated with an increased risk of death. Use of inhaled corticosteroids (ICS; HR: 0.79, 95% CI: 0.66-0.94), beta-blockers (HR: 0.86, 95% CI: 0.76-0.97) and acetylsalicylic acid (ASA; HR: 0.87, 95% CI: 0.77-0.98) was dose-dependently associated with a decreased risk of death, whereas use of long-acting muscarinic antagonists (LAMA; HR: 1.33, 95% CI: 1.14-1.55) and N-acetylcysteine (NAC; HR: 1.26, 95% CI: 1.08-1.48) were dose-dependently associated with an increased risk of death in COPD patients.Conclusion: This large, retrospective, observational study of Swedish real-world primary care COPD patients indicates that coexisting heart failure, stroke and myocardial infarction were the strongest predictors of death, underscoring the importance of timely recognition and treatment of comorbidities. A decreased risk of death associated with the use of ICS, beta-blockers and ASA, and an increased risk associated with the use of LAMA and NAC, was also found.
|
|
| 7. |
|
|
| 8. |
- Ellingsen, Jens, et al.
(författare)
-
Neutrophil-to-lymphocyte ratio, blood eosinophils and COPD exacerbations: a cohort study
- 2021
-
Ingår i: ERJ Open Research. - : ERS Publications. - 2312-0541. ; 7:4
-
Tidskriftsartikel (refereegranskat)abstract
- Background Blood neutrophil-to-lymphocyte ratio (NLR) and blood eosinophils (B-Eos) are emerging biomarkers in COPD. This study examined whether they could predict acute exacerbations of COPD (AECOPDs), and determined their longitudinal stability.Methods In this closed cohort study, Swedish subjects with spirometry-verified COPD attended three yearly visits in a stable phase of the disease. Blood cell counts, spirometry and questionnaire-assessed AECOPD-history (worsening of COPD leading to an unscheduled visit and/or use of antibiotics and/or oral corticosteroids) were collected at each visit.Results Of 466 included subjects 57% were female. Baseline mean±sd forced expiratory volume in 1 s was 58±17% predicted. High NLR (≥3.0) was more common in subjects with previous AECOPDs than in those without (33.5% versus 20.4%, p=0.002). In two-level mixed-effects logistic regression models adjusted for confounders, NLR as a continuous variable (OR 1.20, 95% CI 1.04–1.38) and B-Eos ≥300 cells·µL−1 (OR 1.54, 95% CI 1.06–2.24) were associated with future AECOPDs. In 386 subjects with blood cell data available at all three visits, the intraclass correlation coefficient for NLR was 0.61 (95% CI 0.56–0.66) and for B-Eos 0.69 (95% CI 0.64–0.73). NLR was persistently ≥3.0 in 10.6% and B-Eos was persistently ≥300 cells·µL−1 in 15.3%.Conclusions Stable phase NLR and B-Eos were associated with future AECOPDs. NLR on its own is probably not useful to predict AECOPDs but might be included in a risk scoring index. A minority of subjects with COPD had persistently elevated stable-phase NLR or B-Eos, and the biomarkers showed fair longitudinal reliability.
|
|
| 9. |
- Furuhashi, Masao, et al.
(författare)
-
Platelet-derived growth factor production by B16 melanoma cells leads to increased pericyte abundance in tumors and an associated increase in tumor growth rate
- 2004
-
Ingår i: Cancer Research. - : American Association for Cancer Research (AACR). - 0008-5472 .- 1538-7445. ; 64:8, s. 2725-2733
-
Tidskriftsartikel (refereegranskat)abstract
- Platelet-derived growth factor (PDGF) receptor signaling participates in different processes in solid tumors, including autocrine stimulation of tumor cell growth, recruitment of tumor stroma fibroblasts, and stimulation of tumor angiogenesis. In the present study, the B16 mouse melanoma tumor model was used to investigate the functional consequences of paracrine PDGF stimulation of host-derived cells. Production of PDGF-BB or PDGF-DD by tumor cells was associated with an increased tumor growth rate. Characterization of tumors revealed an increase in pericyte abundance in tumors derived from B16 cells producing PDGF-BB or PDGF-DD. The increased tumor growth rate associated with PDGF-DD production was not seen in mice expressing an attenuated PDGF beta-receptor and was thus dependent on host PDGF beta-receptor signaling. The increased pericyte abundance was not associated with an increased tumor vessel density. However, tumor cell apoptosis, but not proliferation, was reduced in tumors displaying PDGF-induced increased pericyte coverage. Our findings thus demonstrate that paracrine PDGF production stimulates pericyte recruitment to tumor vessels and suggest that pericyte abundance influences tumor cell apoptosis and tumor growth.
|
|
| 10. |
|
|
| 11. |
- Sundh, Josefin, 1972-, et al.
(författare)
-
Beta-blockeRs tO patieNts with CHronIc Obstructive puLmonary diseasE (BRONCHIOLE) - Study protocol from a randomized controlled trial
- 2020
-
Ingår i: Trials. - : BioMed Central (BMC). - 1745-6215. ; 21:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Observational studies indicate that beta-blockers are associated with a reduced risk of exacerbation and mortality in patients with chronic obstructive pulmonary disease (COPD) even without overt cardiovascular disease, but data from randomized controlled trials (RCT) are lacking. The aim of this RCT is to investigate whether beta-blocker therapy in patients with COPD without diagnosed cardiovascular disease is associated with a decreased 1-year risk of the composite endpoint of death, exacerbations, or cardiovascular events.Methods: The Beta-blockeRs tO patieNts with CHronIc Obstructive puLmonary diseasE (BRONCHIOLE) study is an open-label, multicentre, prospective RCT. A total of 1700 patients with COPD will be randomly assigned to either standard COPD care and metoprolol at a target dose of 100 mg per day or to standard COPD care only. The primary endpoint is a composite of death, COPD exacerbations, and cardiovascular events. Major exclusion criteria are ischemic heart disease, left-sided heart failure, cerebrovascular disease, critical limb ischemia, and atrial fibrillation/flutter. Study visits are an inclusion visit, a metoprolol titration visit at 1 month, follow-up by telephone at 6 months, and a final study visit after 1 year. Outcome data are obtained from medical history and record review during study visits, as well as from national registries.Discussion: BRONCHIOLE is a pragmatic randomized trial addressing the potential of beta-blockers in patients with COPD. The trial is expected to provide relevant clinical data on the efficacy of this treatment on patient-related outcomes in patients with COPD.
|
|
