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Sökning: WFRF:(Sävman Karin 1960)

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1.
  • Challis, Pontus, et al. (författare)
  • Factors associated with the increased incidence of necrotising enterocolitis in extremely preterm infants in Sweden between two population-based national cohorts (2004-2007 vs 2014-2016)
  • 2024
  • Ingår i: Archives of Disease in Childhood. - : BMJ Publishing Group Ltd. - 1359-2998 .- 1468-2052. ; 109:1, s. 87-93
  • Tidskriftsartikel (refereegranskat)abstract
    • Objective To investigate potential risk factors behind the increased incidence of necrotising enterocolitis (NEC) in Swedish extremely preterm infants.Design Registry data from two population-based national cohorts were studied. NEC diagnoses (Bell stage >= II) were validated against hospital records.Patients All liveborn infants <27 weeks of gestation 2004-2007 (n=704) and 2014-2016 (n=895) in Sweden.Main outcome measures NEC incidence.Results The validation process resulted in a 28% reduction of NEC cases but still confirmed a higher NEC incidence in the later epoch compared with the earlier (73/895 (8.2%) vs 27/704 (3.8%), p=0.001), while the composite of NEC or death was lower (244/895 (27.3%) vs 229/704 (32.5%), p=0.022). In a multivariable Cox regression model, censored for mortality, there was no significant difference in early NEC (0-7 days of life) between epochs (HR=0.9 (95% CI 0.5 to 1.9), p=0.9), but being born in the later epoch remained an independent risk factor for late NEC (>7 days) (HR=2.7 (95% CI 1.5 to 5.0), p=0.001). In propensity score analysis, a significant epoch difference in NEC incidence (12% vs 2.8%, p<0.001) was observed only in the tertile of infants at highest risk of NEC, where the 28-day mortality was lower in the later epoch (35% vs 50%, p=0.001). More NEC cases were diagnosed with intramural gas in the later epoch (33/73 (45.2%) vs 6/26 (23.1%), p=0.047).Conclusions The increase in NEC incidence between epochs was limited to cases occurring after 7 days of life and was partly explained by increased survival in the most extremely preterm infants. Misclassification of NEC is common.
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2.
  • Forsman, Huamei, et al. (författare)
  • Galectin 3 Aggravates Joint Inflammation and Destruction in Antigen-Induced Arthritis
  • 2011
  • Ingår i: ARTHRITIS AND RHEUMATISM. - : John Wiley and Sons, Ltd. - 0004-3591 .- 1529-0131. ; 63:2, s. 445-454
  • Tidskriftsartikel (refereegranskat)abstract
    • Objective. Galectin 3, an endogenous beta galactoside-binding lectin, plays an important role in the modulation of immune responses. The finding that galectin 3 is present in the inflamed synovium in patients with rheumatoid arthritis suggests that the protein is associated with the pathogenesis of this disease. We undertook this study to investigate the influence of galectin 3 deficiency in a murine model of arthritis. Methods. Wild-type (WT) and galectin 3-deficient (galectin 3(-/-)) mice were subjected to antigen-induced arthritis (AIA) through immunization with methylated bovine serum albumin. The concentration of serum cytokines (interleukin-6 [IL-6] and tumor necrosis factor alpha [TNF alpha]) and antigen-specific antibodies was evaluated using a cytometric bead array platform and enzyme-linked immunosorbent assay (ELISA). Cellular IL-17 responses were examined by flow cytometry, ELISA, and enzyme-linked immunospot assay. Results. The joint inflammation and bone erosion of AIA were markedly suppressed in galectin 3(-/-) mice as compared with WT mice. The reduced arthritis in galectin 3(-/-) mice was accompanied by decreased levels of antigen-specific IgG and proinflammatory cytokines. The frequency of IL-17-producing cells in the spleen was reduced in galectin 3(-/-) mice as compared with WT mice. Exogenously added recombinant galectin 3 could partially restore the reduced arthritis and cytokines in galectin 3(-/-) mice. Conclusion. Our findings show that galectin 3 plays a pathogenic role in the development and progression of AIA and that the disease severity is accompanied by alterations of antigen-specific IgG levels, systemic levels of TNF alpha and IL-6, and frequency of IL-17-producing T cells. To our knowledge, this is the first report of in vivo evidence that galectin 3 plays a crucial role in the development of arthritis.
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3.
  • Golubinskaya, Veronika, 1974, et al. (författare)
  • Expression of S100A Alarmins in Cord Blood Monocytes Is Highly Associated With Chorioamnionitis and Fetal Inflammation in Preterm Infants
  • 2020
  • Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 11
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Preterm infants exposed to chorioamnionitis and with a fetal inflammatory response are at risk for neonatal morbidity and adverse outcome. Alarmins S100A8, S100A9, and S100A12 are expressed by myeloid cells and have been associated with inflammatory activation and monocyte modulation. Aim: To study S100A alarmin expression in cord blood monocytes from term healthy and preterm infants and relate results to clinical findings, inflammatory biomarkers and alarmin protein levels, as well as pathways identified by differentially regulated monocyte genes. Methods: Cord blood CD14+ monocytes were isolated from healthy term (n = 10) and preterm infants (<30 weeks gestational age, n = 33) by MACS technology. Monocyte RNA was sequenced and gene expression was analyzed by Principal Component Analysis and hierarchical clustering. Pathways were identified by Ingenuity Pathway Analysis. Inflammatory proteins were measured by Multiplex ELISA, and plasma S100A proteins by mass spectrometry. Histological chorioamnionitis (HCA) and fetal inflammatory response syndrome (FIRS) were diagnosed by placenta histological examination. Results: S100A8, S100A9, and S100A12 gene expression was significantly increased and with a wider range in preterm vs. term infants. High S100A8 and S100A9 gene expression (n = 17) within the preterm group was strongly associated with spontaneous onset of delivery, HCA, FIRS and elevated inflammatory proteins in cord blood, while low expression (n = 16) was associated with impaired fetal growth and physician-initiated delivery. S100A8 and S100A9 protein levels were significantly lower in preterm vs. term infants, but within the preterm group high S100A gene expression, spontaneous onset of labor, HCA and FIRS were associated with elevated protein levels. One thousand nine hundred genes were differentially expressed in preterm infants with high vs. low S100A alarmin expression. Analysis of 124 genes differentially expressed in S100A high as well as FIRS and HCA groups identified 18 common pathways and S100A alarmins represented major hubs in network analyses. Conclusion: High expression of S100A alarmins in cord blood monocytes identifies a distinct clinical risk group of preterm infants exposed to chorioamnionitis and with a fetal inflammatory response. Gene and pathway analyses suggest that high S100A alarmin expression also affects monocyte function. The connection with monocyte phenotype and inflammation-stimulated S100A expression in other cell types (e.g., neutrophils) warrants further investigation.
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4.
  • Holst, Rose-Marie, 1946, et al. (författare)
  • Expression of cytokines and chemokines in cervical and amniotic fluid: Relationship to histological chorioamnionitis
  • 2007
  • Ingår i: J Matern Fetal Neonatal Med. - : Informa UK Limited. ; 20:12, s. 885-893
  • Tidskriftsartikel (refereegranskat)abstract
    • Objective. To correlate cervical and amniotic fluid cytokines and macrophage-related chemokines to the development of histological chorioamnionitis (HCA) in patients with preterm labor (PTL) and preterm prelabor rupture of the membranes (PPROM). Study design. Cervical and amniotic fluid interleukin (IL)-6, IL-8, IL-18, monocyte chemotactic protein (MCP)-1, MCP-2, and MCP-3 from pregnant women (at
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5.
  • Sundqvist, Martina, et al. (författare)
  • Cord blood neutrophils display a galectin-3 responsive phenotype accentuated by vaginal delivery.
  • 2013
  • Ingår i: BMC pediatrics. - : Springer Science and Business Media LLC. - 1471-2431. ; 13
  • Tidskriftsartikel (refereegranskat)abstract
    • Term neonates are at increased risk of infections due to undeveloped immune mechanisms, and proper neutrophil function is important for perinatal immune defence. Galectin-3, an endogenous β-galactoside-binding lectin, is emerging as an inflammatory mediator and we have previously shown that primed/activated, but not resting, adult neutrophils respond to this lectin by production of reactive oxygen species (ROS). We investigated if galectin-3 is of importance in perinatal immune defence, focusing on plasma levels and neutrophil responsiveness.
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6.
  • Sundqvist, Martina, et al. (författare)
  • Increased intracellular oxygen radical production in neutrophils during febrile episodes of PFAPA syndrome.
  • 2013
  • Ingår i: Arthritis and rheumatism. - : Wiley. - 1529-0131 .- 0004-3591. ; 65:11, s. 2971-2983
  • Tidskriftsartikel (refereegranskat)abstract
    • Objective: Periodic Fever, Aphthous stomatitis, Pharyngitis, and cervical Adenitis (PFAPA) syndrome is an autoinflammatory disease of unknown etiology that primarily affects preschool children. PFAPA is characterized by recurrent attacks of fever and inflammatory symptoms consistent with the disease acronym. Since autoinflammatory diseases by definition are mediated by cells of the innate immune system, we aimed at evaluating functional features of neutrophils, the most abundant innate immune cell in circulation, in PFAPA syndrome. Methods: Blood neutrophils, obtained from PFAPA patients during both febrile and asymptomatic afebrile phases of disease, as well as from healthy children (afebrile controls) and children with fever and abdominal pain (febrile controls) were analysed for three key neutrophil characteristics: (i) apoptosis (measured by Annexin V/7AAD staining), (ii) production of reactive oxygen species (ROS; by luminol/isoluminol-amplified chemiluminescence), and (iii) priming status (as responsiveness to galectin-3 and upregulation of CD11b). Results: Compared to neutrophils from both PFAPA patients in an afebrile interval and from febrile controls, neutrophils obtained during a PFAPA flare produced elevated levels of intracellular NADPH-oxidase-derived ROS, had significantly diminished rates of spontaneous apoptosis, and displayed signatures of priming. In contrast, neutrophils from afebrile PFAPA patients had a significantly elevated rate of spontaneous apoptosis compared to neutrophils from afebrile controls. Conclusions: We demonstrate that three key aspects of neutrophil innate immune function, namely apoptosis, priming, and generation of an intracellular oxidative burst are altered, most prominently during febrile attacks in PFAPA syndrome. © 2013 American College of Rheumatology.
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7.
  • Thorell, Anna, et al. (författare)
  • Microbial invasion of the amniotic cavity is associated with impaired cognitive and motor function at school age in preterm children.
  • 2020
  • Ingår i: Pediatric research. - : Springer Science and Business Media LLC. - 1530-0447 .- 0031-3998. ; 87:5, s. 924-931
  • Tidskriftsartikel (refereegranskat)abstract
    • Chorioamnionitis is an important cause of preterm delivery. Data on neurodevelopmental outcome in exposed infants are inconsistent due to difficulties in diagnosing intrauterine infection/inflammation and lack of detailed long-term follow-up. We investigate cognitive and motor function in preterm infants at early school age and relate the findings to bacteria in amniotic fluid obtained by amniocentesis (microbial invasion of the amniotic cavity (MIAC)) or placenta findings of histological chorioamnionitis (HCA) or fetal inflammatory response syndrome (FIRS).Sixty-six infants with gestational age <34 weeks at birth and without major disabilities were assessed using WISC-III and the Bruininks-Oseretsky Test of Motor Proficiency. Results were corrected for gestational age and sex.Children exposed to MIAC had significantly lower scores for full-scale IQ and verbal IQ compared to the non-MIAC group and the difference in full-scale IQ remained after correction for confounding factors. The MIAC group had also significantly lower motor scores after correction. In contrast, motor function was not affected in infants exposed to HCA or FIRS and differences between groups for cognitive scores were lost after corrections.Exposure to bacteria in amniotic fluid is associated with lower motor and cognitive scores in school age preterm infants without major disabilities.
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8.
  • Tsiartas, Panos, et al. (författare)
  • The association between histological chorioamnionitis, funisitis and neonatal outcome in women with preterm prelabor rupture of membranes.
  • 2013
  • Ingår i: The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians. - : Informa UK Limited. - 1476-4954. ; 26:13, s. 1332-1336
  • Tidskriftsartikel (refereegranskat)abstract
    • Abstract Objective: To determine the impact of histological chorioamnionitis (HCA) and funisitis on neonatal outcome in preterm prelabor rupture of membranes (PPROM) pregnancies. Methods: Women with PPROM between 24+0 to 36+6 weeks of gestation, admitted to the Department of Obstetrics and Gynecology at the University Hospital Hradec Kralove in the Czech Republic, between July 2008 and October 2010, were enrolled in the study (n=231). Results: The incidence of early-onset sepsis (EOS) differed significantly in neonates born to women with and without HCA, after adjustment for gestational age (11% versus 1%, p=0.011). The incidence of EOS in neonates was also significantly different, after adjustment for gestational age, in cases with and without funisitis (18% versus 4%, p=0.002). The same was also found for retinopathy of prematurity (ROP) cases with and without funisitis (23% versus 4%, p=0.014), after adjustment for gestational age. Conclusions: HCA and funisitis increase the risk of adverse perinatal outcome in PPROM pregnancies.
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9.
  • Viklund, Felicia, et al. (författare)
  • Protein Concentrations of Thrombospondin-1, MIP-1β, and S100A8 Suggest the Reflection of a Pregnancy Clock in Mid-Trimester Amniotic Fluid
  • 2020
  • Ingår i: Reproductive Sciences. - : Springer Science and Business Media LLC. - 1933-7205 .- 1933-7191. ; 27:12, s. 2146-2157
  • Tidskriftsartikel (refereegranskat)abstract
    • The development of immunoassays enables more sophisticated studies of the associations between protein concentrations and pregnancy outcomes, allowing early biomarker identification that can improve neonatal outcomes. The aim of this study was to explore associations between selected mid-trimester amniotic fluid proteins and (1) overall gestational duration and (2) spontaneous preterm delivery. A prospective cohort study, including women undergoing mid-trimester transabdominal genetic amniocentesis, was performed in Gothenburg, Sweden, 2008–2016 (n = 1072). A panel of 27 proteins related to inflammation was analyzed using Meso-Scale multiplex technology. Concentrations were adjusted for gestational age at sampling, experimental factors, year of sampling, and covariates (maternal age at sampling, parity (nulliparous/multiparous), smoking at first prenatal visit, and in vitro fertilization). Cox regression analysis of the entire cohort was performed to explore possible associations between protein concentrations and gestational duration. This was followed by Cox regression analysis censored at 259 days or longer, to investigate whether associations were detectable in women with spontaneous preterm delivery (n = 47). Finally, linear regression models were performed to analyze associations between protein concentrations and gestational duration in women with spontaneous onset of labor at term (n = 784). HMG-1, IGFBP-1, IL-18, MIP-1α, MIP-1β, S100A8, and thrombospondin-1 were significantly associated with gestational duration at term, but not preterm. Increased concentrations of thrombospondin-1, MIP-1β, and S100A8, respectively, were significantly associated with decreased gestational duration after the Holm-Bonferroni correction in women with spontaneous onset of labor at term. This adds to the concept of a pregnancy clock, where our findings suggest that such a clock is also reflected in the amniotic fluid at early mid-trimester, but further research is needed to confirm this.
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10.
  • Andersson, Y, et al. (författare)
  • Pasteurization of mother's own milk reduces fat absorption and growth in preterm infants.
  • 2007
  • Ingår i: Acta paediatrica. - : Wiley. - 0803-5253 .- 1651-2227. ; 96:10, s. 1445-9
  • Tidskriftsartikel (refereegranskat)abstract
    • Aim: A randomized study was conducted to evaluate whether pasteurized milk (Holder pasteurization 62.5 degrees C, 30 min) reduces fat absorption and growth in preterm infants. Methods: Preterm infants (825-1325 g) born with gestational age
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11.
  • Bolouri, Hayde, 1957, et al. (författare)
  • Innate defence regulator peptide 1018 protects against perinatal brain injury.
  • 2014
  • Ingår i: Annals of neurology. - : Wiley. - 1531-8249 .- 0364-5134. ; 75:3, s. 395-410
  • Tidskriftsartikel (refereegranskat)abstract
    • Objective: There is currently no pharmacological treatment that provides protection against brain injury in neonates. It is known that activation of an innate immune response is a key, contributing factor in perinatal brain injury, therefore, the neuroprotective therapeutic potential of innate defence regulator peptides (IDRs) was investigated. Methods: The anti-inflammatory effects of three IDRs was measured in LPS-activated murine microglia. IDRs were then assessed for their ability to confer neuroprotection in vivo when given 3h after neonatal brain injury in a clinically relevant model that combines an inflammatory challenge (LPS) with hypoxia-ischemia (HI). To gain insight into peptide-mediated effects on LPS-induced inflammation and neuroprotective mechanisms, global cerebral gene expression patterns were analyzed in pups that were treated with IDR-1018 either 4 h before LPS or 3h after LPS+HI. Results: IDR-1018 reduced inflammatory mediators produced by LPS-stimulated microglia cells in vitro and modulated LPS-induced neuroinflammation in vivo. When administered 3h after LPS+HI, IDR-1018 exerted effects on regulatory molecules of apoptotic (for e.g. Fadd and Tnfsf9) and inflammatory (for e.g. IL-1, TNF-α, chemokines and cell adhesion molecules) pathways and showed marked protection of both white and grey brain matter. Interpretation: IDR-1018 supresses pro-inflammatory mediators and cell injurious mechanisms in the developing brain, and post-insult treatment is efficacious in reducing LPS-induced hypoxic-ischemic brain damage. IDR-1018 is effective in the brain when given systemically, confers neuroprotection of both grey and white matter, and lacks significant effects on the brain under normal conditions. Thus this peptide provides the features of a promising neuroprotective agent in newborns with brain injury. ANN NEUROL 2013. © 2013 American Neurological Association.
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12.
  • Brown, Kelly, 1973, et al. (författare)
  • Profile of blood cells and inflammatory mediators in periodic fever, aphthous stomatitis, pharyngitis and adenitis (PFAPA) syndrome.
  • 2010
  • Ingår i: BMC pediatrics. - : Springer Science and Business Media LLC. - 1471-2431. ; 10
  • Tidskriftsartikel (refereegranskat)abstract
    • ABSTRACT: BACKGROUND: This study aimed to profile levels of blood cells and serum cytokines during afebrile and febrile phases of periodic fever, aphthous stomatitis, pharyngitis and adenitis (PFAPA) syndrome to advance pathophysiological understanding of this pediatric disease. METHODS: A cohort of patients with a median age of 4.9 years experiencing 'typical PFAPA' episodes participated in this study. Blood cells and serum cytokines were analyzed by CBC analysis and multiplex ELISA. RESULTS: Oscillations in the concentration of blood cells during the afebrile and febrile phases of typical PFAPA syndrome were observed; novel findings include increased monocytes and decreased eosinophils during a febrile episode and increased thrombocytes in the afebrile interval. Relatively modest levels of pro-inflammatory cytokines were present in sera. IFNγ-induced cytokine IP10/CXCL10 was increased after the onset of fever while T cell-associated cytokines IL7 and IL17 were suppressed during afebrile and febrile periods. CONCLUSIONS: Identification of dysregulated blood cells and serum cytokines is an initial step towards the identification of biomarkers of PFAPA disease and/or players in disease pathogenesis. Future investigations are required to conclusively discern which mediators are associated specifically with PFAPA syndrome.
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13.
  • Chhor, Vibol, et al. (författare)
  • Characterization of phenotype markers and neuronotoxic potential of polarised primary microglia in vitro.
  • 2013
  • Ingår i: Brain, behavior, and immunity. - : Elsevier BV. - 1090-2139 .- 0889-1591. ; 32, s. 70-85
  • Tidskriftsartikel (refereegranskat)abstract
    • Microglia mediate multiple facets of neuroinflammation, including cytotoxicity, repair, regeneration, and immunosuppression due to their ability to acquire diverse activation states, or phenotypes. Modulation of microglial phenotype is an appealing neurotherapeutic strategy but a comprehensive study of classical and more novel microglial phenotypic markers in vitro is lacking. The aim of this study was to outline the temporal expression of a battery of phenotype markers from polarised microglia to generate an in vitro tool for screening the immunomodulatory potential of novel compounds. We characterised expression of thirty-one macrophage/microglial phenotype markers in primary microglia over time (4, 12, 36, and 72h), using RT-qPCR or multiplex protein assay. Firstly, we selected Interleukin-4 (IL-4) and lipopolysaccharide (LPS) as the strongest M1-M2 polarising stimuli, from six stimuli tested. At each time point, markers useful to identify that microglia were M1 included iNOS, Cox-2 and IL-6 and a loss of M2a markers. Markers useful for quantifying M2b-immunomodulatory microglia included, increased IL-1RA and SOCS3 and for M2a-repair and regeneration, included increased arginase-1, and a loss of the M1 and M2b markers were discriminatory. Additional markers were regulated at fewer time points, but are still likely important to monitor when assessing the immunomodulatory potential of novel therapies. Further, to facilitate identification of how novel immunomodulatory treatments alter the functional affects of microglia, we characterised how the soluble products from polarised microglia affected the type and rate of neuronal death; M1/2b induced increasing and M2a-induced decreasing neuronal loss. We also assessed any effects of prior activation state, to provide a way to identify how a novel compound may alter phenotype depending on the stage of injury/insult progression. We identified generally that a prior M1/2b reduced the ability of microglia to switch to M2a. Altogether, we have characterised a profile of phenotype markers and a mechanism of assessing functional outcome that we can use as a reference guide for first-line screening of novel immunomodulatory therapies in vitro in the search for viable neuroprotectants.
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14.
  • Doverhag, Christina, 1979, et al. (författare)
  • Galectin-3 contributes to neonatal hypoxic-ischemic brain injury.
  • 2010
  • Ingår i: Neurobiology of disease. - : Elsevier BV. - 1095-953X .- 0969-9961. ; 38:1, s. 36-46
  • Tidskriftsartikel (refereegranskat)abstract
    • Inflammation induced by hypoxia-ischemia (HI) contributes to the development of injury in the newborn brain. In this study we investigated the role of galectin-3, a novel inflammatory mediator, in the inflammatory response and development of brain injury in a mouse model for neonatal HI. Galectin-3 gene and protein expression was increased after injury and galectin-3 was located in activated microglia/macrophages. Galectin-3 deficient mice (gal3-/-) were protected from injury particularly in hippocampus and striatum. Microglia accumulation was increased in the gal3-/-mice but accompanied by decreased levels of total matrix metalloproteinase (MMP)-9 and nitrotyrosine. The protection and increase in microglial infiltration was more pronounced in male gal3-/-mice. Trophic factors and apoptotic markers did not significantly differ between groups. In conclusion, galectin-3 contributes to neonatal HI injury particularly in male mice. Our results indicate that galectin-3 exerts its effect by modulating the inflammatory response.
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15.
  • Doverhag, Christina, 1979, et al. (författare)
  • Pharmacological and genetic inhibition of NADPH oxidase does not reduce brain damage in different models of perinatal brain injury in newborn mice
  • 2008
  • Ingår i: Neurobiology of Disease. - : Elsevier BV. - 1095-953X .- 0969-9961. ; 31:1, s. 133-44
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: Inflammation and reactive oxygen species (ROS) are important in the development of perinatal brain injury. The ROS-generating enzyme NADPH oxidase (Nox2) is present in inflammatory cells and contributes to brain injury in adult animal models. HYPOTHESIS: NADPH oxidase contributes to ROS formation and development of injury in the immature brain and inhibition of NADPH oxidase attenuates perinatal brain injury. METHODS: We used animal models of term hypoxia-ischemia (HI) (P9 mice) as well as ibotenate-induced excitotoxic injury (P5 mice) mimicking features of periventricular leukomalacia in preterm infants. In vitro microglia cell cultures were used to investigate NADPH oxidase-dependent ROS formation. In vivo we determined the impact 1) of HI on NADPH oxidase gene expression 2) of genetic (gp91-phox/Nox2 knock-out) and 3) of pharmacological NADPH oxidase inhibition on HI-induced injury and NMDA receptor-mediated excitotoxic injury, respectively. Endpoints were ROS formation, oxidative stress, apoptosis, inflammation and extent of injury. RESULTS: Hypoxia-ischemia increased NADPH oxidase subunits mRNA expression in total brain tissue in vivo. In vitro ibotenate increased NADPH oxidase-dependent formation of reactive oxygen species in microglia. In vivo the inhibition of NADPH oxidase did not reduce the extent of brain injury in any of the animal models. In contrast, the injury was increased by inhibition of NADPH oxidase and genetic inhibition was associated with an increased level of galectin-3 and IL-1beta. CONCLUSION: NADPH oxidase is upregulated after hypoxia-ischemia and activated microglia cells are a possible source of Nox2-derived ROS. In contrast to findings in adult brain, NADPH oxidase does not significantly contribute to the pathogenesis of perinatal brain injury. Results obtained in adult animals cannot be transferred to newborns and inhibition of NADPH oxidase should not be used in attempts to attenuate injury.
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16.
  • Eklind, Saskia, et al. (författare)
  • Effect of lipopolysaccharide on global gene expression in the immature rat brain
  • 2006
  • Ingår i: Pediatr Res. ; 60:2, s. 161-8
  • Tidskriftsartikel (refereegranskat)abstract
    • To improve the understanding of the molecular mechanisms whereby lipopolysaccharide (LPS) affects the immature brain, global gene expression following LPS exposure was investigated in neonatal rats. Brains (n = 5/time point) were sampled 2, 6, and 72 h after LPS and compared with age-matched controls. The mRNA from each brain was analyzed separately on Affymextrix GeneChip Rat Expression Set 230. The number of genes regulated after LPS were 847 at 2 h, 1564 at 6 h, and 1546 genes at 72 h. Gene ontology analysis demonstrated that, at both 2 and 6 h after LPS, genes associated with protein metabolism, response to external stimuli and stress (immune and inflammatory response, chemotaxis) and cell death were overrepresented. At 72 h, the most strongly regulated genes belonged to secretion of neurotransmitters, transport, synaptic transmission, cell migration, and neurogenesis. Several pathways associated with cell death/survival were identified (caspase-tumor necrosis factor alpha [TNF-alpha]-, p53-, and Akt/phosphatidylinositol-3-kinase (PI3 K)-dependent mechanisms). Caspase-3 activity increased and phosphorylation of Akt decreased 8 h after peripheral LPS exposure. These results show a complex cerebral response to peripheral LPS exposure. In addition to the inflammatory response, a significant number of cell death-associated genes were identified, which may contribute to increased vulnerability of the immature brain to hypoxia-ischemia (HI) following LPS exposure.
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17.
  • Elmwall, Jonas, et al. (författare)
  • Galectin-3 Is a Target for Proteases Involved in the Virulence of Staphylococcus aureus
  • 2017
  • Ingår i: Infection and Immunity. - : American Society for Microbiology. - 0019-9567 .- 1098-5522. ; 85:7
  • Tidskriftsartikel (refereegranskat)abstract
    • Staphylococcus aureus is a major cause of skin and soft tissue infection. The bacterium expresses four major proteases that are emerging as virulence factors: aureolysin (Aur), V8 protease (SspA), staphopain A (ScpA), and staphopain B (SspB). We hypothesized that human galectin-3, a beta-galactoside-binding lectin involved in immune regulation and antimicrobial defense, is a target for these proteases and that proteolysis of galectin-3 is a novel immune evasion mechanism. Indeed, supernatants from laboratory strains and clinical isolates of S. aureus caused galectin-3 degradation. Similar proteolytic capacities were found in Staphylococcus epidermidis isolates but not in Staphylococcus saprophyticus. Galectin-3-induced activation of the neutrophil NADPH oxidase was abrogated by bacterium-derived proteolysis of galectin-3, and SspB was identified as the major protease responsible. The impact of galectin-3 and protease expression on S. aureus virulence was studied in a murine skin infection model. In galectin-3 (+)/(+) mice, SspB-expressing S. aureus caused larger lesions and resulted in higher bacterial loads than protease-lacking bacteria. No such difference in bacterial load or lesion size was detected in galectin-3 (+)/(+) mice, which overall showed smaller lesion sizes than the galectin-3 (+)/(+) animals. In conclusion, the staphylococcal protease SspB inactivates galectin-3, abrogating its stimulation of oxygen radical production in human neutrophils and increasing tissue damage during skin infection.
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18.
  • Erkenstam, Nina Hellström, 1976, et al. (författare)
  • Temporal Characterization of Microglia/Macrophage Phenotypes in a Mouse Model of Neonatal Hypoxic-Ischemic Brain Injury.
  • 2016
  • Ingår i: Frontiers in cellular neuroscience. - : Frontiers Media SA. - 1662-5102. ; 10
  • Tidskriftsartikel (refereegranskat)abstract
    • Immune cells display a high degree of phenotypic plasticity, which may facilitate their participation in both the progression and resolution of injury-induced inflammation. The purpose of this study was to investigate the temporal expression of genes associated with classical and alternative polarization phenotypes described for macrophages and to identify related cell populations in the brain following neonatal hypoxia-ischemia (HI). HI was induced in 9-day old mice and brain tissue was collected up to 7 days post-insult to investigate expression of genes associated with macrophage activation. Using cell-markers, CD86 (classic activation) and CD206 (alternative activation), we assessed temporal changes of CD11b(+) cell populations in the brain and studied the protein expression of the immunomodulatory factor galectin-3 in these cells. HI induced a rapid regulation (6 h) of genes associated with both classical and alternative polarization phenotypes in the injured hemisphere. FACS analysis showed a marked increase in the number of CD11b(+)CD86(+) cells at 24 h after HI (+3667%), which was coupled with a relative suppression of CD11b(+)CD206(+) cells and cells that did not express neither CD86 nor CD206. The CD11b(+)CD206(+) population was mixed with some cells also expressing CD86. Confocal microscopy confirmed that a subset of cells expressed both CD86 and CD206, particularly in injured gray and white matter. Protein concentration of galectin-3 was markedly increased mainly in the cell population lacking CD86 or CD206 in the injured hemisphere. These cells were predominantly resident microglia as very few galectin-3 positive cells co-localized with infiltrating myeloid cells in Lys-EGFP-ki mice after HI. In summary, HI was characterized by an early mixed gene response, but with a large expansion of mainly the CD86 positive population during the first day. However, the injured hemisphere also contained a subset of cells expressing both CD86 and CD206 and a large population that expressed neither activation marker CD86 nor CD206. Interestingly, these cells expressed the highest levels of galectin-3 and were found to be predominantly resident microglia. Galectin-3 is a protein involved in chemotaxis and macrophage polarization suggesting a novel role in cell infiltration and immunomodulation for this cell population after neonatal injury.
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19.
  • Gravina, Giacomo, et al. (författare)
  • Proteomics identifies lipocalin-2 in neonatal inflammation associated with cerebrovascular alteration in mice and preterm infants
  • 2023
  • Ingår i: iScience. - 2589-0042. ; 26:7
  • Tidskriftsartikel (refereegranskat)abstract
    • Staphylococcus (S.) epidermidis is the most common nosocomial coagulase-negative staphylococci infection in preterm infants. Clinical signs of infection are often unspecific and novel markers to complement diagnosis are needed. We investigated proteomic alterations in mouse brain after S. epidermidis infection and in preterm infant blood. We identified lipocalin-2 (LCN2) as a crucial protein associated with cerebrovascular changes and astrocyte reactivity in mice. We further proved that LCN2 protein expression was associated with endothelial cells but not astrocyte reactivity. By combining network analysis and differential expression approaches, we identified LCN2 linked to blood C-reactive protein levels in pre term infants born <28 weeks of gestation. Blood LCN2 levels were associated with similar alterations of cytokines and chemokines in both infected mice and human preterm infants with increased levels of C-reactive protein. This experimental and clinical study suggests that LCN2 may be a marker of preterm infection/inflammation associated with cerebrovascular changes and neuroinflammation.
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20.
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21.
  • Hagberg, Henrik, 1955, et al. (författare)
  • Inflammation and Perinatal Brain Injury.
  • 2011
  • Ingår i: Neonatology. A practical Approach to Neonatal Diseases.(eds) G. Buonocore, R.Bracci, M. Weindling. - : Springer Verlag. - 9788847014046
  • Bokkapitel (övrigt vetenskapligt/konstnärligt)
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22.
  • Hagberg, Henrik, 1955, et al. (författare)
  • Inflammation and perinatal brain injury
  • 2012
  • Ingår i: Neonatology: A Practical Approach to Neonatal Diseases. - Milano : Springer. - 9788847014053 ; , s. 1079-1086
  • Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
    • Inflammation is a systemic and local immune reaction to injury secondary to microbial invasion or other damaging events like trauma and hypoxia-ischemia (Fig. 128.1). This response aids in identifying extrinsic pathogens and kills microbes (and affected cells) if the injury is caused by infection [1]. Irrespective of the primary triggering event, inflammation often causes brain damage during its acute stage (collateral damage) followed by a secondary phase that in most cases promotes tissue repair and regeneration [2]. © Springer-Verlag Italia 2012.
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23.
  • Hagberg, Henrik, 1955, et al. (författare)
  • Inflammation and Perinatal Brain Injury.
  • 2018
  • Ingår i: Neonatology : A Practical Approach to Neonatal Diseases av Giuseppe Buonocore, Rodolfo Bracci, Michael Weindling. - : Springer. - 9783319294889
  • Bokkapitel (refereegranskat)
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24.
  • Hellgren, Gunnel, 1961, et al. (författare)
  • Decreased Platelet Counts and Serum Levels of VEGF-A, PDGF-BB, and BDNF in Extremely Preterm Infants Developing Severe ROP
  • 2021
  • Ingår i: Neonatology. - : S. Karger AG. - 1661-7800 .- 1661-7819. ; 118, s. 18-27
  • Tidskriftsartikel (refereegranskat)abstract
    • Introduction: Thrombocytopenia has been identified as an independent risk factor for retinopathy of prematurity (ROP), although underlying mechanisms are unknown. In this study, the association of platelet count and serum platelet-derived factors with ROP was investigated. Methods: Data for 78 infants born at gestational age (GA) <28 weeks were included. Infants were classified as having no/mild ROP or severe ROP. Serum levels of vascular endothelial growth factor A, platelet-derived growth factor BB, and brain-derived neurotrophic factor were measured in serum samples collected from birth until postmenstrual age (PMA) 40 weeks. Platelet counts were obtained from samples taken for clinical indication. Results: Postnatal platelet counts and serum concentrations of the 3 growth factors followed the same postnatal pattern, with lower levels in infants developing severe ROP at PMA 32 and 36 weeks (p < 0.05-0.001). With adjustment for GA, low platelet counts and low serum concentrations of all 3 factors at PMA 32 weeks were significantly associated with severe ROP. Serum concentrations of all 3 factors also strongly correlated with platelet count (p < 0.001). Conclusion: In this article, we show that ROP, platelet counts, and specific pro-angiogenic factors correlate. These data suggest that platelet-released factors might be involved in the regulation of retinal and systemic angiogenesis after extremely preterm birth. Further investigations are needed.
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25.
  • Hellström, Ann, 1959, et al. (författare)
  • Docosahexaenoic Acid and Arachidonic Acid Levels Are Associated with Early Systemic Inflammation in Extremely Preterm Infants
  • 2020
  • Ingår i: Nutrients. - : MDPI AG. - 2072-6643. ; 12:7
  • Tidskriftsartikel (refereegranskat)abstract
    • Fetal and early postnatal inflammation have been associated with increased morbidity in extremely preterm infants. This study aimed to demonstrate if postpartum levels of docosahexaenoic acid (DHA) and arachidonic acid (AA) were associated with early inflammation. In a cohort of 90 extremely preterm infants, DHA and AA in cord blood, on the first postnatal day and on postnatal day 7 were examined in relation to early systemic inflammation, defined as elevated C-reactive protein (CRP) and/or interleukin-6 (IL-6) within 72 h from birth, with or without positive blood culture. Median serum level of DHA was 0.5 mol% (95% CI (confidence interval) 0.2-0.9,P= 0.006) lower than the first postnatal day in infants with early systemic inflammation, compared to infants without signs of inflammation, whereas levels of AA were not statistically different between infants with and without signs of inflammation. In cord blood, lower serum levels of both DHA (correlation coefficient -0.40;P= 0.010) and AA (correlation coefficient -0.54;p< 0.001) correlated with higher levels of IL-6. Levels of DHA or AA did not differ between infants with and without histological signs of chorioamnionitis or fetal inflammation. In conclusion, serum levels of DHA at birth were associated with the inflammatory response during the early postnatal period in extremely preterm infants.
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26.
  • Hellström, Ann, 1959, et al. (författare)
  • Effect of Enteral Lipid Supplement on Severe Retinopathy of Prematurity A Randomized Clinical Trial
  • 2021
  • Ingår i: JAMA Pediatrics. - : American Medical Association (AMA). - 2168-6203 .- 2168-6211. ; 175:4, s. 359-367
  • Tidskriftsartikel (refereegranskat)abstract
    • IMPORTANCE Lack of arachidonic acid (AA) and docosahexaenoic acid (DHA) after extremely preterm birth may contribute to preterm morbidity, including retinopathy of prematurity (ROP). OBJECTIVE To determine whether enteral supplementation with fatty acids from birth to 40 weeks' postmenstrual age reduces ROP in extremely preterm infants. DESIGN, SETTING, AND PARTICIPANTS The Mega Donna Mega trial, a randomized clinical trial, was a multicenter study performed at 3 university hospitals in Sweden from December 15, 2016, to December 15, 2019. The screening pediatric ophthalmologists were masked to patient groupings. A total of 209 infants born at less than 27 weeks' gestation were tested for eligibility, and 206 infants were included. Efficacy analyses were performed on as-randomized groups on the intention-to-treat population and on the per-protocol population using as-treated groups. Statistical analyses were performed from February to April 2020. INTERVENTIONS Infants received either supplementation with an enteral oil providing AA (100mg/kg/d) and DHA (50mg/kg/d) (AA:DHA group) or no supplementation within 3 days after birth until 40 weeks' postmenstrual age. MAIN OUTCOMES AND MEASURES The primary outcomewas severe ROP (stage 3 and/or type 1). The secondary outcomes were AA and DHA serum levels and rates of other complications of preterm birth. RESULTS A total of 101 infants (58 boys [57.4%]; mean [SD] gestational age, 25.5 [1.5] weeks) were included in the AA:DHA group, and 105 infants (59 boys [56.2%]; mean [SD] gestational age, 25.5 [1.4] weeks) were included in the control group. Treatment with AA and DHA reduced severe ROP compared with the standard of care (16 of 101 [15.8%] in the AA:DHA group vs 35 of 105 [33.3%] in the control group; adjusted relative risk, 0.50 [95% CI, 0.28-0.91]; P =.02). The AA:DHA group had significantly higher fractions of AA and DHA in serum phospholipids compared with controls (overall mean difference in AA:DHA group, 0.82 mol% [95% CI, 0.46-1.18 mol%]; P <.001; overall mean difference in control group, 0.13 mol% [95% CI, 0.01-0.24 mol%]; P =.03). There were no significant differences between the AA:DHA group and the control group in the rates of bronchopulmonary dysplasia (48 of 101 [47.5%] vs 48 of 105 [45.7%]) and of any grade of intraventricular hemorrhage (43 of 101 [42.6%] vs 42 of 105 [40.0%]). In the AA:DHA group and control group, respectively, sepsis occurred in 42 of 101 infants (41.6%) and 53 of 105 infants (50.5%), serious adverse events occurred in 26 of 101 infants (25.7%) and 26 of 105 infants (24.8%), and 16 of 101 infants (15.8%) and 13 of 106 infants (12.3%) died. CONCLUSIONS AND RELEVANCE This study found that, compared with standard of care, enteral AA:DHA supplementation lowered the risk of severe ROP by 50% and showed overall higher serum levels of both AA and DHA. Enteral lipid supplementation with AA:DHA is a novel preventive strategy to decrease severe ROP in extremely preterm infants.
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27.
  • Hellström, Ann, 1959, et al. (författare)
  • Retrospective evaluation of ophthalmological and neurological outcomes for infants born before 24 weeks gestational age in a Swedish cohort
  • 2022
  • Ingår i: Bmj Open. - : BMJ. - 2044-6055. ; 12:8
  • Tidskriftsartikel (refereegranskat)abstract
    • Objectives To retrospectively evaluate ophthalmological and neurological outcomes in a Swedish cohort of infants born before 24 weeks gestational age (GA) and explore risk factors for visual impairment. Setting Eye and paediatric clinics in Sweden. Participants Infants screened for retinopathy of prematurity (ROP) (n=399), born before 24 weeks GA, 2007-2018. Cases were excluded if ophthalmological follow-up records could not be traced. Primary and secondary outcome measures Primary outcomes were ophthalmological, including visual acuity (VA), refractive error, strabismus, nystagmus and cerebral visual impairment (CVI). Secondary outcomes comprised neonatal and neurological morbidities. Data were retrospectively retrieved from medical records. Results The 355 assessed children had a median GA of 23 weeks and 2 days and a median birth weight of 565 g. At the last available ophthalmological examination, the median age was 4.8 years (range 0.5-13.2 years). Nystagmus was recorded in 21.1%, strabismus in 34.8%, and 51.0% wore spectacles. Seventy-three of 333 (21.9%) were visually impaired, defined as being referred to a low vision clinic and/or having a VA less than 20/60 at 3.5 years of age or older. ROP treatment was a significant risk factor for visual impairment (OR 2.244, p=0.003). Visually impaired children, compared with children without visual impairment, more often had neurological deficits such as intellectual disability 63.8% versus 33.3% (p<0.001), epilepsy 21.1% versus 7.5% (p=0.001) and autism spectrum disorders 32.8% versus 20.9% (p=0.043). Nine of the 355 children had been diagnosed with CVI. Conclusions Children born before 24 weeks GA frequently had visual impairment in association with neurological deficits. CVI was rarely diagnosed. A multidisciplinary approach for the evaluation and habilitation of these vulnerable infants is warranted. National follow-up guidelines need to be developed and implemented.
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28.
  • Hellström, William, et al. (författare)
  • C-Peptide Suppression during Insulin Infusion in the Extremely Preterm Infant Is Associated with Insulin Sensitivity
  • 2019
  • Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 104:9, s. 3902-3910
  • Tidskriftsartikel (refereegranskat)abstract
    • Context: Little is known about the individual response of glucose-regulating factors to administration of exogenous insulin infusion in extremely preterm infants. Objective: To evaluate longitudinal serum concentrations of insulin, C-peptide, and plasma glucose levels in a high-frequency sampling regimen in extremely preterm infants treated with insulin because of hyperglycemia. Design: Prospective longitudinal cohort study. Setting: Two university hospitals in Sweden between December 2015 and September 2016. Patients and Intervention: Serum samples were obtained from nine extremely preterm infants, gestational age between 22 (+3) and 26 (+5) weeks (+ days), with hyperglycemia (plasma-glucose >10 mmol/L) at the start of insulin infusion, at 12, 24, and every 24 hours thereafter during ongoing infusion, and 12, 24, and 72 hours after the end of insulin infusion. Main outcome measures: Longitudinal serum concentrations of insulin and C-peptide and plasma glucose levels. Results: During insulin infusion, the serum C-peptide concentrations decreased compared with at start of infusion (P = 0.036), and then increased after ending the infusion. Individual insulin sensitivity based on the nonfasting plasma glucose/insulin ratio at the start of insulin infusion correlated with the initial decrease in serum ΔC-peptide[after 12h] (P = 0.007) and the degree of lasting decrease in serum ΔC-peptide[after end of infusion] (P = 0.015). Conclusion: Exogenous insulin infusion suppressed the C-peptide concentration to individually different degrees. In addition, the effect of insulin infusion on β cells may be linked to individual insulin sensitivity, where a low insulin sensitivity resulted in a more pronounced decrease in C-peptide during insulin infusion.
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29.
  • Hellström, William, et al. (författare)
  • Neonatal clinical blood sampling led to major blood loss and was associated with bronchopulmonary dysplasia
  • 2020
  • Ingår i: Acta Paediatrica, International Journal of Paediatrics. - : Wiley. - 0803-5253 .- 1651-2227. ; 109:4, s. 679-687
  • Tidskriftsartikel (refereegranskat)abstract
    • Aim: Studies indicate that reduced foetal haemoglobin levels are related to increased neonatal morbidity rates. This study investigated the relationships between sampling-related blood loss and adult blood transfusions administered during postnatal days 1-14 and the development of severe neonatal morbidities in extremely preterm infants born before 28 weeks of gestation. Methods: The medical files of 149 extremely preterm infants born at two university hospitals in Sweden from 2013 to 2018 were investigated. Results: Blood sampling resulted in a 58% depletion of the endogenous blood volume postnatal days 1-14 (median 40.4 mL/kg, interquartile range 23.9-53.3 mL/kg) and correlated with the adult erythrocyte transfusion volume (rS = 0.870, P <.001). Sampling-related blood loss on postnatal days 1-7, adjusted for gestational age at birth and birth weight standard deviation score, was associated with the development of bronchopulmonary dysplasia (BPD) (odds ratio by a 10-unit increase 2.4, 95% confidence interval 1.1-5.4) (P =.03). No associations were found between blood sampling and intraventricular haemorrhage or necrotising enterocolitis in the full statistical model. The largest proportion of sampling-related blood was used for blood gas analyses (48.7%). Conclusion: Diagnostic blood sampling led to major endogenous blood loss replaced with adult blood components and was associated with the development of BPD.
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30.
  • Hellström, William, et al. (författare)
  • Postnatal serum IGF-1 levels associate with brain volumes at term in extremely preterm infants
  • 2023
  • Ingår i: Pediatric Research. - : Springer Science and Business Media LLC. - 0031-3998 .- 1530-0447. ; 93:3, s. 666-674
  • Tidskriftsartikel (refereegranskat)abstract
    • Background Growth factors important for normal brain development are low in preterm infants. This study investigated the link between growth factors and preterm brain volumes at term. Material/methods Infants born <28 weeks gestational age (GA) were included. Endogenous levels of insulin-like growth factor (IGF)-1, brain-derived growth factor, vascular endothelial growth factor, and platelet-derived growth factor (expressed as area under the curve [AUC] for serum samples from postnatal days 1, 7, 14, and 28) were utilized in a multivariable linear regression model. Brain volumes were determined by magnetic resonance imaging (MRI) at term equivalent age. Results In total, 49 infants (median [range] GA 25.4 [22.9-27.9] weeks) were included following MRI segmentation quality assessment and AUC calculation. IGF-1 levels were independently positively associated with the total brain (p < 0.001, beta = 0.90), white matter (p = 0.007, beta = 0.33), cortical gray matter (p = 0.002, beta = 0.43), deep gray matter (p = 0.008, beta = 0.05), and cerebellar (p = 0.006, beta = 0.08) volume adjusted for GA at birth and postmenstrual age at MRI. No associations were seen for other growth factors. Conclusions Endogenous exposure to IGF-1 during the first 4 weeks of life was associated with total and regional brain volumes at term. Optimizing levels of IGF-1 might improve brain growth in extremely preterm infants. Impact High serum levels of insulin-like growth factor (IGF)-1 during the first month of life were independently associated with increased total brain volume, white matter, gray matter, and cerebellar volume at term equivalent age in extremely preterm infants. IGF-1 is a critical regulator of neurodevelopment and postnatal levels are low in preterm infants. The effects of IGF-1 levels on brain development in extremely preterm infants are not fully understood. Optimizing levels of IGF-1 may benefit early brain growth in extremely preterm infants. The effects of systemically administered IGF-1/IGFBP3 in extremely preterm infants are now being investigated in a randomized controlled trial (Clinicaltrials.gov: NCT03253263).
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31.
  • Hortensius, Lisa M., et al. (författare)
  • Serum docosahexaenoic acid levels are associated with brain volumes in extremely preterm born infants
  • 2021
  • Ingår i: Pediatric Research. - : Springer Science and Business Media LLC. - 0031-3998 .- 1530-0447. ; 90:6, s. 1177-1185
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Docosahexaenoic acid (DHA) and arachidonic acid (AA) are important for fetal brain growth and development. Our aim was to evaluate the association between serum DHA and AA levels and brain volumes in extremely preterm infants. Methods: Infants born at <28 weeks gestational age in 2013–2015, a cohort derived from a randomized controlled trial comparing two types of parenteral lipid emulsions, were included (n = 90). Serum DHA and AA levels were measured at postnatal days 1, 7, 14, and 28, and the area under the curve was calculated. Magnetic resonance (MR) imaging was performed at term-equivalent age (n = 66), and volumes of six brain regions were automatically generated. Results: After MR image quality assessment and area under the curve calculation, 48 infants were included (gestational age mean [SD] 25.5 [1.4] weeks). DHA levels were positively associated with total brain (B = 7.966, p = 0.012), cortical gray matter (B = 3.653, p = 0.036), deep gray matter (B = 0.439, p = 0.014), cerebellar (B = 0.932, p = 0.003), and white matter volume (B = 3.373, p = 0.022). AA levels showed no association with brain volumes. Conclusions: Serum DHA levels during the first 28 postnatal days were positively associated with volumes of several brain structures in extremely preterm infants at term-equivalent age. Impact: Higher serum levels of DHA in the first 28 postnatal days are positively associated with brain volumes at term-equivalent age in extremely preterm born infants.Especially the most immature infants suffer from low DHA levels in the first 28 postnatal days, with little increase over time.Future research is needed to explore whether postnatal fatty acid supplementation can improve brain development and may serve as a nutritional preventive and therapeutic treatment option in extremely preterm infants.
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32.
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33.
  • Klevebro, Susanna, et al. (författare)
  • Arachidonic acid and docosahexaenoic acid levels correlate with the inflammation proteome in extremely preterm infants
  • 2024
  • Ingår i: Clinical Nutrition. - : Elsevier BV. - 0261-5614 .- 1532-1983. ; 43:5, s. 1162-1170
  • Tidskriftsartikel (refereegranskat)abstract
    • Background & aim: Clinical trials supplementing the long-chain polyunsaturated fatty acids (LCPUFAs) docosahexaenoic acid (DHA) and arachidonic acid (AA) to preterm infants have shown positive effects on inflammation-related morbidities, but the molecular mechanisms underlying these effects are not fully elucidated. This study aimed to determine associations between DHA, AA, and inflammation-related proteins during the neonatal period in extremely preterm infants. Methods: A retrospective exploratory study of infants (n = 183) born below 28 weeks gestation from the Mega Donna Mega trial, a randomized multicenter trial designed to study the effect of DHA and AA on retinopathy of prematurity. Serial serum samples were collected after birth until postnatal day 100 (median 7 samples per infant) and analyzed for phospholipid fatty acids and proteins using targeted proteomics covering 538 proteins. Associations over time between LCPUFAs and proteins were explored using mixed effect modeling with splines, including an interaction term for time, and adjusted for gestational age, sex, and center. Results: On postnatal day one, 55 proteins correlated with DHA levels and 10 proteins with AA levels. Five proteins were related to both fatty acids, all with a positive correlation. Over the first 100 days after birth, we identified 57 proteins to be associated with DHA and/or AA. Of these proteins, 41 (72%) related to inflammation. Thirty-eight proteins were associated with both fatty acids and the overall direction of association did not differ between DHA and AA, indicating that both LCPUFAs similarly contribute to up- and down-regulation of the preterm neonate inflammatory proteome. Primary examples of this were the inflammation-modulating cytokines IL-6 and CCL7, both being negatively related to levels of DHA and AA in the postnatal period. Conclusions: This study supports postnatal non-antagonistic and potentially synergistic effects of DHA and AA on the inflammation proteome in preterm infants, indicating that supplementation with both fatty acids may contribute to limiting the disease burden in this vulnerable population. Clinical registration number: ClinicalTrials.gov (NCT03201588).
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34.
  • Lundgren, Pia, 1967-, et al. (författare)
  • Erythropoietin serum levels, versus anaemia as risk factors for severe retinopathy of prematurity
  • 2019
  • Ingår i: Pediatric Research. - : Nature Publishing Group. - 0031-3998 .- 1530-0447. ; 86:2, s. 276-282
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Preterm infants with anaemia are treated with recombinant human erythropoietin (rhEPO). It is debated whether rhEPO treatment is a risk factor for retinopathy of prematurity (ROP). We evaluated longitudinal EPO and haemoglobin levels, blood transfusions and neonatal morbidities as risk factors for severe ROP.Method: This prospective study included 78 Swedish infants, born <28 weeks gestational age (GA), screened for ROP. We tested serum EPO levels on postnatal days 1, 7, 14 and 28 and at postmenstrual ages 32, 36 and 40 weeks. Haemoglobin levels and blood transfusions were recorded during postnatal weeks 1-4. Anaemia was defined as haemoglobin ≤110 g/L.Results: During postnatal week 1, infants with severe ROP requiring treatment (28%) more frequently developed anaemia (42.9% versus 8.0%, P = 0.003) and had higher mean EPO levels (postnatal day 7: 14.2 versus 10.8 mIU/mL, P = 0.003) compared to infants with no or less severe ROP not requiring treatment. In multivariable analyses, GA and anaemia during week 1 remained significant risk factors, but elevated EPO level postnatal day 7 was no longer significant.Conclusions: Among infants born <28 weeks GA, anaemia during week 1 was a significant risk factor for severe ROP requiring treatment but not elevated EPO levels.
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35.
  • Lundgren, Pia, 1967, et al. (författare)
  • National cohort of infants born before 24 gestational weeks showed increased survival rates but no improvement in neonatal morbidity
  • 2022
  • Ingår i: Acta Paediatrica. - : Wiley. - 0803-5253 .- 1651-2227. ; 111:8, s. 1515-1525
  • Tidskriftsartikel (refereegranskat)abstract
    • Aim To describe survival and neonatal morbidities in infants born before 24 weeks of gestation during a 12-year period. Methods Data were retrieved from national registries and validated in medical files of infants born before 24 weeks of gestation 2007-2018 in Sweden. Temporal changes were evaluated. Results In 2007-2018, 282 live births were recorded at 22 weeks and 460 at 23 weeks of gestation. Survival to discharge from hospital of infants born alive at 22 and 23 weeks increased from 20% to 38% (p = 0.006) and from 45% to 67% (p < 0.001) respectively. Caesarean section increased from 12% to 22% (p = 0.038) for infants born at 22 weeks. Neonatal morbidity rates in infants alive at 40 weeks of postmenstrual age (n = 399) were unchanged except for an increase in necrotising enterocolitis from 0 to 33% (p = 0.017) in infants born at 22 weeks of gestation. Bronchopulmonary dysplasia was more common in boys than girls, 90% versus 82% (p = 0.044). The number of infants surviving to 40 weeks doubled over time. Conclusion Increased survival of infants born before 24 weeks of gestation resulted in increasing numbers of very immature infants with severe neonatal morbidities likely to have a negative impact on long-term outcome.
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36.
  • Lundgren, Pia, 1967, et al. (författare)
  • Visual outcome at 2.5 years of age in ω-3 and ω-6 long-chain polyunsaturated fatty acid supplemented preterm infants: a follow-up of a randomized controlled trial
  • 2023
  • Ingår i: Lancet Regional Health-Europe. - 2666-7762. ; 32
  • Tidskriftsartikel (refereegranskat)abstract
    • Background We investigated ophthalmological outcomes at 2.5 years of corrected age in children born extremely preterm (EPT) to evaluate the effects of postnatal enteral supplementation with omega-3 and omega-6 long-chain polyunsaturated fatty acids.Methods In the Mega Donna Mega clinical trial, EPT infants born at less than 28 weeks of gestation were randomized to receive an enteral supplementation of docosahexaenoic acid (DHA) and arachidonic acid (AA) from birth to 40 weeks postmenstrual age. In this exploratory follow-up at 2.5 years of corrected age, we assessed visual acuity (VA), refraction, manifest strabismus, and nystagmus. Satisfactory VA was defined as >= 20/63. Multiple imputation (MI) was used to address the issue of missing data.Findings Of 178 children in the trial, 115 (with median gestational age (GA) of 25 + 4/7 weeks and median birth weights of 790 g) were ophthalmologically assessed at a median corrected age of 2.7 years (range 2.0-3.9 years). VA assessment was missing in 42.1% (75/178), in 41.7% (35/84) of the AA/DHA supplemented infants, and in 42.6% (40/94) of the control infants. After MI and adjustments for GA, study center, plurality, and corrected age at VA exam, no significant effect of AA/DHA supplementation was detected in VA outcome (>= 20/63) (odds ratio 2.16, confidence interval 95% 0.99-4.69, p = 0.053).Interpretation In this randomized controlled trial follow-up, postnatal supplementation with enteral AA/DHA to EPT children did not significantly alter VA at 2.5 years of corrected age. Due to the high loss to follow-up rate and the limited statistical power, additional studies are needed.
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37.
  • Löfqvist, Chatarina, 1964, et al. (författare)
  • Association of Retinopathy of Prematurity With Low Levels of Arachidonic Acid A Secondary Analysis of a Randomized Clinical Trial
  • 2018
  • Ingår i: Jama Ophthalmology. - : American Medical Association (AMA). - 2168-6165. ; 136:3, s. 271-277
  • Tidskriftsartikel (refereegranskat)abstract
    • IMPORTANCE Mice with oxygen-induced retinopathy fed matched diets except for omega-3 long-chain polyunsaturated fatty acids (LC-PUFAs) vs omega-6 LC-PUFAs demonstrate relative antiangiogenic and neuroprotective associations of omega-3 LC-PUFAs. However, supplementing preterm infants with LC-PUFAs has been inconsistent in reducing major preterm morbidities. However, few studies measured serum lipid levels after supplementation. OBJECTIVE To examine the associated risk of retinopathy of prematurity (ROP) from the levels of circulating omega-3 and omega-6 LC-PUFAs. DESIGN, SETTING, AND PARTICIPANTS This longitudinal clinical study was a further analysis of serum lipid levels from a randomized controlled trial cohort of 90 infants born at gestational age (GA) less than 28 weeks. From April 4, 2013, to September 22, 2015, cord blood samples, followed by venous blood samples, were obtained at birth and at 1, 7, 14, and 28 days after birth and then at postmenstrual age (PMA) 32, 36, and 40 weeks at the neonatal intensive care unit at Sahlgrenska University Hospital in Goteborg, Sweden. MAIN OUTCOMES AND MEASURES Serum phospholipid fatty acids were transmethylated and measured by gas chromatography-mass spectrometry. Mann-Whitney test, logistic regression Spearman rank correlation, and receiver operating characteristic curve analysis were used to compare differences between infants with no ROP and infants who developed ROP. RESULTS Serum levels from 78 infants (43 male [55%]; mean [SD] GA, 25.5 [1.4] weeks) with a known ROP outcome were evaluated. Lower area under the curve (AUC) of arachidonic acid (AA) (20: 4 omega-6) was seen in infants with a later diagnosis of ROP compared with infants with no ROP in the first month of life (mean, 34.05 [95% CI, 32.10-36.00] vs 37.15 [95% CI, 34.85-39.46]; P < .05). In addition, lower levels of AA at 32 weeks' PMA were seen in infants with later severe ROP compared with in those without ROP (mean, 7.06 [95% CI, 6.60-7.52] vs 8.74 [95% CI, 7.80-9.67]; P < .001). In logistic modeling, low postnatal serum levels of AA and GA at birth identified with a sensitivity greater than 90% of infants who developed ROP. CONCLUSIONS AND RELEVANCE Low postnatal levels of the omega-6 LC-PUFAs (AA) are strongly associated with ROP development. Evaluating postnatal AA fraction after birth in addition to GA may be useful for ROP prediction.
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38.
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39.
  • Mattsson, Niklas, 1979, et al. (författare)
  • Converging molecular pathways in human neural development and degeneration.
  • 2010
  • Ingår i: Neuroscience research. - : Elsevier BV. - 1872-8111 .- 0168-0102. ; 66:3, s. 330-2
  • Tidskriftsartikel (refereegranskat)abstract
    • Animal studies suggest that phosphorylation of microtubule-associated protein tau is a physiological way of destabilizing axons in the developing brain, promoting synaptic plasticity, while in the adult human brain tau phosphorylation is a specific sign of Alzheimer's disease. We here show, for the first time, that newborn human infants have extremely high levels of phosphorylated tau in their cerebrospinal fluid, and that these levels decrease during the first years of life. Tau phosphorylation in Alzheimer's disease may be a physiological response to Alzheimer-associated synaptotoxicity.
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40.
  • Najm, Svetlana, et al. (författare)
  • Effects of a lipid emulsion containing fish oil on polyunsaturated fatty acid profiles, growth and morbidities in extremely premature infants: A randomized controlled trial
  • 2017
  • Ingår i: Clinical Nutrition ESPEN. - : Elsevier BV. - 2405-4577. ; 20, s. 17-23
  • Tidskriftsartikel (refereegranskat)abstract
    • © 2017 The Authors Background & aims The purpose of the study was to compare the effects of the parenteral emulsion SMOFlipid ® , with 15% fish oil, with Clinoleic ® on retinopathy of prematurity (ROP) and other morbidities and growth, and to compare their impact on longitudinal serum levels of fatty acids. Retinopathy of prematurity, other morbidity and growth were correlated with each parenteral lipid supplement. Methods Ninety infants born at gestational age < 28 weeks were randomized to treatment with SMOFlipid ® or Clinoleic ® . Two thirds (66%) of the infants received parenteral nutrition for up to 14 days birth (median 8, range 2–14 days), and additional 25% of the infants received for up to 28 days after birth (median 21, range 15–28 days). Cord blood samples and then venous blood samples were obtained at ages 1, 7, 14, and 28 days and at postmenstrual age (PMA) 32, 36, and 40 weeks. Breastmilk was collected at postnatal day 7, and at PMA 32 and 40 weeks. Serum phospholipid and breastmilk total fatty acids were analyzed by gas chromatography–mass spectrometry. Treatment groups were compared with regard to ROP, bronchopulmonary dysplasia, necrotizing enterocolitis, patent ductus arteriosus sepsis and growth between birth and 36 weeks. Results Infants on SMOFlipid ® had higher fractions of omega-3 LCPUFA eicosapentaenoic acid (EPA) and slightly higher omega-3 LCPUFA docosahexaenoic acid (DHA) fraction and a decreased arachidonic acid (AA) to DHA ratio from one week after birth up to 32 postmenstrual weeks compared to infants on Clinoleic ® . Treatment groups did not differ in morbidities or growth. Conclusion Supplementation with SMOFlipid ® containing 15% fish oil during parenteral nutrition increased EPA substantially, DHA marginally, reduced AA and decreased AA to DHA ratio. It did not reduce morbidity or affect growth. Since extremely preterm infants accumulate a large deficit of DHA and AA, studies on more prolonged or different levels of DHA and AA supplementation are warranted.
  •  
41.
  • Nilsson, Anders K., 1982, et al. (författare)
  • Influence of Human Milk and Parenteral Lipid Emulsions on Serum Fatty Acid Profiles in Extremely Preterm Infants.
  • 2019
  • Ingår i: JPEN - Journal of Parenteral and Enteral Nutrition. - : Wiley. - 0148-6071 .- 1941-2444. ; 43:1, s. 152-161
  • Tidskriftsartikel (refereegranskat)abstract
    • Infants born prematurely are at risk of a deficiency in ω-6 and ω-3 long-chain polyunsaturated fatty acids (LC-PUFAs) arachidonic acid (AA) and docosahexaenoic acid (DHA). We investigated how fatty acids from breast milk and parenteral lipid emulsions shape serum LC-PUFA profiles in extremely preterm infants during early perinatal life.Ninety infants born < 28 weeks gestational age were randomized to receive parenteral lipids with or without the ω-3 LC-PUFAs eicosapentaenoic acid (EPA) and DHA (SMOFlipid: Fresenius Kabi, Uppsala, Sweden, or Clinoleic: Baxter Medical AB, Kista, Sweden, respectively). The fatty acid composition of infant serum phospholipids was determined from birth to postmenstrual age 40 weeks, and in mother's milk total lipids on postnatal day 7. Enteral and parenteral intake of LC-PUFAs was correlated with levels in infant serum.Infants administered parenteral ω-3 LC-PUFAs received 4.4 and 19.3 times more DHA and EPA, respectively, over the first 2 weeks of life. Parenteral EPA but not DHA correlated with levels in infant serum. We found linear relationships between dietary EPA and DHA and infant serum levels in the Clinoleic (Baxter Medical AB) group. The volume of administered SMOFlipid (Fresenius Kabi) was inversely correlated with serum AA, whereas Clinoleic (Baxter Medical AB) inversely correlated with serum EPA and DHA.There appears to be no or low correlation between the amount of DHA administered parenterally and levels measured in serum. Whether this observation reflects serum phospholipid fraction only or truly represents the amount of accreted DHA needs to be investigated. None of the parenteral lipid emulsions satisfactorily maintained high levels of both ω-6 and ω-3 LC-PUFAs in infant serum.
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42.
  • Nilsson, Anders K., 1982, et al. (författare)
  • Long-chain polyunsaturated fatty acids decline rapidly in milk from mothers delivering extremely preterm indicating the need for supplementation.
  • 2018
  • Ingår i: Acta paediatrica. - : Wiley. - 1651-2227 .- 0803-5253. ; 107:6, s. 1020-1027
  • Tidskriftsartikel (refereegranskat)abstract
    • Our aim was perform an in-depth analysis of the composition of fatty acids in milk from mothers delivering extremely preterm babies. We investigated longitudinal changes in milk fatty acid profiles and the relationship between several types of fatty acids, including omega-3 and omega-6.Milk samples were collected at three stages of lactation from 78 mothers who delivered at less than 28 weeks of pregnancy at the Sahlgrenska University Hospital, Gothenburg, Sweden, from April 2013 to September 2015. Fatty acid composition was analysed by gas chromatography-mass spectrometry.A reduction in long-chain polyunsaturated fatty acids (LCPUFAs) was observed during the lactation period. The concentrations of arachidonic acid and docosahexaenoic acid declined from medians of 0.34 to 0.22 mol% and 0.29 to 0.15 mol%, respectively, between postnatal day seven and a post-menstrual age of 40 weeks. Strong correlations were found between the intermediates of several classes of fatty acids, including omega-3, omega-6 and omega-9.A rapid reduction in LCPUFA content in the mother's milk during the lactation period emphasises the importance of fatty acid supplementation to infants born extremely preterm, at least during the period corresponding to the third trimester, when rapid development of the brain and adipose tissue require high levels of LCPUFAs. This article is protected by copyright. All rights reserved.
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43.
  • Sjöbom, Ulrika, et al. (författare)
  • Analysis of Brain Injury Biomarker Neurofilament Light and Neurodevelopmental Outcomes and Retinopathy of Prematurity among Preterm Infants
  • 2021
  • Ingår i: JAMA Network Open. - : American Medical Association (AMA). - 2574-3805. ; 4:4
  • Tidskriftsartikel (refereegranskat)abstract
    • Importance: Circulating levels of neurofilament light (NfL) and glial fibrillary acidic protein (GFAP) are important in the course of brain injury in adults, but longitudinal postnatal circulating levels in preterm infants have not been investigated. Objectives: To examine postnatal longitudinal serum levels of NfL and GFAP in preterm infants during the first 15 weeks of life and to explore possible associations between these biomarkers, neonatal morbidities, and neurodevelopmental outcomes at 2 years. Design, Setting, and Participants: This cohort study used data from 3 clinical studies, including 221 infants born before 32 weeks gestational age (GA) from 1999 to 2015; neurodevelopmental outcomes were evaluated in 120 infants. Data were collected at tertiary-level neonatal intensive care units in Gothenburg, Lund, and Uppsala, Sweden. Data analysis was conducted from January to October 2020. Exposure: Preterm birth. Main Outcomes and Measures: Serum NfL and GFAP levels, retinopathy of prematurity (ROP), intraventricular hemorrhage, and Bayley Scales of Infant Development II and III at 2 years of age, analyzed by multivariate logistic regression measured by odds ratio (OR), and receiver operating characteristic curve (ROC) analysis. Area under the curve (AUC) was also measured. Results: The 221 included infants (108 [48.9%] girls) had a mean (SD) GA at birth of 26.5 (2.1) weeks and a mean (SD) birth weight of 896 (301) grams. NfL levels increased after birth, remaining high during the first 4 weeks of life before declining to continuously low levels by postnatal age 12 weeks (median [range] NfL level at birth: 58.8 [11.5-1371.3] ng/L; 1 wk: 83.5 [14.1-952.2] ng/L; 4 wk: 24.4 [7.0-306.0] ng/L; 12 wk: 9.1 [3.7-57.0] ng/L). In a binary logistic regression model adjusted for GA at birth, birth weight SD score, Apgar status at 5 minutes, and mode of delivery, the NfL AUC at weeks 2 to 4 was independently associated with any ROP (OR, 4.79; 95% CI, 2.17-10.56; P <.001). In an exploratory analysis adjusted for GA at birth and sex, NfL AUC at weeks 2 to 4 was independently associated with unfavorable neurodevelopmental outcomes at 2 years corrected age (OR per 10-unit NfL increase, 1.07; 95% CI, 1.02-1.13; P =.01). Longitudinal GFAP levels were not significantly associated with neonatal morbidity or neurodevelopmental outcome. Conclusions and Relevance: In this study, high NfL levels during the first weeks of life were associated with ROP and poor neurodevelopmental outcomes at 2 years of age. Associations between NfL and later neurovascular development in infants born prematurely should be investigated further.
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44.
  • Sjöbom, Ulrika, et al. (författare)
  • Fatty acid composition of milk from mothers giving birth at extremely low gestation in Sweden
  • 2022
  • Ingår i: Experimental Results. - : Cambridge University Press (CUP). - 2516-712X. ; 3
  • Tidskriftsartikel (refereegranskat)abstract
    • Preterm infants show postnatal deficits of long-chain polyunsaturated fatty acids (LCPUFAs) which are essential for adequate growth and neurodevelopment. Human milk is a primary source of fatty acids (FAs) for the preterm infant, and therefore, knowledge about milk FA levels is required to design appropriate supplementation strategies. Here, we expanded on our previous study (Nilsson et al., 2018, Acta Paediatrica, 107, 1020-1027) determining FA composition in milk obtained from mothers of extremely low gestational age (<28 weeks) infants on three occasions during lactation. There was a clear difference in FA composition in milk collected at Day 7 and milk collected at postmenstrual weeks (PMW) 32 or PMW 40. Notably, the proportion of LCPUFAs was low and declined significantly during milk maturation. These results strengthen previous data that the content of FAs required by the preterm infant is not supplied in sufficient amounts when the mother's own milk is the sole source of these essential nutrients.
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45.
  • Sjöbom, Ulrika, et al. (författare)
  • Modification of serum fatty acids in preterm infants by parenteral lipids and enteral docosahexaenoic acid/arachidonic acid: A secondary analysis of the Mega Donna Mega trial
  • 2023
  • Ingår i: Clinical Nutrition. - 0261-5614. ; 42:6, s. 962-971
  • Tidskriftsartikel (refereegranskat)abstract
    • Background & aim: Preterm infants risk deficits of long-chain polyunsaturated fatty acids (LCPUFAs) that may contribute to morbidities and hamper neurodevelopment. We aimed to determine longitudinal serum fatty acid profiles in preterm infants and how the profiles are affected by enteral and parenteral lipid sources. Methods: Cohort study analyzing fatty acid data from the Mega Donna Mega study, a randomized control trial with infants born <28 weeks of gestation (n = 204) receiving standard nutrition or daily enteral lipid supplementation with arachidonic acid (AA):docosahexaenoic acid (DHA) (100:50 mg/kg/day). Infants received an intravenous lipid emulsion containing olive oil:soybean oil (4:1). Infants were followed from birth to postmenstrual age 40 weeks. Levels of 31 different fatty acids from serum phospholipids were determined by GC-MS and reported in relative (mol%) and absolute concentration (mmol l-1) units. Results: Higher parenteral lipid administration resulted in lower serum proportion of AA and DHA relative to other fatty acids during the first 13 weeks of life (p < 0.001 for the 25th vs the 75th percentile). The enteral AA:DHA supplement increased the target fatty acids with little impact on other fatty acids. The absolute concentration of total phospholipid fatty acids changed rapidly in the first weeks of life, peaking at day 3, median (Q1-Q3) 4452 (3645-5466) mmol l-1, and was positively correlated to the intake of parenteral lipids. Overall, infants displayed common fatty acid trajectories over the study period. However, remarkable differences in fatty acid patterns were observed depending on whether levels were expressed in relative or absolute units. For example, the relative levels of many LCPUFAs, including DHA and AA, declined rapidly after birth while their absolute concentrations increased in the first week of life. For DHA, absolute levels were significantly higher compared to cord blood from day 1 until postnatal week 16 (p < 0.001). For AA, absolute postnatal levels were lower compared to cord blood from week 4 throughout the study period (p < 0.05). Conclusions: Our data show that parenteral lipids aggravate the postnatal loss of LCPUFAs seen in preterm infants and that serum AA available for accretion is below that in utero. Further research is needed
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46.
  • Svedin, Pernilla, 1979, et al. (författare)
  • Matrix metalloproteinase-9 gene knock-out protects the immature brain after cerebral hypoxia-ischemia
  • 2007
  • Ingår i: J Neurosci. ; 27:7, s. 1511-8
  • Tidskriftsartikel (refereegranskat)abstract
    • Inhibition of matrix metalloproteinase-9 (MMP-9) protects the adult brain after cerebral ischemia. However, the role of MMP-9 in the immature brain after hypoxia-ischemia (HI) is unknown. We exposed MMP-9(-/-) [MMP-9 knock-out (KO)] and wild-type (WT) mice to HI on postnatal day 9. HI was induced by unilateral ligation of the left carotid artery followed by hypoxia (10% O2; 36 degrees C). Gelatin zymography showed that MMP-9 activity was transiently increased at 24 h after HI in the ipsilateral hemisphere and MMP-9-positive cells were colocalized with activated microglia. Seven days after 50 min of HI, cerebral tissue volume loss was reduced in MMP-9 KO (21.8 +/- 1.7 mm3; n = 22) compared with WT (32.3 +/- 2.1 mm3; n = 22; p < 0.001) pups, and loss of white-matter components was reduced in MMP-9 KO compared with WT pups (neurofilament: WT, 50.9 +/- 5.4%; KO, 18.4 +/- 3.1%; p < 0.0001; myelin basic protein: WT, 57.5 +/- 5.8%; KO, 23.2 +/- 3.5%; p = 0.0001). The neuropathological changes were associated with a delayed and diminished leakage of the blood-brain barrier (BBB) and a decrease in inflammation in MMP-9-deficient animals. In contrast, the neuroprotective effects after HI in MMP-9-deficient animals were not linked to either caspase-dependent (caspase-3 and cytochrome c) or caspase-independent (apoptosis-inducing factor) processes. This study demonstrates that excessive activation of MMP-9 is deleterious to the immature brain, which is associated with the degree of BBB leakage and inflammation. In contrast, apoptosis does not appear to be a major contributing factor.
  •  
47.
  • Sävman, Karin, 1960, et al. (författare)
  • Galectin-3 Modulates Microglia Inflammation in vitro but Not Neonatal Brain Injury in vivo under Inflammatory Conditions
  • 2021
  • Ingår i: Developmental Neuroscience. - : S. Karger AG. - 0378-5866 .- 1421-9859. ; 43:5, s. 296-311
  • Tidskriftsartikel (refereegranskat)abstract
    • Microglia may contribute to injury but may also have neuroprotective properties. Galectin-3 has immunomodulatory properties that may affect the microglia phenotype and subsequent development of injury. Galectin-3 contributes to experimental hypoxic-ischemic (HI) injury in the neonatal brain, but it is unclear if galectin-3 has similar effects on infectious and sterile inflammation. Thus, we investigated the effect of galectin-3 on microglia in vitro under normal as well as infectious and sterile inflammatory conditions, and the effect of galectin-3 on neonatal brain injury following an infectious challenge in vivo. Conditions mimicking infectious or sterile inflammation were evaluated in primary microglia cell cultures from newborn mice, using LPS (10 ng/mL) and TNF-alpha (100 ng/mL). The response to galectin-3 was tested alone or together with LPS or TNF-alpha. Supernatants were collected 24 h after treatment and analyzed for 23 inflammatory mediators including pro- and anti-inflammatory cytokines and chemokines using multiplex protein analysis, as well as ELISA for MCP-1 and insulin-like growth factor (IGF)-1. Phosphorylation of proteins (AKT, ERK1/2, I kappa B-alpha, JNK, and p38) was determined in microglia cells. Neonatal brain injury was induced by a combination of LPS and HI (LPS + HI) in postnatal day 9 transgenic mice lacking functional galectin-3 and wild-type controls. LPS and TNF-alpha induced pro-inflammatory (9/11 vs. 9/10) and anti-inflammatory (6/6 vs. 2/6) cytokines, as well as chemokines (6/6 vs. 4/6) in a similar manner, except generally lower amplitude of the TNF-alpha-induced response. Galectin-3 alone had no effect on any of the proteins analyzed. Galectin-3 reduced the LPS- and TNF-alpha-induced microglia response for cytokines, chemokines, and phosphorylation of I kappa B-alpha. LPS decreased baseline IGF-1 levels, and the levels were restored by galectin-3. Brain injury or microglia response after LPS + HI was not affected by galectin-3 deficiency. Galectin-3 has no independent effect on microglia but modulates inflammatory activation in vitro. The effect was similar under infectious and sterile inflammatory conditions, suggesting that galectin-3 regulates inflammation not just by binding to LPS or toll-like receptor-4. Galectin-3 restores IGF-1 levels reduced by LPS-induced inflammation, suggesting a potential protective effect on infectious injury. However, galectin-3 deficiency did not affect microglia activation and was not beneficial in an injury model encompassing an infectious challenge.
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48.
  • Sävman, Karin, 1960, et al. (författare)
  • Microglia/Macrophage-Derived Inflammatory Mediators Galectin-3 and Quinolinic Acid are Elevated in Cerebrospinal Fluid from Newborn Infants After Birth Asphyxia.
  • 2013
  • Ingår i: Translational stroke research. - : Springer Science and Business Media LLC. - 1868-4483 .- 1868-601X. ; 4:2, s. 228-235
  • Tidskriftsartikel (refereegranskat)abstract
    • Activation of microglia/macrophages is important in neonatal hypoxic-ischemic (HI) brain injury. Based on experimental studies, we identified macrophage/microglia-derived mediators with potential neurotoxic effects after neonatal HI and examined them in cerebrospinal fluid (CSF) from newborn infants after birth asphyxia. Galectin-3 is a novel inflammatory mediator produced by microglia/macrophages. Galectin-3 is chemotactic for inflammatory cells and activates nicotinamide adenine dinucleotide phosphate (NADPH) oxidase resulting in production and release of reactive oxygen species (ROS). Matrix metalloproteinase-9 (MMP-9) is a tissue-degrading protease expressed by activated microglia in the immature brain after HI. Both galectin-3 and MMP-9 contribute to brain injury in animal models for neonatal HI. Quinolinic acid (QUIN) is a neurotoxic N-methyl-d-aspartate (NMDA) receptor agonist also produced by activated microglia/macrophages. Galectin-3 and MMP-9 were measured by ELISA and QUIN by mass spectrometry. Asphyxiated infants (n=20) had higher levels of galectin-3 (mean (SEM) 2.64 (0.43) ng/mL) and QUIN (335.42 (58.9) nM) than controls (n=15) (1.36 (0.46) ng/mL and 116.56 (16.46) nM, respectively), p<0.05 and p<0.01. Infants with septic infections (n=10) did not differ from controls. Asphyxiated infants with abnormal outcome had higher levels of galectin-3 (3.96 (0.67) ng/mL) than those with normal outcome (1.76 (0.32) ng/mL), p=0.02, and the difference remained significant in the clinically relevant group of infants with moderate encephalopathy. MMP-9 was detected in few infants with no difference between groups. The potentially neurotoxic macrophage/microglia-derived mediators galectin-3 and QUIN are increased in CSF after birth asphyxia and could serve as markers and may contribute to injury.
  •  
49.
  • Sävman, Karin, 1960, et al. (författare)
  • Non-protein-bound iron in brain interstitium of newborn pigs after hypoxia
  • 2005
  • Ingår i: Dev Neurosci. - : S. Karger AG. - 0378-5866. ; 27:2-4, s. 176-84
  • Tidskriftsartikel (refereegranskat)abstract
    • Oxidative damage is implied in perinatal hypoxic-ischemic brain injury, most importantly in white matter. Nonprotein-bound iron (NPBI) catalyzes the formation of toxic hydroxyl radicals. We measured the extracellular level of NPBI through microdialysis in the cortex, striatum, and periventricular white matter before, during and after severe hypoxia in newborn pigs. NPBI was analyzed by a new spectrophotometric method in which ferrous iron is chelated by bathophenanthroline. NPBI was present in all brain areas under baseline conditions and increased in white matter from 0.97 (0.69) to 2.75 (1.85) micromol/l (not corrected for recovery rate) during early reoxygenation. NPBI may contribute to oxidative injury after perinatal hypoxic insults.
  •  
50.
  • Sävman, Karin, 1960 (författare)
  • Perinatal brain injury - markers and mediators. Non-protein-bound iron and pro-inflammatory cytokines in newborn infants and neonatal pigs
  • 2001
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Two groups of newborn infants have an increased risk for perinatal brain injury; preterm infants and term infants subjected to birth asphyxia. Experimental studies indicate that hypoxic-ischemic insults in the perinatal period initiate a secondary neurotoxic cascade including formation of toxic reactive oxygen species as well as an inflammatory response with elevated levels of potentially neurotoxic cytokines. In the preterm infant a fetal inflammatory response to maternal infection is also directly implied in the development of brain injury and immature white matter exhibits an intrinsic vulnerability to oxidative injury. Non-protein-bound iron (NPBI), measured by a new spectrophotometric method, is a potent pro-oxidant through its capacity to catalyze the formation of the highly toxic hydroxyl radical.The aims of the study were to evaluate: (a) inflammatory activation expressed as pro-inflammatory cytokines in CSF from infants with birth asphyxia as well as preterm infants with posthemorrhagic ventricular dilatation (PHVD) and subsequent high risk for white matter injury. (b) extracellular levels of NPBI in different areas of the brain under normal conditions as well as during hypoxia and reoxygenation in newborn piglets. (d) the content of NPBI in CSF from preterm infants with PHVD.CSF was obtained from asphyxiated term infants and term control infants within 72 h from birth and from preterm infants with PHVD and preterm control infants approximately two weeks after birth. Newborn piglets were subjected to hypoxia-reoxygenation according to a model that produces clinical encephalopathy and neuropathological changes similar to those seen in term asphyxiated infants. Samples for NPBI analysis were obtained by microdialysis probes inserted into vulnerable parts of the piglet brain.There was a significant increase of the pro-inflammatory cytokines IL-6 and IL-8 in CSF after birth asphyxia. IL-6 and IL-8 levels correlated with the degree of encephalopathy and IL-6 correlated with outcome. The CSF levels of IL-1b, IL-6, IL-8, and TNF-a were elevated in infants with PHVD. NPBI was detected in all examined areas of the piglet brain under normal conditions and increased during early reoxygenation after hypoxia. NPBI was detected frequently and at high levels in CSF from infants with PHVD. Conclusions: Birth asphyxia elicits an inflammatory response with elevated pro-inflammatory cytokines in CSF and elevated cytokine levels are associated with severe clinical course and abnormal outcome. Preterm infants with PHVD exhibit an intense inflammatory response in CSF weeks after the original insult, but at this late time-point no correlation with morphological brain injury or outcome is found. NPBI is present in brain extracellular space under normal conditions and increases during reoxygenation after hypoxia. NPBI is also elevated in CSF from infants with PHVD. Elevated levels of NPBI imply impaired iron-regulation and an increased risk for oxidative injury
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