| 1. |
- Mishra, A, et al.
(författare)
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Diminishing benefits of urban living for children and adolescents' growth and development
- 2023
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 615:7954, s. 874-883
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Tidskriftsartikel (refereegranskat)abstract
- Optimal growth and development in childhood and adolescence is crucial for lifelong health and well-being1–6. Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5–19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few high-income countries. By 2020, the urban height advantage became smaller in most countries, and in many high-income western countries it reversed into a small urban-based disadvantage. The exception was for boys in most countries in sub-Saharan Africa and in some countries in Oceania, south Asia and the region of central Asia, Middle East and north Africa. In these countries, successive cohorts of boys from rural places either did not gain height or possibly became shorter, and hence fell further behind their urban peers. The difference between the age-standardized mean BMI of children in urban and rural areas was <1.1 kg m–2 in the vast majority of countries. Within this small range, BMI increased slightly more in cities than in rural areas, except in south Asia, sub-Saharan Africa and some countries in central and eastern Europe. Our results show that in much of the world, the growth and developmental advantages of living in cities have diminished in the twenty-first century, whereas in much of sub-Saharan Africa they have amplified.
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| 2. |
- Hakansson, P., et al.
(författare)
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Establishment and phenotypic characterization of human U937 cells with inducible P210 BCR/ABL expression reveals upregulation of CEACAM1 (CD66a)
- 2004
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Ingår i: Leukemia. - : Springer Science and Business Media LLC. - 0887-6924 .- 1476-5551. ; 18:3, s. 538-47
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Tidskriftsartikel (refereegranskat)abstract
- Chronic myeloid leukemia (CML) is characterized by the expression of the P210 BCR/ABL fusion protein. The molecular mechanisms behind this oncogene-mediated hematological disease are, however, not fully understood. Here, we describe the establishment and phenotypic characterization of U937 cells in which P210 BCR/ABL can be conditionally expressed using tetracycline. The induction of BCR/ABL in the obtained clones resulted in a rapid phosphorylation of the STAT1, STAT3 and STAT5 molecules, consistent with the findings in other model systems. Phenotypic characterization of the clones revealed that BCR/ABL induces a slight decrease in the proliferation and viability, without a marked effect on cell cycle distribution, the rate of apoptosis or on cellular differentiation, as judged by several cell surface markers and capacity to reduce nitro blue tetrazolium. Interestingly, BCR/ABL was found to upregulate the expression of carcinoembryonic-related antigen (CEA)CAM1 (CD66a), which is a plasma membrane-linked glycoprotein belonging to the CEAs and involved in signal transduction and cellular adhesion. The expression of CEACAM1 was reversible upon imatinib treatment in BCR/ABL-expressing U937 cells as well as in BCR/ABL-positive K562 cells. The established cell lines may prove useful in further modeling and dissection of BCR/ABL-induced leukemogenesis.
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| 3. |
- Lassen, Bo, et al.
(författare)
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Binding of salivary proteins and oral bacteria to hydrophobic and hydrophilic surfaces in vivo and in vitro
- 1994
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Ingår i: Colloid and Polymer Science. - 0303-402X .- 1435-1536. ; 272, s. 1143-1150
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Tidskriftsartikel (refereegranskat)abstract
- Modifications of mineral surfaces were performed in order to gain insight into what surface properties are decisive of the accumulation of dental plaque. A non-charged, hydrophilic surface was made by two consecutive plasma polymerizations, firstly with allyl alcohol, secondly with acrylic acid, followed by adsorption of a poly(ethylene glycol)-poly(ethylene imine) adduct. A strongly hydrophobic surface was obtained by plasma polymerization of hexamethyldisiloxane. Ellipsometry was used to monitor protein interaction with the surfaces. The hydrophilic surface gave very little adsorption of both a model protein, IgG, and of saliva proteins. The hydrophobic surface, on the other hand, adsorbed high amounts of both types of proteins. In vitro adhesion of an oral bacterium, S. mutans, as well as in uivo studies, gave the opposite result, the hydrophobic surface giving less adhesion and less plaque accumulation than the hydrophilic surface. A tentative explanation of this behaviour is that the saliva proteins that bind to the hydrophobic surface adsorb in an unnatural conformation which does not favour bacteria adherence.
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| 4. |
- Lassen, Bo, et al.
(författare)
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Competitive protein adsorption at plasma polymer surfaces
- 1997
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Ingår i: Journal of Colloid and Interface Science. - 0021-9797 .- 1095-7103. ; 186, s. 9-16
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Tidskriftsartikel (refereegranskat)abstract
- Competetive adsorption from a ternary mixture of human serum albumin (HSA), human IgG, and human fibrinogen (FGN) at concentrations corresponding to blood plasma diluted 1/100 was investigated with the combination of Total Internal Reflection Fluorescence spectroscopy (TIRF) and ellipsometry. As substrates, three different plasma polymer surfaces, representing different surface charge and surface energy, were prepared from hexamethyldisiloxane (PP-HMDSO), acrylic acid (PP-AA), and 1,2-diaminocyclohexane (PP-DACH). In addition, adsorption from single and binary protein systems was investigated with ellipsometry. At the hydrophobic PP-HMDSO little or no displacement of any of the proteins was observed. The adsorbed layer was dominated by HSA and IgG, although Fgn was also present to a smaller extent. On PP-DACH and PP-AA, representing positively and negatively charged hydrophilic surfaces, respectively, Fgn completely dominated the adsorbed layer while HSA was almost absent and IgG was present only at a very low level.
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| 5. |
- Lassen, Bo, et al.
(författare)
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Competitive protein adsorption studied with TIRF and ellipsometry
- 1996
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Ingår i: Journal of Colloid and Interface Science. - 0021-9797 .- 1095-7103. ; 179, s. 470-477
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Tidskriftsartikel (refereegranskat)abstract
- Total internal reflection fluorescence (TIRF) and ellipsometry have been used to study competitive protein adsorption to a hydrophobic model surface prepared by radio frequency plasma deposition of hexamethyl disiloxane on silicon. Single, binary, and ternary protein solutions of human serum albumin (HSA), IgG, and fibrogen (Fgn) at concentrations corresponding to 1/100 of those in blood plasma were investigated. It is shown that by employing the combination of ellipsometry and TIRF, information on both the total adsorbed amount and the composition of the adsorbed protein layer can be obtained. It was found that adsorbed HSA is not displaced by IgG and/or Fgn to any large extent. IgG and HSA dominate the adsorption from the ternary protein mixture, although fibrinogen is also present in the adsorbed layer to a smaller extent.
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| 6. |
- Lassen, Bo, et al.
(författare)
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Structure of protein layers during competitive adsorption
- 1996
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Ingår i: Journal of Colloid and Interface Science. - 0021-9797 .- 1095-7103. ; 180, s. 339-349
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Tidskriftsartikel (refereegranskat)abstract
- The formation of protein layers during competitive adsorption was studied with ellipsometry. Single, binary, and ternary protein solutions of human serum albumin (HSA), IgG, and fibrinogen (Fgn) were investigated at concerntrations corresponding to blood plasma diluted 1/100. As a model surface, hydrophobic hexamethyldisiloxane (HMDSO) plasma polymer modified silica was used. By using multiambient media measurements of the bare substrate prior to protein adsorption the adsorbed amount as well as the thickness and refractive index of the adsorbed protein layer could be followed in situ and in real time. Under conditions used in these experiments neither IgG nor fibrinogen could fullydisplace serum albumin from the interface. The buildup of the protein layer occured via different mechanisms for the different protein systems. Fgn adsorbed in a rather flat orientation at low adsorbed amounts, while at higher surface coverage the protein reoriented to a more upright orientation in order to accommodate more molecules in the adsorbed layer. IgG adsorption proceeded mainly end on with little reorientation or conformational change on adsorption. Finally, for HSA an adsorbed layer thickness greater than the molecular dimensions was observed at high concentrations ( although not at low ), indicating that aggregates or multilayers formed on HMDSO plasma polymer surfaces. For all protein mixtures the adsorbed layer structure and buildup indicated that Fgn was the protein dominating the adsorbed layer, although HSA partially blocked the adsorption of this protein. At high surface concentration, HSA/Fgn mixtures show an abrupt change in both adsorbed layer thickness and refractive index suggesting, e.g., an interfacial phase transition of the mixed protein layer. A similar but less pronounced behavior was observed for HSA/IgG. For IgG/Fgn and HSA/Fgn a buildup of the adsorbed layer similar to that displayed by Fgn alone was observed.
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| 7. |
- Malmsten, M, et al.
(författare)
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Adsorption of complement protein C3 at polymer surfaces
- 1996
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Ingår i: Journal of Colloid and Interface Science. - 0021-9797 .- 1095-7103. ; 179, s. 163-172
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Tidskriftsartikel (refereegranskat)abstract
- The adsorption of C3 at poly(methyl methacrylate) (PMMA) and poly(styrene) (PS) surfaces was investigated with in situ ellipsometry and compared to that at (hydrophilic and negatively charged) silica and (hydrophobic) methylated silica. The adsorption of C3 at PMMA was higher than that at PS, while the adsorbed layer thickness was the same for the two surfaces. For both PMMA and PS the adsorbed layer thickness (10±2 nm) corresponds rather closely to that of end-on oriented C3 molecules. The adsorption of C3 at PMMA and PS was found to be intermediate between that at silica and methylated silica, although the adsorbed layer thickness was similar for all surfaces. The competitive adsorption between C3, human serum albumin (HSA), and factor B was investigated with ellipsometry and total internal reflection fluorescence spectroscopy (TIRF). Addition of HSA after C3 preadsorption resulted in fractional C3 desorption for both PMMA and PS. Factor B deposition at PS after preadsorption of C3 and blocking with HSA was found to be largely due to specific binding to C3/C3b, while in the case of PMMA, factor B was largely accumulated through passive (displacement) adsorption.
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| 8. |
- Malmsten, Martin, et al.
(författare)
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Adsorption of complement protein C3 at polymer surfaces and the demonstration of a specific binding of factor B by adsorbed C3
- 1996
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier BV. - 0021-9797 .- 1095-7103. ; 179:1, s. 163-172
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Tidskriftsartikel (refereegranskat)abstract
- The adsorption of C3 at poly(methyl methacrylate) (PMMA) and poly(styrene) (PS) surfaces was investigated within situellipsometry and compared to that at (hydrophilic and negatively charged) silica and (hydrophobic) methylated silica. The adsorption of C3 at PMMA was higher than that at PS, while the adsorbed layer thickness was the same for the two surfaces. For both PMMA and PS the adsorbed layer thickness (10 ± 2 nm) corresponds rather closely to that of end-on oriented C3 molecules. The adsorption of C3 at PMMA and PS was found to be intermediate between that at silica and methylated silica, although the adsorbed layer thickness was similar for all surfaces. The competitive adsorption among C3, human serum albumin (HSA), and factor B was investigated with ellipsometry and total internal reflection fluorescence spectroscopy (TIRF). Addition of HSA after C3 preadsorption resulted in fractional C3 desorption for both PMMA and PS. Factor B deposition at PS after preadsorption of C3 and blocking with HSA was found to be largely due to specific binding to C3/C3b, while in the case of PMMA, factor B was largely accumulated through passive (displacement) adsorption.
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| 9. |
- Malmsten, M, et al.
(författare)
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Adsorption of complement proteins C3 and C1q
- 1996
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Ingår i: Journal of Colloid and Interface Science. - 0021-9797 .- 1095-7103. ; 178, s. 123-134
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Tidskriftsartikel (refereegranskat)abstract
- Surface localization plays a key but ill defined role in activation of the Serum Complement System with or without related "opsonic" proteins. The adsorption of key complement components C3 and C1q and various opsonins, e. g., IgG, were therefore studied on different surfaces using in situ ellipsometry. The affinities of C3 and C1q for silica, methylated silica, and various phospholipid surfaces were shown to be largely reciprocal. While C3 adsorbed more extensively at (hydrophilic and negatively charged) silica than at (hydrophobic) methylated silica (3.1 versus 0.4 mg/m2, respectively) the opposite trend was observed for C1q (1.9 versus 2.6 mg/m2). C3 and C1q adsorbed in 10 to 15 nm thick layers on both silica and methylated silica. Each protein appeared to adsorb with consistent conformation and orientation on either surface. Adsorbed layer formation involves increased protein packing density, and molecular extension normal to the surface. Phospholipid head group properties strongly affect the adsorption of C3 and C1q at phospholipid coated surfaces. The saturation adsorption of C3 at phosphatidic acid was almost as significant as at silica, whereas the amount adsorbed at phosphatidylcholine was three times lower. C3 adsorption at phosphatidylinositol and various poly(ethylene glycol) modified surfaces was virtually absent, as was the adsorption of various opsonins. C1q adsorption was relatively low at all phospholipid and poly(ethylene glycol) coated surfaces investigated, more in the manner of IgG than C3. Preadsorption of IgG increased C1q deposition at phospholipid surfaces strongly. C3 and human serum albumin, but not C1q, showed appreciable hydrophobic affinity for a poly(ethylene glycol)-fatty acid ester of oleic acid. These results are discussed in relation to complement interaction with various surfaces and colloidal drug carriers.
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| 10. |
- Malmsten, M, et al.
(författare)
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Competitive adsorption at hydrophobic surfaces from binary protein systems
- 1994
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Ingår i: Journal of Colloid and Interface Science. - 0021-9797 .- 1095-7103. ; 166, s. 490-498
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Tidskriftsartikel (refereegranskat)abstract
- The adsorption of some model proteins, human serum albumin (HSA), IgG and fibrinogen, at silica made hydrophobic by either methylation or plasma deposition of HMDSO (hexamethyldisiloxane) was investigated with in situ ellipsometry and TIRF. Ellipsometry experiments of the simultaneous adsorption of HSA and either IgG or fibrinogen revealed a preferential adsorption of the latter proteins. This is seen not only from the total adsorbed amount, but also from the adsorbed layer thickness, as well as from the build-up of the adsorbed layer. However, in sequential adsorption experiments, where HSA was first allowed to adsorb, followed by rinsing and addition of either IgG or fibrinogen, the additional adsorption is quite limited. Consequently, when HSA is allowed to adsorb on its own at hydrophobic surfaces, it is not removed by either IgG or fibrinogen to any larger extent. Furthermore, preadsorbed HSA was not exchanged by HSA added after adsorption and rinsing, implying that the mechanism behind this effect is an ”irreversible” adsorption of HSA at hydrophobic surfaces, possibly originating from a surface-induced conformational change of HSA at these surfaces. Analogous findings were obtained with both methylated and HMDSO-treated surfaces, using both ellipsometry and TIRF.
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