| 1. |
- Midtgaard, Søren Roi, et al.
(författare)
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Invisible detergents for structure determination of membrane proteins by small-angle neutron scattering
- 2018
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Ingår i: The FEBS Journal. - : Wiley. - 1742-464X .- 1742-4658. ; 285:2, s. 357-371
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Tidskriftsartikel (refereegranskat)abstract
- A novel and generally applicable method for determining structures of membrane proteins in solution via small-angle neutron scattering (SANS) is presented. Common detergents for solubilizing membrane proteins were synthesized in isotope-substituted versions for utilizing the intrinsic neutron scattering length difference between hydrogen and deuterium. Individual hydrogen/deuterium levels of the detergent head and tail groups were achieved such that the formed micelles became effectively invisible in heavy water (D2 O) when investigated by neutrons. This way, only the signal from the membrane protein remained in the SANS data. We demonstrate that the method is not only generally applicable on five very different membrane proteins but also reveals subtle structural details about the sarco/endoplasmatic reticulum Ca2+ ATPase (SERCA). In all, the synthesis of isotope-substituted detergents makes solution structure determination of membrane proteins by SANS and subsequent data analysis available to non-specialists. This article is protected by copyright. All rights reserved.
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| 2. |
- Hellgren, Gunnel, 1961, et al.
(författare)
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Proliferative Retinopathy Is Associated with Impaired Increase in BDNF and RANTES Expression Levels after Preterm Birth.
- 2010
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Ingår i: Neonatology. - : S. Karger AG. - 1661-7819 .- 1661-7800. ; 98:4, s. 409-418
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Tidskriftsartikel (refereegranskat)abstract
- Background: Extremely preterm delivery is, amongst other complications, associated with retinopathy of prematurity (ROP). Untreated, ROP can progress to visual impairment and blindness due to an overgrowth of new vessels in the retina and vitreous cavity. Objective: The aim of this study was to identify cytokine markers within the first weeks of life that could be used to predict the risk for development of ROP later in life. Methods: Serum levels of 27 different cytokines in infants born at gestational weeks 23-30 were analyzed using a multiplex immunoassay method and compared between infants who did not develop ROP and infants who later developed proliferative ROP. In addition, mRNA levels of brain-derived neurotrophic factor (BDNF) in retinas from mice exposed to hyperoxia were analyzed using quantitative real-time PCR. Results: At birth, serum levels of IL-5 were higher in infants with no ROP compared to infants with proliferative ROP. 10-14 days after birth, serum levels of BDNF and RANTES were lower in infants who later developed proliferative ROP compared to infants who did not develop ROP. Furthermore, mRNA expression levels of BDNF in retinas from mice exposed to hyperoxia were significantly lower at postnatal day 15 compared to retinas from mice in room air. Conclusions: These results indicate that BDNF and RANTES may be important factors in the selective vulnerability of ROP development in preterm infants.
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| 3. |
- Himmelmann, Kate, 1959, et al.
(författare)
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Risk factors for cerebral palsy in children born at term.
- 2011
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Ingår i: Acta obstetricia et gynecologica Scandinavica. - : Wiley. - 1600-0412 .- 0001-6349.
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To provide an overview of current research on risk factors for cerebral palsy (CP) in children born at term and hypothesize how new findings can affect the content of the CP registers worldwide. Data Source. A systematic search in PubMed for original articles, published from 2000 to 2010 regarding risk factors for CP in children born at term was conducted. Methods of study selection. Factors from the prenatal, perinatal and neonatal period considered as possible contributors to the causal pathway to CP in children born at term were regarded as risk factors. Full text review was made of 266 articles. Results. Sixty-two articles met the criteria for an original report on risk factors for CP in children born at term. Perinatal adverse events including stroke were the focus of most publications, followed by genetic studies. Malformations, infections, perinatal adverse events and multiple gestation were risk factors associated with CP. The evidence regarding for example thrombophilic factors and non-CNS abnormalities was inconsistent. Conclusion. Information on maternal and neonatal infections, umbilical cord blood gases at birth, mode of delivery and placental status should be collected in a standardized way in CP registers. Information on social factors such as education level, family income and area of residence is also of importance. More research is needed to understand the risk factors of CP and specifically of how they relate to causal pathways of cerebral palsy.
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| 4. |
- Lund, Henrik, et al.
(författare)
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Perspectives on fourth and fifth generation district heating
- 2021
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Ingår i: Energy. - London : Elsevier. - 0360-5442 .- 1873-6785. ; 227
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Tidskriftsartikel (refereegranskat)abstract
- Fourth-generation district heating (4GDH) has been used as a label or expression since 2008 to describe a transition path for decarbonization of the district heating sector and was defined in more detail in 2014. During recent years, several papers have been published on a concept called fifth generation district heating and cooling (5GDHC). This article identifies differences and similarities between 4GDH and 5GDHC regarding aims and abilities. The analysis shows that these two are common not only in the overarching aim of decarbonization but that they also to some extent share the five essential abilities first defined for 4GDH. The main driver for 5GDHC has been a strong focus on combined heating and cooling, using a collective network close to ambient temperature levels as common heat source or sink for building-level heat pumps. It is found that 5GDHC can be regarded as a promising technology with its own merits, yet a complementary technology that may coexist in parallel with other 4GDH technologies. However, the term “generation” implies a chronological succession, and the label 5GDHC does not seem compatible with the established labels 1GDH to 4GDH. © 2021 The Authors. Published by Elsevier Ltd.
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| 5. |
- Lund, Henrik, et al.
(författare)
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The status of 4th generation district heating : Research and results
- 2018
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Ingår i: Energy. - London : Elsevier. - 0360-5442 .- 1873-6785. ; 164, s. 147-159
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Tidskriftsartikel (refereegranskat)abstract
- This review article presents a description of contemporary developments and findings related to the different elements needed in future 4th generation district heating systems (4GDH). Unlike the first three generations of district heating, the development of 4GDH involves meeting the challenge of more energy efficient buildings as well as the integration of district heating into a future smart energy system based on renewable energy sources. Following a review of recent 4GDH research, the article quantifies the costs and benefits of 4GDH in future sustainable energy systems. Costs involve an upgrade of heating systems and of the operation of the distribution grids, while benefits are lower grid losses, a better utilization of low-temperature heat sources and improved efficiency in the production compared to previous district heating systems. It is quantified how benefits exceed costs by a safe margin with the benefits of systems integration being the most important. © 2018 Elsevier Ltd
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| 6. |
- Menon, Ramkumar, et al.
(författare)
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Ethnic differences in key candidate genes for spontaneous preterm birth: TNF-alpha and its receptors
- 2006
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Ingår i: HUMAN HEREDITY. - : S. Karger AG. - 0001-5652 .- 1423-0062. ; 62:2, s. 107-118
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Tidskriftsartikel (refereegranskat)abstract
- <i>Objectives:</i> Spontaneous preterm birth (PTB) has a significant ethnic disparity with people of African descent having an almost 2-fold higher incidence than those of European descent in the United States. This disparity may be caused by differences in the distribution of genetic risk factors. The objective of this study is to examine genetic differences between African-Americans and European Americans for single nucleotide polymorphisms (SNPs) in candidate genes for PTB. <i>Methods:</i> We examined patterns of variation in 19 SNPs in 3 candidate genes for preterm birth: TNF-α, TNF-receptor 1 and TNF-receptor 2. Allele, genotype and haplotype frequencies were compared between African-Americans (AA) and European-Americans (EA) in cases and controls separately. Both maternal and fetal genotypes were studied, as it is unclear whether one or both of these are important in the etiology of PTB. <i>Results:</i> The vast majority of the SNPs differed significantly between ethnic groups, although there are only a few suggestive results comparing cases and controls within an ethnic group. For TNF-α, four of six SNPs; for TNF-R1, 5/6; and for TNF-R2, 6/7 showed significant differences between ethnic groups in either allele and/or genotype frequency. <i>Conclusions:</i> Our data demonstrate highly significant genetic differences between ethnic groups in genes that may play a role in the risk of PTB.
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| 7. |
- Menon, Ramkumar, 1967, et al.
(författare)
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Increased Bioavailability of TNF-alpha in African Americans During In Vitro Infection: Predisposing Evidence for Immune Imbalance.
- 2007
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Ingår i: Placenta. ; 28:8-9, s. 946-50
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The objective of this study is to examine TNF-alpha and its soluble and membrane bound receptors in fetal membranes derived from blacks and whites in response to in vitro infectious stimulus, and the balance between TNF-alpha and the receptors. Fetal membranes collected from black and white women at term were maintained in an organ explant system and stimulated with lipopolysaccharide (LPS). TNF-alpha, soluble TNF receptors (sTNFR1 and sTNFR2) in culture media and membrane bound TNF receptors (TNFR1 and TNFR2) in tissue homogenates were measured. Molar ratio (TNF/sTNFR) was calculated between LPS stimulated and unstimulated (controls) cultures in both races. TNF-alpha was increased in both races after LPS stimulation and showed no difference between races (p=0.7). LPS decreased sTNFR1 in blacks, but increased in whites, showing a significant difference between races (p=0.001). In blacks sTNFR2 also decreased and increased in whites, but the results were not significant between races (p=0.4). Both TNFR1 and TNFR2 were increased in blacks after LPS stimulation whereas no such changes were seen in whites compared to controls that were also significant between races. After LPS stimulation TNF-alpha bioavailability was increased in blacks with a drop in soluble receptors and with an increase in membrane receptors. This was not evident in whites because in whites soluble receptors were increased with no change in membrane receptors. Our data demonstrated that LPS stimulation results in a molar ratio switch favoring TNF-alpha biofunction in blacks, but not in whites.
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| 8. |
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| 9. |
- Vogel, Ida, et al.
(författare)
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Acquisition and Elimination of Bacterial Vaginosis During Pregnancy: A Danish Population-Based Study
- 2006
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Ingår i: Infectious Diseases in Obstetrics and Gynecology.
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: the aim was to examine factors associated with acquisition and elimination of bacterial vaginosis in pregnancy. Methods: a group of 229 pregnant women were randomly selected from a population-based prospective cohort study of 2927. They were examined at enrollment (mean gestational weeks 16w+0d) and again in mid-third trimester (mean gestational age 32w+3d). Measures: BV (Amsel's clinical criteria), microbiological cultures of the genital tract and questionnaire data. Results: BV prevalence decreased from 17% in early second trimester to 14% in mid-third trimester due to a tenfold higher elimination rate (39%) than incidence rate (4%). Heavy smokers (>10/d) in early pregnancy were at increased risk (5.3[1.1−25]) for the acquisition of BV during pregnancy, as were women receiving public benefits (4.8[1.0−22]), having a vaginal pH above 4.5(6.3[1.4−29]) or vaginal anaerobe bacteria (18[2.7−122]) at enrollment. A previous use of combined oral contraceptives was preventive for the acquisition of BV (0.2[0.03−0.96]). Elimination of BV in pregnancy tended to be associated with a heavy growth of Lactobacillus (3.2[0.8−13]) at enrollment. Conclusions: acquisition of BV during pregnancy is rare and is associated with smoking, while the presence of anaerobe bacteria and a vaginal pH >4.5 are interpreted as steps on a gradual change towards BV. In the same way heavy growth of Lactobacillus spp in early pregnancy may be an indicator of women on the way to eliminate BV.
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| 10. |
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